WorldWideScience

Sample records for vehicle traffic surfaces

  1. Automated mixed traffic vehicle design AMTV 2

    Science.gov (United States)

    Johnston, A. R.; Marks, R. A.; Cassell, P. L.

    1982-01-01

    The design of an improved and enclosed Automated Mixed Traffic Transit (AMTT) vehicle is described. AMTT is an innovative concept for low-speed tram-type transit in which suitable vehicles are equipped with sensors and controls to permit them to operate in an automated mode on existing road or walkway surfaces. The vehicle chassis and body design are presented in terms of sketches and photographs. The functional design of the sensing and control system is presented, and modifications which could be made to the baseline design for improved performance, in particular to incorporate a 20-mph capability, are also discussed. The vehicle system is described at the block-diagram-level of detail. Specifications and parameter values are given where available.

  2. Delay of Vehicle Motion in Traffic Dynamics

    CERN Document Server

    Bando, M; Nakanishi, K; Nakayama, A; Bando, Masako; Hasebe, Katsuya; Nakanishi, Ken; Nakayama, Akihiro

    1996-01-01

    We demonstrate that in Optimal Velocity Model (OVM) delay times of vehicles coming from the dynamical equation of motion of OVM almost explain the order of delay times observed in actual traffic flows without introducing explicit delay times. Delay times in various cases are estimated: the case of a leader vehicle and its follower, a queue of vehicles controlled by traffic lights and many-vehicle case of highway traffic flow. The remarkable result is that in most of the situation for which we can make a reasonable definition of a delay time, the obtained delay time is of order 1 second.

  3. Will Automated Vehicles Negatively Impact Traffic Flow?

    Directory of Open Access Journals (Sweden)

    S. C. Calvert

    2017-01-01

    Full Text Available With low-level vehicle automation already available, there is a necessity to estimate its effects on traffic flow, especially if these could be negative. A long gradual transition will occur from manual driving to automated driving, in which many yet unknown traffic flow dynamics will be present. These effects have the potential to increasingly aid or cripple current road networks. In this contribution, we investigate these effects using an empirically calibrated and validated simulation experiment, backed up with findings from literature. We found that low-level automated vehicles in mixed traffic will initially have a small negative effect on traffic flow and road capacities. The experiment further showed that any improvement in traffic flow will only be seen at penetration rates above 70%. Also, the capacity drop appeared to be slightly higher with the presence of low-level automated vehicles. The experiment further investigated the effect of bottleneck severity and truck shares on traffic flow. Improvements to current traffic models are recommended and should include a greater detail and understanding of driver-vehicle interaction, both in conventional and in mixed traffic flow. Further research into behavioural shifts in driving is also recommended due to limited data and knowledge of these dynamics.

  4. Emergency vehicle traffic signal preemption system

    Science.gov (United States)

    Bachelder, Aaron D. (Inventor); Foster, Conrad F. (Inventor)

    2011-01-01

    An emergency vehicle traffic light preemption system for preemption of traffic lights at an intersection to allow safe passage of emergency vehicles. The system includes a real-time status monitor of an intersection which is relayed to a control module for transmission to emergency vehicles as well as to a central dispatch office. The system also provides for audio warnings at an intersection to protect pedestrians who may not be in a position to see visual warnings or for various reasons cannot hear the approach of emergency vehicles. A transponder mounted on an emergency vehicle provides autonomous control so the vehicle operator can attend to getting to an emergency and not be concerned with the operation of the system. Activation of a priority-code (i.e. Code-3) situation provides communications with each intersection being approached by an emergency vehicle and indicates whether the intersection is preempted or if there is any conflict with other approaching emergency vehicles. On-board diagnostics handle various information including heading, speed, and acceleration sent to a control module which is transmitted to an intersection and which also simultaneously receives information regarding the status of an intersection. Real-time communications and operations software allow central and remote monitoring, logging, and command of intersections and vehicles.

  5. Remotely Accessed Vehicle Traffic Management System

    Science.gov (United States)

    Al-Alawi, Raida

    2010-06-01

    The ever increasing number of vehicles in most metropolitan cities around the world and the limitation in altering the transportation infrastructure, led to serious traffic congestion and an increase in the travelling time. In this work we exploit the emergence of novel technologies such as the internet, to design an intelligent Traffic Management System (TMS) that can remotely monitor and control a network of traffic light controllers located at different sites. The system is based on utilizing Embedded Web Servers (EWS) technology to design a web-based TMS. The EWS located at each intersection uses IP technology for communicating remotely with a Central Traffic Management Unit (CTMU) located at the traffic department authority. Friendly GUI software installed at the CTMU will be able to monitor the sequence of operation of the traffic lights and the presence of traffic at each intersection as well as remotely controlling the operation of the signals. The system has been validated by constructing a prototype that resembles the real application.

  6. Research on cooperative vehicle intersection control scheme without using traffic lights under the connected vehicles environment

    National Research Council Canada - National Science Library

    Zheng, Yi; Jin, Lisheng; Jiang, Yuying; Wang, Fangrong; Guan, Xin; Ji, Shengyuan; Xu, Jun

    2017-01-01

    To improve traffic congestion of urban intersections, this article presents a cooperative vehicle intersection control scheme without using any traffic lights, based on model predictive control theory...

  7. Vehicle Transponder for Preemption of Traffic Lights

    Science.gov (United States)

    Foster, Conrad; Bachelder, Aaron

    2006-01-01

    The purpose of this article is to describe, in more detail, the transponder installed in each vehicle that participates in the emergency traffic-light-preemption system described in the immediately preceding article. The transponder (see figure) is a fully autonomous data--collection, data-processing, information-display, and communication subsystem that performs robustly in preemption of traffic lights and monitoring of the statuses of street intersections. This transponder monitors the condition of the emergency vehicle in which it is installed and determines when the vehicle has been placed in an emergency-response condition with its siren and/or warning lights activated. Upon detection of such a condition, the transponder collects real-time velocity and acceleration data from the onboard diagnostic (OBD) computer of the vehicle. For this purpose, the transponder contains an OBD interface circuit, including a microprocessor that determines the manufacturer and model of the vehicle and then sends the appropriate commands to the OBD computer requesting the speed and acceleration data. At the same time, data from an onboard navigation system are collected to determine the location and the heading of the vehicle. Then acceleration, speed, position, and heading data are processed and combined with a vehicle-identification number and the resulting set of data is transmitted to monitoring and control units located at all intersections within communication range. When the unit at an intersection determines that this vehicle is approaching and has priority to preempt the intersection, it transmits a signal declaring the priority and the preemption to all participating vehicles (including this one) in the vicinity. If the unit at the intersection has determined that other participating vehicles are also approaching the intersection, then this unit also transmits, to the vehicle that has priority, a message that the other vehicles are approaching the same intersection. The

  8. Traffic Management for Emergency Vehicle Priority Based on Visual Sensing

    OpenAIRE

    Kapileswar Nellore; Gerhard P. Hancke

    2016-01-01

    Vehicular traffic is endlessly increasing everywhere in the world and can cause terrible traffic congestion at intersections. Most of the traffic lights today feature a fixed green light sequence, therefore the green light sequence is determined without taking the presence of the emergency vehicles into account. Therefore, emergency vehicles such as ambulances, police cars, fire engines, etc. stuck in a traffic jam and delayed in reaching their destination can lead to loss of property and val...

  9. Automated mixed traffic transit vehicle microprocessor controller

    Science.gov (United States)

    Marks, R. A.; Cassell, P.; Johnston, A. R.

    1981-01-01

    An improved Automated Mixed Traffic Vehicle (AMTV) speed control system employing a microprocessor and transistor chopper motor current controller is described and its performance is presented in terms of velocity versus time curves. The on board computer hardware and software systems are described as is the software development system. All of the programming used in this controller was implemented using FORTRAN. This microprocessor controller made possible a number of safety features and improved the comfort associated with starting and shopping. In addition, most of the vehicle's performance characteristics can be altered by simple program parameter changes. A failure analysis of the microprocessor controller was generated and the results are included. Flow diagrams for the speed control algorithms and complete FORTRAN code listings are also included.

  10. [Risk factors for road traffic injury in agricultural vehicle drivers].

    Science.gov (United States)

    Cui, M J; Chen, Y; Li, Y; Hu, J; Zhang, X J

    2017-08-20

    Objective: To examine the risk factors for road traffic injury in agricultural vehicle drivers. Methods: A total of 103 drivers (who had suffered agricultural vehicle road traffic injury within the past year based on the road traffic injury registrar from the Traffic Management Bureau) who were involved in the annual agricultural vehicle inspection from December 2014 to January 2015 were randomly sampled from the Yixing Agricultural Vehicle Station as the case group for this study. Based on a 1∶2 assignment ratio and matched for sex, age, and education, a total of 206 drivers who had not suffered any agricultural vehicle road traffic injury within the past year were selected as the control group. The general information, vehicle information, driving information, driving behavior, and accident details of the agricultural vehicle drivers were analyzed. Results: The incidence rate of road traffic injury was 7.24% given the 103 agricultural vehicle drivers who had suffered agricultural vehicle road traffic injury in the past year. Univariate logistic regression analysis showed that drinking, debt, pressure, history of car accident, history of drunk driving, smoking and phone use during driving, fatigue driving, and driving with illness were the risk factors for road traffic injury in agricultural vehicle drivers (OR=2.332, 2.429, 19.778, 5.589, 8.517, 2.125, 3.203, 10.249 and 5.639, respectively) . Multivariate logistic regression analysis also demonstrated that pressure, history of car accident, history of drunk driving, fatigue driving, and driving with illness were the risk factors for road traffic injury in agricultural vehicle drivers (OR=12.139, 11.184, 6.729, 5.939, and 6.544, respectively) . Conclusion: Pressure, history of car accident, history of drunk driving, fatigue driving, and driving with illness are the major risk factors for road traffic injury in agricultural vehicle drivers.

  11. Traffic State Estimation Using Connected Vehicles and Stationary Detectors

    Directory of Open Access Journals (Sweden)

    Ellen F. Grumert

    2018-01-01

    Full Text Available Real-time traffic state estimation is of importance for efficient traffic management. This is especially the case for traffic management systems that require fast detection of changes in the traffic conditions in order to apply an effective control measure. In this paper, we propose a method for estimating the traffic state and speed and density, by using connected vehicles combined with stationary detectors. The aim is to allow fast and accurate estimation of changes in the traffic conditions. The proposed method does only require information about the speed and the position of connected vehicles and can make use of sparsely located stationary detectors to limit the dependence on the infrastructure equipment. An evaluation of the proposed method is carried out by microscopic traffic simulation. The traffic state estimated using the proposed method is compared to the true simulated traffic state. Further, the density estimates are compared to density estimates from one detector-based method, one combined method, and one connected-vehicle-based method. The results of the study show that the proposed method is a promising alternative for estimating the traffic state in traffic management applications.

  12. Automated mixed traffic vehicle control and scheduling study

    Science.gov (United States)

    Peng, T. K. C.; Chon, K.

    1976-01-01

    The operation and the expected performance of a proposed automatic guideway transit system which uses low speed automated mixed traffic vehicles (AMTVs) were analyzed. Vehicle scheduling and headway control policies were evaluated with a transit system simulation model. The effect of mixed traffic interference on the average vehicle speed was examined with a vehicle pedestrian interface model. Control parameters regulating vehicle speed were evaluated for safe stopping and passenger comfort. Some preliminary data on the cost and operation of an experimental AMTV system are included. These data were the result of a separate task conducted at JPL, and were included as background information.

  13. Contributions of vehicle inspection operations to traffic system in ...

    African Journals Online (AJOL)

    The general view about the routine vehicle inspection operations is to ensure that vehicles are road worthy and meet safety requirements. This is done to enhance safe and clean transport within urban centres since the nature and condition of vehicles on roads can be associated with the efficiency of traffic system.

  14. Mobile Crowd Sensing for Traffic Prediction in Internet of Vehicles.

    Science.gov (United States)

    Wan, Jiafu; Liu, Jianqi; Shao, Zehui; Vasilakos, Athanasios V; Imran, Muhammad; Zhou, Keliang

    2016-01-11

    The advances in wireless communication techniques, mobile cloud computing, automotive and intelligent terminal technology are driving the evolution of vehicle ad hoc networks into the Internet of Vehicles (IoV) paradigm. This leads to a change in the vehicle routing problem from a calculation based on static data towards real-time traffic prediction. In this paper, we first address the taxonomy of cloud-assisted IoV from the viewpoint of the service relationship between cloud computing and IoV. Then, we review the traditional traffic prediction approached used by both Vehicle to Infrastructure (V2I) and Vehicle to Vehicle (V2V) communications. On this basis, we propose a mobile crowd sensing technology to support the creation of dynamic route choices for drivers wishing to avoid congestion. Experiments were carried out to verify the proposed approaches. Finally, we discuss the outlook of reliable traffic prediction.

  15. Risk analysis of autonomous vehicles in mixed traffic streams.

    Science.gov (United States)

    2017-05-01

    The objective of this study was to identify the risks associated with the failure of autonomous vehicles in mixed traffic streams and develop strategies to minimize these risks. Three distinct and interconnected phases were used to conduct the risk a...

  16. Traffic control and intelligent vehicle highway systems: a survey

    NARCIS (Netherlands)

    Baskar, L.D.; Schutter, B. de; Hellendoorn, J.; Papp, Z.

    2011-01-01

    Traffic congestion in highway networks is one of the main issues to be addressed by today's traffic management schemes. Automation combined with the increasing market penetration of on-line communication, navigation and advanced driver assistance systems will ultimately result in intelligent vehicle

  17. Detecting Approaching Vehicles at Streets with No Traffic Control

    Science.gov (United States)

    Emerson, Robert Wall; Sauerburger, Dona

    2008-01-01

    This study assessed the ability of people with visual impairments to reliably detect oncoming traffic at crossing situations with no traffic control. In at least one condition, the participants could not hear vehicles to afford a safe crossing time when sound levels were as quiet as possible. Significant predictors of detection accounted for a…

  18. Strobe Traffic Lights Warn of Approaching Emergency Vehicles

    Science.gov (United States)

    Bachelder, Aaron

    2004-01-01

    Strobe-enhanced traffic signals have been developed to aid in the preemption of road intersections for emergency vehicles. The strobe-enhanced traffic signals can be incorporated into both new and pre-existing traffic-control systems in which the traffic-signal heads are of a relatively new type based on arrays of light-emitting diodes (LEDs). The strobe-enhanced traffic signals offer a less expensive, less complex alternative to a recently developed system of LED-based warning signs placed next to traffic signals. Because of its visual complexity, the combination of traffic signals and warning signs is potentially confusing to motorists. The strobe-enhanced traffic signals present less visual clutter. In a given traffic-signal head, the strobe-enhanced traffic signal is embedded in the red LED array of the stop signal. Two strobe LED strips one horizontal and one vertical are made capable of operating separately from the rest of the red LED matrix. When no emergency vehicle is approaching, the red LED array functions as a normal stop signal: all the red LEDs are turned on and off together. When the intersection is to be preempted for an approaching emergency vehicle, only the LEDs in one of the strobe strips are lit, and are turned on in a sequence that indicates the direction of approach. For example (see figure), if an emergency vehicle approaches from the right, the strobe LEDs are lit in a sequence moving from right to left. Important to the success of strobe-enhanced traffic signals is conformance to city ordinances and close relation to pre-existing traffic standards. For instance, one key restriction is that new icons must not include arrows, so that motorists will not confuse new icons with conventional arrows that indicate allowed directions of movement. It is also critical that new displays like strobe-enhanced traffic signals be similar to displays used in traffic-control systems in large cities. For example, Charleston, South Carolina uses horizontal

  19. Robust Vehicle and Traffic Information Extraction for Highway Surveillance

    Directory of Open Access Journals (Sweden)

    Yeh Chia-Hung

    2005-01-01

    Full Text Available A robust vision-based traffic monitoring system for vehicle and traffic information extraction is developed in this research. It is challenging to maintain detection robustness at all time for a highway surveillance system. There are three major problems in detecting and tracking a vehicle: (1 the moving cast shadow effect, (2 the occlusion effect, and (3 nighttime detection. For moving cast shadow elimination, a 2D joint vehicle-shadow model is employed. For occlusion detection, a multiple-camera system is used to detect occlusion so as to extract the exact location of each vehicle. For vehicle nighttime detection, a rear-view monitoring technique is proposed to maintain tracking and detection accuracy. Furthermore, we propose a method to improve the accuracy of background extraction, which usually serves as the first step in any vehicle detection processing. Experimental results are given to demonstrate that the proposed techniques are effective and efficient for vision-based highway surveillance.

  20. Piezoelectric Energy Generation from Vehicle Traffic with Technoeconomic Analysis

    Directory of Open Access Journals (Sweden)

    Hiba Najini

    2017-01-01

    Full Text Available This paper presents a technical simulation based system to support the concept of generating energy from road traffic using piezoelectric materials. The simulation based system design replicates a real life system implementation. It investigates practicality and feasibility using a real-time simulation platform known as MATLAB-Simulink. The system design structure was proposed considering factors involved with the field of material sciences for piezoelectric generator modeling and field of power electronics for additional components in producing a realist outcome. It also ensures ease of vehicle performance, as this system utilizes energy source derived as kinetic energy released from vehicles into electrical power output, that is, obtained by harnessing kinetic energy due to strain of vehicles over asphalt road surface. Due to the real-time simulation platform, the system simulation predicts the effective global carbon footprint. In addition to evaluating technical viability, a technoeconomical business analysis provides a strategic perspective. By using the simulation based power generation results, an estimation of implementation cost and payback time in real life (for United Arab Emirates was derived, hence validating and predicting real-time economic outcome. This is followed by a comparative study with other sources of renewable energy based on levelized energy cost factor that justifies the performance of the proposed system over other renewable energy sources, in support of providing an economical solution on reducing global carbon footprint.

  1. A vehicle overtaking model of traffic dynamics.

    Science.gov (United States)

    Jamison, S; McCartney, M

    2007-09-01

    Mathematical models that describe the dynamical behavior of a group of vehicles as they move along a stretch of road are known as car following models. They attempt to model the interactions between individual vehicles where the behavior of each vehicle is dependent on the motion of the vehicle directly in front and overtaking is not permitted. In this paper, the traditional car following model is modified by removing this "no overtaking" restriction and its behavior is investigated for a group of vehicles traveling on a closed loop. The resulting model is described in terms of a set of coupled time delay differential equations, and these are solved numerically to analyze their post transient behavior under a periodic perturbation. The effect of varying both the time taken for the driver to respond to the behavior of the vehicle in front and the length of the closed loop is examined. For certain parameter choices, the post transient behavior is found to be chaotic, and in these cases the degree of chaos is estimated using the Grassberger-Procaccia dimension.

  2. Dynamics of Motorized Vehicle Flow under Mixed Traffic Circumstance

    Science.gov (United States)

    Guo, Hong-Wei; Gao, Zi-You; Zhao, Xiao-Mei; Xie, Dong-Fan

    2011-04-01

    To study the dynamics of mixed traffic flow consisting of motorized and non-motorized vehicles, a car-following model based on the principle of collision free and cautious driving is proposed. Lateral friction and overlapping driving are introduced to describe the interactions between motorized vehicles and non-motorized vehicles. By numerical simulations, the flux-density relation, the temporal-spatial dynamics, and the velocity evolution are investigated in detail. The results indicate non-motorized vehicles have a significant impact on the motorized vehicle flow and cause the maximum flux to decline by about 13%. Non-motorized vehicles can decrease the motorized vehicle velocity and cause velocity oscillation when the motorized vehicle density is low. Moreover, non-motorized vehicles show a significant damping effect on the oscillating velocity when the density is medium and high, and such an effect weakens as motorized vehicle density increases. The results also stress the necessity for separating motorized vehicles from non-motorized vehicles.

  3. Tribological approach to study polishing of road surface under traffic

    OpenAIRE

    KANE, Malal; DO, Minh Tan

    2007-01-01

    The polishing phenomenon of road pavements under the vehicle traffic constitutes the main mechanism inherent to the loss of skid resistance over time. A better understanding of this phenomenon would allow an improvement of road safety. This study comprises a review of laboratory test and a model simulating the polishing of road surfaces. The laboratory test uses a polishing machine so called 'Wehner-Schulze' which can reproduce the evolution of the road texture from specimens taken directly f...

  4. Agricultural Vehicles and Rural Road Traffic Safety: an Engineering Challenge

    NARCIS (Netherlands)

    Jaarsma, C.F.; Vries, de J.R.

    2012-01-01

    Road collisions are a problem world-wide. Related to the kilometers traveled on public roads agricultural vehicles (AVs) are over-represented in reported numbers of traffic victims. We aim to investigate how agricultural engineering can reduce accidents with AVs involved on public roads. We

  5. 77 FR 39927 - Vehicles and Traffic Safety-Bicycles

    Science.gov (United States)

    2012-07-06

    ... for accommodating bicycle use, or prescribes a sustainable trail design for the construction of new... National Park Service 36 CFR Part 4 RIN 1024-AD97 Vehicles and Traffic Safety--Bicycles AGENCY: National... designating bicycle routes and managing bicycle use within park units throughout the National Park System. It...

  6. Taking Over Control From Highly Automated Vehicles in Complex Traffic Situations: The Role of Traffic Density.

    Science.gov (United States)

    Gold, Christian; Körber, Moritz; Lechner, David; Bengler, Klaus

    2016-06-01

    The aim of this study was to quantify the impact of traffic density and verbal tasks on takeover performance in highly automated driving. In highly automated vehicles, the driver has to occasionally take over vehicle control when approaching system limits. To ensure safety, the ability of the driver to regain control of the driving task under various driving situations and different driver states needs to be quantified. Seventy-two participants experienced takeover situations requiring an evasive maneuver on a three-lane highway with varying traffic density (zero, 10, and 20 vehicles per kilometer). In a between-subjects design, half of the participants were engaged in a verbal 20-Questions Task, representing speaking on the phone while driving in a highly automated vehicle. The presence of traffic in takeover situations led to longer takeover times and worse takeover quality in the form of shorter time to collision and more collisions. The 20-Questions Task did not influence takeover time but seemed to have minor effects on the takeover quality. For the design and evaluation of human-machine interaction in takeover situations of highly automated vehicles, the traffic state seems to play a major role, compared to the driver state, manipulated by the 20-Questions Task. The present results can be used by developers of highly automated systems to appropriately design human-machine interfaces and to assess the driver's time budget for regaining control. © 2016, Human Factors and Ergonomics Society.

  7. Is vehicle automation enough to prevent crashes? Role of traffic operations in automated driving environments for traffic safety.

    Science.gov (United States)

    Jeong, Eunbi; Oh, Cheol; Lee, Seolyoung

    2017-07-01

    Automated driving systems (ADSs) are expected to prevent traffic accidents caused by driver carelessness on freeways. There is no doubt regarding this safety benefit if all vehicles in the transportation system were equipped with ADSs; however, it is implausible to expect that ADSs will reach 100% market penetration rate (MPR) in the near future. Therefore, the following question arises: 'Can ADSs, which consider only situations in the vicinity of an equipped vehicle, really contribute to a significant reduction in traffic accidents?' To address this issue, the interactions between equipped and unequipped vehicles must be investigated, which is the purpose of this study. This study evaluated traffic safety at different MPRs based on a proposed index to represent the overall rear-end crash risk of the traffic stream. Two approaches were evaluated for adjusting longitudinal vehicle maneuvers: vehicle safety-based maneuvering (VSM), which considers the crash risk of an equipped vehicle and its neighboring vehicles, and traffic safety-based maneuvering (TSM), which considers the overall crash risk in the traffic stream. TSM assumes that traffic operational agencies are able to monitor all the vehicles and to intervene in vehicle maneuvering. An optimization process, which attempts to obtain vehicle maneuvering control parameters to minimize the overall crash risk, is integrated into the proposed evaluation framework. The main purpose of employing the optimization process for vehicle maneuvering in this study is to identify opportunities to improve traffic safety through effective traffic management rather than developing a vehicle control algorithm that can be implemented in practice. The microscopic traffic simulator VISSIM was used to simulate the freeway traffic stream and to conduct systematic evaluations based on the proposed methodology. Both TSM and VSM achieved significant reductions in the potential for rear-end crashes. However, TSM obtained much greater

  8. System Would Predictively Preempt Traffic Lights for Emergency Vehicles

    Science.gov (United States)

    Bachelder, Aaron; Foster, Conrad

    2004-01-01

    Two electronic communication-and-control systems have been proposed as means of modifying the switching of traffic lights to give priority to emergency vehicles. Both systems would utilize the inductive loops already installed in the streets of many municipalities to detect vehicles for timing the switching of traffic lights. The proposed systems could be used alone or to augment other automated emergency traffic-light preemption systems that are already present in some municipalities, including systems that recognize flashing lights or siren sounds or that utilize information on the positions of emergency vehicles derived from the Global Positioning System (GPS). Systems that detect flashing lights and siren sounds are limited in range, cannot "see" or "hear" well around corners, and are highly vulnerable to noise. GPS-based systems are effective in rural areas and small cities, but are often ineffective in large cities because of frequent occultation of GPS satellite signals by large structures. In contrast, the proposed traffic-loop forward prediction system would be relatively invulnerable to noise, would not be subject to significant range limitations, and would function well in large cities -- even in such places as underneath bridges and in tunnels, where GPS-based systems do not work. One proposed system has been characterized as "car-active" because each participating emergency vehicle would be equipped with a computer and a radio transceiver that would communicate with stationary transceivers at the traffic loops. The other proposed system has been characterized as "car-passive" because a passive radio transponder would be installed on the underside of a participating vehicle.

  9. Traffic Congestion Detection System through Connected Vehicles and Big Data

    Directory of Open Access Journals (Sweden)

    Néstor Cárdenas-Benítez

    2016-04-01

    Full Text Available This article discusses the simulation and evaluation of a traffic congestion detection system which combines inter-vehicular communications, fixed roadside infrastructure and infrastructure-to-infrastructure connectivity and big data. The system discussed in this article permits drivers to identify traffic congestion and change their routes accordingly, thus reducing the total emissions of CO2 and decreasing travel time. This system monitors, processes and stores large amounts of data, which can detect traffic congestion in a precise way by means of a series of algorithms that reduces localized vehicular emission by rerouting vehicles. To simulate and evaluate the proposed system, a big data cluster was developed based on Cassandra, which was used in tandem with the OMNeT++ discreet event network simulator, coupled with the SUMO (Simulation of Urban MObility traffic simulator and the Veins vehicular network framework. The results validate the efficiency of the traffic detection system and its positive impact in detecting, reporting and rerouting traffic when traffic events occur.

  10. Assessment of the influence on vehicle emissions of driving style, vehicle technology and traffic measures

    NARCIS (Netherlands)

    Burgwal, H.C. van de; Gense, N.L.J.; Mierlo, J. van; Maggetto, G.

    2002-01-01

    The influence of traffic measures and driving style on different vehicle emissions and on primary energy consumption, and the definition of vehicle parameters influencing the relation between them, is an interesting issue to be assessed in order to allow more realistic estimations of the impact of

  11. Reactive Planning of Autonomous Vehicles for Traffic Scenarios

    Directory of Open Access Journals (Sweden)

    Rahul Kala

    2015-10-01

    Full Text Available Autonomous vehicles operate in real time traffic scenarios and aim to reach their destination from their source in the most efficient manner possible. Research in mobile robotics provides a variety of sophisticated means with which to plan the path of these vehicles. Conversely professional human drivers usually drive using instinctive means, which enables them to reach their goal almost optimally whilst still obeying all traffic laws. In this paper we propose the use of fuzzy logic for novel motion planning. The planner is generated using an evolutionary algorithm which resembles the learning stage of professional drivers. Whether to overtake or not, is a decision which affects one’s driving and the decision is made using some deliberation. We further extend the approach to perform decision making regarding overtaking for all vehicles. Further we coordinate the motion of the vehicles at a traffic crossing to avoid any potential jam or collision. Experimental results prove that by using this approach we have been able to make the vehicles move in an optimal manner in a variety of scenarios.

  12. Road traffic safety in conjunction with in-vehicle ITS

    Directory of Open Access Journals (Sweden)

    Darja TOPOLŠEK

    2014-06-01

    Full Text Available Interest in Intelligent Transportation Systems comes from the problems caused by traffic congestion, road accidents and air pollution. Traffic congestion continues to grow worldwide as a result of increased motorization, population growth, changes in population density and urbanization. Interest in ITS can also be attributed to reducing road accidents and increasing traffic safety. The most common causes for road accidents are excessive speed, inattentive driving and ignorance of the right-of-way rules. To eliminate these causes, experience, knowledge of traffic regulations and a new car are not enough – vehicle safety systems have to take part as well. Therefore, the European Union issued a directive on the installation of intelligent systems, whose functions are active support during driving, warning the driver in dangerous situations and alerting passengers of the car in case of irregularities in motor function or actions carried out by the driver that may cause danger, such as swerving while falling asleep. These systems help drivers to avoid accidents, and in the event of a collision, an emergency call is automatically made. Furthermore, they can be used to regulate traffic patterns or to reduce engine performance, which would reduce pollution. With these benefits in mind, the EU has indicated to the automotive industry that installation of these new Intelligent Transportation Systems should be mandatory in their new vehicles.

  13. Modeling connected and autonomous vehicles in heterogeneous traffic flow

    Science.gov (United States)

    Ye, Lanhang; Yamamoto, Toshiyuki

    2018-01-01

    The objective of this study was to develop a heterogeneous traffic-flow model to study the possible impact of connected and autonomous vehicles (CAVs) on the traffic flow. Based on a recently proposed two-state safe-speed model (TSM), a two-lane cellular automaton (CA) model was developed, wherein both the CAVs and conventional vehicles were incorporated in the heterogeneous traffic flow. In particular, operation rules for CAVs are established considering the new characteristics of this emerging technology, including autonomous driving through the adaptive cruise control and inter-vehicle connection via short-range communication. Simulations were conducted under various CAV-penetration rates in the heterogeneous flow. The impact of CAVs on the road capacity was numerically investigated. The simulation results indicate that the road capacity increases with an increase in the CAV-penetration rate within the heterogeneous flow. Up to a CAV-penetration rate of 30%, the road capacity increases gradually; the effect of the difference in the CAV capability on the growth rate is insignificant. When the CAV-penetration rate exceeds 30%, the growth rate is largely decided by the capability of the CAV. The greater the capability, the higher the road-capacity growth rate. The relationship between the CAV-penetration rate and the road capacity is numerically analyzed, providing some insights into the possible impact of the CAVs on traffic systems.

  14. Traffic Management for Emergency Vehicle Priority Based on Visual Sensing

    Directory of Open Access Journals (Sweden)

    Kapileswar Nellore

    2016-11-01

    Full Text Available Vehicular traffic is endlessly increasing everywhere in the world and can cause terrible traffic congestion at intersections. Most of the traffic lights today feature a fixed green light sequence, therefore the green light sequence is determined without taking the presence of the emergency vehicles into account. Therefore, emergency vehicles such as ambulances, police cars, fire engines, etc. stuck in a traffic jam and delayed in reaching their destination can lead to loss of property and valuable lives. This paper presents an approach to schedule emergency vehicles in traffic. The approach combines the measurement of the distance between the emergency vehicle and an intersection using visual sensing methods, vehicle counting and time sensitive alert transmission within the sensor network. The distance between the emergency vehicle and the intersection is calculated for comparison using Euclidean distance, Manhattan distance and Canberra distance techniques. The experimental results have shown that the Euclidean distance outperforms other distance measurement techniques. Along with visual sensing techniques to collect emergency vehicle information, it is very important to have a Medium Access Control (MAC protocol to deliver the emergency vehicle information to the Traffic Management Center (TMC with less delay. Then only the emergency vehicle is quickly served and can reach the destination in time. In this paper, we have also investigated the MAC layer in WSNs to prioritize the emergency vehicle data and to reduce the transmission delay for emergency messages. We have modified the medium access procedure used in standard IEEE 802.11p with PE-MAC protocol, which is a new back off selection and contention window adjustment scheme to achieve low broadcast delay for emergency messages. A VANET model for the UTMS is developed and simulated in NS-2. The performance of the standard IEEE 802.11p and the proposed PE-MAC is analysed in detail. The NS-2

  15. Traffic Management for Emergency Vehicle Priority Based on Visual Sensing.

    Science.gov (United States)

    Nellore, Kapileswar; Hancke, Gerhard P

    2016-11-10

    Vehicular traffic is endlessly increasing everywhere in the world and can cause terrible traffic congestion at intersections. Most of the traffic lights today feature a fixed green light sequence, therefore the green light sequence is determined without taking the presence of the emergency vehicles into account. Therefore, emergency vehicles such as ambulances, police cars, fire engines, etc. stuck in a traffic jam and delayed in reaching their destination can lead to loss of property and valuable lives. This paper presents an approach to schedule emergency vehicles in traffic. The approach combines the measurement of the distance between the emergency vehicle and an intersection using visual sensing methods, vehicle counting and time sensitive alert transmission within the sensor network. The distance between the emergency vehicle and the intersection is calculated for comparison using Euclidean distance, Manhattan distance and Canberra distance techniques. The experimental results have shown that the Euclidean distance outperforms other distance measurement techniques. Along with visual sensing techniques to collect emergency vehicle information, it is very important to have a Medium Access Control (MAC) protocol to deliver the emergency vehicle information to the Traffic Management Center (TMC) with less delay. Then only the emergency vehicle is quickly served and can reach the destination in time. In this paper, we have also investigated the MAC layer in WSNs to prioritize the emergency vehicle data and to reduce the transmission delay for emergency messages. We have modified the medium access procedure used in standard IEEE 802.11p with PE-MAC protocol, which is a new back off selection and contention window adjustment scheme to achieve low broadcast delay for emergency messages. A VANET model for the UTMS is developed and simulated in NS-2. The performance of the standard IEEE 802.11p and the proposed PE-MAC is analysed in detail. The NS-2 simulation results

  16. Traffic-Light-Preemption Vehicle-Transponder Software Module

    Science.gov (United States)

    Bachelder, Aaron; Foster, Conrad

    2005-01-01

    A prototype wireless data-communication and control system automatically modifies the switching of traffic lights to give priority to emergency vehicles. The system, which was reported in several NASA Tech Briefs articles at earlier stages of development, includes a transponder on each emergency vehicle, a monitoring and control unit (an intersection controller) at each intersection equipped with traffic lights, and a central monitoring subsystem. An essential component of the system is a software module executed by a microcontroller in each transponder. This module integrates and broadcasts data on the position, velocity, acceleration, and emergency status of the vehicle. The position, velocity, and acceleration data are derived partly from the Global Positioning System, partly from deductive reckoning, and partly from a diagnostic computer aboard the vehicle. The software module also monitors similar broadcasts from other vehicles and from intersection controllers, informs the driver of which intersections it controls, and generates visible and audible alerts to inform the driver of any other emergency vehicles that are close enough to create a potential hazard. The execution of the software module can be monitored remotely and the module can be upgraded remotely and, hence, automatically

  17. Connect & Drive - On the use of vehicle-to-vehicle communications to increase Traffic Stability and Efficiency

    NARCIS (Netherlands)

    Heijenk, Geert

    2009-01-01

    At moderate to high traffic densities, road traffic exhibits an unstable behavior, resulting in decrease traffic efficiency. One of the phenomena that can be observed at these densities is the propagation of shock waves against the flow of traffic, which seriously reduce the speed of vehicles. The

  18. Evaluating the Interference of Bicycle Traffic on Vehicle Operation on Urban Streets with Bike Lanes

    OpenAIRE

    Pu, Ziyuan; Li, Zhibin; Wang, Yong; Ye, Mao; Fan, Wei

    2017-01-01

    Many urban streets are designed with on-street bike lanes to provide right-of-way for bicycle traffic. However, when bicycle flow is large, extensive passing maneuvers could occupy vehicle lanes and thus cause interferences to vehicle traffic. The primary objective of this study is to evaluate how bicycle traffic affects vehicle operation on urban streets with bike lanes. Data were collected on six street segments in Nanjing, China. The cumulative curves were constructed to extract traffic fl...

  19. Control techniques for an automated mixed traffic vehicle

    Science.gov (United States)

    Meisenholder, G. W.; Johnston, A. R.

    1977-01-01

    The paper describes an automated mixed traffic vehicle (AMTV), a driverless low-speed tram designed to operate in mixed pedestrian and vehicular traffic. The vehicle is a six-passenger electric tram equipped with sensing and control which permit it to function on existing streets in an automatic mode. The design includes established wire-following techniques for steering and near-IR headway sensors. A 7-mph cruise speed is reduced to 2 mph or a complete stop in response to sensor (or passenger) inputs. The AMTV performance is evaluated by operation on a loop route and by simulation. Some necessary improvements involving sensors, sensor pattern, use of an audible signal, and control lag are discussed. It is suggested that appropriate modifications will eliminate collision incidents.

  20. Shadow-Based Vehicle Detection in Urban Traffic.

    Science.gov (United States)

    Ibarra-Arenado, Manuel; Tjahjadi, Tardi; Pérez-Oria, Juan; Robla-Gómez, Sandra; Jiménez-Avello, Agustín

    2017-04-27

    Vehicle detection is a fundamental task in Forward Collision Avoiding Systems (FACS). Generally, vision-based vehicle detection methods consist of two stages: hypotheses generation and hypotheses verification. In this paper, we focus on the former, presenting a feature-based method for on-road vehicle detection in urban traffic. Hypotheses for vehicle candidates are generated according to the shadow under the vehicles by comparing pixel properties across the vertical intensity gradients caused by shadows on the road, and followed by intensity thresholding and morphological discrimination. Unlike methods that identify the shadow under a vehicle as a road region with intensity smaller than a coarse lower bound of the intensity for road, the thresholding strategy we propose determines a coarse upper bound of the intensity for shadow which reduces false positives rates. The experimental results are promising in terms of detection performance and robustness in day time under different weather conditions and cluttered scenarios to enable validation for the first stage of a complete FACS.

  1. Shadow-Based Vehicle Detection in Urban Traffic

    Directory of Open Access Journals (Sweden)

    Manuel Ibarra-Arenado

    2017-04-01

    Full Text Available Vehicle detection is a fundamental task in Forward Collision Avoiding Systems (FACS. Generally, vision-based vehicle detection methods consist of two stages: hypotheses generation and hypotheses verification. In this paper, we focus on the former, presenting a feature-based method for on-road vehicle detection in urban traffic. Hypotheses for vehicle candidates are generated according to the shadow under the vehicles by comparing pixel properties across the vertical intensity gradients caused by shadows on the road, and followed by intensity thresholding and morphological discrimination. Unlike methods that identify the shadow under a vehicle as a road region with intensity smaller than a coarse lower bound of the intensity for road, the thresholding strategy we propose determines a coarse upper bound of the intensity for shadow which reduces false positives rates. The experimental results are promising in terms of detection performance and robustness in day time under different weather conditions and cluttered scenarios to enable validation for the first stage of a complete FACS.

  2. “Charge while driving” for electric vehicles: road traffic modeling and energy assessment

    National Research Council Canada - National Science Library

    DEFLORIO, Francesco Paolo; CASTELLO, Luca; PINNA, Ivano; GUGLIELMI, Paolo

    2015-01-01

    ...) electric vehicles, from both traffic and energy points of view. To accurately quantify the electric power required from an energy supplier for the proper management of the charging system, a traffic simulation model is implemented...

  3. Agricultural vehicles and sustainable safe road traffic: solving conflicts on arterial highways

    NARCIS (Netherlands)

    Jaarsma, C.F.; Botma, H.; Ark, van R.G.H.; Willems, G.P.A.

    2003-01-01

    Addressing the issues of traffic safety in rural areas presents a constant challenge. The mix of light and heavy vehicles and the considerable differences in speed among these traffic participants result in high risks and delays for the faster vehicles. Agricultural vehicles (AVs) in particular have

  4. Performance of an Automated-Mixed-Traffic-Vehicle /AMTV/ System. [urban people mover

    Science.gov (United States)

    Peng, T. K. C.; Chon, K.

    1978-01-01

    This study analyzes the operation and evaluates the expected performance of a proposed automatic guideway transit system which uses low-speed Automated Mixed Traffic Vehicles (AMTV's). Vehicle scheduling and headway control policies are evaluated with a transit system simulation model. The effect of mixed-traffic interference on the average vehicle speed is examined with a vehicle-pedestrian interface model. Control parameters regulating vehicle speed are evaluated for safe stopping and passenger comfort.

  5. Traffic lanes for vehicles of mass public passenger transport on city streets

    Directory of Open Access Journals (Sweden)

    Gladović Pavle V.

    2015-01-01

    Full Text Available Some of the basic measures of regulating public mass passenger transport in a city network are the introduction and management of traffic lanes reserved for the public transportation. These traffic lanes are important for several reasons: faster moving and shorter travelling time for the vehicles, reducing operating costs, improving the safety, increasing passenger comfort, maintaining of the timetable quality, etc. In most cities, an intensive use of the public transport is concentrated in the morning and the afternoon peak period. The state of the public transport system during these periods is reflected in the crowds inside the vehicles, long vehicle queues at intersections and at bus stops, which cause congestion on the streets and result in delays of public transport vehicles. This paper provides an overview of the current situation on an example in the city of Belgrade. The capacity and the quality of service for the street surfaces reserved for the public transportation vehicles were analysed on the aforementioned example.

  6. Intelligent vehicle based traffic monitoring – exploring application in South Africa

    CSIR Research Space (South Africa)

    Labuschagne, FJJ

    2010-08-01

    Full Text Available The paper details the anticipated benefits of an intelligent vehicle based traffic monitoring approach holds. The approach utilises advanced technology with the potential to reduce crashes and includes the monitor of vehicle speeds and flows...

  7. Fine-Tuning ADAS Algorithm Parameters for Optimizing Traffic Safety and Mobility in Connected Vehicle Environment

    Science.gov (United States)

    With the development of the Connected Vehicle technology that facilitates wirelessly communication among vehicles and road-side infrastructure, the Advanced Driver Assistance Systems (ADAS) can be adopted as an effective tool for accelerating traffic safety and mobility optimizat...

  8. Surface properties-vehicle interaction

    Science.gov (United States)

    Huft, D. L.; Her, I.; Agrawal, S. K.; Zimmer, R. A.; Bester, C. J.

    Several topics related to the surface properties of aircraft runways are discussed. The South Dakota profilometer; development of a data acquisition method for noncontact pavement macrotexture measurement; the traction of an aircraft tire on grooved and porous asphaltic concrete; holes in the pavements; the effect of pavement type and condition on the fuel consumption of vehicles; the traction loss of a suspended tire on a sinusoidal road; the effect of vehicle and driver characteristics on the psychological evaluation of road roughness; the correlation of subjective panel ratings of pavement ride quality with profilometer-derived measures of pavement roughness; a microprocessor-based noncontact distance measuring control system, and, the representation of pavement surface topography in predicting runoff depths and hydroplaning potential are discussed.

  9. A Joint Vehicle-Vehicle/Vehicle-Roadside Communication Protocol for Highway Traffic Safety

    OpenAIRE

    Bin Hu; Hamid Gharavi

    2011-01-01

    A joint vehicle-vehicle/vehicle-roadside communication protocol is proposed for cooperative collision avoiding in Vehicular Ad Hoc Networks (VANETs). In this protocol, emergency warning messages are simultaneously transmitted via Vehicle-to-Vehicle (V2V) and Vehicle-to-Roadside (V2R) communications in order to achieve multipath diversity routing. In addition, to further improve communication reliability and achieve low latency, a Multi-Channel (MC) technique based on two nonove...

  10. Cellular automata model for traffic flow at intersections in internet of vehicles

    Science.gov (United States)

    Zhao, Han-Tao; Liu, Xin-Ru; Chen, Xiao-Xu; Lu, Jian-Cheng

    2018-03-01

    Considering the effect of the front vehicle's speed, the influence of the brake light and the conflict of the traffic flow, we established a cellular automata model called CE-NS for traffic flow at the intersection in the non-vehicle networking environment. According to the information interaction of Internet of Vehicles (IoV), introducing parameters describing the congestion and the accurate speed of the front vehicle into the CE-NS model, we improved the rules of acceleration, deceleration and conflict, and finally established a cellular automata model for traffic flow at intersections of IoV. The relationship between traffic parameters such as vehicle speed, flow and average travel time is obtained by numerical simulation of two models. Based on this, we compared the traffic situation of the non-vehicle networking environment with conditions of IoV environment, and analyzed the influence of the different degree of IoV on the traffic flow. The results show that the traffic speed is increased, the travel time is reduced, the flux of intersections is increased and the traffic flow is more smoothly under IoV environment. After the vehicle which achieves IoV reaches a certain proportion, the operation effect of the traffic flow begins to improve obviously.

  11. On Making Autonomous Vehicles Respect Traffic Law : a Case Study for Dutch Law

    NARCIS (Netherlands)

    Prakken, H.

    Among the problems that still need to be solved before autonomous vehicles can fully autonomously participate in traffic is the one of making them respect the traffic laws. This paper discusses this problem by way of a case study of Dutch traffic law. First it is discussed to what extent Dutch

  12. 77 FR 24560 - National Highway Traffic Safety Administration Electric Vehicle Safety Technical Symposium

    Science.gov (United States)

    2012-04-24

    ... National Highway Traffic Safety Administration Electric Vehicle Safety Technical Symposium AGENCY: National... electric vehicles powered by lithium-ion (Li-ion) batteries. The symposium will include brief NHTSA... lithium-ion (Li-ion) battery-powered vehicles. Electric vehicles show great promise as an innovative and...

  13. 78 FR 56267 - Article 19-A of the State of New York's Vehicle and Traffic Law

    Science.gov (United States)

    2013-09-12

    ... Federal Motor Carrier Safety Administration Article 19-A of the State of New York's Vehicle and Traffic... a determination that Article 19-A of the State of New York's Vehicle and Traffic Law governing... comments on whether Article 19-A has safety benefits, how it is being enforced against interstate passenger...

  14. Automated Mixed Traffic Vehicle (AMTV) technology and safety study

    Science.gov (United States)

    Johnston, A. R.; Peng, T. K. C.; Vivian, H. C.; Wang, P. K.

    1978-01-01

    Technology and safety related to the implementation of an Automated Mixed Traffic Vehicle (AMTV) system are discussed. System concepts and technology status were reviewed and areas where further development is needed are identified. Failure and hazard modes were also analyzed and methods for prevention were suggested. The results presented are intended as a guide for further efforts in AMTV system design and technology development for both near term and long term applications. The AMTV systems discussed include a low speed system, and a hybrid system consisting of low speed sections and high speed sections operating in a semi-guideway. The safety analysis identified hazards that may arise in a properly functioning AMTV system, as well as hardware failure modes. Safety related failure modes were emphasized. A risk assessment was performed in order to create a priority order and significant hazards and failure modes were summarized. Corrective measures were proposed for each hazard.

  15. Traffic Control Models Based on Cellular Automata for At-Grade Intersections in Autonomous Vehicle Environment

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2017-01-01

    Full Text Available Autonomous vehicle is able to facilitate road safety and traffic efficiency and has become a promising trend of future development. With a focus on highways, existing literatures studied the feasibility of autonomous vehicle in continuous traffic flows and the controllability of cooperative driving. However, rare efforts have been made to investigate the traffic control strategies in autonomous vehicle environment on urban roads, especially in urban intersections. In autonomous vehicle environment, it is possible to achieve cooperative driving with V2V and V2I wireless communication. Without signal control, conflicted traffic flows could pass intersections through mutual cooperative, which is a remarkable improvement to existing traffic control methods. This paper established a cellular automata model with greedy algorithm for the traffic control of intersections in autonomous vehicle environment, with autonomous vehicle platoon as the optimization object. NetLogo multiagent simulation platform model was employed to simulate the proposed model. The simulation results are compared with the traffic control programs in conventional Synchro optimization. The findings suggest that, on the premises of ensuring traffic safety, the control strategy of the proposed model significantly reduces average delays and number of stops as well as increasing traffic capacity.

  16. Road traffic crashes among farm vehicle drivers in southern China: A cross-sectional survey.

    Science.gov (United States)

    Zhang, Xujun; Yang, Yaming; Chen, Yu; Yao, Hongyan; Wu, Ming; Cui, Mengjing; Li, Yang; Hu, Jie; Zhang, Cong; Li, Zhen; Stallones, Lorann; Xiang, Huiyun

    2017-01-02

    The objective of this study was to identify the prevalence and potential risk factors of farm vehicle-related road traffic crashes among farm vehicle drivers in southern China. A cross-sectional study was used to interview 1,422 farm vehicle drivers in southern China. Farm vehicle-related road traffic crashes that occurred from December 2013 to November 2014 were investigated. Data on farm vehicle-related road traffic crashes and related factors were collected by face-to-face interviews. The prevalence of farm vehicle-related road traffic crashes among the investigated drivers was 7.2%. Farm vehicle-related road traffic crashes were significantly associated with self-reported vision problem (adjusted odds ratio [AOR] = 6.48, 95% confidence interval [CI], 3.86-10.87), self-reported sleep disorders (AOR = 10.03, 95% CI, 6.28-15.99), self-reported stress (AOR = 20.47, 95% CI, 9.96-42.08), reported history of crashes (AOR = 5.40, 95% CI, 3.47-8.42), reported history of drunk driving (AOR = 5.07, 95% CI, 2.97-8.65), and reported history of fatigued driving (AOR = 5.72, 95% CI, 3.73-8.78). The number of road traffic crashes was highest in the daytime and during harvest season. In over 96% of farm vehicle-related road traffic crashes, drivers were believed to be responsible for the crash. Major crash-causing factors included improper driving, careless driving, violating of traffic signals or signs, and being in the wrong lane. Findings of this study suggest that farm vehicle-related road traffic crashes have become a burgeoning public health problem in China. Programs need to be developed to prevent farm vehicle-related road traffic crashes in this emerging country.

  17. Efficient queue length detection at traffic signals using probe vehicle data and data fusion

    OpenAIRE

    Neumann, Thorsten

    2009-01-01

    In this paper, a new method for the detection of queue lengths at traffic signals is described. Based on conventional probe vehicle data and implementing an extremely flexible data fusion approach for the integration of nearly arbitrary additional traffic information, it provides an efficient way to get high-quality estimates for the traffic states at traffic signals. A systematic evaluation based on extensive simulations addresses several issues concerning quality and demonstrates both th...

  18. Dynamic route guidance strategy in a two-route pedestrian-vehicle mixed traffic flow system

    Science.gov (United States)

    Liu, Mianfang; Xiong, Shengwu; Li, Bixiang

    2016-05-01

    With the rapid development of transportation, traffic questions have become the major issue for social, economic and environmental aspects. Especially, during serious emergencies, it is very important to alleviate road traffic congestion and improve the efficiency of evacuation to reduce casualties, and addressing these problems has been a major task for the agencies responsible in recent decades. Advanced road guidance strategies have been developed for homogeneous traffic flows, or to reduce traffic congestion and enhance the road capacity in a symmetric two-route scenario. However, feedback strategies have rarely been considered for pedestrian-vehicle mixed traffic flows with variable velocities and sizes in an asymmetric multi-route traffic system, which is a common phenomenon in many developing countries. In this study, we propose a weighted road occupancy feedback strategy (WROFS) for pedestrian-vehicle mixed traffic flows, which considers the system equilibrium to ease traffic congestion. In order to more realistic simulating the behavior of mixed traffic objects, the paper adopted a refined and dynamic cellular automaton model (RDPV_CA model) as the update mechanism for pedestrian-vehicle mixed traffic flow. Moreover, a bounded rational threshold control was introduced into the feedback strategy to avoid some negative effect of delayed information and reduce. Based on comparisons with the two previously proposed strategies, the simulation results obtained in a pedestrian-vehicle traffic flow scenario demonstrated that the proposed strategy with a bounded rational threshold was more effective and system equilibrium, system stability were reached.

  19. Evaluating the Interference of Bicycle Traffic on Vehicle Operation on Urban Streets with Bike Lanes

    Directory of Open Access Journals (Sweden)

    Ziyuan Pu

    2017-01-01

    Full Text Available Many urban streets are designed with on-street bike lanes to provide right-of-way for bicycle traffic. However, when bicycle flow is large, extensive passing maneuvers could occupy vehicle lanes and thus cause interferences to vehicle traffic. The primary objective of this study is to evaluate how bicycle traffic affects vehicle operation on urban streets with bike lanes. Data were collected on six street segments in Nanjing, China. The cumulative curves were constructed to extract traffic flow information including individual bicycle and vehicle speeds and aggregated traffic parameters such as flow and density. The results showed that as bicycle density on bike lanes continuously increases faster bicycles may run into vehicle lanes causing considerable reductions in vehicle speeds. A generalized linear model was estimated to predict the vehicle delay. Results showed that vehicle delay increases as bicycle flow and vehicle flow increase. Number of vehicle lanes and width of bike lane also have significant impact on vehicle delay. Findings of the study are helpful to regions around the world in bike infrastructure design in order to improve operations of both bicycles and vehicles.

  20. Analysis of energy consumption and emission of the heterogeneous traffic flow consisting of traditional vehicles and electric vehicles

    Science.gov (United States)

    Xiao, Hong; Huang, Hai-Jun; Tang, Tie-Qiao

    2017-12-01

    Electric vehicle (EV) has become a potential traffic tool, which has attracted researchers to explore various traffic phenomena caused by EV (e.g. congestion, electricity consumption, etc.). In this paper, we study the energy consumption (including the fuel consumption and the electricity consumption) and emissions of heterogeneous traffic flow (that consists of the traditional vehicle (TV) and EV) under three traffic situations (i.e. uniform flow, shock and rarefaction waves, and a small perturbation) from the perspective of macro traffic flow. The numerical results show that the proportion of electric vehicular flow has great effects on the TV’s fuel consumption and emissions and the EV’s electricity consumption, i.e. the fuel consumption and emissions decrease while the electricity consumption increases with the increase of the proportion of electric vehicular flow. The results can help us better understand the energy consumption and emissions of the heterogeneous traffic flow consisting of TV and EV.

  1. Satellite vehicle tracking aiming to increase traffic safety within the Serbian Armed Forces

    Directory of Open Access Journals (Sweden)

    Igor S. Milanović

    2012-10-01

    Full Text Available The purpose of this work is to show how to affect the most important factor of traffic safety - an individual, by using some technical solutions of satellite tracking of vehicles. By using units of the Land Forces as an example, a brief analysis of traffic safety for vehicles less than 5 years old has been performed. It is noticed that the number of traffic accidents with these vehicles involved has increased, so we tried to use one software package commercially available in order to show all advantages and disadvantages which could be noticed during this kind of vehicle tracking. The conclusion is that preventive vehicle tracking can improve traffic safety, but that a techno-economic analysis has to be done as well, in order to create all the necessary conditions for the introduction of this system in the units of the Serbian Armed Forces.

  2. Self-control of traffic lights and vehicle flows in urban road networks

    Science.gov (United States)

    Lämmer, Stefan; Helbing, Dirk

    2008-04-01

    Based on fluid-dynamic and many-particle (car-following) simulations of traffic flows in (urban) networks, we study the problem of coordinating incompatible traffic flows at intersections. Inspired by the observation of self-organized oscillations of pedestrian flows at bottlenecks, we propose a self-organization approach to traffic light control. The problem can be treated as a multi-agent problem with interactions between vehicles and traffic lights. Specifically, our approach assumes a priority-based control of traffic lights by the vehicle flows themselves, taking into account short-sighted anticipation of vehicle flows and platoons. The considered local interactions lead to emergent coordination patterns such as 'green waves' and achieve an efficient, decentralized traffic light control. While the proposed self-control adapts flexibly to local flow conditions and often leads to non-cyclical switching patterns with changing service sequences of different traffic flows, an almost periodic service may evolve under certain conditions and suggests the existence of a spontaneous synchronization of traffic lights despite the varying delays due to variable vehicle queues and travel times. The self-organized traffic light control is based on an optimization and a stabilization rule, each of which performs poorly at high utilizations of the road network, while their proper combination reaches a superior performance. The result is a considerable reduction not only in the average travel times, but also of their variation. Similar control approaches could be applied to the coordination of logistic and production processes.

  3. Predictive control strategies for energy saving of hybrid electric vehicles based on traffic light information

    Directory of Open Access Journals (Sweden)

    Kaijiang YU

    2015-10-01

    Full Text Available As the conventional control method for hybrid electric vehicle doesn’t consider the effect of known traffic light information on the vehicle energy management, this paper proposes a model predictive control intelligent optimization strategies based on traffic light information for hybrid electric vehicles. By building the simplified model of the hybrid electric vehicle and adopting the continuation/generalized minimum residual method, the model prediction problem is solved. The simulation is conducted by using MATLAB/Simulink platform. The simulation results show the effectiveness of the proposed model of the traffic light information, and that the proposed model predictive control method can improve fuel economy and the real-time control performance significantly. The research conclusions show that the proposed control strategy can achieve optimal control of the vehicle trajectory, significantly improving fuel economy of the vehicle, and meet the system requirements for the real-time optimal control.

  4. Modeling Vehicle Collision Angle in Traffic Crashes Based on Three-Dimensional Laser Scanning Data.

    Science.gov (United States)

    Lyu, Nengchao; Huang, Gang; Wu, Chaozhong; Duan, Zhicheng; Li, Pingfan

    2017-02-28

    In road traffic accidents, the analysis of a vehicle's collision angle plays a key role in identifying a traffic accident's form and cause. However, because accurate estimation of vehicle collision angle involves many factors, it is difficult to accurately determine it in cases in which less physical evidence is available and there is a lack of monitoring. This paper establishes the mathematical relation model between collision angle, deformation, and normal vector in the collision region according to the equations of particle deformation and force in Hooke's law of classical mechanics. At the same time, the surface reconstruction method suitable for a normal vector solution is studied. Finally, the estimation model of vehicle collision angle is presented. In order to verify the correctness of the model, verification of multi-angle collision experiments and sensitivity analysis of laser scanning precision for the angle have been carried out using three-dimensional (3D) data obtained by a 3D laser scanner in the collision deformation zone. Under the conditions with which the model has been defined, validation results show that the collision angle is a result of the weighted synthesis of the normal vector of the collision point and the weight value is the deformation of the collision point corresponding to normal vectors. These conclusions prove the applicability of the model. The collision angle model proposed in this paper can be used as the theoretical basis for traffic accident identification and cause analysis. It can also be used as a theoretical reference for the study of the impact deformation of elastic materials.

  5. A Genetic Algorithm Approach for Expedited Crossing of Emergency Vehicles in Connected and Autonomous Intersection Traffic

    Directory of Open Access Journals (Sweden)

    Qiang Lu

    2017-01-01

    Full Text Available This paper proposes an intersection control algorithm which aims to determine an efficient vehicle-passing sequence that allows the emergency vehicle to cross an intersection as soon as possible while the travel times of other vehicles are minimally affected. When there are no emergency vehicles within the intersection area, the vehicles are controlled by the DICA that we proposed in our earlier work. When there are emergency vehicles entering the communication range, we prioritize emergency vehicles through optimal ordering of vehicles. Since the number of possible vehicle-passing sequences increases rapidly with the number of vehicles, finding an efficient sequence of vehicles in a short time is the main challenge of the study. A genetic algorithm is proposed to solve the optimization problem which finds the optimal vehicle sequence that gives the emergency vehicles the highest priority. The efficiency of the proposed approach for expedited crossing of emergency vehicles is validated through comparisons with DICA and a reactive traffic light algorithm through extensive simulations. The results show that the proposed genetic algorithm is able to decrease the travel times of emergency vehicles significantly in light and medium traffic volumes without causing any noticeable performance degradation of normal vehicles.

  6. Agent-based transport simulation versus equilibrium assignment for private vehicle traffic in Gauteng

    CSIR Research Space (South Africa)

    Fourie, PJ

    2010-08-01

    Full Text Available This paper compares the performance of an agent-based microsimulation technology (MATSim) with that of an established equilibrium assignment model (EMME/2) for the private vehicle traffic demands description from the Gauteng Transportation Study...

  7. On the problem of making autonomous vehicles conform to traffic law

    NARCIS (Netherlands)

    Prakken, H.

    2017-01-01

    Autonomous vehicles are one of the most spectacular recent developments of Artificial Intelligence. Among the problems that still need to be solved before they can fully autonomously participate in traffic is the one of making their behaviour conform to the traffic laws. This paper discusses this

  8. Vehicle Routing with Traffic Congestion and Drivers' Driving and Working Rules

    NARCIS (Netherlands)

    Kok, A.L.; Hans, Elias W.; Schutten, Johannes M.J.; Zijm, Willem H.M.

    2010-01-01

    For the intensively studied vehicle routing problem (VRP), two real-life restrictions have received only minor attention in the VRP-literature: traffic congestion and driving hours regulations. Traffic congestion causes late arrivals at customers and long travel times resulting in large transport

  9. Early estimate of motor vehicle traffic fatalities in 2009 : a brief statistical summary

    Science.gov (United States)

    2010-03-01

    statistical projection of traffic fatalities in 2009 shows that an estimated 33,963 people died in motor vehicle traffic crashes. This represents a decline of about 8.9 percent as compared to the 37,261 fatalities that occurred in 2008, as shown in T...

  10. INVESTIGATION OF ROADWAY GEOMETRIC AND TRAFFIC FLOW FACTORS FOR VEHICLE CRASHES USING SPATIOTEMPORAL INTERACTION

    Directory of Open Access Journals (Sweden)

    G. Gill

    2017-09-01

    Full Text Available Traffic safety is a major concern in the transportation industry due to immense monetary and emotional burden caused by crashes of various severity levels, especially the injury and fatality ones. To reduce such crashes on all public roads, the safety management processes are commonly implemented which include network screening, problem diagnosis, countermeasure identification, and project prioritization. The selection of countermeasures for potential mitigation of crashes is governed by the influential factors which impact roadway crashes. Crash prediction model is the tool widely adopted by safety practitioners or researchers to link various influential factors to crash occurrences. Many different approaches have been used in the past studies to develop better fitting models which also exhibit prediction accuracy. In this study, a crash prediction model is developed to investigate the vehicular crashes occurring at roadway segments. The spatial and temporal nature of crash data is exploited to form a spatiotemporal model which accounts for the different types of heterogeneities among crash data and geometric or traffic flow variables. This study utilizes the Poisson lognormal model with random effects, which can accommodate the yearly variations in explanatory variables and the spatial correlations among segments. The dependency of different factors linked with roadway geometric, traffic flow, and road surface type on vehicular crashes occurring at segments was established as the width of lanes, posted speed limit, nature of pavement, and AADT were found to be correlated with vehicle crashes.

  11. Investigation of Roadway Geometric and Traffic Flow Factors for Vehicle Crashes Using Spatiotemporal Interaction

    Science.gov (United States)

    Gill, G.; Sakrani, T.; Cheng, W.; Zhou, J.

    2017-09-01

    Traffic safety is a major concern in the transportation industry due to immense monetary and emotional burden caused by crashes of various severity levels, especially the injury and fatality ones. To reduce such crashes on all public roads, the safety management processes are commonly implemented which include network screening, problem diagnosis, countermeasure identification, and project prioritization. The selection of countermeasures for potential mitigation of crashes is governed by the influential factors which impact roadway crashes. Crash prediction model is the tool widely adopted by safety practitioners or researchers to link various influential factors to crash occurrences. Many different approaches have been used in the past studies to develop better fitting models which also exhibit prediction accuracy. In this study, a crash prediction model is developed to investigate the vehicular crashes occurring at roadway segments. The spatial and temporal nature of crash data is exploited to form a spatiotemporal model which accounts for the different types of heterogeneities among crash data and geometric or traffic flow variables. This study utilizes the Poisson lognormal model with random effects, which can accommodate the yearly variations in explanatory variables and the spatial correlations among segments. The dependency of different factors linked with roadway geometric, traffic flow, and road surface type on vehicular crashes occurring at segments was established as the width of lanes, posted speed limit, nature of pavement, and AADT were found to be correlated with vehicle crashes.

  12. Reducing Traffic Congestions by Introducing CACC-Vehicles on a Multi-Lane Highway Using Agent-Based Approach

    Science.gov (United States)

    Arnaout, Georges M.; Bowling, Shannon R.

    2011-01-01

    Traffic congestion is an ongoing problem of great interest to researchers from different areas in academia. With the emerging technology for inter-vehicle communication, vehicles have the ability to exchange information with predecessors by wireless communication. In this paper, we present an agent-based model of traffic congestion and examine the impact of having CACC (Cooperative Adaptive Cruise Control) embedded vehicle(s) on a highway system consisting of 4 traffic lanes without overtaking. In our model, CACC vehicles adapt their acceleration/deceleration according to vehicle-to-vehicle inter-communication. We analyze the average speed of the cars, the shockwaves, and the evolution of traffic congestion throughout the lifecycle of the model. The study identifies how CACC vehicles affect the dynamics of traffic flow on a complex network and reduce the oscillatory behavior (stop and go) resulting from the acceleration/deceleration of the vehicles.

  13. Effects of vehicle-pedestrian interaction and speed limit on traffic performance of intersections

    Science.gov (United States)

    Li, Xiang; Sun, Jian-Qiao

    2016-10-01

    The intersection model consisting of vehicle model, pedestrian model, pedestrian-vehicle interaction model and intersection rules has been presented in this paper. The well-established vehicle and pedestrian movement models in the literature are combined and applied to the intersection system with additional rules. Extensive numerical simulations with different scenarios are carried out. The effects of road speed limit, vehicle arrival rate, pedestrian regularity rate and vehicle rational rate on the intersection performance are quantitatively investigated. Three measures of the traffic performance are studied including transportation efficiency, energy economy and traffic safety. We have found that the energy economy can be achieved with the high transportation efficiency, and that the traffic safety is in conflict with the efficiency. Furthermore, we have found that the pedestrian interference makes the intersection performance worse, resulting in lower transportation efficiency, more energy consumptions and higher safety risk.

  14. Network origin-destination demand estimation using limited link traffic counts : strategic deployment of vehicle detectors through an integrated corridor management framework.

    Science.gov (United States)

    2009-10-15

    In typical road traffic corridors, freeway systems are generally well-equipped with traffic surveillance systems such as vehicle detector (VD) and/or closed circuit television (CCTV) systems in order to gather timely traffic information for traffic c...

  15. SMART VIDEO SURVEILLANCE SYSTEM FOR VEHICLE DETECTION AND TRAFFIC FLOW CONTROL

    Directory of Open Access Journals (Sweden)

    A. A. SHAFIE

    2011-08-01

    Full Text Available Traffic signal light can be optimized using vehicle flow statistics obtained by Smart Video Surveillance Software (SVSS. This research focuses on efficient traffic control system by detecting and counting the vehicle numbers at various times and locations. At present, one of the biggest problems in the main city in any country is the traffic jam during office hour and office break hour. Sometimes it can be seen that the traffic signal green light is still ON even though there is no vehicle coming. Similarly, it is also observed that long queues of vehicles are waiting even though the road is empty due to traffic signal light selection without proper investigation on vehicle flow. This can be handled by adjusting the vehicle passing time implementing by our developed SVSS. A number of experiment results of vehicle flows are discussed in this research graphically in order to test the feasibility of the developed system. Finally, adoptive background model is proposed in SVSS in order to successfully detect target objects such as motor bike, car, bus, etc.

  16. Modeling Vehicle Collision Angle in Traffic Crashes Based on Three-Dimensional Laser Scanning Data

    Directory of Open Access Journals (Sweden)

    Nengchao Lyu

    2017-02-01

    Full Text Available In road traffic accidents, the analysis of a vehicle’s collision angle plays a key role in identifying a traffic accident’s form and cause. However, because accurate estimation of vehicle collision angle involves many factors, it is difficult to accurately determine it in cases in which less physical evidence is available and there is a lack of monitoring. This paper establishes the mathematical relation model between collision angle, deformation, and normal vector in the collision region according to the equations of particle deformation and force in Hooke’s law of classical mechanics. At the same time, the surface reconstruction method suitable for a normal vector solution is studied. Finally, the estimation model of vehicle collision angle is presented. In order to verify the correctness of the model, verification of multi-angle collision experiments and sensitivity analysis of laser scanning precision for the angle have been carried out using three-dimensional (3D data obtained by a 3D laser scanner in the collision deformation zone. Under the conditions with which the model has been defined, validation results show that the collision angle is a result of the weighted synthesis of the normal vector of the collision point and the weight value is the deformation of the collision point corresponding to normal vectors. These conclusions prove the applicability of the model. The collision angle model proposed in this paper can be used as the theoretical basis for traffic accident identification and cause analysis. It can also be used as a theoretical reference for the study of the impact deformation of elastic materials.

  17. Online Traffic Condition Evaluation Method for Connected Vehicles Based on Multisource Data Fusion

    Directory of Open Access Journals (Sweden)

    Pang-wei Wang

    2017-01-01

    Full Text Available With the development of connected vehicle (CV and Vehicle to X (V2X communication, more traffic data is being collected from the road network. In order to predict future traffic condition from connected vehicles’ data in real-time, we present an online traffic condition evaluation model utilizing V2X communication. This model employs the Analytic Hierarchy Process (AHP and the multilevel fuzzy set theory to fuse multiple sources of information for prediction. First, the contemporary vehicle data from the On Board Diagnostic (OBD is fused with the static road data in the Road Side Unit (RSU. Then, the real-time traffic evaluation scores are calculated using the variable membership model. The real data collected by OBU in field test demonstrates the feasibility of the evaluation model. Compared with traditional evaluation systems, the proposed model can handle more types of data but demands less data transfer.

  18. Vehicle-class Specific Control of Freeway Traffic

    NARCIS (Netherlands)

    Schreiter, T.

    2013-01-01

    The increase of mobility of the past decades has led to substantial congestion on the freeways. Traffic jams emerge both on a daily basis at the same location, as well as during accidents when a part of the freeways is temporarily blocked. In those cases, traffic management centers intervene into

  19. Traffic noise and vehicle movement at a controlled intersection

    NARCIS (Netherlands)

    Salomons, E.M.

    2014-01-01

    Traffic noise at an intersection controlled by traffic lights shows noise level variations due to the alternating green and red lights for the different trafficstreams. Noise peaks caused by automobiles pulling up or passing by at highspeed may be quite annoying for people living near the

  20. Safely towards self-driving vehicles : new opportunities new risks and new challenges during the automation of the traffic system.

    NARCIS (Netherlands)

    Nes, C.N. van & Duivenvoorden, C.W.A.E.

    2017-01-01

    There are more and more systems on the market to support the driver in his vehicle. Step by step the automation of our vehicles increases, the traffic system is in a transition towards self-driving vehicles. The automation offers opportunities to make our traffic safer, cleaner and more efficient.

  1. Mobile Crowd Sensing for Traffic Prediction in Internet of Vehicles

    National Research Council Canada - National Science Library

    Wan, Jiafu; Liu, Jianqi; Shao, Zehui; Vasilakos, Athanasios V; Imran, Muhammad; Zhou, Keliang

    2016-01-01

    The advances in wireless communication techniques, mobile cloud computing, automotive and intelligent terminal technology are driving the evolution of vehicle ad hoc networks into the Internet of Vehicles (IoV) paradigm...

  2. Traffic Congestion Detection System through Connected Vehicles and Big Data

    National Research Council Canada - National Science Library

    Cárdenas-Benítez, Néstor; Aquino-Santos, Raúl; Magaña-Espinoza, Pedro; Aguilar-Velazco, José; Edwards-Block, Arthur; Medina Cass, Aldo

    2016-01-01

    ...-to-infrastructure connectivity and big data. The system discussed in this article permits drivers to identify traffic congestion and change their routes accordingly, thus reducing the total emissions of CO₂...

  3. Characteristic Analysis of Mixed Traffic Flow of Regular and Autonomous Vehicles Using Cellular Automata

    Directory of Open Access Journals (Sweden)

    Yangzexi Liu

    2017-01-01

    Full Text Available The technology of autonomous vehicles is expected to revolutionize the operation of road transport systems. The penetration rate of autonomous vehicles will be low at the early stage of their deployment. It is a challenge to explore the effects of autonomous vehicles and their penetration on heterogeneous traffic flow dynamics. This paper aims to investigate this issue. An improved cellular automaton was employed as the modeling platform for our study. In particular, two sets of rules for lane changing were designed to address mild and aggressive lane changing behavior. With extensive simulation studies, we obtained some promising results. First, the introduction of autonomous vehicles to road traffic could considerably improve traffic flow, particularly the road capacity and free-flow speed. And the level of improvement increases with the penetration rate. Second, the lane-changing frequency between neighboring lanes evolves with traffic density along a fundamental-diagram-like curve. Third, the impacts of autonomous vehicles on the collective traffic flow characteristics are mainly related to their smart maneuvers in lane changing and car following, and it seems that the car-following impact is more pronounced.

  4. Multiple-vehicle collision induced by a sudden stop in traffic flow

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, Naoki [Department of Mechanical Engineering, Division of Thermal Science, Shizuoka University, Hamamatsu 432-8561 (Japan); Nagatani, Takashi, E-mail: tmtnaga@ipc.shizuoka.ac.jp [Department of Mechanical Engineering, Division of Thermal Science, Shizuoka University, Hamamatsu 432-8561 (Japan)

    2012-04-30

    We study the dynamic process of the multiple-vehicle collision when a vehicle stops suddenly in a traffic flow. We apply the optimal-velocity model to the vehicular motion. If a vehicle does not decelerate successfully, it crashes into the vehicle ahead with a residual speed. The collision criterion is presented by v{sub i}(t)/Δx{sub i}(t)→∞ if Δx{sub i}(t)→0 where v{sub i}(t) and Δx{sub i}(t) are the speed and headway of vehicle i at time t. The number of crumpled vehicles depends on the initial velocity, the sensitivity, and the initial headway. We derive the region map (or phase diagram) for the multiple-vehicle collision. -- Highlights: ► We studied the dynamic process of the multiple-vehicle collision in traffic flow. ► We presented the collision criterion that a vehicle comes into collision with the vehicle in front. ► We clarified the dependence of the multiple-vehicle collision on the density and sensitivity.

  5. Multiple-vehicle collision in traffic flow by a sudden slowdown

    Science.gov (United States)

    Sugiyama, Naoki; Nagatani, Takashi

    2013-04-01

    We study the multiple-vehicle collision when a vehicle decelerates suddenly in a single-lane traffic flow. The extended optimal velocity model is used for the vehicular motion to take into account the relative velocity. If a vehicle slows down suddenly and the following vehicle does not decelerate successfully, it crashes into the vehicle ahead with a residual speed and the crash may induce more collisions. The number of crumpled vehicles depends on the initial headway, the sensitivity, the initial velocity, and the relative velocity. We derive the region map (phase diagram) for the multiple-vehicle collision. The dependence of the multiple-vehicle collision on the density, sensitivity, and relative velocity is shown.

  6. A Study on the Model of Traffic Flow and Vehicle Exhaust Emission

    Directory of Open Access Journals (Sweden)

    Han Xue

    2013-01-01

    Full Text Available The increase of traffic flow in cities causes traffic congestion and accidents as well as air pollution. Traffic problems have attracted the interest of many researchers from the perspective of theory and engineering. In order to provide a simple and practical method for measuring the exhaust emission and assessing the effect of pollution control, a model is based on the relationship between traffic flow and vehicle exhaust emission under a certain level of road capacity constraints. In the proposed model, the hydrocarbons (HC, carbon monoxide (CO, and nitrogen oxides (NOx are considered as the indexes of total exhaust emission, and the speed is used as an intermediate variable. To verify the rationality and practicality of the model, a case study for Beijing, China, is provided in which the effects of taxi fare regulation and the specific vehicle emission reduction policy are analyzed.

  7. Human factors evaluation of an in-vehicle active traffic and demand management (ATDM) system : final report.

    Science.gov (United States)

    2016-02-15

    This research study focused on the development and subsequent evaluation of an in-vehicle Active Traffic and Demand Management (ATDM) system deployed on Interstate 66 in Northern Virginia. The ATDM elements inside the vehicle allowed drivers to remai...

  8. The effects of incorporating vehicle acceleration explicitly into a microscopic traffic simulation model

    Directory of Open Access Journals (Sweden)

    Burger, A. P.

    2013-08-01

    Full Text Available Explicitly incorporating individual vehicle acceleration into a traffic simulation model is not a trivial task, and typically results in a considerable increase in model complexity. For this reason, alternative implicit techniques have been introduced in the literature to compensate for the delay times associated with acceleration. In this paper, the claim is investigated that these implicit modelling techniques adequately account for the time delays due to vehicle acceleration; the modelling techniques are implemented in a simulated environment, and compared with models in which vehicle acceleration has been incorporated explicitly for a number of traffic network topologies and traffic densities. It is found that considerable discrepancies may result between the two approaches.

  9. Multiple-vehicle collision induced by a sudden stop in traffic flow

    Science.gov (United States)

    Sugiyama, Naoki; Nagatani, Takashi

    2012-04-01

    We study the dynamic process of the multiple-vehicle collision when a vehicle stops suddenly in a traffic flow. We apply the optimal-velocity model to the vehicular motion. If a vehicle does not decelerate successfully, it crashes into the vehicle ahead with a residual speed. The collision criterion is presented by vi(t)/Δxi(t)→∞ if Δxi(t)→0 where vi(t) and Δxi(t) are the speed and headway of vehicle i at time t. The number of crumpled vehicles depends on the initial velocity, the sensitivity, and the initial headway. We derive the region map (or phase diagram) for the multiple-vehicle collision.

  10. Poster Abstract: Automatic Calibration of Device Attitude in Inertial Measurement Unit Based Traffic Probe Vehicles

    KAUST Repository

    Mousa, Mustafa

    2016-04-28

    Probe vehicles consist in mobile traffic sensor networks that evolve with the flow of vehicles, transmitting velocity and position measurements along their path, generated using GPSs. To address the urban positioning issues of GPSs, we propose to replace them with inertial measurement units onboard vehicles, to estimate vehicle location and attitude using inertial data only. While promising, this technology requires one to carefully calibrate the orientation of the device inside the vehicle to be able to process the acceleration and rate gyro data. In this article, we propose a scheme that can perform this calibration automatically by leveraging the kinematic constraints of ground vehicles, and that can be implemented on low-end computational platforms. Preliminary testing shows that the proposed scheme enables one to accurately estimate the actual accelerations and rotation rates in the vehicle coordinates. © 2016 IEEE.

  11. Identification of Drivers in Traffic Accidents and Determination of Passenger Position in a Vehicle by Finger Marks

    Directory of Open Access Journals (Sweden)

    Matej Trapečar

    2012-01-01

    Full Text Available The following paper aims to illustrate certain investigative activities in the forensic analysis and examination of the scene of traffic accidents. When a traffic accident occurs, the scene must be secured as soon as possible to enable professional and proper forensic investigation. Failure to secure the accident scene might result in losing or contaminating the traces, which makes it more difficult to prove or explain trace evidence in further procedure or even makes such evidence inadmissible. The topic is discussed from the viewpoint of crime scene examination, since analysing and investigating traffic accidents requires a great deal of expertise and attention of the investigators. Complex traffic accidents include feigned accidents, hit-and-run accidents as well as accidents in which the driver and passengers, dead or alive, need to be identified. In identifying the passengers, standard criminal investigation methods as well as police forensic and forensic medicine methods are followed. Such methods include confirming the identities with identity documents, other documents and vehicle ownership, fingerprints, biological traces, fibre traces, contact traces, traces of physical injuries on the driver and passengers, etc. According to the results obtained in fingerprint detection on human skin surfaces, this method can also be applied in confirming physical contact between the driver and the passengers in the accident, e.g. in the event of moving the victims and changing the scene of the accident.   Key words: traffic accidents, accident analysis, driver's identity, passengers' position, finger marks, human skin

  12. A cellular automata model for traffic flow based on kinetics theory, vehicles capabilities and driver reactions

    Science.gov (United States)

    Guzmán, H. A.; Lárraga, M. E.; Alvarez-Icaza, L.; Carvajal, J.

    2018-02-01

    In this paper, a reliable cellular automata model oriented to faithfully reproduce deceleration and acceleration according to realistic reactions of drivers, when vehicles with different deceleration capabilities are considered is presented. The model focuses on describing complex traffic phenomena by coding in its rules the basic mechanisms of drivers behavior, vehicles capabilities and kinetics, while preserving simplicity. In particular, vehiclés kinetics is based on uniform accelerated motion, rather than in impulsive accelerated motion as in most existing CA models. Thus, the proposed model calculates in an analytic way three safe preserving distances to determine the best action a follower vehicle can take under a worst case scenario. Besides, the prediction analysis guarantees that under the proper assumptions, collision between vehicles may not happen at any future time. Simulations results indicate that all interactions of heterogeneous vehicles (i.e., car-truck, truck-car, car-car and truck-truck) are properly reproduced by the model. In addition, the model overcomes one of the major limitations of CA models for traffic modeling: the inability to perform smooth approach to slower or stopped vehicles. Moreover, the model is also capable of reproducing most empirical findings including the backward speed of the downstream front of the traffic jam, and different congested traffic patterns induced by a system with open boundary conditions with an on-ramp. Like most CA models, integer values are used to make the model run faster, which makes the proposed model suitable for real time traffic simulation of large networks.

  13. Engineering Social Justice into Traffic Control for Self-Driving Vehicles?

    Science.gov (United States)

    Mladenovic, Milos N; McPherson, Tristram

    2016-08-01

    The convergence of computing, sensing, and communication technology will soon permit large-scale deployment of self-driving vehicles. This will in turn permit a radical transformation of traffic control technology. This paper makes a case for the importance of addressing questions of social justice in this transformation, and sketches a preliminary framework for doing so. We explain how new forms of traffic control technology have potential implications for several dimensions of social justice, including safety, sustainability, privacy, efficiency, and equal access. Our central focus is on efficiency and equal access as desiderata for traffic control design. We explain the limitations of conventional traffic control in meeting these desiderata, and sketch a preliminary vision for a next-generation traffic control tailored to address better the demands of social justice. One component of this vision is cooperative, hierarchically distributed self-organization among vehicles. Another component of this vision is a priority system enabling selection of priority levels by the user for each vehicle trip in the network, based on the supporting structure of non-monetary credits.

  14. Information-Aided Smart Schemes for Vehicle Flow Detection Enhancements of Traffic Microwave Radar Detectors

    Directory of Open Access Journals (Sweden)

    Tan-Jan Ho

    2016-07-01

    Full Text Available For satisfactory traffic management of an intelligent transport system, it is vital that traffic microwave radar detectors (TMRDs can provide real-time traffic information with high accuracy. In this study, we develop several information-aided smart schemes for traffic detection improvements of TMRDs in multiple-lane environments. Specifically, we select appropriate thresholds not only for removing noise from fast Fourier transforms (FFTs of regional lane contexts but also for reducing FFT side lobes within each lane. The resulting FFTs of reflected vehicle signals and those of clutter are distinguishable. We exploit FFT and lane-/or time stamp-related information for developing smart schemes, which mitigate adverse effects of lane-crossing FFT side lobes of a vehicle signal. As such, the proposed schemes can enhance the detection accuracy of both lane vehicle flow and directional traffic volume. On-site experimental results demonstrate the advantages and feasibility of the proposed methods, and suggest the best smart scheme.

  15. Locating replenishment stations for electric vehicles: Application to Danish traffic data

    DEFF Research Database (Denmark)

    Wen, Min; Laporte, Gilbert; Madsen, Oli B.G.

    2012-01-01

    Environment-friendly electric vehicles have gained substantial attention in governments, industry and universities. The deployment of a network of recharging stations is essential given their limited travel range. This paper considers the problem of locating electronic replenishment stations for ...... formulations are proposed to model the problem. These models are tested on real-life traffic data collected in Denmark. Computational results are presented....

  16. Longitudinal annoyance responses to a road traffic noise management strategy that reduced heavy vehicles at night.

    Science.gov (United States)

    Brown, A L

    2015-01-01

    A traffic management strategy was designed to reduce trucks using an urban corridor. The intervention had potential to affect night-time truck flows, but did not target truck traffic in the day, or vehicles other than trucks at any hour. A two-year long panel study measured the community's response to this intervention, using five repeated measurements of response. There were significant reductions in the panel's response to noise, both for night-time annoyance and for interference with activities. This was remarkable given that noise monitoring showed that the intervention produced no change in conventional traffic noise indicators. However, there were measureable changes in the number of articulated truck movements at night, and the benefit can be attributed to reduction in the number of noise events from heavy vehicles. The parallel tracking of changes in reported noise effects and the numbers of heavy vehicles in the night hours in this longitudinal study provides strong support to the notion that noise effects at night depend on the number of noise events experienced, not only on the overall level of traffic noise. The latter appear to be unresponsive indicators by which to assess the noise-effect benefit of heavy vehicle reduction strategies.

  17. In-vehicle stereo vision system for identification of traffic conflicts between bus and pedestrian

    Directory of Open Access Journals (Sweden)

    Salvatore Cafiso

    2017-02-01

    Full Text Available The traffic conflict technique (TCT was developed as “surrogate measure of road safety” to identify near-crash events by using measures of the spatial and temporal proximity of road users. Traditionally applications of TCT focus on a specific site by the way of manually or automated supervision. Nowadays the development of in-vehicle (IV technologies provides new opportunities for monitoring driver behavior and interaction with other road users directly into the traffic stream. In the paper a stereo vision and GPS system for traffic conflict investigation is presented for detecting conflicts between vehicle and pedestrian. The system is able to acquire geo-referenced sequences of stereo frames that are used to provide real time information related to conflict occurrence and severity. As case study, an urban bus was equipped with a prototype of the system and a trial in the city of Catania (Italy was carried out analyzing conflicts with pedestrian crossing in front of the bus. Experimental results pointed out the potentialities of the system for collection of data that can be used to get suitable traffic conflict measures. Specifically, a risk index of the conflict between pedestrians and vehicles is proposed to classify collision probability and severity using data collected by the system. This information may be used to develop in-vehicle warning systems and urban network risk assessment.

  18. Prevision of vehicle headway effect on urban traffic with a new car-following model

    Science.gov (United States)

    Peng, Guanghan; Lu, Weizhen; He, Hongdi; Gu, Zhenghua

    2017-04-01

    In this study, a new car-following model is established aiming to predict the variation of vehicle headways on urban road. The linear stability condition is derived corresponding to the prevision of headway in moving. The modified Korteweg-de Vries (mKdV) equation is deduced through the nonlinear analysis. The kink-antikink soliton solution of the mKdV equation can interpret the urban traffic jams near the critical point under the prevision of vehicle headway. Moreover, it is clear that the prevision of headway effect did improve the stability of urban traffic flow since the traffic jams are alleviated efficiently by taking into account the prevision of headway term in numerical simulations, which are consistent with the theoretical analysis.

  19. What do autonomous vehicles mean to traffic congestion and crash? : Network traffic flow modeling and simulation for autonomous vehicles.

    Science.gov (United States)

    2016-01-01

    Transportation infrastructure is quickly moving towards revolutionary changes to : accommodate the deployment of AVs. On the other hand, the transition to new : vehicle technologies will be shaped in large part by changes in performance of : roadway ...

  20. Effect of vehicles' changing lanes in the Biham-Middleton-Levine traffic flow model

    Science.gov (United States)

    Li, Qi-Lang; Jiang, Rui; Ding, Zhong-Jun; Min, Jie; Wang, Bing-Hong

    2015-08-01

    This paper studies the effect of vehicles' changing lanes in the original Biham-Middleton-Levine traffic flow model. According to local vehicular information, the dynamics allows for vehicles changing their rows or columns. Simulation results show that the intermediate stable phase identified in the original model can be observed and maintained in a wide range of the vehicle density in our model. Some new kinds of space configurations have been first presented and discussed. One also notes that the geometric structure of such intermediate stable phases is highly regular for square and rectangular aspect rations.

  1. Exploiting Spatial Abstraction in Predictive Analytics of Vehicle Traffic

    Directory of Open Access Journals (Sweden)

    Natalia Andrienko

    2015-04-01

    Full Text Available By applying visual analytics techniques to vehicle traffic data, we found a way to visualize and study the relationships between the traffic intensity and movement speed on links of a spatially abstracted transportation network. We observed that the traffic intensities and speeds in an abstracted network are interrelated in the same way as they are in a detailed street network at the level of street segments. We developed interactive visual interfaces that support representing these interdependencies by mathematical models. To test the possibility of utilizing them for performing traffic simulations on the basis of abstracted transportation networks, we devised a prototypical simulation algorithm employing these dependency models. The algorithm is embedded in an interactive visual environment for defining traffic scenarios, running simulations, and exploring their results. Our research demonstrates a principal possibility of performing traffic simulations on the basis of spatially abstracted transportation networks using dependency models derived from real traffic data. This possibility needs to be comprehensively investigated and tested in collaboration with transportation domain specialists.

  2. IMPROVEMENT OF TRAFFIC SAFETY BY ROAD-VEHICLE COOPERATIVE SMART CRUISE SYSTEMS

    Directory of Open Access Journals (Sweden)

    Akio HOSAKA

    2000-01-01

    Full Text Available Hopes have been pinned on the development of intelligent systems for road traffic as a way of solving road traffic safety and other such issues. To be sure, work is moving ahead with the incorporation of intelligent systems into automobiles but, with automobiles alone, there are limits in areas such as environment recognition. Compensation for the limits imposed by automobiles can be provided by the support given to environment recognition and related areas of road infrastructure. This paper examines the special features of vehicles and road infrastructure, and describes what role is played by roads and what role is played by vehicles. On the basis of the observations made, road-vehicle cooperative support systems called “smart cruise systems”, which are currently being developed, will be introduced and the expected effects of these systems will be outlined.

  3. SDP Policy Iteration-Based Energy Management Strategy Using Traffic Information for Commuter Hybrid Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Xiaohong Jiao

    2014-07-01

    Full Text Available This paper demonstrates an energy management method using traffic information for commuter hybrid electric vehicles. A control strategy based on stochastic dynamic programming (SDP is developed, which minimizes on average the equivalent fuel consumption, while satisfying the battery charge-sustaining constraints and the overall vehicle power demand for drivability. First, according to the sample information of the traffic speed profiles, the regular route is divided into several segments and the statistic characteristics in the different segments are constructed from gathered data on the averaged vehicle speeds. And then, the energy management problem is formulated as a stochastic nonlinear and constrained optimal control problem and a modified policy iteration algorithm is utilized to generate a time-invariant state-dependent power split strategy. Finally, simulation results over some driving cycles are presented to demonstrate the effectiveness of the proposed energy management strategy.

  4. Man, road and vehicle: risk factors associated with the severity of traffic accidents.

    Science.gov (United States)

    Almeida, Rosa Lívia Freitas de; Bezerra Filho, José Gomes; Braga, José Ueleres; Magalhães, Francismeire Brasileiro; Macedo, Marinila Calderaro Munguba; Silva, Kellyanne Abreu

    2013-08-01

    To describe the main characteristics of victims, roads and vehicles involved in traffic accidents and the risk factors involved in accidents resulting in death. METHODS A non-concurrent cohort study of traffic accidents in Fortaleza, CE, Northeastern Brazil, in the period from January 2004 to December 2008. Data from the Fortaleza Traffic Accidents Information System, the Mortality Information System, the Hospital Information System and the State Traffic Department Driving Licenses and Vehicle database. Deterministic and probabilistic relationship techniques were used to integrate the databases. First, descriptive analysis of data relating to people, roads, vehicles and weather was carried out. In the investigation of risk factors for death by traffic accident, generalized linear models were used. The fit of the model was verified by likelihood ratio and ROC analysis. RESULTS There were 118,830 accidents recorded in the period. The most common types of accidents were crashes/collisions (78.1%), running over pedestrians (11.9%), colliding with a fixed obstacle (3.9%), and with motorcycles (18.1%). Deaths occurred in 1.4% of accidents. The factors that were independently associated with death by traffic accident in the final model were bicycles (OR = 21.2, 95%CI 16.1;27.8), running over pedestrians OR = 5.9 (95%CI 3.7;9.2), collision with a fixed obstacle (OR = 5.7, 95%CI 3.1;10.5) and accidents involving motorcyclists (OR = 3.5, 95%CI 2.6;4.6). The main contributing factors were a single person being involved (OR = 6.6, 95%CI 4.1;10.73), presence of unskilled drivers (OR = 4.1, 95%CI 2.9;5.5) a single vehicle (OR = 3.9, 95%CI 2,3;6,4), male (OR = 2.5, 95%CI 1.9;3.3), traffic on roads under federal jurisdiction (OR = 2.4, 95%CI 1.8;3.7), early morning hours (OR = 2.4, 95%CI 1.8;3.0), and Sundays (OR = 1.7, 95%CI 1.3;2.2), adjusted according to the log-binomial model. CONCLUSIONS Activities promoting the prevention of traffic accidents should primarily focus on

  5. Road rage and road traffic accidents among commercial vehicle drivers in Lahore, Pakistan.

    Science.gov (United States)

    Shaikh, M A; Shaikh, I A; Siddiqui, Z

    2012-04-01

    Road rage and road traffic accidents increase the burden of morbidity and mortality in a population. A cross-sectional survey with convenience sampling was conducted among commercial vehicle drivers in Lahore, Pakistan (n = 901) to record their behaviours/experiences regarding road rage and road traffic accidents. Respondents were asked about incidents of shouting/cursing/rude gestures or threats to physically hurt the person/vehicle, by others or themselves, in the previous 24 hours or 3 months, and their involvement in road traffic accidents in the previous 12 months. Auto-rickshaw drivers were significantly more likely to report various road rage experiences/behaviours and involvement in accidents compared with bus and wagon drivers. A total of 112 respondents (12.4%) reported being involved in a road traffic accident in the previous 12 months but traffic police did not record the accident in 52.7% of cases. The results of this study underline the need to improve road safety in Pakistan.

  6. Highway Traffic Accident Influence Area Based on Vehicle Bypass Decision-Making Index

    Directory of Open Access Journals (Sweden)

    Zhenjun Zhu

    2017-01-01

    Full Text Available In order to reduce the impact of highway traffic accidents on surrounding road networks, accident influence area should be determined reasonably. According to the relationship between vehicle bypass decision-making index and threshold under accident condition, the vehicles’ route choice behavior at upstream of the accident spot can be divided into two types: bypass and nonbypass. Under nonbypass condition, the method of using traffic wave theory was put forward to determine the upstream influence area. Under bypass condition, the total number of bypass vehicles is determined based on bypass decision-making index being greater than bypass threshold. Assignment algorithms based on routes were proposed. Using improved Logit model to get the selection probability and the traffic flow of each route, then traffic flow of surrounding links could be obtained. At last, the road network influenced by the accident could be determined by comparing with the level of service of each link under normal condition. The paper takes Beijing-Kunming highway as an example, and the results show that the road network formed by the influenced links was highway traffic accident influence area. Comparing with the actual survey results, correctness of the calculation method is verified. Therefore, the analytical method based on bypass decision-making is applicable to determining highway accident influence area.

  7. Road Safety Data, Collection, Transfer and Analysis DaCoTa. Factsheet Traffic safety basic facts 2010 : single vehicle accidents.

    NARCIS (Netherlands)

    Yannis, G. Evgenikos, P. Argyropoulou, E. Papantoniou, P. Kirk, A. Broughton, J. Knowles, J. Brandstaetter, C. Candappa, N. Christoph, M. Vis, M. Pace, J.-F. López de Cozar, E. Pérez-Fuster, P. Sanmartín, J. Haddak, M. & Moutengou, E.

    2012-01-01

    In this Basic Fact Sheet, "single vehicle accident" or single vehicle collision is a type of road traffic accident in which only one vehicle and no other road user is involved. Run-off-road collisions, collisions with fallen rocks or debris in the road, rollover crashes within the roadway and

  8. Validation of Microscopic Traffic Models Based on GPS Precise Measurement of Vehicle Dynamics

    Directory of Open Access Journals (Sweden)

    Tomas Apeltauer

    2013-04-01

    Full Text Available A necessary stage in the development of traffic models is model validation, where the developed model is verified by comparing its outputs with observed data. The most frequently used variables are average value of speed, flow intensity and flow density (during a selected period.It is possible to use these values for the calibration of macroscopic models, but one cannot always obtain a relevant microscopic dynamic model in this way. A typical use of the microsimulation models is the capacity assessment, where this sort of data (flow, speed and queues is considered to be standard and sufficient. However microsimulation is also increasingly being used for other assessments (e.g. noise and emissions where the correct representation of each vehicle’s acceleration and deceleration plays a crucial role. Another emerging area is the use of microsimulation to predict near-miss situations and conflicts to identify dangerous and accident prone locations. In such assessments the vehicle trajectory, distance from other vehicles as well as velocity and acceleration are very important.Additional source of data, which can be used to validate vehicle dynamics in microsimulation models, is the Global Positioning System (GPS that is able to determine vehicle position with centimeter accuracy.In this article we discuss validation of selected microscopic traffic models, based on the comparison of simulated vehicle dynamics with observed dynamic characteristics of vehicles recorded by the precise geodetic GPS equipment.

  9. An RFID-Based Intelligent Vehicle Speed Controller Using Active Traffic Signals

    Directory of Open Access Journals (Sweden)

    Joshué Pérez

    2010-06-01

    Full Text Available These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS. One prime example of ITS is vehicle Cruise Control (CC, which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver’s attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results.

  10. An RFID-Based Intelligent Vehicle Speed Controller Using Active Traffic Signals

    Science.gov (United States)

    Pérez, Joshué; Seco, Fernando; Milanés, Vicente; Jiménez, Antonio; Díaz, Julio C.; de Pedro, Teresa

    2010-01-01

    These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS). One prime example of ITS is vehicle Cruise Control (CC), which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver’s attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V) communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID) technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results. PMID:22219692

  11. Time-delay neural network for audio monitoring of road traffic and vehicle classification

    Science.gov (United States)

    Nooralahiyan, Amir Y.; Lopez, Louis; Mckewon, Denis; Ahmadi, Masoud

    1997-02-01

    The aim of this research is to investigate the feasibility of developing a cost effective traffic monitoring detector for the purpose of reliable on-line vehicle classification to aid traffic management systems. The detector used was a directional microphone connected to a DAT recorder. The digital signal was preprocessed by LPC (Linear Predictive Coding) parameter conversion based on autocorrelation analysis. A Time Delay Neural Network (TDNN) was chosen to classify individual travelling vehicles based on their speed-independent acoustic signature. The network was trained and tested with real data for four types of vehicles. The paper provides a description of the TDNN architecture and training algorithm and an overview of the LPC pre-processing and feature extraction technique as applied to audio monitoring of road traffic. The performance of TDNN vehicle classification, convergence and accuracy for the training patterns are fully illustrated. In generalizing to a limited number of test patterns available, 100% accuracy in classification was achieved. The net was also robust to changes in the starting position of the acoustic waveforms with 86% accuracy for the same test data set.

  12. An Open Data Platform for Traffic Parameters Measurement via Multirotor Unmanned Aerial Vehicles Video

    Directory of Open Access Journals (Sweden)

    Yuchuan Du

    2017-01-01

    Full Text Available Multirotor unmanned aerial vehicle video observation can obtain accurate information about traffic flow of large areas over extended times. This paper aims to construct an open data test platform for updated traffic data accumulation and traffic simulation model verification by analyzing real time aerial video. Common calibration boards were used to calibrate internal camera parameters and image distortion correction was performed using a high-precision distortion model. To solve external parameters calibration problems, an existing algorithm was improved by adding two sets of orthogonal equations, achieving higher accuracy with only four calibrated points. A simplified algorithm is proposed to calibrate cameras by calculating the relationship between pixel and true length under the camera optical axis perpendicular to road conditions. Aerial video (160 min from the Shanghai inner ring expressway was collected and real time traffic parameter values were obtained from analyzing and processing the aerial visual data containing spatial, time, velocity, and acceleration data. The results verify that the proposed platform provides a reasonable and objective approach to traffic simulation model verification and improvement. The proposed data platform also offers significant advantages over conventional methods that use historical and outdated data to run poorly calibrated traffic simulation models.

  13. Low level off-road vehicle (ORV) traffic negatively impacts macroinvertebrate assemblages at sandy beaches in south-western Australia

    Science.gov (United States)

    Davies, Rebecca; Speldewinde, Peter C.; Stewart, Barbara A.

    2016-04-01

    Off-road vehicle use is arguably one of the most environmentally damaging human activities undertaken on sandy beaches worldwide. Existing studies focused on areas of high traffic volumes have demonstrated significantly lower abundance, diversity and species richness of fauna in zones where traffic is concentrated. The impact of lower traffic volumes is unknown. This study aimed to investigate the impacts of relatively low-level vehicle traffic on sandy beach fauna by sampling invertebrate communities at eight beaches located in south-western Australia. We found that even low-level vehicle traffic negatively impacts the physical beach environment, and consequently, the ability of many species to survive in this habitat in the face of this disturbance. Compaction, rutting and displacement of the sand matrix were observed over a large area, resulting in significant decreases in species diversity and density, and measurable shifts in community structure on beaches that experienced off-road vehicle traffic. Communities at impact sites did not display seasonal recovery as traffic was not significantly different between seasons. Given a choice between either reducing traffic volumes, or excluding ORV traffic from beaches, our results suggest that the latter would be more appropriate when the retention of ecological integrity is the objective.

  14. Effect of velocity-dependent friction on multiple-vehicle collisions in traffic flow

    Science.gov (United States)

    Nagatani, Takashi

    2017-01-01

    We present the dynamic model for the multiple-vehicle collisions to take into account the velocity-dependent friction force. We study the effect of the velocity-dependent friction on the chain-reaction crash on a road. In the traffic situation, drivers brake according to taillights of the forward vehicle and the friction force depends highly on the vehicular speed. The first crash may induce more collisions. We investigate whether or not the first collision induces the multiple-vehicle collisions, numerically and analytically. The dynamic transitions occur from no collisions, through a single collision and double collisions, to multiple collisions with decreasing the headway. We explore the effect of the velocity-dependent friction on the dynamic transitions and the region maps in the multiple-vehicle collisions.

  15. Two-vehicle injury severity models based on integration of pavement management and traffic engineering factors.

    Science.gov (United States)

    Jiang, Ximiao; Huang, Baoshan; Yan, Xuedong; Zaretzki, Russell L; Richards, Stephen

    2013-01-01

    The severity of traffic-related injuries has been studied by many researchers in recent decades. However, the evaluation of many factors is still in dispute and, until this point, few studies have taken into account pavement management factors as points of interest. The objective of this article is to evaluate the combined influences of pavement management factors and traditional traffic engineering factors on the injury severity of 2-vehicle crashes. This study examines 2-vehicle rear-end, sideswipe, and angle collisions that occurred on Tennessee state routes from 2004 to 2008. Both the traditional ordered probit (OP) model and Bayesian ordered probit (BOP) model with weak informative prior were fitted for each collision type. The performances of these models were evaluated based on the parameter estimates and deviances. The results indicated that pavement management factors played identical roles in all 3 collision types. Pavement serviceability produces significant positive effects on the severity of injuries. The pavement distress index (PDI), rutting depth (RD), and rutting depth difference between right and left wheels (RD_df) were not significant in any of these 3 collision types. The effects of traffic engineering factors varied across collision types, except that a few were consistently significant in all 3 collision types, such as annual average daily traffic (AADT), rural-urban location, speed limit, peaking hour, and light condition. The findings of this study indicated that improved pavement quality does not necessarily lessen the severity of injuries when a 2-vehicle crash occurs. The effects of traffic engineering factors are not universal but vary by the type of crash. The study also found that the BOP model with a weak informative prior can be used as an alternative but was not superior to the traditional OP model in terms of overall performance.

  16. Model of the Heavy Freight Vehicle's Running Speed Used for Diversion Traffic Routes Determination

    Directory of Open Access Journals (Sweden)

    Hanzl Jiří

    2017-01-01

    Full Text Available This paper describes the construction process of a discrete model of a heavy truck running speed. The running speed calculation is based on the technical parameters of the road (geometry, gradient, curves, etc. and valid Czech legislation for road designing. In this article, road factors influencing the final heavy freight vehicle's running speed are presented as well. The main assumption is the fact that every heavy vehicle moves on the road by speed allowed by the geometry of this road, road signs and traffic flow characteristics (intensity, density or road capacity.

  17. [Emission Characteristics of Vehicle Exhaust in Beijing Based on Actual Traffic Flow Information].

    Science.gov (United States)

    Fan, Shou-bin; Tian, Ling-di; Zhang, Dong-xu; Qu, Song

    2015-08-01

    The basic data of traffic volume, vehicle type constitute and speed on road networks in Beijing was obtained fly modei simulation and field survey. Based on actual traffic flow information and. emission factors data with temporal and spatial distribution features, emission inventory of motor vehicle exhaust in Beijing was built on the ArcGIS platform, meanwhile, the actual road emission characteristics and spatial distribution of the pollutant emissions were analyzed. The results showed that the proportion of passenger car was higher than 89% on each type of road in the urban, and the proportion of passenger car was the highest in suburban roads as well while the pickup truck, medium truck, heavy truck, motorbus, tractor and motorcycle also occupied a certain proportion. There was a positive correlation between the pollutant emission intensity and traffic volume, and the emission intensity was generally higher in daytime than nighttime, but the diurnal variation trend of PM emission was not clear for suburban roads and the emission intensity was higher in nighttime than daytime for highway. The emission intensities in urban area, south, southeast and northeast areas near urban were higher than those in the western and northern mountainous areas with lower density of road network. The ring roads in urban and highways in suburban had higher emission intensity because of the heavy traffic volume.

  18. Big data analytics : predicting traffic flow regimes from simulated connected vehicle messages using data analytics and machine learning.

    Science.gov (United States)

    2016-12-25

    The key objectives of this study were to: 1. Develop advanced analytical techniques that make use of a dynamically configurable connected vehicle message protocol to predict traffic flow regimes in near-real time in a virtual environment and examine ...

  19. Design Of Fuzzy Logic Traffic Controller For Isolated Intersections With Emergency Vehicle Priority System Using MATLAB Simulation

    OpenAIRE

    Jha, Mohit; Shukla, Shailja

    2014-01-01

    Traffic is the chief puzzle problem which every country faces because of the enhancement in number of vehicles throughout the world, especially in large urban towns. Hence the need arises for simulating and optimizing traffic control algorithms to better accommodate this increasing demand. Fuzzy optimization deals with finding the values of input parameters of a complex simulated system which result in desired output. This paper presents a MATLAB simulation of fuzzy logic traffic controller f...

  20. Impact of Different Spacing Policies for Adaptive Cruise Control on Traffic and Energy Consumption of Electric Vehicles

    OpenAIRE

    Bayar, Bilgehan; Sajadi Alamdari, Seyed Amin; Viti, Francesco; Voos, Holger

    2016-01-01

    This paper assesses the impact of different spacing policies for Adaptive Cruise Control (ACC) systems on traffic and environment. The largest deal of existing studies focus on assessing the performance in terms of safety, while only few deal with the effect of ACC on the traffic flow and the environment. In particular, very little is know on traffic stability and energy consumption. In this study, the vehicles equipped with ACC are modelled and controlled by two different spacing policies. B...

  1. Early estimate of motor vehicle traffic fatalities for the first half (January-June) of 2009 : a brief statistical summary

    Science.gov (United States)

    2009-10-01

    A statistical projection of traffic fatalities for the first three quarters of 2009 shows that an estimated 25,576 people died in motor vehicle traffic crashes. This represents a decline of about 7.9 percent as compared to the 27,771 fa-talities that...

  2. Early estimate of motor vehicle traffic fatalities for the first quarter (January-March) of 2009 : a brief statistical summary

    Science.gov (United States)

    2009-06-01

    A statistical projection of traffic fatalities for the first quarter of 2009 shows that an estimated 7,689 people died in motor vehicle traffic crashes. This represents a decline of about 9 percent as compared to the 8,451 fatalities that occurred in...

  3. Early estimate of motor vehicle traffic fatalities for the first half (January-June) of 2010 : a brief statistical summary

    Science.gov (United States)

    2010-09-01

    A statistical projection of traffic fatalities for the first half of : 2010 shows that an estimated 14,996 people died in motor : vehicle traffic crashes. This represents a decline of about 9.2 : percent as compared to the 16,509 fatalities that occu...

  4. A Pilot Study of Pedestrians with Visual Impairments Detecting Traffic Gaps and Surges Containing Hybrid Vehicles

    Science.gov (United States)

    Emerson, Robert Wall; Naghshineh, Koorosh; Hapeman, Julie; Wiener, William

    2010-01-01

    The increasing number of hybrid and quiet internal combustion engine vehicles may impact the travel abilities of pedestrians who are blind. Pedestrians who rely on auditory cues for structuring their travel may face challenges in making crossing decisions in the presence of quiet vehicles. This article describes results of initial studies looking at the crossing decisions of pedestrians who are blind at an uncontrolled crossing (no traffic control) and a light controlled intersection. The presence of hybrid vehicles was a factor in each situation. At the uncontrolled crossing, Toyota hybrids were most difficult to detect but crossing decisions were made more often in small gaps ended by a Honda hybrid. These effects were seen only at speed under 20 mph. At the light controlled intersection, parallel surges of traffic were most difficult to detect when made up only of a Ford Escape hybrid. Results suggest that more controlled studies of vehicle characteristics impacting crossing decisions of pedestrians who are blind are warranted. PMID:21379367

  5. Operational performance of a congested corridor with lanes dedicated to autonomous vehicle traffic

    Directory of Open Access Journals (Sweden)

    Zachary Vander Laan

    2017-06-01

    Full Text Available This paper considers the operational performance impact of autonomous vehicles (AV on a multi-lane freeway corridor with separate lanes dedicated to AV and non-AV traffic. Autonomous vehicle behavior is modeled at the macroscopic level by modifying the fundamental diagram relating hourly traffic flow and vehicle density, a step that is justified by adjusting a parameter from Newell’s car-following model at the microscopic level and transforming back to a macroscopic representation. The model is applied to the I-95 corridor between Washington, DC and Baltimore, MD during the PM peak period, where the impact of introducing a managed AV-only lane is assessed at varying penetration rates of autonomous vehicles. The results show that the overall corridor performance metrics improve with increasing penetration rates up to 30%, 40% or 50% (depending on the underlying assumptions that govern AV behavior, after which the performance deteriorates drastically. Implications of the results are discussed in light of the per-lane and aggregated metrics, and future directions for research are proposed.

  6. A Region Tracking-Based Vehicle Detection Algorithm in Nighttime Traffic Scenes

    Directory of Open Access Journals (Sweden)

    Jianqiang Wang

    2013-12-01

    Full Text Available The preceding vehicles detection technique in nighttime traffic scenes is an important part of the advanced driver assistance system (ADAS. This paper proposes a region tracking-based vehicle detection algorithm via the image processing technique. First, the brightness of the taillights during nighttime is used as the typical feature, and we use the existing global detection algorithm to detect and pair the taillights. When the vehicle is detected, a time series analysis model is introduced to predict vehicle positions and the possible region (PR of the vehicle in the next frame. Then, the vehicle is only detected in the PR. This could reduce the detection time and avoid the false pairing between the bright spots in the PR and the bright spots out of the PR. Additionally, we present a thresholds updating method to make the thresholds adaptive. Finally, experimental studies are provided to demonstrate the application and substantiate the superiority of the proposed algorithm. The results show that the proposed algorithm can simultaneously reduce both the false negative detection rate and the false positive detection rate.

  7. Characterizing spatial variability of air pollution from vehicle traffic around the Houston Ship Channel area

    Science.gov (United States)

    Zhang, Xueying; Craft, Elena; Zhang, Kai

    2017-07-01

    Mobile emissions are a major source of urban air pollution and have been associated with a variety of adverse health outcomes. The Houston Ship Channel area is the home of a large number of diesel-powered vehicles emitting fine particulate matter (PM2.5; ≤2.5 μm in aerodynamic diameter) and nitrogen oxides (NOx). However, the spatial variability of traffic-related air pollutants in the Houston Ship Channel area has rarely been investigated. The objective of this study is to characterize spatial variability of PM2.5 and NOx concentrations attributable to on-road traffic in the Houston Ship Channel area in the year of 2011. We extracted the road network from the Texas Department of Transportation Road Inventory, and calculated emission rates using the Motor Vehicle Emission Simulator version 2014a (MOVES2014a). These parameters and preprocessed meteorological parameters were entered into a Research LINE-source Dispersion Model (RLINE) to conduct a simulation. Receptors were placed at 50 m resolution within 300 m to major roads and at 150 m resolution in the rest of the area. Our findings include that traffic-related PM2.5 were mainly emitted from trucks, while traffic-related NOx were emitted from both trucks and cars. The traffic contributed 0.90 μg/m3 PM2.5 and 29.23 μg/m3 NOx to the annual average mass concentrations of on-road air pollution, and the concentrations of the two pollutants decreased by nearly 40% within 500 m distance to major roads. The pollution level of traffic-related PM2.5 and NOx was higher in winter than those in the other three seasons. The Houston Ship Channel has earlier morning peak hours and relative late afternoon hours, which indicates the influence of goods movement from port activity. The varied near-road gradients illustrate that proximities to major roads are not an accurate surrogate of traffic-related air pollution.

  8. Collaboration over IEEE 802.11p to enable an intelligent traffic light function for emergency vehicles

    OpenAIRE

    Sawade, Oliver; Schäufele, Bernd; Radusch, Ilja

    2016-01-01

    With the advent of cooperative automated functions a host of novel functions becomes feasible - cooperative driver assistance systems (CoDAS). We present an example for a novel collaborative vehicle-2-infrastructure interaction with the "automated emergency vehicle green-light" (AEVGL) function. In our approach we combine traffic light infrastructure with Dedicated Short Range Communication (DSRC) over IEEE 802.11p to address a serious issue: accidents containing emergency vehicles at interse...

  9. Stationary tailgating in Gaborone, Botswana: the influence of gender, time of day, type of vehicle and presence of traffic officer

    Directory of Open Access Journals (Sweden)

    Nicole M. Monteiro

    2015-03-01

    Full Text Available This study investigated stationary tailgating in Gaborone, Botswana. We observed and measured the distance between 722 vehicles (541 male drivers, 181 female drivers stopped at three traffic intersections in Gaborone during rush-hour and non-rush hour. Gender of driver, type of vehicle (private, commercial, government or company, whether it was rush-hour or not, whether or not a traffic officer was present and distance from the car in front, were recorded. Based on a benchmark of 350 centimetres, derived from the recommendation that cars maintain the distance of the length of a car from the vehicle in front of them when stopped, it was found that 76% of drivers tailgated. In general, men tailgated more than women and tailgating occurred more during rush-hour and when there was a traffic officer present. In addition, a series of four-way analysis of variance tests yielded a main effect for presence of officer, such that the average distance kept from the car in front was significantly less when a traffic officer was present than when a traffic officer was not present. The main effects of gender, time of day and vehicle type were not significant. Findings are discussed in relation to the impact on pedestrians as well as drivers and implications for traffic regulation procedures.

  10. System for Road Vehicle Energy Optimization Using Real Time Road and Traffic Information

    Directory of Open Access Journals (Sweden)

    Felipe Jiménez

    2014-06-01

    Full Text Available Nowadays, reducing the energy and fuel consumption of road vehicles is a key issue. Different strategies have been proposed. One of them is to promote Eco-driving behaviour among drivers. Most Eco-driving tips take into account only the road stretch where the vehicle is located. However, larger improvements could be achieved if information from subsequent stretches is used. The main objective of this work is to develop a system to warn the driver in real time of the optimal speed that should be maintained on every road segment in order to optimize the energy used and the fuel consumed while observing a time schedule. The system takes into account the road vertical profile, the fixed and variable speed limits and the traffic information retrieved using V2V and V2I communications. The system has been tested on real road sections with satisfactory results in fuel savings.

  11. Noise abatement and traffic safety: The trade-off of quieter engines and pavements on vehicle detection.

    Science.gov (United States)

    Mendonça, C; Freitas, E; Ferreira, J P; Raimundo, I D; Santos, J A

    2013-03-01

    Road traffic sounds are a major source of noise pollution in urban areas. But recent developments such as low noise pavements and hybrid/electric engine vehicles cast an optimistic outlook over such an environmental problem. However, it can be argued that engine, tire, and road noise could be relevant sources of information to avoid road traffic conflicts and accidents. In this paper, we analyze the potential trade-offs of traffic-noise abatement approaches in an experimental study, focusing for the first time on the impact and interaction of relevant factors such as pavement type, vehicle type, listener's age, and background noise, on vehicle detection levels. Results reveal that vehicle and pavement type significantly affect vehicle detection. Age is a significant factor, as both younger and older people exhibit lower detection levels of incoming vehicles. Low noise pavements combined with all-electric and hybrid vehicles might pose a severe threat to the safety of vulnerable road users. All factors interact simultaneously, and vehicle detection is best predicted by the loudness signal-to-noise ratio. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Deriving average delay of traffic flow around intersections from vehicle trajectory data

    Science.gov (United States)

    Zhao, Minyue; Li, Xiang

    2013-03-01

    Advances of positioning and wireless communication technologies make it possible to collect a large number of trajectory data of moving vehicles in a fast and convenient fashion. The data can be applied to various fields such as traffic study. In this paper, we attempt to derive average delay of traffic flow around intersections and verify the results with changes of time. The intersection zone is delineated first. Positioning points geographically located within this zone are selected, and then outliers are removed. Turn trips are extracted from selected trajectory data. Each trip, physically consisting of time-series positioning points, is identified with entry road segment and turning direction, i.e. target road segment. Turn trips are grouped into different categories according to their time attributes. Then, delay of each trip during a turn is calculated with its recorded speed. Delays of all trips in the same period of time are plotted to observe the change pattern of traffic conditions. Compared to conventional approaches, the proposed method can be applied to those intersections without fixed data collection devices such as loop detectors since a large number of trajectory data can always provide a more complete spatio-temporal picture of a road network. With respect to data availability, taxi trajectory data and an intersection in Shanghai are employed to test the proposed methodology. Results demonstrate its applicability.

  13. Evaluation of Environmental Impact of Biodiesel Vehicles in Real Traffic Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Susumu; Mizushima, Norifumi [National Traffic Safety and Environment Laboratory (NTSEL) (Japan); Saito, Akira; Takada, Yutaka [Organization for the Promotion of Low Emission Vehicles (LEVO)(Japan

    2012-01-15

    This report focuses on the comparison of the real-world emissions between the case of using diesel oil and BDF (biodiesel fuel) for fuel. For this purpose, the on-road driving tests were made, by applying BDF, with the latest diesel vehicles complying with the latest emission regulations while avoiding any particular modification to them. For measurement, a PEMS (Portable Emission Measurement System) was used. Note that the heavy diesel vehicles complying with the latest emission gas regulations of Japan also meet the heavy vehicle fuel economy regulations introduced by Japan ahead of other countries of the world. Since application of BDF presents problems not only for the emission gas, but also has non-negligible influence on the fuel economy, the survey was also made for the real-world fuel economy. This report has been produced as the final version deliverable from the International Energy Agency’s (IEA’s) Advanced Motor Fuels (AMF) Implementing Agreement (Annex XXXVIII - Evaluation of Environmental Impact of Biodiesel Vehicle in Real Traffic Conditions).

  14. Robust Vehicle Detection under Various Environmental Conditions Using an Infrared Thermal Camera and Its Application to Road Traffic Flow Monitoring

    Directory of Open Access Journals (Sweden)

    Toshiyuki Nakamiya

    2013-06-01

    Full Text Available We have already proposed a method for detecting vehicle positions and their movements (henceforth referred to as “our previous method” using thermal images taken with an infrared thermal camera. Our experiments have shown that our previous method detects vehicles robustly under four different environmental conditions which involve poor visibility conditions in snow and thick fog. Our previous method uses the windshield and its surroundings as the target of the Viola-Jones detector. Some experiments in winter show that the vehicle detection accuracy decreases because the temperatures of many windshields approximate those of the exterior of the windshields. In this paper, we propose a new vehicle detection method (henceforth referred to as “our new method”. Our new method detects vehicles based on tires’ thermal energy reflection. We have done experiments using three series of thermal images for which the vehicle detection accuracies of our previous method are low. Our new method detects 1,417 vehicles (92.8% out of 1,527 vehicles, and the number of false detection is 52 in total. Therefore, by combining our two methods, high vehicle detection accuracies are maintained under various environmental conditions. Finally, we apply the traffic information obtained by our two methods to traffic flow automatic monitoring, and show the effectiveness of our proposal.

  15. Robust vehicle detection under various environmental conditions using an infrared thermal camera and its application to road traffic flow monitoring.

    Science.gov (United States)

    Iwasaki, Yoichiro; Misumi, Masato; Nakamiya, Toshiyuki

    2013-06-17

    We have already proposed a method for detecting vehicle positions and their movements (henceforth referred to as "our previous method") using thermal images taken with an infrared thermal camera. Our experiments have shown that our previous method detects vehicles robustly under four different environmental conditions which involve poor visibility conditions in snow and thick fog. Our previous method uses the windshield and its surroundings as the target of the Viola-Jones detector. Some experiments in winter show that the vehicle detection accuracy decreases because the temperatures of many windshields approximate those of the exterior of the windshields. In this paper, we propose a new vehicle detection method (henceforth referred to as "our new method"). Our new method detects vehicles based on tires' thermal energy reflection. We have done experiments using three series of thermal images for which the vehicle detection accuracies of our previous method are low. Our new method detects 1,417 vehicles (92.8%) out of 1,527 vehicles, and the number of false detection is 52 in total. Therefore, by combining our two methods, high vehicle detection accuracies are maintained under various environmental conditions. Finally, we apply the traffic information obtained by our two methods to traffic flow automatic monitoring, and show the effectiveness of our proposal.

  16. Evaluation of Traffic Density Parameters as an Indicator of Vehicle Emission-Related Near-Road Air Pollution: A Case Study with NEXUS Measurement Data on Black Carbon

    Science.gov (United States)

    An important factor in evaluating health risk of near-road air pollution is to accurately estimate the traffic-related vehicle emission of air pollutants. Inclusion of traffic parameters such as road length/area, distance to roads, and traffic volume/intensity into models such as...

  17. Convergence of Vehicle and Infrastructure Data for Traffic and Demand Management

    Energy Technology Data Exchange (ETDEWEB)

    Young, Stanley E.

    2015-11-16

    The increasing availability of highly granular, vehicle trajectory data combined with ever increasing stores of roadway sensor data has provided unparalleled observability into the operation of our urban roadway networks. These data sources are quickly moving from research and prototype environments into full-scale commercial deployment and data offerings. The observability gained allows for increased control opportunities to enhance transportation mobility, safety and energy efficiency. The National Renewable Energy Laboratory (NREL) is involved in three initiatives to leverage these data for positive outcomes: 1) In 2015 NREL, in cooperation with industry and university partners, was awarded an ARPA-E research grant to research a control architecture to incentivize individual travelers toward more sustainable travel behavior. Based on real-time data on the traveler's destination and state of the system, the traveler is presented with route and/or mode choices and offered incentives to accept sustainable alternatives over less-sustainable ones. The project tests the extent to which small incentives can influence, or tip the balance toward more sustainable travel behavior. 2) Although commercial sources of travel time and speed have emerged in recent years based on vehicle probe data, volume estimates continue to rely primarily on historical count data factored for the time of day, day of week, and season of year. Real-time volume flows would enable better tools, simulation in the loop, and ultimately more effective control outcomes. NREL in cooperation with the University of Maryland and industry traffic data providers (INRIX, HERE and TomTom), are attempting to accelerate the timeframe to a viable real-time vehicle volume data feed based on probe data. 3) Signal control on urban arterials for years has had to rely on models rather than measured data to assess performance. High-resolution controller data and low-cost re-identification data now allows for

  18. An electric vehicle driving behavior model in the traffic system with a wireless charging lane

    Science.gov (United States)

    He, Jia; Huang, Hai-Jun; Yang, Hai; Tang, Tie-Qiao

    2017-09-01

    In this paper, a car-following model is proposed to study each EV's (electric vehicle) motion behavior near the WCL (wireless charging lane) and a lane-changing rule is designed to describe the EV's lane-changing behavior. Then, the car-following model and lane-changing rule are used to explore each EV's micro driving behavior in a two-lane system with a WCL. Finally, the impacts of the WCL on each EV's motion behavior are investigated. The numerical results show that each EV should run slowly on the WCL if it needs charge of electricity, that the EV's lane-changing behavior has great effects on the whole system, that the delay time caused by the WCL turns more prominent when the traffic turns heavy, and that lane-changing frequently occurs near the WCL (especially at the downstream of the WCL).

  19. Robust vehicle detection under various environments to realize road traffic flow surveillance using an infrared thermal camera.

    Science.gov (United States)

    Iwasaki, Yoichiro; Misumi, Masato; Nakamiya, Toshiyuki

    2015-01-01

    To realize road traffic flow surveillance under various environments which contain poor visibility conditions, we have already proposed two vehicle detection methods using thermal images taken with an infrared thermal camera. The first method uses pattern recognition for the windshields and their surroundings to detect vehicles. However, the first method decreases the vehicle detection accuracy in winter season. To maintain high vehicle detection accuracy in all seasons, we developed the second method. The second method uses tires' thermal energy reflection areas on a road as the detection targets. The second method did not achieve high detection accuracy for vehicles on left-hand and right-hand lanes except for two center-lanes. Therefore, we have developed a new method based on the second method to increase the vehicle detection accuracy. This paper proposes the new method and shows that the detection accuracy for vehicles on all lanes is 92.1%. Therefore, by combining the first method and the new method, high vehicle detection accuracies are maintained under various environments, and road traffic flow surveillance can be realized.

  20. Effects of autonomy, traffic conditions and driver personality traits on attitudes and trust towards in-vehicle agents

    NARCIS (Netherlands)

    Cramer, H.; Evers, V.; Kemper, N.; Wielinga, B.; Li, Y.; Pasi, G.; Zhang, C.; Cercone, N.; Cao, L.

    2008-01-01

    In-vehicle agents can potentially avert dangerous driving situations by adapting to the driver, context and traffic conditions. However, perceptions of system autonomy, the way agents offer assistance, driving contexts and users’ personality traits can all affect acceptance and trust. This paper

  1. Preliminary solution of traffic surfaces within the parcel of the faculty of civil Engineering in Subotica

    Directory of Open Access Journals (Sweden)

    Škondrić Jovan

    2017-01-01

    Full Text Available Extension of the capacities of the Faculty of Civil Engineering building in Subotica in the form of annexes and sports hall (second phase requires an adequate traffic infrastructure that would satisfy the additional demands. The paper presents the possible solution of traffic surfaces that service the entire lot, as well as the landscaping on the free part of the lot.

  2. Sensors measure surface ablation rate of reentry vehicle heat shield

    Science.gov (United States)

    Russel, J. M., III

    1966-01-01

    Sensors measure surface erosion rate of ablating material in reentry vehicle heat shield. Each sensor, which is placed at precise depths in the heat shield is activated when the ablator surface erodes to the location of a sensing point. Sensor depth and activation time determine ablator surface erosion rate.

  3. Cooperative vehicles for robust traffic congestion reduction: An analysis based on algorithmic, environmental and agent behavioral factors.

    Directory of Open Access Journals (Sweden)

    Prajakta Desai

    Full Text Available Traffic congestion continues to be a persistent problem throughout the world. As vehicle-to-vehicle communication develops, there is an opportunity of using cooperation among close proximity vehicles to tackle the congestion problem. The intuition is that if vehicles could cooperate opportunistically when they come close enough to each other, they could, in effect, spread themselves out among alternative routes so that vehicles do not all jam up on the same roads. Our previous work proposed a decentralized multiagent based vehicular congestion management algorithm entitled Congestion Avoidance and Route Allocation using Virtual Agent Negotiation (CARAVAN, wherein the vehicles acting as intelligent agents perform cooperative route allocation using inter-vehicular communication. This paper focuses on evaluating the practical applicability of this approach by testing its robustness and performance (in terms of travel time reduction, across variations in: (a environmental parameters such as road network topology and configuration; (b algorithmic parameters such as vehicle agent preferences and route cost/preference multipliers; and (c agent-related parameters such as equipped/non-equipped vehicles and compliant/non-compliant agents. Overall, the results demonstrate the adaptability and robustness of the decentralized cooperative vehicles approach to providing global travel time reduction using simple local coordination strategies.

  4. Influence of the pavement surface on the vibrations induced by heavy traffic in road bridges

    National Research Council Canada - National Science Library

    Paje, S.E; Vázquez, V.F; Camara, A; Ruiz-Teran, A.M

    2017-01-01

    The irregularity of the pavement surface governs the traffic-induced vibrations in road bridges, but it is either ignored or simulated by means of ideal pavements that differ significantly from real cases...

  5. Traffic data collection and anonymous vehicle detection using wireless sensor networks : research summary.

    Science.gov (United States)

    2012-05-01

    Problem: : Most Intelligent Transportation System (ITS) applications require distributed : acquisition of various traffic metrics such as traffic speed, volume, and density. : The existing measurement technologies, such as inductive loops, infrared, ...

  6. Traffic data collection and anonymous vehicle detection using wireless sensor networks.

    Science.gov (United States)

    2012-05-01

    New traffic sensing devices based on wireless sensing technologies were designed and tested. Such devices encompass a cost-effective, battery-free, and energy self-sustained architecture for real-time traffic measurement over distributed points in a ...

  7. Mathematical relationships for metal build-up on urban road surfaces based on traffic and land use characteristics.

    Science.gov (United States)

    Gunawardena, Janaka; Ziyath, Abdul M; Egodawatta, Prasanna; Ayoko, Godwin A; Goonetilleke, Ashantha

    2014-03-01

    The study investigated the influence of traffic and land use parameters on metal build-up on urban road surfaces. Mathematical relationships were developed to predict metals originating from fuel combustion and vehicle wear. The analysis undertaken found that nickel and chromium originate from exhaust emissions, lead, copper and zinc from vehicle wear, cadmium from both exhaust and wear and manganese from geogenic sources. Land use does not demonstrate a clear pattern in relation to the metal build-up process, though its inherent characteristics such as traffic activities exert influence. The equation derived for fuel related metal load has high cross-validated coefficient of determination (Q(2)) and low Standard Error of Cross-Validation (SECV) values which indicates that the model is reliable, while the equation derived for wear-related metal load has low Q(2) and high SECV values suggesting its use only in preliminary investigations. Relative Prediction Error values for both equations are considered to be well within the error limits for a complex system such as an urban road surface. These equations will be beneficial for developing reliable stormwater treatment strategies in urban areas which specifically focus on mitigation of metal pollution. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Modified Motor Vehicles Travel Speed Models on the Basis of Curb Parking Setting under Mixed Traffic Flow

    Directory of Open Access Journals (Sweden)

    Zhenyu Mei

    2012-01-01

    Full Text Available The ongoing controversy about in what condition should we set the curb parking has few definitive answers because comprehensive research in this area has been lacking. Our goal is to present a set of heuristic urban street speed functions under mixed traffic flow by taking into account impacts of curb parking. Two impacts have been defined to classify and quantify the phenomena of motor vehicles' speed dynamics in terms of curb parking. The first impact is called Space impact, which is caused by the curb parking types. The other one is the Time impact, which results from the driver maneuvering in or out of parking space. In this paper, based on the empirical data collected from six typical urban streets in Nanjing, China, two models have been proposed to describe these phenomena for one-way traffic and two-way traffic, respectively. An intensive experiment has been conducted in order to calibrate and validate these proposed models, by taking into account the complexity of the model parameters. We also provide guidelines in terms of how to cluster and calculate those models' parameters. Results from these models demonstrated promising performance of modeling motor vehicles' speed for mixed traffic flow under the influence of curb parking.

  9. Multiple Depots Vehicle Routing Problem in the Context of Total Urban Traffic Equilibrium

    Directory of Open Access Journals (Sweden)

    Dongxu Chen

    2017-01-01

    Full Text Available A multidepot VRP is solved in the context of total urban traffic equilibrium. Under the total traffic equilibrium, the multidepot VRP is changed to GDAP (the problem of Grouping Customers + Estimating OD Traffic + Assigning traffic and bilevel programming is used to model the problem, where the upper model determines the customers that each truck visits and adds the trucks’ trips to the initial OD (Origin/Destination trips, and the lower model assigns the OD trips to road network. Feedback between upper model and lower model is iterated through OD trips; thus total traffic equilibrium can be simulated.

  10. Prediction of vehicle crashes by drivers' characteristics and past traffic violations in Korea using a zero-inflated negative binomial model.

    Science.gov (United States)

    Kim, Dae-Hwan; Ramjan, Lucie M; Mak, Kwok-Kei

    2016-01-01

    Traffic safety is a significant public health challenge, and vehicle crashes account for the majority of injuries. This study aims to identify whether drivers' characteristics and past traffic violations may predict vehicle crashes in Korea. A total of 500,000 drivers were randomly selected from the 11.6 million driver records of the Ministry of Land, Transport and Maritime Affairs in Korea. Records of traffic crashes were obtained from the archives of the Korea Insurance Development Institute. After matching the past violation history for the period 2004-2005 with the number of crashes in year 2006, a total of 488,139 observations were used for the analysis. Zero-inflated negative binomial model was used to determine the incident risk ratio (IRR) of vehicle crashes by past violations of individual drivers. The included covariates were driver's age, gender, district of residence, vehicle choice, and driving experience. Drivers violating (1) a hit-and-run or drunk driving regulation at least once and (2) a signal, central line, or speed regulation more than once had a higher risk of a vehicle crash with respective IRRs of 1.06 and 1.15. Furthermore, female gender, a younger age, fewer years of driving experience, and middle-sized vehicles were all significantly associated with a higher likelihood of vehicle crashes. Drivers' demographic characteristics and past traffic violations could predict vehicle crashes in Korea. Greater resources should be assigned to the provision of traffic safety education programs for the high-risk driver groups.

  11. Using Probe Vehicle Data for Automatic Extraction of Road Traffic Parameters

    Directory of Open Access Journals (Sweden)

    Roman Popescu Maria Alexandra

    2016-12-01

    Full Text Available Through this paper the author aims to study and find solutions for automatic detection of traffic light position and for automatic calculation of the waiting time at traffic light. The first objective serves mainly the road transportation field, mainly because it removes the need for collaboration with local authorities to establish a national network of traffic lights. The second objective is important not only for companies which are providing navigation solutions, but especially for authorities, institutions, companies operating in road traffic management systems. Real-time dynamic determination of traffic queue length and of waiting time at traffic lights allow the creation of dynamic systems, intelligent and flexible, adapted to actual traffic conditions, and not to generic, theoretical models. Thus, cities can approach the Smart City concept by boosting, efficienting and greening the road transport, promoted in Europe through the Horizon 2020, Smart Cities, Urban Mobility initiative.

  12. Early estimate of motor vehicle traffic fatalities for the first three quarters (January-September) of 2009 : a brief statistical summary

    Science.gov (United States)

    2010-01-01

    A statistical projection of traffic fatalities for the first three quarters of 2009 shows that an estimated 25,576 people died in motor vehicle traffic crashes. This represents a decline of about 7.9 percent as compared to the 27,771 fa-talities that...

  13. A Space-Time Network-Based Modeling Framework for Dynamic Unmanned Aerial Vehicle Routing in Traffic Incident Monitoring Applications

    Directory of Open Access Journals (Sweden)

    Jisheng Zhang

    2015-06-01

    Full Text Available It is essential for transportation management centers to equip and manage a network of fixed and mobile sensors in order to quickly detect traffic incidents and further monitor the related impact areas, especially for high-impact accidents with dramatic traffic congestion propagation. As emerging small Unmanned Aerial Vehicles (UAVs start to have a more flexible regulation environment, it is critically important to fully explore the potential for of using UAVs for monitoring recurring and non-recurring traffic conditions and special events on transportation networks. This paper presents a space-time network- based modeling framework for integrated fixed and mobile sensor networks, in order to provide a rapid and systematic road traffic monitoring mechanism. By constructing a discretized space-time network to characterize not only the speed for UAVs but also the time-sensitive impact areas of traffic congestion, we formulate the problem as a linear integer programming model to minimize the detection delay cost and operational cost, subject to feasible flying route constraints. A Lagrangian relaxation solution framework is developed to decompose the original complex problem into a series of computationally efficient time-dependent and least cost path finding sub-problems. Several examples are used to demonstrate the results of proposed models in UAVs’ route planning for small and medium-scale networks.

  14. A Genetic Algorithm Approach for Expedited Crossing of Emergency Vehicles in Connected and Autonomous Intersection Traffic

    OpenAIRE

    Qiang Lu; Kyoung-Dae Kim

    2017-01-01

    This paper proposes an intersection control algorithm which aims to determine an efficient vehicle-passing sequence that allows the emergency vehicle to cross an intersection as soon as possible while the travel times of other vehicles are minimally affected. When there are no emergency vehicles within the intersection area, the vehicles are controlled by the DICA that we proposed in our earlier work. When there are emergency vehicles entering the communication range, we prioritize emergency ...

  15. Increasing Intelligence in Inter-Vehicle Communications to Reduce Traffic Congestions: Experiments in Urban and Highway Environments.

    Directory of Open Access Journals (Sweden)

    Rodolfo I Meneguette

    Full Text Available Intelligent Transportation Systems (ITS rely on Inter-Vehicle Communication (IVC to streamline the operation of vehicles by managing vehicle traffic, assisting drivers with safety and sharing information, as well as providing appropriate services for passengers. Traffic congestion is an urban mobility problem, which causes stress to drivers and economic losses. In this context, this work proposes a solution for the detection, dissemination and control of congested roads based on inter-vehicle communication, called INCIDEnT. The main goal of the proposed solution is to reduce the average trip time, CO emissions and fuel consumption by allowing motorists to avoid congested roads. The simulation results show that our proposed solution leads to short delays and a low overhead. Moreover, it is efficient with regard to the coverage of the event and the distance to which the information can be propagated. The findings of the investigation show that the proposed solution leads to (i high hit rate in the classification of the level of congestion, (ii a reduction in average trip time, (iii a reduction in fuel consumption, and (iv reduced CO emissions.

  16. Numerical study of aerodynamic effects on road vehicles lifting surfaces

    Science.gov (United States)

    Cernat, Mihail Victor; Cernat Bobonea, Andreea

    2017-01-01

    The aerodynamic performance analysis of road vehicles depends on the study of engine intake and cooling flow, internal ventilation, tire cooling, and overall external flow as the motion of air around a moving vehicle affects all of its components in one form or another. Due to the complex geometry of these, the aerodynamic interaction between the various body components is significant, resulting in vortex flow and lifting surface shapes. The present study, however focuses on the effects of external aerodynamics only, and in particular on the flow over the lifting surfaces of a common compact car, designed especially for this study.

  17. Proposal for a limit value reduction scenario for road vehicles compatible with the German national traffic noise prevention. Package II

    Energy Technology Data Exchange (ETDEWEB)

    Steven, Heinz [Data Analysis and Consultancy, Heinsberg (Germany)

    2012-03-15

    With COM(2011) 856 final from 09.12.2011 the EU Commission launched a proposal for a regulation of the European Parliament and of the Council on the sound level of motor vehicles. This proposal is related to motor vehicles having at least four wheels. Objective and aim are described as follows: ''The objective of the proposal is to ensure a high level of health and environmental protection and to safeguard the Internal Market for motor vehicles as regards their sound level. The proposal aims at reducing environmental noise by introducing a new test method for measuring noise emissions, by lowering the noise limit values, by including additional sound emission provisions in the type-approval procedure...'' (see paragraph 1 of the explanatory memorandum). Under the bullet point ''- new limit values'' of paragraph 1 of the explanatory memorandum the following statements are listed: ''On the basis of the results of the monitoring data an impact assessment has been prepared with different policy options for the noise test method and corresponding limit values. According to the most preferable option the limit values for light and medium size vehicles will be lowered in two steps of each 2 dB(A) and for heavy vehicles in a first step of 1 and a second step of 2 dB(A). This will result in a reduction of the noise impact of about 3 dB(A) for free flowing traffic and up to 4 dB(A) for intermittent traffic. The reduction of the number of highly annoyed people will be 25 %. The cost-benefit ratio for this measure is estimated to be around 20 times in favour of the noise reduction compared to no action taken.'' The forecast for the reduction of the noise impact in real traffic is far too optimistic. It is highly unlikely that the reduction of limit values by 3 to 4 dB will lead to a reduction of the noise impact in real traffic by the same amount without any deterioration factor. Own calculations with the TRANECAM

  18. Factors influencing the number distribution and size of the particles emitted from a modern diesel vehicle in real urban traffic

    Science.gov (United States)

    Barrios, C. C.; Domínguez-Sáez, A.; Rubio, J. R.; Pujadas, M.

    2012-09-01

    Particle emissions from diesel engine cars depend firstly on exhaust aftertreatment systems but the use of the vehicle becomes also crucial. In urban areas, this use depends on: transport demand, route choices, traffic density, street conditions, weather, driver behaviour and topographical characteristics of the roads. Nowadays, most diesel vehicles in urban areas across Europe are equipped with exhaust aftertreatment systems aiming to reduce the total mass of emitted particles. In comparison to earlier aftertreatment systems, the implementation of modern procedures is causing a reduction in the size of the emitted particles up to a nanometric range. The main goal of this work is the characterization of particle size and number distribution in the submicrometric range from a modern diesel vehicle emission in real traffic conditions in the city of Madrid with the purpose of assessing the actual weight of the different city parameters influencing the particle emission. In order to accomplish this objective, up to 12 on board emission measurement experiments have been performed with a Euro IV Diesel passenger car driving along a single urban circuit in Madrid City. To cover the main external factors, stretch, traffic conditions and driving directions have been considered as independent variables for this study. Assuming a proper car operating conditions, the results show that street characteristics, vehicle density and topographic features are the main factors conditioning the particle emission. Extrapolating our results, a diesel standard passenger car circulating across a city like Madrid can emit more nanoparticles per kilometre (up to 114% more in this study) at peak hour than at off peak hour. Moreover, the driving direction can also influence dramatically the emission of nanoparticles per second. This difference in the emission rate depends on the street but in our study it can be higher than 110% depending on the driving direction.

  19. Bicycle-vehicle interactions at mid-sections of mixed traffic streets: Examining passing distance and bicycle comfort perception.

    Science.gov (United States)

    Apasnore, Peter; Ismail, Karim; Kassim, Ali

    2017-09-01

    This paper studies the relevant factors in mixed urban traffic that may impact the lateral spacing between bicycles and vehicles (passing distance, PD), and their resulting effect on a bicyclists' comfort based on a study of six sites in Ottawa, Canada. The observations are: [i] the average position of bicycles from the curb is 0.57m, and lesser (i.e. 0.35m) in the presence of parking; [ii] 90% of passes exceed 1.23m; [iii] PD is positively correlated with motor vehicle speed, lane width, and bicycle position from adjacent curb edge line, whiles inversely correlated to ambient traffic density and bicycle speed; [iv] motor vehicle speed has the highest prediction of PD variability; [v] PD and ambient traffic density (ATD) are found to be the most important factors to a bicyclists' comfort perception (BCP). Two linear regression models for PD and BCP were developed and significant variables are identified as: motor vehicle speed, bicycle speed, ATD, number of lanes, and lane width. The presence or absence of a grade slope is found to be significant to the PD model and not to BCP. The models both exhibit limited predictive ability, however residual plots and significance of included variables are indicative of correct assumptions for the models. It is recommended that speed calming, sharrows, road signs instructing road sharing, and educating road users against "dooring" crashes be considered in improving road sharing, especially for narrow lanes (i.e. less than 3.6m) and lanes wider than 4.5m. It is also prudent for designers to avoid installing parking zones on narrow shared roads. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Multiple-vehicle collision induced by lane changing in traffic flow

    Science.gov (United States)

    Nagatani, Takashi; Yonekura, Shoichi

    2014-06-01

    We study the multiple-vehicle collision when a vehicle changes from the first lane to the second lane on a two-lane highway. If a vehicle with high (low) speed on the first lane enters into the second lane, it may crash into the forward (rear) vehicle on the second lane and the crash may induce more collisions. We investigate whether or not the incoming vehicle induces the multiple-vehicle collision. The number of collisions depends on the initial velocity, the initial density, the incoming velocity, the incoming headway, the sensitivity, and the relative velocity. We derive the region map for the multiple-vehicle collision induced by lane changing.

  1. Stationary LiDAR for traffic and safety applications - vehicles interpretation and tracking.

    Science.gov (United States)

    2014-01-01

    The goal of the T-Scan project is to develop a data processing module for a novel LiDAR-based traffic scanner to collect highly accurate microscopic traffic data at road intersections. : T-Scan uses Light Detection and Ranging (LiDAR) technology that...

  2. High-resolution simulation of link-level vehicle emissions and concentrations for air pollutants in a traffic-populated eastern Asian city

    Science.gov (United States)

    Zhang, Shaojun; Wu, Ye; Huang, Ruikun; Wang, Jiandong; Yan, Han; Zheng, Yali; Hao, Jiming

    2016-08-01

    Vehicle emissions containing air pollutants created substantial environmental impacts on air quality for many traffic-populated cities in eastern Asia. A high-resolution emission inventory is a useful tool compared with traditional tools (e.g. registration data-based approach) to accurately evaluate real-world traffic dynamics and their environmental burden. In this study, Macau, one of the most populated cities in the world, is selected to demonstrate a high-resolution simulation of vehicular emissions and their contribution to air pollutant concentrations by coupling multimodels. First, traffic volumes by vehicle category on 47 typical roads were investigated during weekdays in 2010 and further applied in a networking demand simulation with the TransCAD model to establish hourly profiles of link-level vehicle counts. Local vehicle driving speed and vehicle age distribution data were also collected in Macau. Second, based on a localized vehicle emission model (e.g. the emission factor model for the Beijing vehicle fleet - Macau, EMBEV-Macau), this study established a link-based vehicle emission inventory in Macau with high resolution meshed in a temporal and spatial framework. Furthermore, we employed the AERMOD (AMS/EPA Regulatory Model) model to map concentrations of CO and primary PM2.5 contributed by local vehicle emissions during weekdays in November 2010. This study has discerned the strong impact of traffic flow dynamics on the temporal and spatial patterns of vehicle emissions, such as a geographic discrepancy of spatial allocation up to 26 % between THC and PM2.5 emissions owing to spatially heterogeneous vehicle-use intensity between motorcycles and diesel fleets. We also identified that the estimated CO2 emissions from gasoline vehicles agreed well with the statistical fuel consumption in Macau. Therefore, this paper provides a case study and a solid framework for developing high-resolution environment assessment tools for other vehicle-populated cities

  3. High-resolution simulation of link-level vehicle emissions and concentrations for air pollutants in a traffic-populated eastern Asian city

    Directory of Open Access Journals (Sweden)

    S. Zhang

    2016-08-01

    Full Text Available Vehicle emissions containing air pollutants created substantial environmental impacts on air quality for many traffic-populated cities in eastern Asia. A high-resolution emission inventory is a useful tool compared with traditional tools (e.g. registration data-based approach to accurately evaluate real-world traffic dynamics and their environmental burden. In this study, Macau, one of the most populated cities in the world, is selected to demonstrate a high-resolution simulation of vehicular emissions and their contribution to air pollutant concentrations by coupling multimodels. First, traffic volumes by vehicle category on 47 typical roads were investigated during weekdays in 2010 and further applied in a networking demand simulation with the TransCAD model to establish hourly profiles of link-level vehicle counts. Local vehicle driving speed and vehicle age distribution data were also collected in Macau. Second, based on a localized vehicle emission model (e.g. the emission factor model for the Beijing vehicle fleet – Macau, EMBEV–Macau, this study established a link-based vehicle emission inventory in Macau with high resolution meshed in a temporal and spatial framework. Furthermore, we employed the AERMOD (AMS/EPA Regulatory Model model to map concentrations of CO and primary PM2.5 contributed by local vehicle emissions during weekdays in November 2010. This study has discerned the strong impact of traffic flow dynamics on the temporal and spatial patterns of vehicle emissions, such as a geographic discrepancy of spatial allocation up to 26 % between THC and PM2.5 emissions owing to spatially heterogeneous vehicle-use intensity between motorcycles and diesel fleets. We also identified that the estimated CO2 emissions from gasoline vehicles agreed well with the statistical fuel consumption in Macau. Therefore, this paper provides a case study and a solid framework for developing high-resolution environment assessment tools for other

  4. Effect of Traffic Position Accuracy for Conducting Safe Airport Surface Operations

    Science.gov (United States)

    Jones, Denise R.; Prinzel, Lawrence J., III; Bailey, Randall E.; Arthur, Jarvis J., III; Barnes, James R.

    2014-01-01

    The Next Generation Air Transportation System (NextGen) concept proposes many revolutionary operational concepts and technologies, such as display of traffic information and movements, airport moving maps (AMM), and proactive alerts of runway incursions and surface traffic conflicts, to deliver an overall increase in system capacity and safety. A piloted simulation study was conducted at the National Aeronautics and Space Administration (NASA) Langley Research Center to evaluate the ability to conduct safe and efficient airport surface operations while utilizing an AMM displaying traffic of various position accuracies as well as the effect of traffic position accuracy on airport conflict detection and resolution (CD&R) capability. Nominal scenarios and off-nominal conflict scenarios were conducted using 12 airline crews operating in a simulated Memphis International Airport terminal environment. The data suggest that all traffic should be shown on the airport moving map, whether qualified or unqualified, and conflict detection and resolution technologies provide significant safety benefits. Despite the presence of traffic information on the map, collisions or near collisions still occurred; when indications or alerts were generated in these same scenarios, the incidences were averted.

  5. Impact of vehicle speeds and changes in mean speeds on per vehicle-kilometer traffic accident rates in Japan

    NARCIS (Netherlands)

    Tanishita, M.; van Wee, G.P.

    2016-01-01

    Speed and speed variation are widely believed to be key issues in the understanding of traffic accidents. However, there has not been a substantial amount of research that focuses on the interaction between the mean speed and the change in the mean speeds. In this paper we use a five-minute

  6. A small autonomous surface vehicle for ocean color remote sensing

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.S.; Maurya, P.; Pereira, A.; Pascoal, A.M.; Desai, R.G.P.; Mascarenhas, A.A.M.Q.; Desa, E.; Madhan, R.; Matondkar, S.G.P.; Navelkar, G.S.; Prabhudesai, S.; Afzulpurkar, S.

    turning circle ship maneuver as proposed by the International Towing Tank Conference (ITTC) [6]. Physical considerations on the stability of surface vehicles [7] suggest that the second-order Nomoto model predicts a real zero and two real poles. We... surface temperature has made synoptic monitoring of large tracts of the ocean at a low cost a reality. For example, it has been estimated that the World Ocean Circulation Experiment (WOCE) data set from ships over several years can be repeated for less...

  7. The impact of vehicle moving violations and freeway traffic flow on crash risk: An application of plugin development for microsimulation.

    Science.gov (United States)

    Wang, Junhua; Kong, Yumeng; Fu, Ting; Stipancic, Joshua

    2017-01-01

    This paper presents the use of the Aimsun microsimulation program to simulate vehicle violating behaviors and observe their impact on road traffic crash risk. Plugins for violations of speeding, slow driving, and abrupt stopping were developed using Aimsun's API and SDK module. A safety analysis plugin for investigating probability of rear-end collisions was developed, and a method for analyzing collision risk is proposed. A Fuzzy C-mean Clustering algorithm was developed to identify high risk states in different road segments over time. Results of a simulation experiment based on the G15 Expressway in Shanghai showed that abrupt stopping had the greatest impact on increasing collision risk, and the impact of violations increased with traffic volume. The methodology allows for the evaluation and monitoring of risks, alerting of road hazards, and identification of hotspots, and could be applied to the operations of existing facilities or planning of future ones.

  8. A Multi-dimensional Model for Vehicle Impact on Traffic Safety, Congestion, and Environment

    Science.gov (United States)

    2012-01-01

    The Intelligent Transportation System (ITS) has recently received great attention in the research : community. It offers a revolutionary vision of transportation, in which a full-scale : communication scheme between vehicles (V2V) and vehicles and in...

  9. Hyperpigmentation in the long bones of the lower limbs as a basis for vehicle identification and traffic accident reconstruction.

    Science.gov (United States)

    Lisowski, Z; Marek, Z

    1982-01-01

    Following the earlier studies on the identification of injuries in unbroken cranial bones, the described method was adapted for the examination of the long bones in fatal casualties of traffic accidents. Two types of bumper injuries might occur: the bumper was found to cause fracturing of limbs [1], and femoral muscle contusions and microtraumas within compact and spongiose parts in the femoral with subsequent maculate hyperpigmentation [2]. The authors show that the correlation of above mentioned traces of the trauma, facilitates the reconstruction of the accident and also the identification of the vehicle.

  10. Multi-Modal Intelligent Traffic Signal Systems Vehicle Trajectories for Roadside Equipment

    Data.gov (United States)

    Department of Transportation — Data were collected during the Multi-Modal Intelligent Transportation Signal Systems (MMITSS) study. MMITSS is a next-generation traffic signal system that seeks to...

  11. Traffic collisions between electric mobility devices (wheelchairs) and motor vehicles: Accidents, hubris, or self-destructive behavior?

    Science.gov (United States)

    LaBan, Myron M; Nabity, Thomas S

    2010-07-01

    This study had its genesis in a personally observed collision between a motor vehicle and a motorized wheelchair (electric mobility device) on a busy street in the middle of the block at an unmarked crossing. To the observer, at the time, this appeared to be a suicidal act. This investigation was initiated to both delineate the number of these crashes nationally and understand this phenomena as a potentially planned act of self-destruction. An initial survey of police reports was immediately frustrated by an inability to separate motor vehicle and electric mobility device collisions from the much larger group that involved ambulatory citizens because both types were classified together as "pedestrian" accidents. Instead, the search engine NexisLexis was used to identify 107 newspaper articles each of which described a motor vehicle and electric mobility device accident. In the motor vehicle and electric mobility device collisions, men predominated women (3:1 ratio) with an average age of 56 yrs. Sixty of these accidents were fatal. Ninety-four percent involved an electric mobility device and 6% a manual wheelchair. In 50% of the cases, the motor vehicle was a truck, van, or sport utility vehicle. Fifty percent occurred at dusk or dawn or at night. The electric mobility device occupant was cited as the guilty party in 39% of the cases and the driver of the motor vehicle in 27%. Twenty percent were unwitnessed hit-and-run accidents, whereas "no fault" was found in 8% of the cases. Although many accidents do happen by chance, when an electric mobility device operator openly challenges busy traffic by attempting to traverse it in the middle of the block at an unmarked crossing, predisposing psychosocial factors must also be considered. Hubris or premeditated self-destructive behavior or both need to be explored as preeminent issues with reference to the prodromal of the "accident process."

  12. Application of 3D documentation and geometric reconstruction methods in traffic accident analysis: with high resolution surface scanning, radiological MSCT/MRI scanning and real data based animation.

    Science.gov (United States)

    Buck, Ursula; Naether, Silvio; Braun, Marcel; Bolliger, Stephan; Friederich, Hans; Jackowski, Christian; Aghayev, Emin; Christe, Andreas; Vock, Peter; Dirnhofer, Richard; Thali, Michael J

    2007-07-20

    The examination of traffic accidents is daily routine in forensic medicine. An important question in the analysis of the victims of traffic accidents, for example in collisions between motor vehicles and pedestrians or cyclists, is the situation of the impact. Apart from forensic medical examinations (external examination and autopsy), three-dimensional technologies and methods are gaining importance in forensic investigations. Besides the post-mortem multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI) for the documentation and analysis of internal findings, highly precise 3D surface scanning is employed for the documentation of the external body findings and of injury-inflicting instruments. The correlation of injuries of the body to the injury-inflicting object and the accident mechanism are of great importance. The applied methods include documentation of the external and internal body and the involved vehicles and inflicting tools as well as the analysis of the acquired data. The body surface and the accident vehicles with their damages were digitized by 3D surface scanning. For the internal findings of the body, post-mortem MSCT and MRI were used. The analysis included the processing of the obtained data to 3D models, determination of the driving direction of the vehicle, correlation of injuries to the vehicle damages, geometric determination of the impact situation and evaluation of further findings of the accident. In the following article, the benefits of the 3D documentation and computer-assisted, drawn-to-scale 3D comparisons of the relevant injuries with the damages to the vehicle in the analysis of the course of accidents, especially with regard to the impact situation, are shown on two examined cases.

  13. The effect of motor vehicle airbag deployment on tooth surfaces.

    Science.gov (United States)

    Ashar, A; James, H; Higgins, D; Kaidonis, J; Anderson, R W G

    2009-12-01

    Motor vehicle airbag technology is directed at the reduction of injury to drivers and passengers however a number of researchers have reported cases of injuries caused by airbags. Injuries to tooth surfaces, particularly tooth wear following the deployment of motor vehicle airbags, have never been studied. A review of the literature and clinical experience does not suggest tooth enamel abrasion to be a likely outcome following airbag deployment. This in vitro pilot study was conducted to assess the effect on tooth surfaces following the deployment of motor vehicle airbags, and in particular to attempt to reproduce the injuries claimed in a case report published in the Journal of Forensic Odonto- Stomatology in December 2007. A sample of extracted upper anterior teeth (n = 20) were analyzed using unaided visual observation, photographic and microscopic observation pre- and post- airbag deployment. Teeth were mounted on a fabricated head form (similar to those used in crash test dummies) using dental putty. The tests were performed using a modified airbag test rig with airbags deployed in 5 different positions relative to the head, with respect to distance and angulations. The result of the tests showed no changes to the teeth with unaided observation, macro photography or under the microscope. Tooth wear patterns described in the case report were not observed. Although accurate reproduction of an in vivo situation is not possible, this study has given some insight into the effects of motor vehicle airbag deployment, and suggests that significant tooth wear is an unlikely outcome from airbag deployment.

  14. Data-link and surface map traffic intent displays for NextGen 4DT and equivalent visual surface operations

    Science.gov (United States)

    Shelton, Kevin J.; Prinzel, Lawrence (Lance) J., III; Arthur, Jarvis (Trey) J., III; Jones, Denise R.; Allamandola, Angela S.; Bailey, Randall E.

    2009-05-01

    By 2025, U.S. air traffic is predicted to increase 3-fold and may strain the current air traffic management system, which may not be able to accommodate this growth. In response to this challenge, a consortium of industry, academia and government agencies have proposed a revolutionary new concept for U.S. aviation operations, termed the Next Generation Air Transportation System or "NextGen". Many key capabilities are being identified to enable NextGen, including the concept of "net-centric" operations whereby each aircraft and air services provider shares information to allow real-time adaptability to ever-changing factors such as weather, traffic, flight trajectories, and security. Data-link is likely to be the primary source of communication in NextGen. Because NextGen represents a radically different approach to air traffic management and requires a dramatic shift in the tasks, roles, and responsibilities for the flight deck, there are numerous research issues and challenges that must be overcome to ensure a safe, sustainable air transportation system. Flight deck display and crew-vehicle interaction concepts are being developed that proactively investigate and overcome potential technology and safety barriers that might otherwise constrain the full realization of NextGen.

  15. Evaluation of Traffic Density Parameters as an Indicator of Vehicle Emission-Related Near-Road Air Pollution: A Case Study with NEXUS Measurement Data on Black Carbon.

    Science.gov (United States)

    Liu, Shi V; Chen, Fu-Lin; Xue, Jianping

    2017-12-15

    An important factor in evaluating health risk of near-road air pollution is to accurately estimate the traffic-related vehicle emission of air pollutants. Inclusion of traffic parameters such as road length/area, distance to roads, and traffic volume/intensity into models such as land use regression (LUR) models has improved exposure estimation. To better understand the relationship between vehicle emissions and near-road air pollution, we evaluated three traffic density-based indices: Major-Road Density (MRD), All-Traffic Density (ATD) and Heavy-Traffic Density (HTD) which represent the proportions of major roads, major road with annual average daily traffic (AADT), and major road with commercial annual average daily traffic (CAADT) in a buffered area, respectively. We evaluated the potential of these indices as vehicle emission-specific near-road air pollutant indicators by analyzing their correlation with black carbon (BC), a marker for mobile source air pollutants, using measurement data obtained from the Near-road Exposures and Effects of Urban Air Pollutants Study (NEXUS). The average BC concentrations during a day showed variations consistent with changes in traffic volume which were classified into high, medium, and low for the morning rush hours, the evening rush hours, and the rest of the day, respectively. The average correlation coefficients between BC concentrations and MRD, ATD, and HTD, were 0.26, 0.18, and 0.48, respectively, as compared with -0.31 and 0.25 for two commonly used traffic indicators: nearest distance to a major road and total length of the major road. HTD, which includes only heavy-duty diesel vehicles in its traffic count, gives statistically significant correlation coefficients for all near-road distances (50, 100, 150, 200, 250, and 300 m) that were analyzed. Generalized linear model (GLM) analyses show that season, traffic volume, HTD, and distance from major roads are highly related to BC measurements. Our analyses indicate that

  16. A Trial-and-Error Method with Autonomous Vehicle-to-Infrastructure Traffic Counts for Cordon-Based Congestion Pricing

    Directory of Open Access Journals (Sweden)

    Zhiyuan Liu

    2017-01-01

    Full Text Available This study proposes a practical trial-and-error method to solve the optimal toll design problem of cordon-based pricing, where only the traffic counts autonomously collected on the entry links of the pricing cordon are needed. With the fast development and adoption of vehicle-to-infrastructure (V2I facilities, it is very convenient to autonomously collect these data. Two practical properties of the cordon-based pricing are further considered in this article: the toll charge on each entry of one pricing cordon is identical; the total inbound flow to one cordon should be restricted in order to maintain the traffic conditions within the cordon area. Then, the stochastic user equilibrium (SUE with asymmetric link travel time functions is used to assess each feasible toll pattern. Based on a variational inequality (VI model for the optimal toll pattern, this study proposes a theoretically convergent trial-and-error method for the addressed problem, where only traffic counts data are needed. Finally, the proposed method is verified based on a numerical network example.

  17. Optimal Airport Surface Traffic Planning Using Mixed-Integer Linear Programming

    Directory of Open Access Journals (Sweden)

    P. C. Roling

    2008-01-01

    Full Text Available We describe an ongoing research effort pertaining to the development of a surface traffic automation system that will help controllers to better coordinate surface traffic movements related to arrival and departure traffic. More specifically, we describe the concept for a taxi-planning support tool that aims to optimize the routing and scheduling of airport surface traffic in such a way as to deconflict the taxi plans while optimizing delay, total taxi-time, or some other airport efficiency metric. Certain input parameters related to resource demand, such as the expected landing times and the expected pushback times, are rather difficult to predict accurately. Due to uncertainty in the input data driving the taxi-planning process, the taxi-planning tool is designed such that it produces solutions that are robust to uncertainty. The taxi-planning concept presented herein, which is based on mixed-integer linear programming, is designed such that it is able to adapt to perturbations in these input conditions, as well as to account for failure in the actual execution of surface trajectories. The capabilities of the tool are illustrated in a simple hypothetical airport.

  18. Traffic Management Based on Negotiations between Vehicles - A Feasibility Demonstration Using Agents

    Science.gov (United States)

    Schepperle, Heiko; Böhm, Klemens; Forster, Simone

    City governments currently make significant efforts to design traffic-control schemes. While existing solutions try to optimize the load of traffic resources, they do not consider one important aspect: Different drivers value short waiting times differently. For instance, the valuation of a truck driver who is part of a just-in-time production chain tends to be higher than the one of a family on an excursion for pleasure. Traffic-control schemes that give preference to drivers with higher valuations will increase the total utility of all drivers. In this paper we propose a new mechanism for traffic control at intersections. It is called Time-Slot Exchange and relies on bilateral negotiations. It tries to optimize the use of traffic resources in a valuation-aware fashion. The mechanism relies on agent-based driver-assistance systems with communication features which negotiate the right to cross an intersection at a certain time. Using simulations, we show that our new mechanism outperforms existing ones regarding average valuation-weighted waiting time.

  19. Local and Global Motion Planning for Unmanned Surface Vehicle

    Directory of Open Access Journals (Sweden)

    Fedorenko Roman

    2016-01-01

    Full Text Available The paper shows approach of unmanned surface vehicle motion planning in an environment with obstacles. The structure of the control system hardware, software architecture, based on client-server model with the loose coupling in ROS software environment, is presented. Global planner is designed using the method of Generalized Voronoi Diagrams. Local planner is implemented using the unstable regimes of control to bypass obstacles near USV. The results of simulation, which showed the efficiency of the proposed approaches, are presented.

  20. Validation of road vehicle and traffic emission models - A review and meta-analysis

    Science.gov (United States)

    Smit, Robin; Ntziachristos, Leonidas; Boulter, Paul

    2010-08-01

    Road transport is often the main source of air pollution in urban areas, and there is an increasing need to estimate its contribution precisely so that pollution-reduction measures (e.g. emission standards, scrapage programs, traffic management, ITS) are designed and implemented appropriately. This paper presents a meta-analysis of 50 studies dealing with the validation of various types of traffic emission model, including 'average speed', 'traffic situation', 'traffic variable', 'cycle variable', and 'modal' models. The validation studies employ measurements in tunnels, ambient concentration measurements, remote sensing, laboratory tests, and mass-balance techniques. One major finding of the analysis is that several models are only partially validated or not validated at all. The mean prediction errors are generally within a factor of 1.3 of the observed values for CO 2, within a factor of 2 for HC and NO x, and within a factor of 3 for CO and PM, although differences as high as a factor of 5 have been reported. A positive mean prediction error for NO x (i.e. overestimation) was established for all model types and practically all validation techniques. In the case of HC, model predictions have been moving from underestimation to overestimation since the 1980s. The large prediction error for PM may be associated with different PM definitions between models and observations (e.g. size, measurement principle, exhaust/non-exhaust contribution). Statistical analyses show that the mean prediction error is generally not significantly different ( p vital elements currently lacking in traffic emissions modelling: 1) guidance on the allowable error margins for different applications/scales, and 2) estimates of prediction errors. It is recommended that current and future emission models incorporate the capability to quantify prediction errors, and that clear guidelines are developed internationally with respect to expected accuracy.

  1. Optimization of Airport Surface Traffic: A Case-Study of Incheon International Airport

    Science.gov (United States)

    Eun, Yeonju; Jeon, Daekeun; Lee, Hanbong; Jung, Yoon Chul; Zhu, Zhifan; Jeong, Myeong-Sook; Kim, Hyoun Kyoung; Oh, Eunmi; Hong, Sungkwon

    2017-01-01

    This study aims to develop a controllers' decision support tool for departure and surface management of ICN. Airport surface traffic optimization for Incheon International Airport (ICN) in South Korea was studied based on the operational characteristics of ICN and airspace of Korea. For surface traffic optimization, a multiple runway scheduling problem and a taxi scheduling problem were formulated into two Mixed Integer Linear Programming (MILP) optimization models. The Miles-In-Trail (MIT) separation constraint at the departure fix shared by the departure flights from multiple runways and the runway crossing constraints due to the taxi route configuration specific to ICN were incorporated into the runway scheduling and taxiway scheduling problems, respectively. Since the MILP-based optimization model for the multiple runway scheduling problem may be computationally intensive, computation times and delay costs of different solving methods were compared for a practical implementation. This research was a collaboration between Korea Aerospace Research Institute (KARI) and National Aeronautics and Space Administration (NASA).

  2. Frequency, causes and human impact of motor vehicle-related road traffic accident (RTA) in Lubumbashi, Democratic Republic of Congo.

    Science.gov (United States)

    Nangana, Luzitu Severin; Monga, Ben; Ngatu, Nlandu Roger; Mbelambela, Etongola Papy; Mbutshu, Lukuke Hendrick; Malonga, Kaj Francoise

    2016-09-01

    Road traffic accident (RTA)-related trauma remains a public health issue. The aim of this study was to determine the frequency, causes and human impact of motor vehicle-related RTA in Lubumbashi, Democratic Republic of Congo. A prospective cross-sectional study was conducted in the first semester of the year 2015 in which 288 drivers (144 RTA-causing drivers and 144 control drivers who have been declared not guilty by road safety agents) involved in 144 motor vehicle-related RTA were interviewed, and only data on all RTA involving two motor vehicles with at least four wheels were recorded and analyzed. Results showed a total of 144 RTA that involved two motor vehicles with four wheels occurring during the study period which affected 104 people, including 93 injury and 11 fatality cases. The mean age of RTA-causing drivers was 33.8 ± 7.4, whereas it was 35 ± 8.8 for control drivers. The majority of RTA-causing drivers (53.4 %) did not attend a driving school. Over speeding (32 %), distracted driving (22 %), overtaking (16 %) and careless driving/risky maneuver (15 %) and driving under the influence of alcohol (9 %) were the main causes of RTA occurrence. In addition, the absence of a valid driving license [aOR = 12.74 (±2.71); 95 % CI 3.877-41.916; p = 0.015], unfastened seat belt for the RTA-causing driver [aOR = 1.85 (±0.62); 95 % CI 1.306-6.661; p = 0.048] and presence of damages on RTA-causing vehicle [aOR = 33.56 (24.01); 95 % CI 1.429-78.352; p = 0.029] were associated with the occurrence of RTA-related fatality. This study showed a relatively high frequency of RTA occurring in Lubumbashi and suggests the necessity to reinforce road traffic regulation.

  3. Micro Unmanned Surface Vehicle for Shallow Littoral Data Sampling

    Science.gov (United States)

    Murphy, R. R.; Wilde, G.

    2016-02-01

    This paper describes the creation of an autonomous air boat that can be carried by one person, called a micro unmanned surface vehicle (USV), for sensor sampling in shallow littoral areas such as inlets and creeks. A USV offers advantages over other types of unmanned marine vehicles. Unlike an autonomous underwater vehicle, the Challenge 1.0 air boat can operate in shallow water of less than 15 cm depth and maintain network connectivity for control and data sampling. A USV does not require a tether, like a remotely operated marine vehicle (ROV), which would limit the distance and mobility. However, a USV operating in shallow littoral areas poses several challenges. Navigation is a challenge since rivers and bays may have semi-submerged obstacles and there may be no depth maps; the approach taken in the Challenge 1.0 project is to let the operator specify a safe area of the water by visual inspection and then the USV autonomously creates a path to optimally sample the collision free area. Navigation is also a challenge because of platform dynamics-the USV we describe is a non-holonomic vehicle; this paper explores spiral paths rather than boustrophedon paths. Another challenge is the quality of sensing. Water-based sensing is noisy and thus a reading at a single point may not reflect the overall value. In practice, areas are sampled rather than a single point, but the noise in the point values within the sampled area produce a survey with widely varying numbers and are difficult for humans to interpret. This paper implements an inverse distance weighting interpolation algorithm to produce a visual "heatmap" that reliably portrays the smoothed data.

  4. An estimation of traffic related CO2 emissions from motor vehicles in the capital city of, Iran

    Directory of Open Access Journals (Sweden)

    Kakouei Aliakbar

    2012-11-01

    Full Text Available Abstract Vehicle exhaust is a major source of anthropogenic carbon dioxide (CO2 in metropolitan cities. Popular community mode (buses and taxies and about 2.4 million private cars are the main emission sources of air pollution in Tehran. A case survey has conducted to measure CO2 in four popular vehicles, bus, taxi, private car and motorcycle, which moved in the city with respectively 7800, 82358, 560000 and 2.4 million per day in 2012. Results indicated that the contribution of CO2 emissions increased in the following order: private car, motorcycle, bus and taxi. The overall average for the contribution of CO2 emissions in the private car, motorcycle, bus, and taxi were 26372, 1648, 1433 and 374 tons per day, respectively. Our results also showed that the urban transport operation consume an estimated 178 and 4224 million liter diesel and petrol per year, respectively, that have released about 10 million tons of CO2. The average contribution of CO2 emissions of private cars in Tehran was higher (88% than other vehicles. It was concluded that high volume of traffic, transport consumption of fossil fuels and shortage of adequate public transport system are responsible for the high CO2 level in environment in Tehran. Thus, it is to be expected that CO2 as a greenhouse gas has risen in Tehran more than ever in the following years and this would be a matter of concern for the authorities to have a comprehensive plan to mitigate this phenomena.

  5. Motor vehicle driver injury severity study under various traffic control at highway-rail grade crossings in the United States.

    Science.gov (United States)

    Hao, Wei; Daniel, Janice

    2014-12-01

    Based on the Federal Railway Administration (FRA) database, approximately 62% of the collisions at highway-rail crossings occurred at locations with active controls (gate and flashing lights), followed by passive controls (cross bucks and stop signs) with approximately 28% of accidents. The study applied an ordered probit model to explore the determinants of driver injury severity under various control measures at highway-rail grade crossing in the United States. The analysis found that schedule factor (peak hour), visibility, motor vehicle speed, train speed, driver's age, area type, traffic volume and highway pavement impact driver injury severity at both active and passive highway-rail crossings. For both active and passive control highway-rail grade crossings, speed control for both trains and vehicles will significantly reduce driver injury severity. However, the level of influence by vehicle speed and train speed at passive control is higher compared with active control. Paving highways at highway-rail grade crossings will also help to reduce driver injury severity at highway-rail crossing accidents. Published by Elsevier Ltd.

  6. "Charge while driving" for electric vehicles: road traffic modeling and energy assessment

    National Research Council Canada - National Science Library

    Francesco Paolo DEFLORIO; Luca CASTELLO; Ivano PINNA; Paolo GUGLIELMI

    2015-01-01

      Issue Title: Special Issue on Electric Vehicles and Their Integration with Power Grid The aim of this research study is to present a method for analyzing the performance of the wireless inductive charge-while-driving (CWD...

  7. Assessing the ground vibrations produced by a heavy vehicle traversing a traffic obstacle.

    Science.gov (United States)

    Ducarne, Loïc; Ainalis, Daniel; Kouroussis, Georges

    2018-01-15

    Despite advancements in alternative transport networks, road transport remains the dominant mode in many modern and developing countries. The ground-borne motions produced by the passage of a heavy vehicle over a geometric obstacle (e.g. speed hump, train tracks) pose a fundamental problem in transport annoyance in urban areas. In order to predict the ground vibrations generated by the passage of a heavy vehicle over a geometric obstacle, a two-step numerical model is developed. The first step involves simulating the dynamic loads generated by the heavy vehicle using a multibody approach, which includes the tyre-obstacle-ground interaction. The second step involves the simulation of the ground wave propagation using a three dimensional finite element model. The simulation is able to be decoupled due to the large difference in stiffness between the vehicle's tyres and the road. First, the two-step model is validated using an experimental case study available in the literature. A sensitivity analysis is then presented, examining the influence of various factors on the generated ground vibrations. Factors investigated include obstacle shape, obstacle dimensions, vehicle speed, and tyre stiffness. The developed model can be used as a tool in the early planning stages to predict the ground vibrations generated by the passage of a heavy vehicle over an obstacle in urban areas. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Piezoelectric composite morphing control surfaces for unmanned aerial vehicles

    Science.gov (United States)

    Ohanian, Osgar J., III; Karni, Etan D.; Olien, Chris C.; Gustafson, Eric A.; Kochersberger, Kevin B.; Gelhausen, Paul A.; Brown, Bridget L.

    2011-04-01

    The authors have explored the use of morphing control surfaces to replace traditional servo-actuated control surfaces in UAV applications. The morphing actuation is accomplished using Macro Fiber Composite (MFC) piezoelectric actuators in a bimorph configuration to deflect the aft section of a control surface cross section. The resulting camber change produces forces and moments for vehicle control. The flexible piezoelectric actuators are damage tolerant and provide excellent bandwidth. The large amplitude morphing deflections attained in bench-top experiments demonstrate the potential for excellent control authority. Aerodynamic performance calculations using experimentally measured morphed geometries indicate changes in sectional lift coefficients that are superior to a servo-actuated hinged flap airfoil. This morphing flight control actuation technology could eliminate the need for servos and mechanical linkages in small UAVs and thereby increase reliability and reduce drag.

  9. Morphological analysis of the introduction of electric vehicles in São Paulo’s urban traffic

    Directory of Open Access Journals (Sweden)

    Lydia Lopes Correia da Silva

    2011-07-01

    Full Text Available Pressures of international organizations and governmental regulations have increased substantially when it comes to the reduction of dependence on fossil fuels and transport pollutants emissions. To meet these challenges, the automotive industry invests large sums in research and development on a broad portfolio of new technologies related to vehicular propulsion. Considering the alternatives under development, electric vehicles, specifically, have received increased attention both in Brazil and abroad. This study aims to contribute with the construction of future scenarios in 2020 concerning the introduction of electric vehicles in São Paulo´s urban traffic, an integral part of the CNPq/FINEP research project which is being undertaken at the University of São Paulo (USP/FEA, coordinated by Prof. James T. C. Wright. The Morphological Analysis method was adopted given the fact that it facilitates the structuring of the managerial and technological complexities of the proposed problem, with views to identifying the variables and their critical relations for the prospection of scenarios. The variables that influence an urban transport system were structured into four logical groups: scope of usage, structural architecture and propulsion system of the vehicle, road and energy supply/recharge infrastructure and finally, business models. These groups, in turn, were analysed at distinct levels, leading to other variables. Subsequently, alternative forms, which the selected variables could take on, were generated. The multidimensional matrix resulting from this set of combinatorial possibilities was then carefully verified in terms of feasibility and consistency in order to identify the basic settings of greatest interest to the scenarios prospecting effort.Key words: Prospective scenarios. Morphological analysis. Electric vehicles.

  10. Intelligent Autonomy for Unmanned Surface and Underwater Vehicles

    Science.gov (United States)

    Huntsberger, Terry; Woodward, Gail

    2011-01-01

    As the Autonomous Underwater Vehicle (AUV) and Autonomous Surface Vehicle (ASV) platforms mature in endurance and reliability, a natural evolution will occur towards longer, more remote autonomous missions. This evolution will require the development of key capabilities that allow these robotic systems to perform a high level of on-board decisionmaking, which would otherwise be performed by humanoperators. With more decision making capabilities, less a priori knowledge of the area of operations would be required, as these systems would be able to sense and adapt to changing environmental conditions, such as unknown topography, currents, obstructions, bays, harbors, islands, and river channels. Existing vehicle sensors would be dual-use; that is they would be utilized for the primary mission, which may be mapping or hydrographic reconnaissance; as well as for autonomous hazard avoidance, route planning, and bathymetric-based navigation. This paper describes a tightly integrated instantiation of an autonomous agent called CARACaS (Control Architecture for Robotic Agent Command and Sensing) developed at JPL (Jet Propulsion Laboratory) that was designed to address many of the issues for survivable ASV/AUV control and to provide adaptive mission capabilities. The results of some on-water tests with US Navy technology test platforms are also presented.

  11. Queueing and traffic

    NARCIS (Netherlands)

    Baër, Niek

    2015-01-01

    Traffic jams are everywhere, some are caused by constructions or accidents but a large portion occurs naturally. These "natural" traffic jams are a result of variable driving speeds combined with a high number of vehicles. To prevent these traffic jams, we must understand traffic in general, and to

  12. Jamitons: Phantom Traffic Jams

    Science.gov (United States)

    Kowszun, Jorj

    2013-01-01

    Traffic on motorways can slow down for no apparent reason. Sudden changes in speed by one or two drivers can create a chain reaction that causes a traffic jam for the vehicles that are following. This kind of phantom traffic jam is called a "jamiton" and the article discusses some of the ways in which traffic engineers produce…

  13. Catalysis study for space shuttle vehicle thermal protection systems. [for vehicle surface

    Science.gov (United States)

    Breen, J.; Rosner, D. E.; Delgass, W. N.; Nordine, P. C.; Cibrian, R.; Krishnan, N. G.

    1973-01-01

    Experimental results on the problem of reducing aerodynamic heating on space shuttle orbiter surfaces are presented. Data include: (1) development of a laboratory flow reactor technique for measuring gamma sub O and gamma sub N on candidate materials at surfaces, T sub w, in the nominal range 1000 to 2000, (2) measurements of gamma sub O and gamma sub N above 1000 K for both the glass coating of a reusable surface insulation material and the siliconized surface of a reinforced pyrolyzed plastic material, (3) measurement of the ablation behavior of the coated RPP material at T sub w is greater than or equal to 2150 K, (4) X-ray photoelectron spectral studies of the chemical constituents on these surfaces before and after dissociated gas exposure, (5) scanning electron micrograph examination of as-received and reacted specimens, and (6) development and exploitation of a method of predicting the aerodynamic heating consquences of these gamma sub O(T sub w) and gamma sub N(T sub w) measurements for critical locations on a radiation cooled orbiter vehicle.

  14. Influence of Urban Traffic Driving Conditions and Vehicle Cubic Capacity on CO and VOC Emissions

    Directory of Open Access Journals (Sweden)

    Arina Negoitescu

    2013-09-01

    Full Text Available The reports regarding the global warming warn on the urgent need to reduce pollutant emissions and in particular greenhouse emissions. The performed analysis shows that cars equipped with engines operating on petrol, lead to a lower level of pollution, from the point of view of CO (carbon monoxide and VOCs (volatile organic compounds emissions at speeds above 50km/ h. Since driving in urban traffic mode involves driving with a speed up to 50km/h, it was comparatively analyzed the automobile engines operation with different cubic capacities. In conclusion, in terms of the analyzed emissions in accordance with the emission standards requirements for urban driving situations, it results that the accepted values of these emissions are recorded for automobile engines of low cubic capacities (under 1.4 l.

  15. An estimation of vehicle kilometer traveled and on-road emissions using the traffic volume and travel speed on road links in Incheon City.

    Science.gov (United States)

    Jung, Sungwoon; Kim, Jounghwa; Kim, Jeongsoo; Hong, Dahee; Park, Dongjoo

    2017-04-01

    The objective of this study is to estimate the vehicle kilometer traveled (VKT) and on-road emissions using the traffic volume in urban. We estimated two VKT; one is based on registered vehicles and the other is based on traffic volumes. VKT for registered vehicles was 2.11 times greater than that of the applied traffic volumes because each VKT estimation method is different. Therefore, we had to define the inner VKT is moved VKT inner in urban to compare two values. Also, we focused on freight modes because these are discharged much air pollutant emissions. From analysis results, we found middle and large trucks registered in other regions traveled to target city in order to carry freight, target city has included many industrial and logistics areas. Freight is transferred through the harbors, large logistics centers, or via locations before being moved to the final destination. During this process, most freight is moved by middle and large trucks, and trailers rather than small trucks for freight import and export. Therefore, these trucks from other areas are inflow more than registered vehicles. Most emissions from diesel trucks had been overestimated in comparison to VKT from applied traffic volumes in target city. From these findings, VKT is essential based on traffic volume and travel speed on road links in order to estimate accurately the emissions of diesel trucks in target city. Our findings support the estimation of the effect of on-road emissions on urban air quality in Korea. Copyright © 2016. Published by Elsevier B.V.

  16. Target Trailing With Safe Navigation for Maritime Autonomous Surface Vehicles

    Science.gov (United States)

    Wolf, Michael; Kuwata, Yoshiaki; Zarzhitsky, Dimitri V.

    2013-01-01

    This software implements a motion-planning module for a maritime autonomous surface vehicle (ASV). The module trails a given target while also avoiding static and dynamic surface hazards. When surface hazards are other moving boats, the motion planner must apply International Regulations for Avoiding Collisions at Sea (COLREGS). A key subset of these rules has been implemented in the software. In case contact with the target is lost, the software can receive and follow a "reacquisition route," provided by a complementary system, until the target is reacquired. The programmatic intention is that the trailed target is a submarine, although any mobile naval platform could serve as the target. The algorithmic approach to combining motion with a (possibly moving) goal location, while avoiding local hazards, may be applicable to robotic rovers, automated landing systems, and autonomous airships. The software operates in JPL s CARACaS (Control Architecture for Robotic Agent Command and Sensing) software architecture and relies on other modules for environmental perception data and information on the predicted detectability of the target, as well as the low-level interface to the boat controls.

  17. Important factors of perceiving and memorizing the city during the process of vehicle and pedestrian traffic

    Science.gov (United States)

    Alihodžić, Rifat; Butyrin, Andrey; Makhov, Dmitry

    2017-10-01

    Moving within the city, both by vehicle and pedestrian, is a prerequisite of creating visual sequences. A variety of factors should be taken into consideration when planning cities, not only of functional nature, but also of the aesthetic one. A particular problem lies in complex cities having a compound identification matrix as a consequence of a boisterous development during long period of time. Considering that the city follows the needs of its user, inevitably moving along it, one of the most important factors required is easy orientation in the complex urban area. Some research has been carried out on the condition of easy orientation and moving in the city, and on appearance of urban elements that provide remembering of the city. This work deals with defining important factors effecting perceiving and memorizing, by inhabitants and also of those visiting it for the first time, regardless they are walking or using a vehicle. Physical structures, topography and a climate and a range of other elements are implied to create a clear idea of some urban area. Many elements were considered - not only being of fixed nature (streets, squares, topography and morphology), but also elements that make the essence of the urban image – elements that can also be some specific public transportation means, such as double-deckers in London, bicycles in Amsterdam or Beijing or gondolas in Venice. The purpose of this work is to notice the rules helping the urban planning process and contribute to reading and memorizing the image of the city.

  18. On the Design of a Robotic System Composed of an Unmanned Surface Vehicle and a Piggybacked VTOL

    OpenAIRE

    Pinto, Eduardo; Santana, Pedro; Marques, Francisco; Mendonça, Ricardo; Lourenço, André; Barata, José

    2014-01-01

    Part 8: Robotics and Mechatronics; International audience; This paper presents the core ideas of the RIVERWATCH experiment and describes its hardware architecture. The RIVERWATCH experiment considers the use of autonomous surface vehicles piggybacking multi-rotor unmanned aerial vehicles for the automatic monitoring of riverine environments. While the surface vehicle benefits from the aerial vehicle to extend its field of view, the aerial vehicle benefits from the surface vehicle to ensure lo...

  19. 32 CFR 634.24 - Traffic planning and codes.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Traffic planning and codes. 634.24 Section 634.24... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.24 Traffic planning and... traffic supervision program includes traffic circulation planning and control of motor vehicle traffic...

  20. Evaluation of Environmental Impact of Biodiesel Vehicles in Real Traffic Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Nylund, N.-O.; Koponen, K. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2012-08-15

    In 2009–2011, a comprehensive project on urban buses was carried out in cooperation with IEA’s Implementing Agreements on Alternative Motor Fuels and Bioenergy, with input from additional IEA Implementing Agreements. The objective of the project was to generate unbiased and solid data for use by policy- and decision-makers responsible for public transport using buses. The project comprised four major parts: (1) a well-to-tank (WTT) assessment of alternative fuel pathways, (2) an assessment of bus end-use (tank-to-wheel, TTW) performance, (3) combining WTT and TTW data into well-to-wheel (WTW) data and (4) a cost assessment, including indirect as well as direct costs. Experts at Argonne National Laboratory, Natural Resources Canada and VTT worked on the WTT part. The WTT emissions of various fossil fuels and biofuels were assessed by using GREET model from the United States, GHGenius model from Canada and RED methodology of the European Union. All these models follow the frame work of life cycle assessment. In the TTW part Environment Canada and VTT generated emission and fuel consumption data by running 21 different buses on chassis dynamometers, generating data for some 180 combinations of vehicle, fuel and driving cycle. The fuels covered included diesel, synthetic diesel, various types of biodiesel fuels, additive treated ethanol, methane and DME. Six different hybrid vehicles were included in the vehicle matrix. The TTW work was topped up by on-road measurements (AVL MTC) as well as some engine dynamometer work (von Thuenen Institute). Based on the findings of the project it is possible to establish the effects of various parameters on bus performance. The largest variations and also uncertainties can be found for WTW CO2eqv emissions, or in fact the WTT part of the CO2eqv emissions. The variation is especially significant for biofuels. The WTT results vary due to the differences in the assessed biofuel chains, the regions of biofuel production, the raw

  1. System safety engineering in the development of advanced surface transportation vehicles

    Science.gov (United States)

    Arnzen, H. E.

    1971-01-01

    Applications of system safety engineering to the development of advanced surface transportation vehicles are described. As a pertinent example, the paper describes a safety engineering efforts tailored to the particular design and test requirements of the Tracked Air Cushion Research Vehicle (TACRV). The test results obtained from this unique research vehicle provide significant design data directly applicable to the development of future tracked air cushion vehicles that will carry passengers in comfort and safety at speeds up to 300 miles per hour.

  2. QuickStats: Age-Adjusted Rate* of Motor Vehicle Traffic Deaths,(†) by Urbanization of County of Residence(§) - 2005 and 2015.

    Science.gov (United States)

    2017-06-02

    The overall age-adjusted rate of motor vehicle traffic deaths in the United States decreased 25% from 14.6 deaths per 100,000 population in 2005 to 10.9 in 2015. During this period, the rate declined in each of the county groupings, with the largest decline of 26% in the large fringe metropolitan and micropolitan counties and the smallest decline of 20% in rural counties. For both years, the rates for motor vehicle traffic deaths were higher in nonmetropolitan areas than in metropolitan areas. In 2015, the age-adjusted rate in rural counties was nearly three times the rate for large central metropolitan counties (23.0 compared with 7.9 per 100,000).

  3. SIG: Multiple Views on Safety-Critical Automation: Aircraft, Autonomous Vehicles, Air Traffic Management and Satellite Ground Segments Perspectives

    Science.gov (United States)

    Feary, Michael; Palanque, Philippe; Martinie, Célia; Tscheligi, Manfred

    2016-01-01

    This SIG focuses on the engineering of automation in interactive critical systems. Automation has already been studied in a number of (sub-) disciplines and application fields: design, human factors, psychology, (software) engineering, aviation, health care, games. One distinguishing feature of the area we are focusing on is that in the field of interactive critical systems properties such as reliability, dependability, fault tolerance are as important as usability, user experience or overall acceptance issues. The SIG targets at two problem areas: first the engineering of the user interaction with (partly-) autonomous systems: how to design, build and assess autonomous behavior, especially in cases where there is a need to represent on the user interface both autonomous and interactive objects. An example of such integration is the representation of an unmanned aerial vehicle (UAV) (where no direct interaction is possible), together with aircrafts (that have to be instructed by an air traffic controller to avoid the UAV). Second the design and engineering of user interaction in general for autonomous objects/systems (for example a cruise control in a car or an autopilot in an aircraft). The goal of the SIG is to raise interest in the CHI community on the general aspects of automation and to identify a community of researchers and practitioners interested in those increasingly prominent issues of interfaces towards (semi)-autonomous systems. The expected audience should be interested in addressing the issues of integration of mainly unconnected research domains to formulate a new joint research agenda.

  4. Multiple Views on Safety-Critical Automation: Aircraft, Autonomous Vehicles, Air Traffic Management and Satellite Ground Segments Perspectives

    Science.gov (United States)

    Feary, Michael S.; Palanque, Philippe Andre Rolan; Martinie, De Almeida; Tscheligi, Manfred

    2016-01-01

    This SIG focuses on the engineering of automation in interactive critical systems. Automation has already been studied in a number of (sub-) disciplines and application fields: design, human factors, psychology, (software) engineering, aviation, health care, games. One distinguishing feature of the area we are focusing on is that in the field of interactive critical systems properties such as reliability, dependability, fault-tolerance are as important as usability, user experience or overall acceptance issues. The SIG targets at two problem areas: first the engineering of the user interaction with (partly-) autonomous systems: how to design, build and assess autonomous behavior, especially in cases where there is a need to represent on the user interface both autonomous and interactive objects. An example of such integration is the representation of an unmanned aerial vehicle (UAV) (where no direct interaction is possible), together with aircrafts (that have to be instructed by an air traffic controller to avoid the UAV). Second the design and engineering of user interaction in general for autonomous objects systems (for example a cruise control in a car or an autopilot in an aircraft). The goal of the SIG is to raise interest in the CHI community on the general aspects of automation and to identify a community of researchers and practitioners interested in those increasingly prominent issues of interfaces towards (semi)-autonomous systems. The expected audience should be interested in addressing the issues of integration of mainly unconnected research domains to formulate a new joint research agenda.

  5. A comparison of injuries, crashes, and outcomes for pediatric rear occupants in traffic motor vehicle collisions.

    Science.gov (United States)

    Charyk Stewart, Tanya; McClafferty, Kevin; Shkrum, Michael; Comeau, Jean-Louis; Gilliland, Jason; Fraser, Douglas D

    2013-02-01

    This study was initiated was initiated to describe pediatric rear-occupant motor vehicle collision (MVC) injuries, including injury patterns and outcomes as well as characteristics associated with severe injury to the head and abdomen. A retrospective cohort of severely injured (Injury Severity Score [ISS] > 12) pediatric (age trauma centers (2001-2010) was studied was studied. Demographic, injury, crash and outcome data were obtained from the trauma registries. Data were statistically compared by two pediatric age groups: children (0-8 years; requiring a child or booster seat) versus adolescents (9-17 years; requiring a lap-shoulder belt). There were 36 children (34%) and 70 adolescents (66%) severely injured as rear occupants in MVCs. Despite similar ISS (p = 0.716) and mortality rates (p = 0.680) between age groups, there were significant differences in injury patterns and risk factors. Children were more likely to have severe head injuries (78% vs. 39%, p child restraints (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.1-10.8; p = 0.029), middle seating (OR, 6.2; 95% CI, 1.5-26.1; p = 0.013), and side-impact crashes (p = 0.007). Adolescents were more likely to have severe abdominal injuries (23% vs. 6%, p child occupants and preferred seating positions are required. Epidemiologic study, level III.

  6. An object detection and tracking system for unmanned surface vehicles

    Science.gov (United States)

    Yang, Jian; Xiao, Yang; Fang, Zhiwen; Zhang, Naiwen; Wang, Li; Li, Tao

    2017-10-01

    Object detection and tracking are critical parts of unmanned surface vehicles(USV) to achieve automatic obstacle avoidance. Off-the-shelf object detection methods have achieved impressive accuracy in public datasets, though they still meet bottlenecks in practice, such as high time consumption and low detection quality. In this paper, we propose a novel system for USV, which is able to locate the object more accurately while being fast and stable simultaneously. Firstly, we employ Faster R-CNN to acquire several initial raw bounding boxes. Secondly, the image is segmented to a few superpixels. For each initial box, the superpixels inside will be grouped into a whole according to a combination strategy, and a new box is thereafter generated as the circumscribed bounding box of the final superpixel. Thirdly, we utilize KCF to track these objects after several frames, Faster-RCNN is again used to re-detect objects inside tracked boxes to prevent tracking failure as well as remove empty boxes. Finally, we utilize Faster R-CNN to detect objects in the next image, and refine object boxes by repeating the second module of our system. The experimental results demonstrate that our system is fast, robust and accurate, which can be applied to USV in practice.

  7. Analysis of crash proportion by vehicle type at traffic analysis zone level: A mixed fractional split multinomial logit modeling approach with spatial effects.

    Science.gov (United States)

    Lee, Jaeyoung; Yasmin, Shamsunnahar; Eluru, Naveen; Abdel-Aty, Mohamed; Cai, Qing

    2017-11-18

    In traffic safety literature, crash frequency variables are analyzed using univariate count models or multivariate count models. In this study, we propose an alternative approach to modeling multiple crash frequency dependent variables. Instead of modeling the frequency of crashes we propose to analyze the proportion of crashes by vehicle type. A flexible mixed multinomial logit fractional split model is employed for analyzing the proportions of crashes by vehicle type at the macro-level. In this model, the proportion allocated to an alternative is probabilistically determined based on the alternative propensity as well as the propensity of all other alternatives. Thus, exogenous variables directly affect all alternatives. The approach is well suited to accommodate for large number of alternatives without a sizable increase in computational burden. The model was estimated using crash data at Traffic Analysis Zone (TAZ) level from Florida. The modeling results clearly illustrate the applicability of the proposed framework for crash proportion analysis. Further, the Excess Predicted Proportion (EPP)-a screening performance measure analogous to Highway Safety Manual (HSM), Excess Predicted Average Crash Frequency is proposed for hot zone identification. Using EPP, a statewide screening exercise by the various vehicle types considered in our analysis was undertaken. The screening results revealed that the spatial pattern of hot zones is substantially different across the various vehicle types considered. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. On-road emissions of carbonyls from vehicles powered by biofuel blends in traffic tunnels in the Metropolitan Area of Sao Paulo, Brazil

    Science.gov (United States)

    Nogueira, Thiago; Souza, Kely Ferreira de; Fornaro, Adalgiza; Andrade, Maria de Fatima; Carvalho, Lilian Rothschild Franco de

    2015-05-01

    On-road emissions of carbonyls from the current vehicle fleet of Brazil were determined in two experimental campaigns, conducted in traffic tunnels located in the Metropolitan Area of São Paulo (MASP), in southeastern Brazil. Among carbonyl species, formaldehyde and acetaldehyde were the most abundant in all sampling periods. In Brazil, heavy-duty vehicles (HDVs) run on a blend of 95% regular diesel/5% biodiesel from soy, whereas light-duty vehicles (LDVs) run on gasohol (75-80% gasoline/20-25% ethanol) or hydrous ethanol. We found that HDVs showed the highest overall carbonyl emissions, although LDVs were responsible for high emissions of acetaldehyde. In comparison with LDVs in California, which are powered by 90% gasoline/10% ethanol, LDVs in Brazil were found to emit 352% and 263% more formaldehyde and acetaldehyde.

  9. Development of vehicle model test-bending of a simple structural surfaces model for automotive vehicle sedan

    Science.gov (United States)

    Nor, M. K. Mohd; Noordin, A.; Ruzali, M. F. S.; Hussen, M. H.; Mustapa@Othman, N.

    2017-04-01

    Simple Structural Surfaces (SSS) method is offered as a means of organizing the process for rationalizing the basic vehicle body structure load paths. The application of this simplified approach is highly beneficial in the development of modern passenger car structure design. In Malaysia, the SSS topic has been widely adopted and seems compulsory in various automotive programs related to automotive vehicle structures in many higher education institutions. However, there is no real physical model of SSS available to gain considerable insight and understanding into the function of each major subassembly in the whole vehicle structures. Based on this motivation, a real physical SSS of sedan model and the corresponding model vehicle tests of bending is proposed in this work. The proposed approach is relatively easy to understand as compared to Finite Element Method (FEM). The results prove that the proposed vehicle model test is useful to physically demonstrate the importance of providing continuous load path using the necessary structural components within the vehicle structures. It is clearly observed that the global bending stiffness reduce significantly when more panels are removed from the complete SSS model. The analysis shows the front parcel shelf is an important subassembly to sustain bending load.

  10. Use of high-scale traffic modeling to estimate road vehicle emissions of CO2 and impact on the atmospheric concentration in São Paulo, Brazil.

    Science.gov (United States)

    Miranda, R. M.; Perez-Martinez, P.; Andrade, M. D. F.

    2015-12-01

    Adequate estimations of motor vehicle CO2 emission inventories at high spatial and temporal urban scales are needed to establish transport policy measures aim to reduce climate change impacts from global cities. The Metropolitan Region of São Paulo (MRSP) is impacted by the emission of 7 million vehicles (97% light-duty gasoline vehicles LDVs and 3% heavy-duty diesel vehicles HDVs) and several environmental programs were implemented to reduce the emissions. Inventories match site measurements and remote sensing and help to assess the real impact of road vehicle emissions on city's air quality. In this paper we presented a high-resolution vehicle-based inventory of motor CO2 emissions mapped at a scale of 100 m and 1 hour. We used origin and destination (O/D) transport area zone trips from the mobility survey of the São Paulo Transport Metropolitan Company (Metro), a road network of the region and traffic datasets from the São Paulo Transport Engineering Company (CET). The inventory was done individually for LDVs and HDVs for the years 2008 and 2013 and was complemented with air quality datasets from the State Environmental Company (CETESB), together with census data from the Brazilian Institute of Geography and Statistics (IBGE). Our inventory showed partial disagreement with the São Paulo State's GHG inventory, caused by the different approach used - bottom vs. top down - and characteristic spatial and temporal biases of the population inputs used (different emission factors). Higher concentrations became apparent near the road-network at the spatial scale used. The total emissions were estimated in 20,781 million tons per year of CO2eq (83.7% by LDVs and 16.3% HDVs). Temporal profiles - diurnal, weekly and monthly - in vehicle emission distributions were calculated using CET's traffic counts and surrogates of congestion. These profiles were compared with average road-site measurements of CO2 for the year 2013. Measurements showed two peaks associated to the

  11. Highway measurements of vehicle-induced turbulence (VIT) and enhanced mixing in the surface layer

    Science.gov (United States)

    Miller, S. J.; Gordon, M.; Staebler, R. M.; Li-Chee-Ming, J.; Taylor, P.

    2016-12-01

    Motor vehicles generate vehicle-induced turbulence (VIT) while in motion, which affects the mixing and transport of emitted trace gases, heat and momentum. During July, 2016 a 40Hz sonic anemometer (ATI) and a co-located 20Hz open path CO2/H2O gas analyzer (LICOR) were assembled and driven on highways in the Greater Toronto Area. An ultra-high sensitivity aerosol spectrometer was employed to measure the total number concentration of particles between 60 and 1000nm at the position of the gas analyzer and sonic anemometer. A video camera with GPS capabilities was also utilized to assess the surrounding features while chasing a specific vehicle type. The following distance of each chased vehicle is calculated as a function of pixel location, with the back edge of each followed vehicle being identified as the initial contrast between the vehicle's shadow and the roadway. Combining the sonic anemometer data with the GPS data allows turbulence statistics to be developed and correlations with vehicle type and following distance to be examined. Vehicle-induced turbulence is assessed using turbulent kinetic energy (TKE), a measure of turbulent mixing, which maximizes near the followed vehicle and decreases with increasing following distance. Vehicle exhaust plumes are identified using the measured CO2 concentration. The CO2 concentration data in conjunction with TKE and turbulent fluxes are used to explore the potential impacts of vehicle-induced turbulence on atmospheric mixing within the surface layer.

  12. The Ageing Effect of Mechanical Joints on the Tyre/Joint Noises Monitored by a Control Vehicle Method without Traffic Disturbance

    Directory of Open Access Journals (Sweden)

    C. K. Wong

    2013-01-01

    Full Text Available This paper studies the ageing effect of mechanical joints reflecting from the tyre/joint impacting noise by measuring the vehicle structure-borne noise change. Field data is collected applying two measurement methods suitable for newly installed and existing old expansion joints. The measurement methodology is improved by designing and applying a trailer for equipment installation. The main advantage of this method is not to disturb existing traffic by lane closure for measurement. Field measurements were conducted regularly for a study period up to 16 months after new joint replacement to monitor the variation of the structure-borne noise change inside a test vehicle while passing through mechanical joints. Empirical relationship is developed based on the field data of the roadside airborne noise change and the vehicle structure-borne noise change. The roadside tyre/joint noises could be converted using calibrated empirical formula. Key result findings include the following. (1 The vehicle structure-borne noise change is found smallest during the 3rd–6th months even lower than that measured when a new joint is installed. The structure-borne noise change then keeps increasing afterwards till the end of the study period. (2 Similar observations are found in all study cases incorporating various mechanical joint types and test vehicle types.

  13. Impacts of tracked vehicles on sediment from a desert soil

    Science.gov (United States)

    Erek H. Fuchs; Karl M. Wood; Tim L. Jones; Brent Racher

    2003-01-01

    Off-road military vehicle traffic is a major consideration in the management of military lands. The objective of this study was to determine the impacts of military tracked M1A1 heavy combat tank vehicles on sediment loss from runoff, surface plant cover, and surface microtopography in a desert military training environment. A randomized block design was used which had...

  14. Platinum(II), palladium(II), rhodium(III) and lead(II) voltammetric determination in sites differently influenced by vehicle traffic.

    Science.gov (United States)

    Melucci, Dora; Locatelli, Clinio

    2007-01-01

    The present work reports analytical results relevant to voltammetric determination of Pt(II), Pd(II), Rh(III) [Platinum Group Metals (PGMs)] and Pb(II) in superficial water sampled in sites differently influenced by vehicle traffic, especially considering their temporal behaviour. For all the elements, in addition to detection limits, precision, expressed as relative standard deviation (s(r) %) and accuracy, expressed as percentage recovery (R %) are also reported. In all cases they show to be good, being the former lower than 6% and the latter in the range 94-105%. A critical comparison with spectroscopic measurements is also discussed.

  15. Spatio-temporal organization of vehicles in a cellular automata model of traffic with `slow-to-start' rule

    Science.gov (United States)

    Chowdhury, Debashish; Santen, Ludger; Schadschneider, Andreas; Sinha, Shishir; Pasupathy, Abhay

    1999-05-01

    The spatio-temporal organizations of vehicular traffic in cellular-automata models with `slow-to-start' rules are qualitatively different from those in the Nagel-Schreckenberg (NaSch) model of highway traffic. Here we study the effects of such a slow-to-start rule, introduced by Benjamin, Johnson and Hui (BJH), on the distributions of the distance-headways, time-headways, jam sizes and sizes of the gaps between successive jams by a combination of approximate analytical calculations and extensive computer simulations. We compare these results for the BJH model with the corresponding results for the NaSch model and interpret the qualitative differences in the nature of the spatio-temporal organizations of traffic in these two models in terms of a phase separation of the traffic caused by the slow-to-start rule in the BJH model.

  16. Method of Determining the Aerodynamic Characteristics of a Flying Vehicle from the Surface Pressure

    Science.gov (United States)

    Volkov, V. F.; Dyad'kin, A. A.; Zapryagaev, V. I.; Kiselev, N. P.

    2017-11-01

    The paper presents a description of the procedure used for determining the aerodynamic characteristics (forces and moments acting on a model of a flying vehicle) obtained from the results of pressure measurements on the surface of a model of a re-entry vehicle with operating retrofire brake rockets in the regime of hovering over a landing surface is given. The algorithm for constructing the interpolation polynomial over interpolation nodes in the radial and azimuthal directions using the assumption on the symmetry of pressure distribution over the surface is presented. The aerodynamic forces and moments at different tilts of the vehicle are obtained. It is shown that the aerodynamic force components acting on the vehicle in the regime of landing and caused by the action of the vertical velocity deceleration nozzle jets are negligibly small in comparison with the engine thrust.

  17. Soviet and East European Developments in Surface Effect Vehicles

    Science.gov (United States)

    1975-11-30

    57 UrsynowM-6 Agricultural ACV ,. 57 in C. ROMANIA 60 023E Experimental ACV 60 R-7 Experimental ACV 60 D. BULGARIA 61 Ikar-2 Amateur ACV...personnel, geologists , communications workers, and construction workers in such areas as the desert, tundra, the Arctic, etc. [89, 90, 95...BULGARIA The only evidence ol Bulgarian activity in ACV development was the 1974 showing of the Ikar-2 amateur vehicle (see Fig. 59). This ACV was

  18. Using a traffic simulation model (VISSIM) with an emissions model (MOVES) to predict emissions from vehicles on a limited-access highway.

    Science.gov (United States)

    Abou-Senna, Hatem; Radwan, Essam; Westerlund, Kurt; Cooper, C David

    2013-07-01

    The Intergovernmental Panel on Climate Change (IPCC) estimates that baseline global GHG emissions may increase 25-90% from 2000 to 2030, with carbon dioxide (CO2 emissions growing 40-110% over the same period. On-road vehicles are a major source of CO2 emissions in all the developed countries, and in many of the developing countries in the world. Similarly, several criteria air pollutants are associated with transportation, for example, carbon monoxide (CO), nitrogen oxides (NO(x)), and particulate matter (PM). Therefore, the need to accurately quantify transportation-related emissions from vehicles is essential. The new US. Environmental Protection Agency (EPA) mobile source emissions model, MOVES2010a (MOVES), can estimate vehicle emissions on a second-by-second basis, creating the opportunity to combine a microscopic traffic simulation model (such as VISSIM) with MOVES to obtain accurate results. This paper presents an examination of four different approaches to capture the environmental impacts of vehicular operations on a 10-mile stretch of Interstate 4 (I-4), an urban limited-access highway in Orlando, FL. First (at the most basic level), emissions were estimated for the entire 10-mile section "by hand" using one average traffic volume and average speed. Then three advanced levels of detail were studied using VISSIM/MOVES to analyze smaller links: average speeds and volumes (AVG), second-by-second link drive schedules (LDS), and second-by-second operating mode distributions (OPMODE). This paper analyzes how the various approaches affect predicted emissions of CO, NO(x), PM2.5, PM10, and CO2. The results demonstrate that obtaining precise and comprehensive operating mode distributions on a second-by-second basis provides more accurate emission estimates. Specifically, emission rates are highly sensitive to stop-and-go traffic and the associated driving cycles of acceleration, deceleration, and idling. Using the AVG or LDS approach may overestimate or

  19. Runoff and windblown vehicle spray from road surfaces, risks and measures for soil and water.

    NARCIS (Netherlands)

    Schipper, P.N.M.; Comans, R.N.J.; Dijkstra, J.J.; Vergouwen, L.

    2007-01-01

    Soil and surface water along roads are exposed to pollution from motorways. The main pollutants are polycyclic aromatic hydrocarbons (PAH), mineral oil, heavy metals and salt. These pollutants originate from vehicles (fuel, wires, leakage), wear and degradation of road surfaces and road furniture

  20. Multiplicative models of analysis : a description and the use in analysing accident ratios as a function of hourly traffic volume and road-surface skidding resistance.

    NARCIS (Netherlands)

    Oppe, S.

    1977-01-01

    Accident ratios are analysed with regard to the variables road surface skidding resistance and hourly traffic volume. It is concluded that the multiplicative model describes the data better than the additive model. Moreover that there is no interaction between skidding resistance and traffic volume

  1. Science aspects of a remotely controlled Mars surface roving vehicle.

    Science.gov (United States)

    Choate, R.; Jaffe, L. D.

    1973-01-01

    Particular attention is given to aspects pertinent to teleoperation, remote control, onboard control, and man-machine relationships in carrying out scientific operations with such a vehicle. It is assumed that landed operations would comprise one Martian year and that the traverse would extend across an area approximately 500 km wide. The mission is assumed to be planned for the early 1980s. Its objective is to obtain data which will aid in answering a number of questions regarding the history of the solar system, the formation of Mars, and the evolution of life on Mars. A series of candidate rover payloads is proposed to meet the requirements. The smallest payload includes a TV camera, a general-purpose manipulator arm, a crusher and siever, an X-ray diffractometer-spectrometer, a gravimeter, a magnetometer, meteorological instruments, and a radio transponder.

  2. Allegheny County Traffic Counts

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Traffic sensors at over 1,200 locations in Allegheny County collect vehicle counts for the Pennsylvania Department of Transportation. Data included in the Health...

  3. Survey of Disturbance to Alpine Tundra in Atigun Gorge from Snow-Vehicle Traffic in November 2003

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Snow vehicles operated by Alyeska Pipeline Service Company Alyeska traveled from the Dalton Highway into Atigun Gorge in the Arctic National Wildlife Refuge in...

  4. Development and validation of light-duty vehicle modal emissions and fuel consumption values for traffic models.

    Science.gov (United States)

    1999-03-01

    A methodology for developing modal vehicle emissions and fuel consumption models has been developed by Oak Ridge National Laboratory (ORNL), sponsored by the Federal Highway Administration. These models, in the form of look-up tables for fuel consump...

  5. Vibration of the soil caused by a vehicle moving over the randomly uneven surface of a slab track

    OpenAIRE

    Grundmann, H.;Lenz, St.

    2012-01-01

    A vehicle which passes an uneven surface of a slab track causes vibrations of the whole system: the vehicle, the slab track and the subsoil. For a given random unevenness ?w of the slab track surface, covariances of the soil surface motion are calculated.

  6. Thermal Control System Development to Support the Crew Exploration Vehicle and Lunar Surface Access Module

    Science.gov (United States)

    Anderson, Molly; Westheimer, David

    2006-01-01

    All space vehicles or habitats require thermal management to maintain a safe and operational environment for both crew and hardware. Active Thermal Control Systems (ATCS) perform the functions of acquiring heat from both crew and hardware within a vehicle, transporting that heat throughout the vehicle, and finally rejecting that energy into space. Almost all of the energy used in a space vehicle eventually turns into heat, which must be rejected in order to maintain an energy balance and temperature control of the vehicle. For crewed vehicles, Active Thermal Control Systems are pumped fluid loops that are made up of components designed to perform these functions. NASA has recently evaluated all of the agency s technology development work and identified key areas that must be addressed to aid in the successful development of a Crew Exploration Vehicle (CEV) and a Lunar Surface Access Module (LSAM). The technologies that have been selected and are currently under development include: fluids that enable single loop ATCS architectures, a gravity insensitive vapor compression cycle heat pump, a sublimator with reduced sensitivity to feedwater contamination, an evaporative heat sink that can operate in multiple ambient pressure environments, a compact spray evaporator, and lightweight radiators that take advantage of carbon composites and advanced optical coatings.

  7. Simulating the Effects of Surface Roughness on Reinforced Concrete T Beam Bridge under Single and Multiple Vehicles

    Directory of Open Access Journals (Sweden)

    Rahul Kalyankar

    2016-01-01

    Full Text Available This research focuses on the application of the spatial system of finite element modeling for the vehicle-bridge interaction on reinforced concrete US Girder Bridge in order to obtain the effect of surface roughness. Single vehicle and multiple vehicles on reinforced concrete T beam bridge were studied with variable surface roughness profiles. The effects of six different surface roughness profiles (very good, good, measured, average, poor, and very poor were investigated for vehicle-bridge interaction. The values of the Dynamic Amplification Factor (DAF were obtained for single and multiple vehicles on T Beam Bridge for different surface roughness profiles, along with the distances between the axles of heavy vehicle. It was observed that when the bridge has very good, good, measured, and average surface roughness, the DAF values for the single vehicle over the bridge were observed to be within acceptable limits specified by AASHTO. However, for the bridge with multiple vehicles only very good and measured surface roughness profiles showed a DAF and vehicle axle distances within the acceptable limits. From the current studies, it was observed that the spatial system showed reliable responses for predicting the behavior of the bridge under variable road surface roughness conditions and was reliable in vehicle axle detection, and therefore, it has a potential to be use for realistic simulations.

  8. The Arctic Environment and the Arctic Surface Effect Vehicle

    Science.gov (United States)

    1976-01-01

    was confined to those four missions during which there was sufficient light. Ninety-three laser profile sections , each approx- imately 40 km long...surface features (e.g. sastrugi or drifts), which rarely ever exceed 2 ft in height, was eliminated. Figure 10 shows the location of the 26 laser sam...variations in ridging are sum- marized in the section on ridging intensity. In addi- tion, two interim sea ice statistics reports docu- ~£ ^ ,— V

  9. Users’ Perception And Reported Effects Of Long-term Access To In-Vehicle Traffic Information Services Mediated Through Nomadic Devices

    Directory of Open Access Journals (Sweden)

    Skoglund Tor

    2015-09-01

    Full Text Available ICT-mediated traffic information has been argued to contribute to a more sustainable transport system through affecting drivers. Nevertheless, long-term effects of travellers having access to nomadic in-vehicle systems for traveller information are not well known. This study presents the results from a multi-national large-scale field operational test (FOT. The results show that the users in general were positive to the tested systems and that there were several effects on their driving behaviour but in many cases the effects were limited. Moreover the effects varied between system types. Positive effects were related to comfort, as well as individual and system efficiency. One could also notice that perceived effects were not as high as the participants had expected, leading to some disappointment. Most of the times this was due to the tested systems functioning in a less than optimal way.

  10. Freeway Driving Cycle Construction Based on Real-Time Traffic Information and Global Optimal Energy Management for Plug-In Hybrid Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Hongwen He

    2017-11-01

    Full Text Available This paper presents a freeway driving cycle (FDC construction method based on traffic information. A float car collected different type of roads in California and we built a velocity fragment database. We selected a real freeway driving cycle (RFDC and established the corresponding time traffic information tensor model by using the data in California Department of Transportation performance measure system (PeMS. The correlation of road velocity in the time dimension and spatial dimension are analyzed. According to the average velocity of road sections at different times, the kinematic fragments are stochastically selected in the velocity fragment database to construct a real-time FDC of each section. The comparison between construction freeway driving cycle (CFDC and real freeway driving cycle (RFDC show that the CFDC well reflects the RFDC characteristic parameters. Compared to its application in plug-in electric hybrid vehicle (PHEV optimal energy management based on a dynamic programming (DP algorithm, CFDC and RFDC fuel consumption are similar within approximately 5.09% error, and non-rush hour fuel economy is better than rush hour 3.51 (L/100 km at non-rush hour, 4.29 (L/km at rush hour. Moreover, the fuel consumption ratio can be up to 13.17% in the same CFDC at non-rush hour.

  11. The Influence of Intersections on Fuel Consumption in Urban Arterial Road Traffic: A Single Vehicle Test in Harbin, China.

    Directory of Open Access Journals (Sweden)

    Lina Wu

    Full Text Available The calculating method for fuel consumption (FC was put forward and calibrated and the characteristics of the fuel consumption on intersections were analyzed based on 18 groups of vehicular operating data which were acquired from the test experiment of a single vehicle along the urban arterial roads in Harbin, China. The results obtained show that 50.36% of the fuel consumption for the test vehicle was used at the area of intersections compared with 28.9% of the influencing distance and 68.5% of the running time; and 78.4% of them was burnt at the stages of acceleration and idling. Meanwhile, the type

  12. Heat pipe and surface mass transfer cooling of hypersonic vehicle structures

    Science.gov (United States)

    Colwell, Gene T.; Modlin, James M.

    1992-01-01

    The problem of determining the feasibility of cooling hypersonic vehicle leading-edge structures exposed to severe aerodynamic surface heating using heat pipe and mass transfer cooling techniques is addressed. A description is presented of a numerical finite-difference-based hypersonic leading-edge cooling model incorporating poststartup liquid metal heat pipe cooling with surface transpiration and film cooling to predict the transient structural temperature distributions and maximum surface temperatures of hypersonic vehicle leading edge. An application of this model to the transient cooling of a typical aerospace plane wing leading-edge section. The results of this application indicated that liquid metal heat pipe cooling alone is insufficient to maintain surface temperatures below an assumed maximum level of 1800 K for about one-third of a typical aerospace plane ascent trajectory through the earth's atmosphere.

  13. U.S. Navy Employment Options for Unmanned Surface Vehicles (USVs)

    Science.gov (United States)

    2013-01-01

    Marlin Elbit Israel R SPICE NAVSEA United States S Stingray Elbit Israel T UISS Oregon Iron Works United States U U-Ranger Calzoni/L3 United States V...to remote bases—e.g., San Clemente Island — 112 U.S. Navy Employment Options for Unmanned Surface Vehicles (USVs) shuttling supplies and equipment

  14. Smart Sensor Based Obstacle Detection for High-Speed Unmanned Surface Vehicle

    DEFF Research Database (Denmark)

    Hermann, Dan; Galeazzi, Roberto; Andersen, Jens Christian

    2015-01-01

    This paper describes an obstacle detection system for a high-speed and agile unmanned surface vehicle (USV), running at speeds up to 30 m/s. The aim is a real-time and high performance obstacle detection system using both radar and vision technologies to detect obstacles within a range of 175 m. ...

  15. Parameter Estimation for Traffic Noise Models Using a Harmony Search Algorithm

    Directory of Open Access Journals (Sweden)

    Deok-Soon An

    2013-01-01

    Full Text Available A technique has been developed for predicting road traffic noise for environmental assessment, taking into account traffic volume as well as road surface conditions. The ASJ model (ASJ Prediction Model for Road Traffic Noise, 1999, which is based on the sound power level of the noise emitted by the interaction between the road surface and tires, employs regression models for two road surface types: dense-graded asphalt (DGA and permeable asphalt (PA. However, these models are not applicable to other types of road surfaces. Accordingly, this paper introduces a parameter estimation procedure for ASJ-based noise prediction models, utilizing a harmony search (HS algorithm. Traffic noise measurement data for four different vehicle types were used in the algorithm to determine the regression parameters for several road surface types. The parameters of the traffic noise prediction models were evaluated using another measurement set, and good agreement was observed between the predicted and measured sound power levels.

  16. Stochastic Model of Traffic Jam and Traffic Signal Control

    Science.gov (United States)

    Shin, Ji-Sun; Cui, Cheng-You; Lee, Tae-Hong; Lee, Hee-Hyol

    Traffic signal control is an effective method to solve the traffic jam. and forecasting traffic density has been known as an important part of the Intelligent Transportation System (ITS). The several methods of the traffic signal control are known such as random walk method, Neuron Network method, Bayesian Network method, and so on. In this paper, we propose a new method of a traffic signal control using a predicted distribution of traffic jam based on a Dynamic Bayesian Network model. First, a forecasting model to predict a probabilistic distribution of the traffic jam during each period of traffic lights is built. As the forecasting model, the Dynamic Bayesian Network is used to predict the probabilistic distribution of a density of the traffic jam. According to measurement of two crossing points for each cycle, the inflow and outflow of each direction and the number of standing vehicles at former cycle are obtained. The number of standing vehicle at k-th cycle will be calculated synchronously. Next, the probabilistic distribution of the density of standing vehicle in each cycle will be predicted using the Dynamic Bayesian Network constructed for the traffic jam. And then a control rule to adjust the split and the cycle to increase the probability between a lower limit and ceiling of the standing vehicles is deduced. As the results of the simulation using the actual traffic data of Kitakyushu city, the effectiveness of the method is shown.

  17. Speed Tracking Control of a Vehicle Robot Driver System Using Multiple Sliding Surface Control Schemes

    Directory of Open Access Journals (Sweden)

    Gang Chen

    2013-02-01

    Full Text Available To overcome the drawbacks of using a traditional proportional-integral-derivative (PID control method for a robot driver system, such as requiring preliminary offline learning, big overshoot and large speed fluctuation, a new method for speed tracking of a robot driver system based on sliding mode control is proposed in this paper. Firstly, the coordinated control model of multiple manipulators for the robot driver is built, which achieved coordinated control of the throttle mechanical leg, clutch mechanical leg, brake mechanical leg and shift mechanical arm for the robot driver. On the basis of this, a speed tracking sliding mode controller for a vehicle robot driver is designed using the method of multiple sliding surfaces design, and the variable structure control laws of throttle and brake are designed respectively, which realize the speed tracking of the given driving test cycle. Experimental results demonstrate that compared with the PID control method, the proposed method can obviously reduce the overshoot of vehicle speed tracking control and greatly improve the accuracy of vehicle speed tracking. The vehicle speed tracking accuracy stays within a tolerance band of ±2 km/h, which meets the requirements of national vehicle test standards. Furthermore, the action of the speed tracking control in the same driving test cycle using the proposed method is consistent, so that the robot driver has good repeatability. Therefore, it can ensure the effectiveness of the vehicle emission test.

  18. Influence of traffic on build-up of polycyclic aromatic hydrocarbons on urban road surfaces: A Bayesian network modelling approach.

    Science.gov (United States)

    Li, Yingxia; Jia, Ziliang; Wijesiri, Buddhi; Song, Ningning; Goonetilleke, Ashantha

    2017-12-04

    Due to their carcinogenic effects, Polycyclic Aromatic Hydrocarbons (PAHs) deposited on urban surfaces are a major concern in the context of stormwater pollution. However, the design of effective pollution mitigation strategies is challenging due to the lack of reliability in stormwater quality modelling outcomes. Current modelling approaches do not adequately replicate the interdependencies between pollutant processes and their influential factors. Using Bayesian Network modelling, this research study characterised the influence of vehicular traffic on the build-up of the sixteen US EPA classified priority PAHs. The predictive analysis was conditional on the structure of the proposed BN, which can be further improved by including more variables. This novel modelling approach facilitated the characterisation of the influence of traffic as a source of origin and also as a key factor that influences the re-distribution of PAHs, with positive or negative relationship between traffic volume and PAH build-up. It was evident that the re-distribution of particle-bound PAHs is determined by the particle size rather than the chemical characteristics such as volatility. Moreover, compared to commercial and residential land uses, mostly industrial land use contributes to the PAHs load released to the environment. Carcinogenic PAHs in industrial areas are likely to be associated with finer particles, while PAHs, which are not classified as human carcinogens, are likely to be found in the coarser particle fraction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Empirical analysis of heterogeneous traffic flow

    NARCIS (Netherlands)

    Ambarwati, L.; Pel, A.J.; Verhaeghe, R.J.; Van Arem, B.

    2013-01-01

    Traffic flow in many developing countries is strongly mixed comprising vehicle types, such as motorcycles, cars, (mini) buses, and trucks; furthermore, traffic flow typically exhibits free inter-lane exchanges. This phenomenon causes a complex vehicle interaction, rendering most existing traffic

  20. Computational intelligence for traffic and mobility

    CERN Document Server

    Wang, Wuhong

    2012-01-01

    This book presents the new development of computation intelligence for traffic, transportation and mobility, the main contents include traffic safety, mobility analysis, intelligent transportation system, smart vehicle, transportation behavior, driver modeling and assistance, transportation risk analysis and reliability system analysis, vehicle operation and active safety, urban traffic management and planning.

  1. A control strategy for steering an autonomous surface sailing vehicle in a tacking maneuver

    DEFF Research Database (Denmark)

    Jouffroy, Jerome

    2009-01-01

    Sailing vessels such as sailboats but also landyachts are vehicles representing a real challenge for automation. However, the control aspects of such vehicles were hitherto very little studied. This paper presents a simplied dynamic model of a so-called landyacht allowing to capture the main...... elements of the behavior of surface sailing vessels. We then propose a path generation scheme and a controller design for a well-known and fundamental maneuver in sailing referred to as tacking. Simulation results are presented to illustrate the approach....

  2. Utilisation of electric vehicle: Is the drivers' behaviour going to change? Frame conditions: Utilisation profiles and experience gained with electric vehicles: Potentials in terms of environment and traffic policy; Elektroautoeinsatz: Wird sich das Fahrverhalten aendern? Rahmenbedingungen, Einsatzprofile und Erfahrungen von Elektrofahrzeugen: Umwelt- und verkehrspolitische Potentiale

    Energy Technology Data Exchange (ETDEWEB)

    Knie, A. [Wissenschaftszentrum Berlin fuer Sozialforschung (Germany)

    1997-07-01

    Assuming that the functional area for vehicles with combustion engines will be limited in some densely populated areas in the coming years and that improved expansion possibilities are also available for alternative drive and vehicle concepts such as the electric vehicle, this vehicle technology promises to develop very interesting potentials in terms of environmental and traffic technology. Until an unforeseeable time electric vehicles will continue to be technically down-graded vehicles with a high fun factor which can also be used in environmentally sensitive areas. The limitation in use forces the user to combine and to carry out the own route plan with other traffic carriers. Conventional automobiles are autarkic means of traffic in the functional area that has been provided so far. Electric vehicles can only be used in a co-operative traffic network and thus provide an important link for a realistic change in traffic policy that is not any longer supported by moral but by use-orientated arguments. (orig.) [German] Unter der Annahme, dass sich der Funktionsraum fuer Fahrzeuge mit Verbrennungsmotoren in den naechsten Jahren zumindest in einigen Ballungsraeumen einschraenken wird und damit auch alternativen Antriebs- und Fahrzeugkonzepten wie das E-Fahrzeug bessere Verbreitungsmoeglichkeiten eingeraeumt werden, verspricht diese Fahrzeugtechnik sehr interessante umwelt- und verkehrstechnische Potentiale zu entwickeln. Denn E-Fahrzeuge werden auf absehbare Zeit technisch abgeruestete Fahrzeuge mit hohem Fahrspass bleiben, die auch in umweltsensiblen Gebieten einsetzbar sind. Die Einschraenkungen in der Verwendung zwingt Nutzer dazu, die eigene Routenplanung zusammen mit anderen Verkehrstraegern zu entwerfen und auch zu realisieren. Konventionelle Automobile sind im bisher gewaehrten Funktionsraum autarke Verkehrsmittel, E-Fahrzeuge dagegen koennen nur in einem kooperativen Verkehrsverbund eingesetzt werden und bieten somit ein wichtiges Verbindungsglied fuer eine

  3. Neural classifier of the communication damage size being a result of collision of vehicles in road traffic

    Directory of Open Access Journals (Sweden)

    Krystian WILK

    2010-01-01

    Full Text Available In the article the results of the attempts of MLP neural network application to define the size of a communication damage being the result of a road collision were presented. The size of the damage was used as a research parameter defined by the coefficient dependent on the cost of repair of the damaged vehicle and its market value. The elements of the damage mechanism determining the way of damage qualification were the inner factors of the system, that is; the technical features of the vehicles, the character features of the drivers, the influence of the weather conditions and the location of the event in time and space. The research was conducted on one thousand cases reported for liquidation in Silesian branch of one of the insurance companies. In the conducted research the working of the neural networks with the limited input data was checked.

  4. The Influence of Intersections on Fuel Consumption in Urban Arterial Road Traffic: A Single Vehicle Test in Harbin, China.

    Science.gov (United States)

    Wu, Lina; Ci, Yusheng; Chu, Jiangwei; Zhang, Hongsheng

    2015-01-01

    The calculating method for fuel consumption (FC) was put forward and calibrated and the characteristics of the fuel consumption on intersections were analyzed based on 18 groups of vehicular operating data which were acquired from the test experiment of a single vehicle along the urban arterial roads in Harbin, China. The results obtained show that 50.36% of the fuel consumption for the test vehicle was used at the area of intersections compared with 28.9% of the influencing distance and 68.5% of the running time; and 78.4% of them was burnt at the stages of acceleration and idling. Meanwhile, the type (c) of the vehicular operating status was illustrated to be the worst way of reducing fuel consumption, the causes were analyzed and four improvement strategies were put forward.

  5. Field Scale Spatial Modelling of Surface Soil Quality Attributes in Controlled Traffic Farming

    Science.gov (United States)

    Guenette, Kris; Hernandez-Ramirez, Guillermo

    2017-04-01

    The employment of controlled traffic farming (CTF) can yield improvements to soil quality attributes through the confinement of equipment traffic to tramlines with the field. There is a need to quantify and explain the spatial heterogeneity of soil quality attributes affected by CTF to further improve our understanding and modelling ability of field scale soil dynamics. Soil properties such as available nitrogen (AN), pH, soil total nitrogen (STN), soil organic carbon (SOC), bulk density, macroporosity, soil quality S-Index, plant available water capacity (PAWC) and unsaturated hydraulic conductivity (Km) were analysed and compared among trafficked and un-trafficked areas. We contrasted standard geostatistical methods such as ordinary kriging (OK) and covariate kriging (COK) as well as the hybrid method of regression kriging (ROK) to predict the spatial distribution of soil properties across two annual cropland sites actively employing CTF in Alberta, Canada. Field scale variability was quantified more accurately through the inclusion of covariates; however, the use of ROK was shown to improve model accuracy despite the regression model composition limiting the robustness of the ROK method. The exclusion of traffic from the un-trafficked areas displayed significant improvements to bulk density, macroporosity and Km while subsequently enhancing AN, STN and SOC. The ability of the regression models and the ROK method to account for spatial trends led to the highest goodness-of-fit and lowest error achieved for the soil physical properties, as the rigid traffic regime of CTF altered their spatial distribution at the field scale. Conversely, the COK method produced the most optimal predictions for the soil nutrient properties and Km. The use of terrain covariates derived from light ranging and detection (LiDAR), such as of elevation and topographic position index (TPI), yielded the best models in the COK method at the field scale.

  6. Lagrangian Multi-Class Traffic State Estimation

    NARCIS (Netherlands)

    Yuan, Y.

    2013-01-01

    Road traffic is important to everybody in the world. People travel and commute everyday. For those who travel by cars (or other types of road vehicles), traffic congestion is a daily experience. One essential goal of traffic researchers is to reduce traffic congestion and to improve the whole

  7. A coupled road dust and surface moisture model to predict non-exhaust road traffic induced particle emissions (NORTRIP). Part 2: Surface moisture and salt impact modelling

    Science.gov (United States)

    Denby, B. R.; Sundvor, I.; Johansson, C.; Pirjola, L.; Ketzel, M.; Norman, M.; Kupiainen, K.; Gustafsson, M.; Blomqvist, G.; Kauhaniemi, M.; Omstedt, G.

    2013-12-01

    Non-exhaust traffic induced emissions are a major source of airborne particulate matter in most European countries. This is particularly important in Nordic and Alpine countries where winter time road traction maintenance occurs, e.g. salting and sanding, and where studded tyres are used. Though the total mass generated by wear sources is a key factor in non-exhaust emissions, these emissions are also strongly controlled by surface moisture conditions. In this paper, Part 2, the road surface moisture sub-model of a coupled road dust and surface moisture model (NORTRIP) is described. We present a description of the road surface moisture part of the model and apply the coupled model to seven sites in Stockholm, Oslo, Helsinki and Copenhagen over 18 separate periods, ranging from 3.5 to 24 months. At two sites surface moisture measurements are available and the moisture sub-model is compared directly to these observations. The model predicts the frequency of wet roads well at both sites, with an average fractional bias of -2.6%. The model is found to correctly predict the hourly surface state, wet or dry, 85% of the time. From the 18 periods modelled using the coupled model an average absolute fractional bias of 15% for PM10 concentrations was found. Similarly the model predicts the 90'th daily mean percentiles of PM10 with an average absolute bias of 19% and an average correlation (R2) of 0.49. When surface moisture is not included in the modelling then this average correlation is reduced to 0.16, demonstrating the importance of the surface moisture conditions. Tests have been carried out to assess the sensitivity of the model to model parameters and input data. The model provides a useful tool for air quality management and for improving our understanding of non-exhaust traffic emissions.

  8. Runoff and windblown vehicle spray from road surfaces, risks and measures for soil and water.

    Science.gov (United States)

    Schipper, P N M; Comans, R N J; Dijkstra, J J; Vergouwen, L

    2007-01-01

    Soil and surface water along roads are exposed to pollution from motorways. The main pollutants are polycyclic aromatic hydrocarbons (PAH), mineral oil, heavy metals and salt. These pollutants originate from vehicles (fuel, wires, leakage), wear and degradation of road surfaces and road furniture (i.e. crash barriers) and the application of de-icing salts. Runoff, vehicle spray and dry deposition disperse these contaminants into the soft shoulder (verges) of the roads and surface water to a measurable distance of about 50 up to more then 150 m from the road. Despite many monitoring programs, little is known about the risks of this diffuse pollution for soil and water quality and the geochemical and physical factors which determine these risks. Also little is known about the effects of possible measures. Therefore, extensive research has been carried out at two local motorways. Specific measurements on runoff, vehicle spray and effects of measures have been carried out for one year (13 months). This resulted in several new insights. The pollutants appear to adsorb effectively to natural soils. In vulnerable areas groundwater can be protected by adjusting the policy to removing the contaminated upper topsoil of the verges. Discharges of runoff into local surface water are not recommended.

  9. System and method for traffic signal timing estimation

    KAUST Repository

    Dumazert, Julien

    2015-12-30

    A method and system for estimating traffic signals. The method and system can include constructing trajectories of probe vehicles from GPS data emitted by the probe vehicles, estimating traffic signal cycles, combining the estimates, and computing the traffic signal timing by maximizing a scoring function based on the estimates. Estimating traffic signal cycles can be based on transition times of the probe vehicles starting after a traffic signal turns green.

  10. Near Space Hypersonic Unmanned Aerial Vehicle Dynamic Surface Backstepping Control Design

    Directory of Open Access Journals (Sweden)

    Jinyong YU

    2014-07-01

    Full Text Available Compared with traditional aircraft, the near space hypersonic unmanned aerial vehicle control system design must deal with the extra prominent dynamics characters, which are differ from the traditional aircrafts control system design. A new robust adaptive control design method is proposed for one hypersonic unmanned aerial vehicle (HSUAV uncertain MIMO nonaffine block control system by using multilayer neural networks, feedback linearization technology, and dynamic surface backstepping. Multilayer neural networks are used to compensate the influence from the uncertain, which designs the robust terms to solve the problem from approach error. Adaptive backstepping is adopted designed to ensure control law, the dynamic surface control strategy to eliminate “the explosion of terms” by introducing a series of first order filters to obtain the differentiation of the virtual control inputs. Finally, nonlinear six-degree-of-freedom (6-DOF numerical simulation results for a HSUAV model are presented to demonstrate the effectiveness of the proposed method.

  11. 32 CFR 634.32 - Traffic violation reports.

    Science.gov (United States)

    2010-07-01

    ... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.32 Traffic violation... Government vehicle at the time of the violation. (2) A Federal Magistrate is either not available or lacks... refer violations of State traffic laws made applicable to the installation (Assimilative Crimes Act (18...

  12. The Influence of Sensor-Based Intelligent Traffic Light Control On Traffic Flow In Dublin

    OpenAIRE

    Rademacher, Katja

    2017-01-01

    With growing cities and the increased use of vehicles for transportation purposes, there is a demand to make the traffic management in cities smarter. An intelligent traffic light control that dynamically adapts to the existing traffic conditions can help reduce traffic congestion and CO2 emissions. This thesis reviews the popular traffic light control approaches - static, actuated and adaptive – based on their influences on recorded traffic conditions in Dublin. The Irish capital relies heav...

  13. Traffic planning for non-homogeneous traffic

    Indian Academy of Sciences (India)

    2Civil and Architectural Engineering Department, Illinois Institute of. Technology, Illinois, Chicago ..... parametric test, i.e., the Wilcoxon signed-rank test, compared between observed and derived densities. ..... istics related to freeway design, vehicle performance, and the traffic stream on passenger-car equivalents for heavy ...

  14. Surface Catalysis and Characterization of Proposed Candidate TPS for Access-to-Space Vehicles

    Science.gov (United States)

    Stewart, David A.

    1997-01-01

    Surface properties have been obtained on several classes of thermal protection systems (TPS) using data from both side-arm-reactor and arc-jet facilities. Thermochemical stability, optical properties, and coefficients for atom recombination were determined for candidate TPS proposed for single-stage-to-orbit vehicles. The systems included rigid fibrous insulations, blankets, reinforced carbon carbon, and metals. Test techniques, theories used to define arc-jet and side-arm-reactor flow, and material surface properties are described. Total hemispherical emittance and atom recombination coefficients for each candidate TPS are summarized in the form of polynomial and Arrhenius expressions.

  15. Water level observations from Unmanned Aerial Vehicles for improving estimates of surface water-groundwater interaction

    DEFF Research Database (Denmark)

    Bandini, Filippo; Butts, Michael; Vammen Jacobsen, Torsten

    2017-01-01

    . However, traditional river gauging stations are normally spaced too far apart to capture spatial patterns in the water surface, while spaceborne observations have limited spatial and temporal resolution. UAVs (Unmanned Aerial Vehicles) can retrieve river water level measurements, providing: i) high...... spatial resolution; ii) spatially continuous profiles along or across the water body; iii) flexible timing of sampling. A semi-synthetic study was conducted to analyse the value of the new UAV-borne datatype for improving hydrological models, in particular estimates of GW (Groundwater)- SW (Surface Water...

  16. Surface shape description of 3D data from under vehicle inspection robot

    Science.gov (United States)

    Sukumar, Sreenivas R.; Page, David L.; Gribok, Andrei V.; Koschan, Andreas F.; Abidi, Mongi A.; Gorsich, David J.; Gerhart, Grant R.

    2005-05-01

    Our research efforts focus on the deployment of 3D sensing capabilities to a multi-modal under vehicle inspection robot. In this paper, we outline the various design challenges towards the automation of the 3D scene modeling task. We employ laser-based range imaging techniques to extract the geometry of a vehicle's undercarriage and present our results after range integration. We perform shape analysis on the digitized triangle mesh models by segmenting them into smooth surface patches based on the curvedness of the surface. Using a region-growing procedure, we then obtain the patch adjacency. On each of these patches, we apply our definition of the curvature variation measure (CVM) as a descriptor of surface shape complexity. We base the information-theoretic CVM on shape curvature, and extract shape information as the entropic measure of curvature to represent a component as a graph network of patches. The CVM at the nodes of the graph describe the surface patch. We then demonstrate our algorithm with results on automotive components. With apriori manufacturer information about the CAD models in the undercarriage we approach the technical challenge of threat detection with our surface shape description algorithm on the laser scanned geometry.

  17. Automated vehicle guidance using discrete reference markers. [road surface steering techniques

    Science.gov (United States)

    Johnston, A. R.; Assefi, T.; Lai, J. Y.

    1979-01-01

    Techniques for providing steering control for an automated vehicle using discrete reference markers fixed to the road surface are investigated analytically. Either optical or magnetic approaches can be used for the sensor, which generates a measurement of the lateral offset of the vehicle path at each marker to form the basic data for steering control. Possible mechanizations of sensor and controller are outlined. Techniques for handling certain anomalous conditions, such as a missing marker, or loss of acquisition, and special maneuvers, such as u-turns and switching, are briefly discussed. A general analysis of the vehicle dynamics and the discrete control system is presented using the state variable formulation. Noise in both the sensor measurement and in the steering servo are accounted for. An optimal controller is simulated on a general purpose computer, and the resulting plots of vehicle path are presented. Parameters representing a small multipassenger tram were selected, and the simulation runs show response to an erroneous sensor measurement and acquisition following large initial path errors.

  18. Conservation tillage and traffic effects on soil condition

    Energy Technology Data Exchange (ETDEWEB)

    Raper, R.L.; Reeves, D.W.; Burt, E.C. [USDA-Agricultural Research Service, Auburn, AL (United States); Torbert, H.A. [USDA-Agricultural Research Service, Temple, TX (United States)

    1994-05-01

    The soil condition resulting from a five-year cotton-wheat double cropping experiment in a sandy loam Coastal Plain soil was investigated using intensive measurements of cone index and dry bulk density. Four tillage treatments including a strip-till (no surface tillage with in-row subsoiling) conservation tillage practice were analyzed. The traffic was controlled in the experimental plots with the USDA-ARS Wide-Frame Tractive Vehicle. Besides the environmental benefits of maintaining the surface residue, the strip-till treatment decreased cone index directly beneath the row, decreased surface bulk density, increased surface moisture content, decreased energy usage, and increased yields. Controlled traffic was beneficial only when in-row subsoiling was not used as an annual tillage treatment. Although differences in soil condition were seen beneath the row middles where traffic occurred, this did not affect the soil condition directly beneath the row. 16 refs., 7 figs., 2 tabs.

  19. Dynamic Gas Flow Effects on the ESD of Aerospace Vehicle Surfaces

    Science.gov (United States)

    Hogue, Michael D.; Kapat, Jayanta; Ahmed, Kareem; Cox, Rachel E.; Wilson, Jennifer G.; Calle, Luz M.; Mulligan, Jaysen

    2016-01-01

    The purpose of this work is to develop a dynamic version of Paschen's Law that takes into account the flow of ambient gas past aerospace vehicle surfaces. However, the classic Paschen's Law does not take into account the flow of gas of an aerospace vehicle, whose surfaces may be triboelectrically charged by dust or ice crystal impingement, traversing the atmosphere. The basic hypothesis of this work is that the number of electron-ion pairs created per unit distance by the electric field between the electrodes is mitigated by the electron-ion pairs removed per unit distance by the flow of gas. The revised Paschen equation must be a function of the mean velocity, v(sub xm), of the ambient gas and reduces to the classical version of Paschen's law when the gas mean velocity, v(sub xm) = 0. New formulations of Paschen's Law, taking into account Mach number and dynamic pressure, derived by the authors, will be discussed. These equations will be evaluated by wind tunnel experimentation later this year. Based on the results of this work, it is hoped that the safety of aerospace vehicles will be enhanced with a redefinition of electrostatic launch commit criteria. It is also possible that new products, such as new anti-static coatings, may be formulated from this data.

  20. Revision of Paschen's Law Relating to the ESD of Aerospace Vehicle Surfaces

    Science.gov (United States)

    Hogue, Michael D.; Cox, Rachel E.; Mulligan, Jaysen; Kapat, Jayanta; Ahmed, Kareem; Wilson, Jennifer G.; Calle, Luz M.

    2017-01-01

    The purpose of this work is to develop a version of Paschen's law that takes into account the flow of ambient gas past electrode surfaces. Paschen's law does not consider the flow of gas past an aerospace vehicle whose surfaces may be triboelectrically charged by dust or ice crystal impingement while traversing the atmosphere. The basic hypothesis of this work is that the number of electron-ion pairs created per unit distance between electrode surfaces is mitigated by the electron-ion pairs removed per unit distance by the flow of gas. The revised theoretical model must be a function of the mean velocity vxm of the ambient gas and reduce to Paschen's law when the mean velocity is zero. A new theoretical formulation of Paschen's law, taking into account the Mach number and compressible dynamic pressure, derived by the authors, will be discussed. This equation has been evaluated by wind tunnel experimentation. Initial data of the baseline wind tunnel experiments show results consistent with the hypothesis. This work may enhance the safety of aerospace vehicles through a redefinition of electrostatic launch commit criteria. It is also possible for new products, such as antistatic coatings, to be formulated based on this data.

  1. Traffic fatalities and economic growth

    Science.gov (United States)

    2003-04-01

    As countries develop death rates usually fall, especially for diseases that affect the young and result in substantial life-years lost. Deaths due to traffic accidents are a notable exception: the growth in motor vehicles that accompanies economic gr...

  2. Unified Approach of Unmanned Surface Vehicle Navigation in Presence of Waves

    Directory of Open Access Journals (Sweden)

    Oren Gal

    2011-01-01

    Full Text Available Most of the present work for unmanned surface vehicle (USV navigation does not take into account environmental disturbances such as ocean waves, winds, and currents. In some scenarios, waves should be treated as special case of dynamic obstacle and can be critical to USV’s safety. For the first time, this paper presents unique concept facing this challenge by combining ocean waves' formulation with the probabilistic velocity obstacle (PVO method for autonomous navigation. A simple navigation algorithm is presented in order to apply the method of USV’s navigation in presence of waves. A planner simulation dealing with waves and obstacles avoidance is introduced.

  3. Sleep apnea-related risk of motor vehicle accidents is reduced by continuous positive airway pressure: Swedish Traffic Accident Registry data.

    Science.gov (United States)

    Karimi, Mahssa; Hedner, Jan; Häbel, Henrike; Nerman, Olle; Grote, Ludger

    2015-03-01

    Obstructive sleep apnea (OSA) is associated with an increased risk of motor vehicle accidents (MVAs). The rate of MVAs in patients suspected of having OSA was determined and the effect of continuous positive airway pressure (CPAP) was investigated. MVA rate in patients referred for OSA was compared to the rate in the general population using data from the Swedish Traffic Accident Registry (STRADA), stratified for age and calendar year. The risk factors for MVAs, using demographic and polygraphy data, and MVA rate before and after CPAP were evaluated in the patient group. Clinical sleep laboratory and population based control (n = 635,786). There were 1,478 patients, male sex 70.4%, mean age 53.6 (12.8) y. CPAP. The number of accidents (n = 74) among patients was compared with the expected number (n = 30) from a control population (STRADA). An increased MVA risk ratio of 2.45 was found among patients compared with controls (P risk was most prominent in the elderly patients (65-80 y, seven versus two MVAs). In patients, driving distance (km/y), EDS (Epworth Sleepiness score ≥ 16), short habitual sleep time (≤5 h/night), and use of hypnotics were associated with increased MVA risk (odds ratios 1.2, 2.1, 2.7 and 2.1, all P ≤ 0.03). CPAP use ≥ 4 h/night was associated with a reduction of MVA incidence (7.6 to 2.5 accidents/1,000 drivers/y). The MVA risk in this large cohort of unselected patients with OSA suggests a need for accurate tools to identify individuals at risk. Sleep apnea severity (e.g., apnea-hypopnea index) failed to identify patients at risk. © 2015 Associated Professional Sleep Societies, LLC.

  4. 76 FR 72888 - Federal Motor Vehicle Safety Standards; Small Business Impacts of Motor Vehicle Safety

    Science.gov (United States)

    2011-11-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION National Highway Traffic Safety Administration 49 CFR Part 571 Federal Motor Vehicle Safety Standards; Small Business Impacts of Motor Vehicle Safety AGENCY: National Highway Traffic Safety Administration...

  5. Visualization of Traffic Accidents

    Science.gov (United States)

    Wang, Jie; Shen, Yuzhong; Khattak, Asad

    2010-01-01

    Traffic accidents have tremendous impact on society. Annually approximately 6.4 million vehicle accidents are reported by police in the US and nearly half of them result in catastrophic injuries. Visualizations of traffic accidents using geographic information systems (GIS) greatly facilitate handling and analysis of traffic accidents in many aspects. Environmental Systems Research Institute (ESRI), Inc. is the world leader in GIS research and development. ArcGIS, a software package developed by ESRI, has the capabilities to display events associated with a road network, such as accident locations, and pavement quality. But when event locations related to a road network are processed, the existing algorithm used by ArcGIS does not utilize all the information related to the routes of the road network and produces erroneous visualization results of event locations. This software bug causes serious problems for applications in which accurate location information is critical for emergency responses, such as traffic accidents. This paper aims to address this problem and proposes an improved method that utilizes all relevant information of traffic accidents, namely, route number, direction, and mile post, and extracts correct event locations for accurate traffic accident visualization and analysis. The proposed method generates a new shape file for traffic accidents and displays them on top of the existing road network in ArcGIS. Visualization of traffic accidents along Hampton Roads Bridge Tunnel is included to demonstrate the effectiveness of the proposed method.

  6. Traffic Light Detection at Night

    DEFF Research Database (Denmark)

    Jensen, Morten Bornø; Philipsen, Mark Philip; Bahnsen, Chris

    2015-01-01

    Traffic light recognition (TLR) is an integral part of any in- telligent vehicle, it must function both at day and at night. However, the majority of TLR research is focused on day-time scenarios. In this paper we will focus on detection of traffic lights at night and evalu- ate the performance o...

  7. Surface (S)-layer proteins of Deinococcus radiodurans and their utility as vehicles for surface localization of functional proteins.

    Science.gov (United States)

    Misra, Chitra Seetharam; Basu, Bhakti; Apte, Shree Kumar

    2015-12-01

    The radiation resistant bacterium, Deinococcus radiodurans contains two major surface (S)-layer proteins, Hpi and SlpA. The Hpi protein was shown to (a) undergo specific in vivo cleavage, and (b) closely associate with the SlpA protein. Using a non-specific acid phosphatase from Salmonella enterica serovar Typhi, PhoN as a reporter, the Surface Layer Homology (SLH) domain of SlpA was shown to bind deinococcal peptidoglycan-containing cell wall sacculi. The association of SlpA with Hpi on one side and peptidoglycan on the other, localizes this protein in the 'interstitial' layer of the deinoccocal cell wall. Gene chimeras of hpi-phoN and slh-phoN were constructed to test efficacy of S-layer proteins, as vehicles for cell surface localization in D. radiodurans. The Hpi-PhoN protein localized exclusively in the membrane fraction, and displayed cell-based phosphatase activity in vivo. The SLH-PhoN, which localized to both cytosolic and membrane fractions, displayed in vitro activity but no cell-based in vivo activity. Hpi, therefore, emerged as an efficient surface localizing protein and can be exploited for suitable applications of this superbug. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. NONLINEAR MODEL OF STABILITY STUDY OF SYSTEM "SURFACE CONTROL – ACTUATOR" OF MANEUVERABLE UNMANNED AERIAL VEHICLE

    Directory of Open Access Journals (Sweden)

    V. N. Akimov

    2017-01-01

    Full Text Available One of the important problems of the designing of maneuverable unmanned aerial vehicles (UAV is to ensure aeroelastic stability with automatic control system (ACS. One of the possible types of aeroelastic instability of UAV with ACS is loss of stability in the system "surface control – actuator".  A nonlinear model for the study of the stability of the system "surface control – actuator" is designed for solving problems of joint design of airframe and ACS with the requirements of aeroelasticity. The electric actuator is currently the most widely used on highly maneuverable UAV. The wide bandwidth and the availability of frequency characteristic lifts are typical for the modern electric actuator. This exacerbates the problem of providing aeroelastic stability of the UAV with ACS, including the problem of ensuring the stability of the system "surface control – actuator". In proposed model the surface control, performing bending-torsion oscillations in aerodynamic flow, in fact, is the loading for the actuator. Experimental frequency characteristics of the isolated actuator, obtained for different levels of the control signal, are used for the mathematical description of the actuator, then, as dynamic hinge moment, which is determined by aeroelastic vibrations of the surface control in the air flow, is calculated. Investigation of the stability of the system "surface control – actuator" is carried out by frequency method using frequency characteristics of the open-loop system. The undeniable advantage of the proposed model is the simplicity of obtaining the transfer functions of the isolated actuator. The experiment by its definition is a standard method of determining frequency characteristics of the actuator in contrast to time-consuming experiments for determining the dynamic stiffness of the actuator (with the surface control or the transfer function of the actuator using electromechanical simulation of aeroelastic loading of the

  9. Design of Automatic Comprehensive Traffic Data Management System for Pennsylvania

    OpenAIRE

    Goulias, Konstadinos G.

    1998-01-01

    With the highway infrastructure under strain, there is a need to collect and analyze traffic volume, vehicle classification, and weight data in an integrated manner. Most research focuses on collection and quality of data with little emphasis on an integrated traffic data management system. Design of an integrated traffic data management system that allows for editing, storage, and reporting of traffic volumes, vehicle classification, and vehicle weight along with quality assurance of data is...

  10. 360-Degree Visual Detection and Target Tracking on an Autonomous Surface Vehicle

    Science.gov (United States)

    Wolf, Michael T; Assad, Christopher; Kuwata, Yoshiaki; Howard, Andrew; Aghazarian, Hrand; Zhu, David; Lu, Thomas; Trebi-Ollennu, Ashitey; Huntsberger, Terry

    2010-01-01

    This paper describes perception and planning systems of an autonomous sea surface vehicle (ASV) whose goal is to detect and track other vessels at medium to long ranges and execute responses to determine whether the vessel is adversarial. The Jet Propulsion Laboratory (JPL) has developed a tightly integrated system called CARACaS (Control Architecture for Robotic Agent Command and Sensing) that blends the sensing, planning, and behavior autonomy necessary for such missions. Two patrol scenarios are addressed here: one in which the ASV patrols a large harbor region and checks for vessels near a fixed asset on each pass and one in which the ASV circles a fixed asset and intercepts approaching vessels. This paper focuses on the ASV's central perception and situation awareness system, dubbed Surface Autonomous Visual Analysis and Tracking (SAVAnT), which receives images from an omnidirectional camera head, identifies objects of interest in these images, and probabilistically tracks the objects' presence over time, even as they may exist outside of the vehicle's sensor range. The integrated CARACaS/SAVAnT system has been implemented on U.S. Navy experimental ASVs and tested in on-water field demonstrations.

  11. Dynamic surface tracking controller design for a constrained hypersonic vehicle based on disturbance observer

    Directory of Open Access Journals (Sweden)

    Fang Wang

    2017-05-01

    Full Text Available The tracking control problem of a flexible air-breathing hypersonic vehicle subjects to aerodynamic parameter uncertainty and input constraint is investigated by combining nonlinear disturbance observer and dynamic surface control. To design controller simply, a control-oriented model is firstly derived and divided into two subsystems, velocity subsystem and altitude subsystem based on the engineering backgrounds of flexible air-breathing hypersonic vehicle. In every subsystem, compounded disturbances are included to consider aerodynamic uncertainty and the effect of the flexible modes. Then, disturbance observer is not only used to handle the compounded disturbance but also to handle the input constraint, where the estimation error converges to a random small region through appropriately choosing the observer parameters. To sequel, the disturbance observer–based robust control scheme and the disturbance observer-based dynamic surface control scheme are developed for the velocity subsystem and altitude subsystem, respectively. Besides, novel filters are designed to alleviate the problem of “explosion of terms” induced by backstepping method. On the basis of Lyapunov stability theory, the presented control scheme can assure that tracking error converges to an arbitrarily small neighborhood around zero by rigorous theoretical analysis. At last, simulation result shows the effectiveness of the presented control method.

  12. Underwater Vehicle

    National Research Council Canada - National Science Library

    Dick, James L

    2007-01-01

    There is thus provided an underwater vehicle having facility for maneuvering alongside a retrieving vehicle, as by manipulation of bow and stern planes, for engaging a hull surface of the retrieving...

  13. Reproducibility of crop surface maps extracted from Unmanned Aerial Vehicle (UAV) derived digital surface maps

    KAUST Repository

    Parkes, Stephen

    2016-10-25

    Crop height measured from UAVs fitted with commercially available RGB cameras provide an affordable alternative to retrieve field scale high resolution estimates. The study presents an assessment of between flight reproducibility of Crop Surface Maps (CSM) extracted from Digital Surface Maps (DSM) generated by Structure from Motion (SfM) algorithms. Flights were conducted over a centre pivot irrigation system covered with an alfalfa crop. An important step in calculating the absolute crop height from the UAV derived DSM is determining the height of the underlying terrain. Here we use automatic thresholding techniques applied to RGB vegetation index maps to classify vegetated and soil pixels. From interpolation of classified soil pixels, a terrain map is calculated and subtracted from the DSM. The influence of three different thresholding techniques on CSMs are investigated. Median Alfalfa crop heights determined with the different thresholding methods varied from 18cm for K means thresholding to 13cm for Otsu thresholding methods. Otsu thresholding also gave the smallest range of crop heights and K means thresholding the largest. Reproducibility of median crop heights between flight surveys was 4-6cm for all thresholding techniques. For the flight conducted later in the afternoon shadowing caused soil pixels to be classified as vegetation in key locations around the domain, leading to lower crop height estimates. The range of crop heights was similar for both flights using K means thresholding (35-36cm), local minimum thresholding depended on whether raw or normalised RGB intensities were used to calculate vegetation indices (30-35cm), while Otsu thresholding had a smaller range of heights and varied most between flights (26-30cm). This study showed that crop heights from multiple survey flights are comparable, however, they were dependent on the thresholding method applied to classify soil pixels and the time of day the flight was conducted.

  14. Methods for estimating pressure and thermal loads induced by elevon deflections on hypersonic-vehicle surfaces with turbulent boundary layers

    Science.gov (United States)

    Kaufman, L. G., II; Johnson, C. B.

    1981-09-01

    Empirical anaytic methods are presented for calculating thermal and pressure distributions in three-dimensional, shock-wave turbulent-boundary-layer, interaction-flow regions on the surface of controllable hypersonic aircraft and missiles. The methods, based on several experimental investigations, are useful and reliable for estimating both the extent and magnitude of the increased thermal and pressure loads on the vehicle surfaces.

  15. System architecture and operational analysis of medium displacement unmanned surface vehicle sea hunter as a surface warfare component of distributed lethality

    Science.gov (United States)

    2017-06-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release. Distribution is unlimited. SYSTEM ARCHITECTURE ...TITLE AND SUBTITLE SYSTEM ARCHITECTURE AND OPERATIONAL ANALYSIS OF MEDIUM DISPLACEMENT UNMANNED SURFACE VEHICLE SEA HUNTER AS A SURFACE WARFARE...traceability, requirements and capabilities while determining the architecture framework in accordance with the Department of Defense Architectural

  16. FPGA Based Efficient Design of Traffic Light Controller using Frequency Scaling for Family of HSTL

    DEFF Research Database (Denmark)

    Sharma, Shivani; Khan, Sadiq; Das, Bhagwan

    2016-01-01

    Traffic blockage is one of the major issues faced by world today. That can be road traffic or air traffic or even water traffic .Traffic Controllers provide the right direction by providing a rule for any kind of Vehicles. The idea goes around designing traffic light controller system which...... are studied for the purpose of making Light Controller Efficient using VHDL....

  17. Implementation of the vehicle recognition systems using wireless ...

    Indian Academy of Sciences (India)

    Wireless network sensors and their use in traffic monitoring, traffic density determination or vehicle speed detection and classification have recently been the ... With the proposed logic algorithm, it was possible tocategorise the instantaneous traffic status of a road in four levels: no traffic, mild traffic, heavy traffic and very ...

  18. Effectiveness of Unmanned Surface Vehicles in Anti-submarine Warfare with the Goal of Protecting a High Value Unit

    Science.gov (United States)

    2015-06-01

    author and do not reflect the official policy or position of the Department of Defense or the U.S. Government . IRB Protocol number ____N/A...Communication SOA Speed of Advance SSK Diesel Electric Submarine TDZ Torpedo Danger Zone UAV Unmanned Aerial Vehicle USV Unmanned Surface Vehicle UUV...sensors. Agent-based models can perform non-linear behavior patterns , capture organizational dynamics, and provide valuable insights about real-world

  19. A FMM-FFT accelerated hybrid volume surface integral equation solver for electromagnetic analysis of re-entry space vehicles

    KAUST Repository

    Yücel, Abdulkadir C.

    2014-07-01

    Space vehicles that re-enter the atmosphere often experience communication blackout. The blackout occurs when the vehicle becomes engulfed in plasma produced by interactions between the vehicle surface and the atmosphere. The plasma often is concentrated in a relatively thin shell around the vehicle, with higher densities near its nose than rear. A less structured, sometimes turbulent plasma wake often trails the vehicle. The plasma shell severely affects the performance of side-mounted antennas as it alters their characteristics (frequency response, gain patterns, axial ratio, and impedance) away from nominal, free-space values, sometimes entirely shielding the antenna from the outside world. The plasma plume/turbulent wake similarly affect the performance of antennas mounted at the back of the vehicle. The electromagnetic characteristics of the thin plasma shell and plume/turbulent wake heavily depend on the type of re-entry trajectory, the vehicle\\'s speed, angles of attack, and chemical composition, as well as environmental conditions. To analyze the antennas\\' performance during blackout and to design robust communication antennas, efficient and accurate simulation tools for charactering the antennas\\' performance along the trajectory are called for.

  20. Using Large Scale Particle Image Velocimetry with Unmanned Aerial Vehicle to Measure Surface Flow Fields

    Science.gov (United States)

    Ko, T. Y.; Chan, H. C.; Chen, B. A.

    2016-12-01

    Large Scale Particle Image Velocimetry (LSPIV) is a nonintrusive measurement technology. It requires fewer operators and less time than other intrusive methods. While using the LSPIV methods to measure surface flow fields, a camera is usually installed on a fixed position of river sides to record the flow conditions. However, it leads to image distortion and error of image processing. This study attempts to apply an unmanned aerial vehicle (UAV) with a camera to record the images of the water surface. It is expected to improve the orthogonality of the recording images. The tracing particles of image velocimetry used the ripples and foams on the water surface. Then, the LSPIV was used to analyze the spatially information of flow fields. The results showed the flow velocities determined by the LSPIV was close to the velocities measured by the velocimetry. It was showed that using LSPIV with UAV to measure water surface flow fields is a feasible, accurate and safe flow measuring method. It is expected to apply in future study, such as habitat survey and hydraulic characteristic.

  1. Fault-tolerant control with mixed aerodynamic surfaces and RCS jets for hypersonic reentry vehicles

    Directory of Open Access Journals (Sweden)

    Jingjing He

    2017-04-01

    Full Text Available This paper proposes a fault-tolerant strategy for hypersonic reentry vehicles with mixed aerodynamic surfaces and reaction control systems (RCS under external disturbances and subject to actuator faults. Aerodynamic surfaces are treated as the primary actuator in normal situations, and they are driven by a continuous quadratic programming (QP allocator to generate torque commanded by a nonlinear adaptive feedback control law. When aerodynamic surfaces encounter faults, they may not be able to provide sufficient torque as commanded, and RCS jets are activated to augment the aerodynamic surfaces to compensate for insufficient torque. Partial loss of effectiveness and stuck faults are considered in this paper, and observers are designed to detect and identify the faults. Based on the fault identification results, an RCS control allocator using integer linear programming (ILP techniques is designed to determine the optimal combination of activated RCS jets. By treating the RCS control allocator as a quantization element, closed-loop stability with both continuous and quantized inputs is analyzed. Simulation results verify the effectiveness of the proposed method.

  2. Design and evaluation of impact of traffic light priority for trucks on traffic flow.

    Science.gov (United States)

    2015-06-01

    Current traffic light control systems treat all vehicles the same. Trucks however have : different dynamics than passenger vehicles. They take a longer distance to stop, have : lower acceleration rates, have bigger turning rates that cause bigger tra...

  3. Air pollution from traffic and cancer incidence: a Danish cohort study

    DEFF Research Database (Denmark)

    Raaschou-Nielsen, Ole; Andersen, Zorana J; Hvidberg, Martin

    2011-01-01

    Vehicle engine exhaust includes ultrafine particles with a large surface area and containing absorbed polycyclic aromatic hydrocarbons, transition metals and other substances. Ultrafine particles and soluble chemicals can be transported from the airways to other organs, such as the liver, kidneys......, and brain. Our aim was to investigate whether air pollution from traffic is associated with risk for other cancers than lung cancer....

  4. Directions for next generation microscopic traffic simulation modeling tool under the IntelliDrive environment

    NARCIS (Netherlands)

    Park, Byungkyu "Brian"; van Arem, Bart; van Noort, Martijn; Abadi, A.; Abdel-Rahim, A.; Preuveneers e.a., D.

    2010-01-01

    Microscopic traffic simulation models have been widely accepted in the evaluations of new treatments in the surface transportation system. These include new highway, lane usage (e.g., high occupancy vehicle lane or high occupancy toll lane), speed limits (e.g., variable speed limit, and uniform or

  5. Vehicle classification using mobile sensors.

    Science.gov (United States)

    2013-04-01

    In this research, the feasibility of using mobile traffic sensors for binary vehicle classification on arterial roads is investigated. Features (e.g. : speed related, acceleration/deceleration related, etc.) are extracted from vehicle traces (passeng...

  6. Development of a low-cost, unmanned surface vehicle for military applications

    Science.gov (United States)

    Cadena, A.

    2012-06-01

    This paper describes the development of an USV (Unmanned Surface Vehicle) prototype that serves as an educational platform and can be use for coastal patrol and operations in the jungle. The USV length is less than 2 m and range of 5000 m. It's composed by the following modules: propulsion, power, motor driver, CPU, sensor suite, camera system, communication and weapon system. The weapon system is formed by an experimental assault rifle and a rocket launcher with a fire control system. The assault rifle haven't got mechanical moving parts, the bullets (7.62x51mm round) are electronically ignited. The CPU is an FPGA development kit. The USV can be operate in remote mode or fully autonomous. Results of some systems from laboratory and sea trials are show.

  7. Dynamic Gas Flow Effects on the ESD of Aerospace Vehicle Surfaces

    Science.gov (United States)

    Hogue, Michael D.; Cox, Rachel E.; Mulligan, Jaysen; Ahmed, Kareem; Wilson, Jennifer G.; Calle, Luz M.

    2017-01-01

    The purpose of this work is to develop a version of Paschen's Law that takes into account the flow of ambient gas past electrode surfaces. Paschen's Law does not consider the flow of gas past an aerospace vehicle, whose surfaces may be triboelectrically charged by dust or ice crystal impingement while traversing the atmosphere. The basic hypothesis of this work is that the number of electron-ion pairs created per unit distance between electrode surfaces is mitigated by the electron-ion pairs removed per unit distance by the flow of gas. The revised theoretical model must be a function of the mean velocity, v (sub xm), of the ambient gas and reduce to Paschen's law when the gas mean velocity, v (sub xm) equals 0. A new theoretical formulation of Paschen's Law, taking into account the Mach number and dynamic pressure, derived by the authors, will be discussed. This equation was evaluated by wind tunnel experimentation whose results were consistent with the model hypothesis.

  8. Calculating Distribution and Intensity of Agricultural Traffic for Sustainable Development

    NARCIS (Netherlands)

    Hospers, A.; Louwsma, M.A.; Lammeren, van R.J.A.; Kuiper, P.P.

    2016-01-01

    Land from many holdings is dispersed, which compels farmers to use public roads to access distant parcels. Agricultural traffic is different from other traffic with its large and heavy vehicles. When agricultural traffic mixes with other traffic, safety issues may arise. Another issue of

  9. 32 CFR 634.40 - General off installation traffic activities.

    Science.gov (United States)

    2010-07-01

    ... reports received from civil authorities on serious traffic violations, accidents, and intoxicated driving... 32 National Defense 4 2010-07-01 2010-07-01 true General off installation traffic activities. 634... (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision...

  10. Delays at signalized intersections with exhaustive traffic control

    NARCIS (Netherlands)

    Boon, M.A.A.; Adan, I.J.B.F.; Winands, E.M.M.; Down, D.G.

    2012-01-01

    In this paper, we study a traffic intersection with vehicle-actuated traffic signal control. Traffic lights stay green until all lanes within a group are emptied. Assuming general renewal arrival processes, we derive exact limiting distributions of the delays under heavy traffic (HT) conditions.

  11. Aerodynamics of Tracked Ram Air Cushion Vehicles - Effects of Pitch Attitude and Upper Surface Flow

    Science.gov (United States)

    1979-12-01

    Three types of experiments were conducted on geometrically similar model of a Tracked Ram Air Cushion Vehicle (TRACV). The first consisted of wind tunnel tests with the vehicle model positioned within a short segment of stationary guideway. In the se...

  12. Traffic, diesel and asthma : a literature review

    OpenAIRE

    Schembri, Gabriel

    2007-01-01

    This article details the major pollutants from motor vehicle exhaust, mainly particulate matter, nitrogen dioxide and polycyclic aromatic hydrocarbons. The emphasis is on motor vehicle emissions from diesel powered engines, which have become a significant source of air pollution in urban areas. The impact of motor vehicle pollutants on respiratory health is explored, and the major studies relating asthma to high volume of traffic and proximity to major traffic arteries are reviewed.

  13. Traffic Light Detection

    DEFF Research Database (Denmark)

    Philipsen, Mark Philip; Jensen, Morten Bornø; Møgelmose, Andreas

    2015-01-01

    Traffic light recognition (TLR) is an integral part of any intelligent vehicle, which must function in the existing infrastructure. Pedestrian and sign detection have recently seen great improvements due to the introduction of learning based detectors using integral channel features. A similar push...... database is collected based on footage from US roads. The database consists of both test and training data, totaling 46,418 frames and 112,971 annotated traffic lights, captured in continuous sequences under a varying light and weather conditions. The learning based detector achieves an AUC of 0.4 and 0...

  14. Traffic speed management

    Directory of Open Access Journals (Sweden)

    Subotić Jovana Lj.

    2014-01-01

    Full Text Available Speed, and vehicles themselves, affect the level of service and road safety, quality of life, noise from traffic, the environment, health, air pollution, emission of carbon dioxide, global warming, the economy and consumption of non-renewable energy such as oil. Therefore, the speed management of the traffic of multiple significance and that should be primarily to provide effective and economical conditions of the modern and preventive protection of human life as the greatest treasure and then the material resources. The way to accomplish this is by using various (different measures such as: appropriate planning and projecting roads and streets, speed control, the legislation, enforcement, campaigns, education, advanced technologies (ITS.

  15. Agent Based Individual Traffic guidance

    DEFF Research Database (Denmark)

    Wanscher, Jørgen Bundgaard

    2004-01-01

    When working with traffic planning or guidance it is common practice to view the vehicles as a combined mass. >From this models are employed to specify the vehicle supply and demand for each region. As the models are complex and the calculations are equally demanding the regions and the detail...... of the road network is aggregated. As a result the calculations reveal only what the mass of vehicles are doing and not what a single vehicle is doing. This is the crucial difference to ABIT (Agent Based Individual Trafficguidance). ABIT is based on the fact that information on the destination of each vehicle...

  16. Mapping surface temperature variability on a debris-covered glacier with an unmanned aerial vehicle

    Science.gov (United States)

    Kraaijenbrink, P. D. A.; Litt, M.; Shea, J. M.; Treichler, D.; Koch, I.; Immerzeel, W.

    2016-12-01

    Debris-covered glacier tongues cover about 12% of the glacier surface in high mountain Asia and much of the melt water is generated from those glaciers. A thin layer of supraglacial debris enhances ice melt by lowering the albedo, while thicker debris insulates the ice and reduces melt. Data on debris thickness is therefore an important input for energy balance modelling of these glaciers. Thermal infrared remote sensing can be used to estimate the debris thickness by using an inverse relation between debris surface temperature and thickness. To date this has only been performed using coarse spaceborne thermal imagery, which cannot reveal small scale variation in debris thickness and its influence on the heterogeneous melt patterns on debris-covered glaciers. We deployed an unmanned aerial vehicle mounted with a thermal infrared sensor over the debris-covered Lirung Glacier in Nepal three times in May 2016 to reveal the spatial and temporal variability of surface temperature in high detail. The UAV survey matched a Landsat 8 overpass to be able to make a comparison with spaceborne thermal imagery. The UAV-acquired data is processed using Structure from Motion photogrammetry and georeferenced using DGPS-measured ground control points. Different surface types were distinguished by using data acquired by an additional optical UAV survey in order to correct for differences in surface emissivity. In situ temperature measurements and incoming solar radiation data are used to calibrate the temperature calculations. Debris thicknesses derived are validated by thickness measurements of a ground penetrating radar. Preliminary analysis reveals a spatially highly heterogeneous pattern of surface temperature over Lirung Glacier with a range in temperature of over 40 K. At dawn the debris is relatively cold and its temperature is influenced strongly by the ice underneath. Exposed to the high solar radiation at the high altitude the debris layer heats up very rapidly as sunrise

  17. Intelligent Traffic Light Based on PLC Control

    Science.gov (United States)

    Mei, Lin; Zhang, Lijian; Wang, Lingling

    2017-11-01

    The traditional traffic light system with a fixed control mode and single control function is contradicted with the current traffic section. The traditional one has been unable to meet the functional requirements of the existing flexible traffic control system. This paper research and develop an intelligent traffic light called PLC control system. It uses PLC as control core, using a sensor module for receiving real-time information of vehicles, traffic control mode for information to select the traffic lights. Of which control mode is flexible and changeable, and it also set the countdown reminder to improve the effectiveness of traffic lights, which can realize the goal of intelligent traffic diversion, intelligent traffic diversion.

  18. The Physics of Traffic

    Science.gov (United States)

    Davis, L. Craig

    2006-03-01

    Congestion in freeway traffic is an example of self-organization in the language of complexity theory. Nonequilibrium, first-order phase transitions from free flow cause complex spatiotemporal patterns. Two distinct phases of congestion are observed in empirical traffic data--wide moving jams and synchronous flow. Wide moving jams are characterized by stopped or slowly moving vehicles within the jammed region, which widens and moves upstream at 15-20 km/h. Above a critical density of vehicles, a sudden decrease in the velocity of a lead vehicle can initiate a transition from metastable states to this phase. Human behaviors, especially delayed reactions, are implicated in the formation of jams. The synchronous flow phase results from a bottleneck such as an on-ramp. Thus, in contrast to a jam, the downstream front is pinned at a fixed location. The name of the phase comes from the equilibration (or synchronization) of speed and flow rate across all lanes caused by frequent vehicle lane changes. Synchronous flow occurs when the mainline flow and the rate of merging from an on-ramp are sufficiently large. Large-scale simulations using car-following models reproduce the physical phenomena occurring in traffic and suggest methods to improve flow and mediate congestion.

  19. Research on Roll Stabilizing Based on Energy Optimization for Autonomous Surface Vehicle

    Directory of Open Access Journals (Sweden)

    Hongjian Wang

    2014-01-01

    Full Text Available Considering the case of ASV (autonomous surface vehicle navigating with low speed near water surface, a new method for design of roll motion controller is proposed in order to restrain wave disturbance effectively and improve roll stabilizing performance. Control system design is based on GPC (general predictive control theory and working principle of zero-speed fin stabilizer. Coupling horizontal motion model of ASV is decoupled, and an equivalent transfer function of roll motion is obtained and transformed into a discrete difference equation through inverse Laplace transformation and Euler approximation. Finally, predictive model of GPC, namely, the difference equation of roll motion, is given. GPC algorithm of ASV roll motion is derived from performance index based on roll stabilizing performance and energy consumption used for driving fin stabilizer. In allusion to time-variant parameters in roll motion model, recursive least square method is adopted for parameter estimation. Simulation results of ASV roll motion control show better stabilizing performance and minimized energy consumption improved by self-adaptive GPC.

  20. Real-time Accurate Surface Reconstruction Pipeline for Vision Guided Planetary Exploration Using Unmanned Ground and Aerial Vehicles

    Science.gov (United States)

    Almeida, Eduardo DeBrito

    2012-01-01

    This report discusses work completed over the summer at the Jet Propulsion Laboratory (JPL), California Institute of Technology. A system is presented to guide ground or aerial unmanned robots using computer vision. The system performs accurate camera calibration, camera pose refinement and surface extraction from images collected by a camera mounted on the vehicle. The application motivating the research is planetary exploration and the vehicles are typically rovers or unmanned aerial vehicles. The information extracted from imagery is used primarily for navigation, as robot location is the same as the camera location and the surfaces represent the terrain that rovers traverse. The processed information must be very accurate and acquired very fast in order to be useful in practice. The main challenge being addressed by this project is to achieve high estimation accuracy and high computation speed simultaneously, a difficult task due to many technical reasons.

  1. Review of Our National Heritage of Launch Vehicles Using Aerodynamic Surfaces and Current Use of These by Other Nations. Part II; Center Director's Discretionary Fund Project Numbe

    Science.gov (United States)

    Barret, C.

    1996-01-01

    Marshall Space Flight Center has a rich heritage of launch vehicles that have used aerodynamic surfaces for flight stability and for flight control. Recently, due to the aft center-of-gravity (cg) locations on launch vehicles currently being studied, the need has arisen for the vehicle control augmentation that can be provided by these flight controls. Aerodynamic flight control can also reduce engine gimbaling requirements, provide actuator failure protection, enhance crew safety, and increase vehicle reliability and payload capability. As a starting point for the novel design of aerodynamic flight control augmentors for a Saturn class, aft cg launch vehicle, this report undertakes a review of our national heritage of launch vehicles using aerodynamic surfaces, along with a survey of current use of aerodynamic surfaces on large launch vehicles of other nations. This report presents one facet of Center Director's Discretionary Fund Project 93-05 and has a previous and subsequent companion publication.

  2. How shall we design the future vehicle for Chinese market.

    Science.gov (United States)

    Chen, Fang; Wang, Minjuan; Zhu, Xi Chan; Li, Jiaqi

    2012-01-01

    Surface transportation system is developing very fast in China and the number of vehicles is increasing quickly as well. This development creates a lot of problems on traffic safety and the number of accident is also increasing. In this paper, we made deep analysis of different possible causes of safety problems through three aspects: the traffic environment and infrastructure, in-vehicle information system design and the characteristics of drivers. There are many factors in each aspects may contribute to the transportation safety problems. Problems with infrastructure design and traffic design contribute over 50% of the traffic accident. Another important factor is that people has very little traffic safety concept and very weak on understanding the important of right behavior on the road. This paper has pointed the urgent needs to study the human factors in road and transportation system and vehicle HMI design, as there are very few such studies available in literature based on Chinese situation. The paper also proposed the needs to develop proactive educational system that can promote driver's understanding of traffic safety and to take the right action during drive.

  3. Analysis of the Effects of Vitiates on Surface Heat Flux in Ground Tests of Hypersonic Vehicles

    Science.gov (United States)

    Cuda, Vincent; Gaffney, Richard L

    2008-01-01

    To achieve the high enthalpy conditions associated with hypersonic flight, many ground test facilities burn fuel in the air upstream of the test chamber. Unfortunately, the products of combustion contaminate the test gas and alter gas properties and the heat fluxes associated with aerodynamic heating. The difference in the heating rates between clean air and a vitiated test medium needs to be understood so that the thermal management system for hypersonic vehicles can be properly designed. This is particularly important for advanced hypersonic vehicle concepts powered by air-breathing propulsion systems that couple cooling requirements, fuel flow rates, and combustor performance by flowing fuel through sub-surface cooling passages to cool engine components and preheat the fuel prior to combustion. An analytical investigation was performed comparing clean air to a gas vitiated with methane/oxygen combustion products to determine if variations in gas properties contributed to changes in predicted heat flux. This investigation started with simple relationships, evolved into writing an engineering-level code, and ended with running a series of CFD cases. It was noted that it is not possible to simultaneously match all of the gas properties between clean and vitiated test gases. A study was then conducted selecting various combinations of freestream properties for a vitiated test gas that matched clean air values to determine which combination of parameters affected the computed heat transfer the least. The best combination of properties to match was the free-stream total sensible enthalpy, dynamic pressure, and either the velocity or Mach number. This combination yielded only a 2% difference in heating. Other combinations showed departures of up to 10% in the heat flux estimate.

  4. How connected vehicles work.

    Science.gov (United States)

    2011-01-01

    Connected vehicles have the potential to transform the way Americans travel through the creation : of a safe, interoperable wireless communications networka system that includes cars, buses, : trucks, trains, traffic signals, cell phones, and othe...

  5. Automated Traffic Management System and Method

    Science.gov (United States)

    Glass, Brian J. (Inventor); Spirkovska, Liljana (Inventor); McDermott, William J. (Inventor); Reisman, Ronald J. (Inventor); Gibson, James (Inventor); Iverson, David L. (Inventor)

    2000-01-01

    A data management system and method that enables acquisition, integration, and management of real-time data generated at different rates, by multiple heterogeneous incompatible data sources. The system achieves this functionality by using an expert system to fuse data from a variety of airline, airport operations, ramp control, and air traffic control tower sources, to establish and update reference data values for every aircraft surface operation. The system may be configured as a real-time airport surface traffic management system (TMS) that electronically interconnects air traffic control, airline data, and airport operations data to facilitate information sharing and improve taxi queuing. In the TMS operational mode, empirical data shows substantial benefits in ramp operations for airlines, reducing departure taxi times by about one minute per aircraft in operational use, translating as $12 to $15 million per year savings to airlines at the Atlanta, Georgia airport. The data management system and method may also be used for scheduling the movement of multiple vehicles in other applications, such as marine vessels in harbors and ports, trucks or railroad cars in ports or shipping yards, and railroad cars in switching yards. Finally, the data management system and method may be used for managing containers at a shipping dock, stock on a factory floor or in a warehouse, or as a training tool for improving situational awareness of FAA tower controllers, ramp and airport operators, or commercial airline personnel in airfield surface operations.

  6. The Research of Vehicle Acceleration at Signalized Intersections

    Directory of Open Access Journals (Sweden)

    Vuk Bogdanović

    2013-02-01

    Full Text Available Vehicle acceleration is an important parameter used in planning various road elements, traffic signalization, geometric elements of an intersection, signal plans of traffic lights, etc. The knowledge of vehicle acceleration values is also necessary in using simulation softwares for more accurate analysis of the total situation at an intersection, on a road section or in a traffic network. In a lot of earlier studies, acceleration values were analysed and defined, mostly in optimal conditions for traffic functioning. However, values of almost all traffic flow parameters have been changed over time, due to changes in driving-dynamic vehicle characteristics, pneumatic tyres, material used for building road surface, etc. Besides, local environment influence and changes in drivers’ behaviour also significantly affect values of this parameter. According to HCM, it is advisable to perform local research for all values of the parameters recommended within the framework of this handbook, and to adapt their values to local conditions as well. The results of measuring the values of vehicles acceleration at signalized intersections in Novi Sad, Serbia, have been shown in this paper, using the procedure based on video recording processing.

  7. Structuring of Road Traffic Flows

    Directory of Open Access Journals (Sweden)

    Planko Rožić

    2005-09-01

    Full Text Available Systemic traffic count on the Croatian road network hasbeen carried out for more than three decades in different ways.During this period a large number of automatic traffic countershave been installed, and they operate on different principles.The traffic count has been analyzed from the aspect of vehicleclassification. The count results can be only partly comparedsince they yield different structures of traffic flows. Special analysisrefers to the classification of vehicles by automatic trafficcounters.During the research, a database has been formed with physicalelements of vehicles of over five thousand vehicle types. Theresearch results prove that the vehicle length only is not sufficientfor the classification of vehicles, the way it is used in thepresent automatic traffic counts, but rather the number of axles,the wheelbase as well as the front and rear overhangs needto be considered as well. Therefore, the detector system shouldapply also the detector of axles.The results have been presented that were obtained as partof the program TEST- Technological, research, developmentproject supported by the Minist1y of Science, Education andSport.

  8. Bridge Expansion Joint in Road Transition Curve: Effects Assessment on Heavy Vehicles

    Directory of Open Access Journals (Sweden)

    Paola Di Mascio

    2017-06-01

    Full Text Available Properly-designed road surfaces provide a durable surface on which traffic can pass smoothly and safely. In fact, the main causes that determine the structural decay of the pavement and its parts are the traffic loads. These repeated actions can create undesirable unevennesses on the road surface, which induce vertical accelerations on vehicles, up to hindering contact between pavement and tire, with dangerous consequences on traffic safety. The dynamic actions transmitted by the vehicles depend on these irregularities: often, a bridge expansion joint (BEJ, introducing a necessary discontinuity between different materials, determines from the beginning a geometric irregularity in the running surface. Besides, some structural conditions could emphasize the problem (e.g., local cracking due to the settlement of the subgrade near the abutment or the discontinuity of stiffness due to the presence of different materials. When the BEJ is located in a transition curve, an inevitable vertical irregularity between road and joint can reach values of some centimeters, with serious consequences for the road safety. This paper deals with the analysis of a case study of a BEJ. Several test surveys were performed in order to fully characterize the effects on both vehicles and pavement. The three-dimensional representation of the pavement surface and the acceleration measurements on a heavy test vehicle were performed to analyze the joint behavior under traffic. Finally, a finite element model was implemented to evaluate the stress contribution on vehicle components induced by the vertical irregularities.

  9. Assessment of the contribution of traffic emissions to the mobile vehicle measured PM2.5 concentration by means of WRF-CMAQ simulations.

    Science.gov (United States)

    2012-03-01

    The Alaska adapted version of the Weather Research and Forecasting and the Community Modeling and Analysis Quality (WRF-CMAQ) modeling : systems was used to assess the contribution of traffic to the PM2.5-concentration in the Fairbanks nonattainment ...

  10. Estimates of CO2 traffic emissions from mobile concentration measurements

    Science.gov (United States)

    Maness, H. L.; Thurlow, M. E.; McDonald, B. C.; Harley, R. A.

    2015-03-01

    We present data from a new mobile system intended to aid in the design of upcoming urban CO2-monitoring networks. Our collected data include GPS probe data, video-derived traffic density, and accurate CO2 concentration measurements. The method described here is economical, scalable, and self-contained, allowing for potential future deployment in locations without existing traffic infrastructure or vehicle fleet information. Using a test data set collected on California Highway 24 over a 2 week period, we observe that on-road CO2 concentrations are elevated by a factor of 2 in congestion compared to free-flow conditions. This result is found to be consistent with a model including vehicle-induced turbulence and standard engine physics. In contrast to surface concentrations, surface emissions are found to be relatively insensitive to congestion. We next use our model for CO2 concentration together with our data to independently derive vehicle emission rate parameters. Parameters scaling the leading four emission rate terms are found to be within 25% of those expected for a typical passenger car fleet, enabling us to derive instantaneous emission rates directly from our data that compare generally favorably to predictive models presented in the literature. The present results highlight the importance of high spatial and temporal resolution traffic data for interpreting on- and near-road concentration measurements. Future work will focus on transport and the integration of mobile platforms into existing stationary network designs.

  11. Effective Waterline Detection of Unmanned Surface Vehicles Based on Optical Images

    Directory of Open Access Journals (Sweden)

    Yangjie Wei

    2016-09-01

    Full Text Available Real-time and accurate detection of the sailing or water area will help realize unmanned surface vehicle (USV systems. Although there are some methods for using optical images in USV-oriented environmental modeling, both the robustness and precision of these published waterline detection methods are comparatively low for a real USV system moving in a complicated environment. This paper proposes an efficient waterline detection method based on structure extraction and texture analysis with respect to optical images and presents a practical application to a USV system for validation. First, the basic principles of local binary patterns (LBPs and gray level co-occurrence matrix (GLCM were analyzed, and their advantages were integrated to calculate the texture information of river images. Then, structure extraction was introduced to preprocess the original river images so that the textures resulting from USV motion, wind, and illumination are removed. In the practical application, the waterlines of many images captured by the USV system moving along an inland river were detected with the proposed method, and the results were compared with those of edge detection and super pixel segmentation. The experimental results showed that the proposed algorithm is effective and robust. The average error of the proposed method was 1.84 pixels, and the mean square deviation was 4.57 pixels.

  12. Approach and landing guidance design for reusable launch vehicle using multiple sliding surfaces technique

    Directory of Open Access Journals (Sweden)

    Xiangdong LIU

    2017-08-01

    Full Text Available An autonomous approach and landing (A&L guidance law is presented in this paper for landing an unpowered reusable launch vehicle (RLV at the designated runway touchdown. Considering the full nonlinear point-mass dynamics, a guidance scheme is developed in three-dimensional space. In order to guarantee a successful A&L movement, the multiple sliding surfaces guidance (MSSG technique is applied to derive the closed-loop guidance law, which stems from higher order sliding mode control theory and has advantage in the finite time reaching property. The global stability of the proposed guidance approach is proved by the Lyapunov-based method. The designed guidance law can generate new trajectories on-line without any specific requirement on off-line analysis except for the information on the boundary conditions of the A&L phase and instantaneous states of the RLV. Therefore, the designed guidance law is flexible enough to target different touchdown points on the runway and is capable of dealing with large initial condition errors resulted from the previous flight phase. Finally, simulation results show the effectiveness of the proposed guidance law in different scenarios.

  13. Surface functionalized exosomes as targeted drug delivery vehicles for cerebral ischemia therapy.

    Science.gov (United States)

    Tian, Tian; Zhang, Hui-Xin; He, Chun-Peng; Fan, Song; Zhu, Yan-Liang; Qi, Cui; Huang, Ning-Ping; Xiao, Zhong-Dang; Lu, Zu-Hong; Tannous, Bakhos A; Gao, Jun

    2018-01-01

    The safe and effective delivery of drugs is a major obstacle in the treatment of ischemic stroke. Exosomes hold great promise as an endogenous drug delivery nanosystem for the treatment of cerebral ischemia given their unique properties, including low immunogenicity, innate stability, high delivery efficiency, and ability to cross the blood-brain barrier (BBB). However, exosome insufficient targeting capability limits their clinical applications. In this study, the c(RGDyK) peptide has been conjugated to the exosome surface by an easy, rapid, and bio-orthogonal chemistry. In the transient middle cerebral artery occlusion (MCAO) mice model, The engineered c(RGDyK)-conjugated exosomes (cRGD-Exo) target the lesion region of the ischemic brain after intravenous administration. Furthermore, curcumin has been loaded onto the cRGD-Exo, and administration of these exosomes has resulted in a strong suppression of the inflammatory response and cellular apoptosis in the lesion region. The results suggest a targeting delivery vehicle for ischemic brain based on exosomes and provide a strategy for the rapid and large-scale production of functionalized exosomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. A Sea-Sky Line Detection Method for Unmanned Surface Vehicles Based on Gradient Saliency

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2016-04-01

    Full Text Available Special features in real marine environments such as cloud clutter, sea glint and weather conditions always result in various kinds of interference in optical images, which make it very difficult for unmanned surface vehicles (USVs to detect the sea-sky line (SSL accurately. To solve this problem a saliency-based SSL detection method is proposed. Through the computation of gradient saliency the line features of SSL are enhanced effectively, while other interference factors are relatively suppressed, and line support regions are obtained by a region growing method on gradient orientation. The SSL identification is achieved according to region contrast, line segment length and orientation features, and optimal state estimation of SSL detection is implemented by introducing a cubature Kalman filter (CKF. In the end, the proposed method is tested on a benchmark dataset from the “XL” USV in a real marine environment, and the experimental results demonstrate that the proposed method is significantly superior to other state-of-the-art methods in terms of accuracy rate and real-time performance, and its accuracy and stability are effectively improved by the CKF.

  15. An Automatic Navigation System for Unmanned Surface Vehicles in Realistic Sea Environments

    Directory of Open Access Journals (Sweden)

    Xiaojie Sun

    2018-01-01

    Full Text Available In recent years, unmanned surface vehicles (USVs have received notable attention because of their many advantages in civilian and military applications. To improve the autonomy of USVs, this paper describes a complete automatic navigation system (ANS with a path planning subsystem (PPS and collision avoidance subsystem (CAS. The PPS based on the dynamic domain tunable fast marching square (DTFMS method is able to build an environment model from a real electronic chart, where both static and dynamic obstacles are well represented. By adjusting the S a t u r a t i o n , the generated path can be changed according to the requirements for security and path length. Then it is used as a guidance trajectory for the CAS through a dynamic target point. In the CAS, according to finite control set model predictive control (FCS-MPC theory, a collision avoidance control algorithm is developed to track trajectory and avoid collision based on a three-degree of freedom (DOF planar motion model of USV. Its target point and security evaluation come from the planned path and environmental model of the PPS. Moreover, the prediction trajectory of the CAS can guide changes in the dynamic domain model of the vessel itself. Finally, the system has been tested and validated using the situations of three types of encounters in a realistic sea environment.

  16. Use of Heated Helium to Simulate Surface Pressure Fluctuations on the Launch Abort Vehicle During Abort Motor Firing

    Science.gov (United States)

    Panda, Jayanta; James, George H.; Burnside, Nathan J.; Fong, Robert; Fogt, Vincent A.

    2011-01-01

    The solid-rocket plumes from the Abort motor of the Multi-Purpose Crew Vehicle (MPCV, also know as Orion) were simulated using hot, high pressure, Helium gas to determine the surface pressure fluctuations on the vehicle in the event of an abort. About 80 different abort situations over a wide Mach number range, (0.3abort case, typically two different Helium plume and wind tunnel conditions were used to bracket different flow matching critera. This unique, yet cost-effective test used a custom-built hot Helium delivery system, and a 6% scale model of a part of the MPCV, known as the Launch Abort Vehicle. The test confirmed the very high level of pressure fluctuations on the surface of the vehicle expected during an abort. In general, the fluctuations were found to be dominated by the very near-field hydrodynamic fluctuations present in the plume shear-layer. The plumes were found to grow in size for aborts occurring at higher flight Mach number and altitude conditions. This led to an increase in the extent of impingement on the vehicle surfaces; however, unlike some initial expectations, the general trend was a decrease in the level of pressure fluctuations with increasing impingement. In general, the highest levels of fluctuations were found when the outer edges of the plume shear layers grazed the vehicle surface. At non-zero vehicle attitudes the surface pressure distributions were found to become very asymmetric. The data from these wind-tunnel simulations were compared against data collected from the recent Pad Abort 1 flight test. In spite of various differences between the transient flight situation and the steady-state wind tunnel simulations, the hot-Helium data were found to replicate the PA1 data fairly reasonably. The data gathered from this one-of-a-kind wind-tunnel test fills a gap in the manned-space programs, and will be used to establish the acoustic environment for vibro-acoustic qualification testing of the MPCV.

  17. Smart limbed vehicles for naval applications. Part II. Relevant technologies and performance evaluation. Interim report on research work on smart vehicle concepts for military use on the ocean surface

    Energy Technology Data Exchange (ETDEWEB)

    Weisberg, A.; Wood, L.

    1976-09-30

    Research work in smart, unmanned water-traversing limbed vehicles for naval warfare applications is reported. The areas covered include prime movers, power transformers and actuators, structural considerations, physical control, joint servo-control, motion control, visual data and the ocean surface, smartness, and vehicle characterization. (TFD)

  18. [The pediatrician and traffic safety].

    Science.gov (United States)

    Waksman, Renata D; Pirito, Regina M B K

    2005-11-01

    To instruct children and teenagers about safe transportation and about their behavior as cyclists and pedestrians. The MEDLINE and LILACS databases were searched, using the following terms, from 1995 to 2005: traffic accidents, child, adolescent, morbidity, mortality, age, and gender. Scientific articles on morbidity and mortality from traffic accidents, children in a pedestrian situation, as cyclists or as motor vehicle passengers, were selected. More than 300 scientific articles were found, but only the studies that addressed those issues in a broad manner were selected. Traffic-related mortality rates are still very high and show the necessity to intensify educational campaigns for community awareness, in addition to encouraging investments in effective pedestrian safety. The pediatrician s role is to decrease the number of children and adolescents who get involved in traffic accidents by providing them with traffic guidance and education.

  19. A traffic situation analysis system

    Science.gov (United States)

    Sidla, Oliver; Rosner, Marcin

    2011-01-01

    The observation and monitoring of traffic with smart visions systems for the purpose of improving traffic safety has a big potential. For example embedded vision systems built into vehicles can be used as early warning systems, or stationary camera systems can modify the switching frequency of signals at intersections. Today the automated analysis of traffic situations is still in its infancy - the patterns of vehicle motion and pedestrian flow in an urban environment are too complex to be fully understood by a vision system. We present steps towards such a traffic monitoring system which is designed to detect potentially dangerous traffic situations, especially incidents in which the interaction of pedestrians and vehicles might develop into safety critical encounters. The proposed system is field-tested at a real pedestrian crossing in the City of Vienna for the duration of one year. It consists of a cluster of 3 smart cameras, each of which is built from a very compact PC hardware system in an outdoor capable housing. Two cameras run vehicle detection software including license plate detection and recognition, one camera runs a complex pedestrian detection and tracking module based on the HOG detection principle. As a supplement, all 3 cameras use additional optical flow computation in a low-resolution video stream in order to estimate the motion path and speed of objects. This work describes the foundation for all 3 different object detection modalities (pedestrians, vehi1cles, license plates), and explains the system setup and its design.

  20. Linearized Theory of Traffic Flow

    CERN Document Server

    Cohan, Tal

    2014-01-01

    The equation of motion of a general class of macroscopic traffic flow models is linearized around a steady uniform flow. A closed-form solution of a boundary-initial value problem is obtained, and it is used to describe several phenomena. Specifically, the scenarios examined involve a smooth velocity field in stop-and-go traffic, a discontinuous velocity field with shock waves in a traffic light problem, and discontinuous displacement fields in a problem where a single platoon of vehicles splits into two, and later merges back into one.

  1. Enabling high-quality observations of surface imperviousness for water runoff modelling from unmanned aerial vehicles

    Science.gov (United States)

    Tokarczyk, Piotr; Leitao, Joao Paulo; Rieckermann, Jörg; Schindler, Konrad; Blumensaat, Frank

    2015-04-01

    Modelling rainfall-runoff in urban areas is increasingly applied to support flood risk assessment particularly against the background of a changing climate and an increasing urbanization. These models typically rely on high-quality data for rainfall and surface characteristics of the area. While recent research in urban drainage has been focusing on providing spatially detailed rainfall data, the technological advances in remote sensing that ease the acquisition of detailed land-use information are less prominently discussed within the community. The relevance of such methods increase as in many parts of the globe, accurate land-use information is generally lacking, because detailed image data is unavailable. Modern unmanned air vehicles (UAVs) allow acquiring high-resolution images on a local level at comparably lower cost, performing on-demand repetitive measurements, and obtaining a degree of detail tailored for the purpose of the study. In this study, we investigate for the first time the possibility to derive high-resolution imperviousness maps for urban areas from UAV imagery and to use this information as input for urban drainage models. To do so, an automatic processing pipeline with a modern classification method is tested and applied in a state-of-the-art urban drainage modelling exercise. In a real-life case study in the area of Lucerne, Switzerland, we compare imperviousness maps generated from a consumer micro-UAV and standard large-format aerial images acquired by the Swiss national mapping agency (swisstopo). After assessing their correctness, we perform an end-to-end comparison, in which they are used as an input for an urban drainage model. Then, we evaluate the influence which different image data sources and their processing methods have on hydrological and hydraulic model performance. We analyze the surface runoff of the 307 individual sub-catchments regarding relevant attributes, such as peak runoff and volume. Finally, we evaluate the model

  2. Investigation on the Temporal Surface Thermal Conditions for Thermal Comfort Researches Inside A Vehicle Cabin Under Summer Season Climate

    Directory of Open Access Journals (Sweden)

    Zhang Wencan

    2016-01-01

    Full Text Available With the proposes of improving occupant's thermal comfort and reducing the air conditioning power consumption, the present research carried out a comprehensive study on the surface thermal conductions and their influence parameters. A numerical model was built considering the transient conduction, convective and radiation heat transfer inside a vehicle cabin. For more accurate simulation of the radiation heat transfer behaviors, the radiation was considered into two spectral bands (short wave and long wave radiation, and the solar radiation was calculated by two solar fluxes (beam and diffuse solar radiation. An experiment was conducted to validate the numerical approach, showing a good agreement with the surface temperature. The surface thermal conditions were numerically simulated. The results show that the solar radiation is the most important factor in determining the internal surface thermal conditions. Effects of the window glass properties and the car body surface conditions were investigated. The numerical calculation results indicate that reducing the transitivity of window glass can effectively reduce the internal surface temperature. And the reflectivity of the vehicle cabin also has an important influence on the surface temperature, however, it's not so obvious as comparison to the window glass.

  3. Relationship between road vehicle traffic and noise pollution of Khojir National Park in the viewpoint of feasibility of fencing and soundproofing

    Directory of Open Access Journals (Sweden)

    Minoo Moshtaghie

    2012-01-01

    Full Text Available Aims: The main aim of this study was to investigate the relationship between the amount of noise pollution and traffic rates in Khojir National park and regarding that finding a suitable distance for installing fencing according to the standard level of noise pollution. Materials and Methods: Eight stations located exactly above channels have been selected. In each station, three different substations including near the road, 25, and 50 m from the road were chosen. For determining the essentiality of soundproof installation, noise levels were measured at the opening and in the middle of the channel. Traffic rates have been measured daily from 6 AM to 6 PM for two continuous weeks and noise levels were then determined in three different days according to the traffic peak. Results: Results obtained showed a significant relationship between traffic rates and noise levels in near-road stations (R 2 linear = 0.341. The relationship between interval and noise level was also significant (R 2 quadratic = 0.701, P < 0.05. Furthermore, a distance with 55 dB (A (i.e., 50 m in this study was achieved as a proper site for fencing. Conclusion: Although the amount of noise levels in the middle of channels were less than the standard level, this amount in some channel throats were higher and need to be considered for soundproof installation as well. In addition to finding an area for fencing, using solution(s for reducing either noise pollution or its impact at this area should be taken into consideration.

  4. MOTOR VEHICLE SAFETY RESEARCH METHODOLOGY

    Directory of Open Access Journals (Sweden)

    A. Stepanov

    2015-07-01

    Full Text Available The issues of vehicle safety are considered. The methodology of approach to analyzing and solving the problem of safety management of vehicles and overall traffic is offered. The distinctive features of organization and management of vehicle safety are shown. There has been drawn a conclusion that the methodological approach to solving traffic safety problems is reduced to selection and classification of safety needs.

  5. Evaluation of traffic pollution on Moscow network

    Energy Technology Data Exchange (ETDEWEB)

    Lukanin, V.N.; Buslaev, A.P.; Yashina, M. [Moscow State Automobile and Road Technical University, MADI-TU, Mscow (Russian Federation)

    2000-07-01

    The Moscow vehicle fleet grows each year and traffic is a major source of air pollutants in Moscow. We have developed a model for air quality evaluation and management in a megalopolis in order to improve ecological parameters of vehicles. We have received estimations of traffic influence on human health. These analytical methods allow to regulate traffic flows on road network and structure of car fleet in order to minimise damage to the environment in large cities. Simulation methods are tested on traffic data of Moscow City. The purpose of the research is development of principles, modelling and experimental methods of air quality management in a large city in order to improve ecological parameters of vehicles, to regulate traffic flows on road network and structure of car fleet. (authors)

  6. Application of travel time information for traffic management.

    Science.gov (United States)

    2012-03-01

    This report summarizes findings and implementations of probe vehicle data collection based on Bluetooth MAC address matching : technology. Probe vehicle travel time data are studied in the following field deployment case studies: analysis of traffic ...

  7. Aggregate strength for bituminous surfacings for low volume roads: a heavy vehicle simulator experience

    CSIR Research Space (South Africa)

    Paige-Green, P

    2004-09-01

    Full Text Available This paper discusses an investigation using the CSIR Transportek Heavy Vehicle Simulator (HVS) to determine the impact of using aggregates softer than specified in chip seals and to propose possible relaxations in the currently specified strength...

  8. Physics of Traffic Flow

    Science.gov (United States)

    Davis, L. C.

    2015-03-01

    The Texas A&M Transportation Institute estimated that traffic congestion cost the United States 121 billion in 2011 (the latest data available). The cost is due to wasted time and fuel. In addition to accidents and road construction, factors contributing to congestion include large demand, instability of high-density free flow and selfish behavior of drivers, which produces self-organized traffic bottlenecks. Extensive data collected on instrumented highways in various countries have led to a better understanding of traffic dynamics. From these measurements, Boris Kerner and colleagues developed a new theory called three-phase theory. They identified three major phases of flow observed in the data: free flow, synchronous flow and wide moving jams. The intermediate phase is called synchronous because vehicles in different lanes tend to have similar velocities. This congested phase, characterized by lower velocities yet modestly high throughput, frequently occurs near on-ramps and lane reductions. At present there are only two widely used methods of congestion mitigation: ramp metering and the display of current travel-time information to drivers. To find more effective methods to reduce congestion, researchers perform large-scale simulations using models based on the new theories. An algorithm has been proposed to realize Wardrop equilibria with real-time route information. Such equilibria have equal travel time on alternative routes between a given origin and destination. An active area of current research is the dynamics of connected vehicles, which communicate wirelessly with other vehicles and the surrounding infrastructure. These systems show great promise for improving traffic flow and safety.

  9. Concept of operations and policy implications for unmanned aircraft systems use for traffic incident management (UAS-TIM) : final report.

    Science.gov (United States)

    2017-03-01

    Texas freeways experience considerable traffic congestionsome from high traffic volumes and some from traffic incidents, both minor (e.g., crashes, stalls, and road debris) and major (e.g., vehicle rollovers, chemical spills, flooding, and hurrica...

  10. Traffic safety facts 1995 : large trucks

    Science.gov (United States)

    1996-01-01

    In 1995, 376,000 large trucks (gross vehicle weight rating greater than 10,000 pounds) were involved in traffic crashes in the United States; 4,453 were involved in fatal crashes. A total of 4,903 people died (12 percent of all the traffic fatalities...

  11. Traffic safety facts 1993 : large trucks

    Science.gov (United States)

    1994-01-01

    In 1994, 4,615 large trucks (gross vehicle weight rating greater than 10,000 pounds) were involved in fatal traffic crashes in the United States. A total of 5,112 people died in those crashes-13 percent of the 40,676 traffic fatalities reported in 19...

  12. Traffic safety facts 1996 : large trucks

    Science.gov (United States)

    1997-01-01

    In 1996, 393,000 large trucks (gross vehicle weight rating greater than 10,000 pounds) were involved in traffic crashes in the United States; 4,740 were involved in fatal crashes. A total of 5,126 people died (12 percent of all the traffic fatalities...

  13. Traffic safety facts 1994 : large trucks

    Science.gov (United States)

    1995-01-01

    In 1994, 4,615 large trucks (gross vehicle weight rating greater than 10,000 pounds) were involved in fatal traffic crashes in the United States. A total of 5,112 people died in those crashes-13 percent of the 40,676 traffic fatalities reported in 19...

  14. Traffic safety facts 1999 : large trucks

    Science.gov (United States)

    2000-01-01

    In 1999, 475,000 large trucks (gross vehicle weight rating greater than 10,000 lb) were involved in traffic crashes in the United States; 4,898 were involved in fatal crashes. A total of 5,362 people died (13% of all the traffic fatalities reported i...

  15. 77 FR 69586 - Federal Motor Vehicle Safety Standards; Small Business Impacts of Motor Vehicle Safety

    Science.gov (United States)

    2012-11-20

    ... National Highway Traffic Safety Administration 49 CFR Part 571 Federal Motor Vehicle Safety Standards; Small Business Impacts of Motor Vehicle Safety AGENCY: National Highway Traffic Safety Administration..., and motor vehicle equipment. DATES: You should submit comments early enough to ensure that Docket...

  16. Overview of the state-of-the-practice in disseminating traffic information by advanced traffic management systems: Translink{trademark} innovative surface transportation management. Research report, September 1996--August 1997

    Energy Technology Data Exchange (ETDEWEB)

    Stout, T.; Poe, C.; Dixon, M.

    1997-10-01

    Recent improvements in traffic sensor and data acquisition methods now allow public agencies to expand the capabilities of their transportation management systems by providing a better representation of the network. By having the ability to acquire better traffic data, each agency has information that is more valuable to itself, to the public, and potentially to provide enterprise than similar information of just a few years ago. However, several procedural and institutional questions arise when an agency contemplates undertaking the acquisition and dissemination of traffic information. To determine how other agencies have answered these questions and to provide a practice of traffic information dissemination within the United States by conducting a survey of some of the agencies that are operating traffic management centers and disseminating traffic information. This project also synthesizes the findings.

  17. Surface engineering of macrophages with nanoparticles to generate a cell-nanoparticle hybrid vehicle for hypoxia-targeted drug delivery.

    Science.gov (United States)

    Holden, Christopher A; Yuan, Quan; Yeudall, W Andrew; Lebman, Deborah A; Yang, Hu

    2010-02-02

    Tumors frequently contain hypoxic regions that result from a shortage of oxygen due to poorly organized tumor vasculature. Cancer cells in these areas are resistant to radiation- and chemotherapy, limiting the treatment efficacy. Macrophages have inherent hypoxia-targeting ability and hold great advantages for targeted delivery of anticancer therapeutics to cancer cells in hypoxic areas. However, most anticancer drugs cannot be directly loaded into macrophages because of their toxicity. In this work, we designed a novel drug delivery vehicle by hybridizing macrophages with nanoparticles through cell surface modification. Nanoparticles immobilized on the cell surface provide numerous new sites for anticancer drug loading, hence potentially minimizing the toxic effect of anticancer drugs on the viability and hypoxia-targeting ability of the macrophage vehicles. In particular, quantum dots and 5-(aminoacetamido) fluorescein-labeled polyamidoamine dendrimer G4.5, both of which were coated with amine-derivatized polyethylene glycol, were immobilized to the sodium periodate-treated surface of RAW264.7 macrophages through a transient Schiff base linkage. Further, a reducing agent, sodium cyanoborohydride, was applied to reduce Schiff bases to stable secondary amine linkages. The distribution of nanoparticles on the cell surface was confirmed by fluorescence imaging, and it was found to be dependent on the stability of the linkages coupling nanoparticles to the cell surface.

  18. Area-wide traffic calming for preventing traffic related injuries.

    Science.gov (United States)

    Bunn, F; Collier, T; Frost, C; Ker, K; Roberts, I; Wentz, R

    2003-01-01

    It is estimated that by 2020 road traffic crashes will have moved from ninth to third in the world disease burden ranking, as measured in disability adjusted life years, and second in developing countries. The identification of effective strategies for the prevention of traffic related injuries is of global health importance. Area-wide traffic calming schemes that discourage through traffic on residential roads is one such strategy. To evaluate the effectiveness of area-wide traffic calming in preventing traffic related crashes, injuries, and deaths. We searched the following electronic databases: Cochrane Injuries Group's Specialised Register, Cochrane Controlled Trials Register, MEDLINE, EMBASE and TRANSPORT (NTIS, TRIS, TRANSDOC). We searched the web sites of road safety organisations, handsearched conference proceedings, checked reference lists of relevant papers and contacted experts in the area. The search was not restricted by language or publication status. Randomised controlled trials, and controlled before-after studies of area-wide traffic calming schemes. Two reviewers independently extracted data on type of study, characteristics of intervention and control areas, and length of data collection periods. Before and after data were collected on the total number of road traffic crashes, all road user deaths and injuries, pedestrian-motor vehicle collisions and road user deaths. The statistical package STATA was used to calculate rate ratios for each study, which were then pooled to give an overall estimate using a random effects model. We found no randomised controlled trials, but 16 controlled before-after trials met our inclusion criteria. Seven studies were done in Germany, six in the UK, two in Australia and one in the Netherlands. There were no studies in low or middle income countries. Eight trials reported the number of road traffic crashes resulting in deaths. The pooled rate ratio was 0.63 (0.14, 2.59 95% CI). Sixteen studies reported the number

  19. Electric vehicle - near or far

    Energy Technology Data Exchange (ETDEWEB)

    Laiho, Y.

    1997-11-01

    Traffic is rapidly becoming the number one environmental problem, especially in metropolitan areas. Electric vehicles have many important advantages to offer. Air quality would be improved, since electric vehicles do not pollute the environment. The improvement obtained might be equated with that resulting from the introduction of district heat for the heating of residential buildings. Electric vehicles also present considerable potential for energy conservation

  20. Design and Testing of a Prototype Lunar or Planetary Surface Landing Research Vehicle (LPSLRV)

    Science.gov (United States)

    Murphy, Gloria A.

    2010-01-01

    This handbook describes a two-semester senior design course sponsored by the NASA Office of Education, the Exploration Systems Mission Directorate (ESMD), and the NASA Space Grant Consortium. The course was developed and implemented by the Mechanical and Aerospace Engineering Department (MAE) at Utah State University. The course final outcome is a packaged senior design course that can be readily incorporated into the instructional curriculum at universities across the country. The course materials adhere to the standards of the Accreditation Board for Engineering and Technology (ABET), and is constructed to be relevant to key research areas identified by ESMD. The design project challenged students to apply systems engineering concepts to define research and training requirements for a terrestrial-based lunar landing simulator. This project developed a flying prototype for a Lunar or Planetary Surface Landing Research Vehicle (LPSRV). Per NASA specifications the concept accounts for reduced lunar gravity, and allows the terminal stage of lunar descent to be flown either by remote pilot or autonomously. This free-flying platform was designed to be sufficiently-flexible to allow both sensor evaluation and pilot training. This handbook outlines the course materials, describes the systems engineering processes developed to facilitate design fabrication, integration, and testing. This handbook presents sufficient details of the final design configuration to allow an independent group to reproduce the design. The design evolution and details regarding the verification testing used to characterize the system are presented in a separate project final design report. Details of the experimental apparatus used for system characterization may be found in Appendix F, G, and I of that report. A brief summary of the ground testing and systems verification is also included in Appendix A of this report. Details of the flight tests will be documented in a separate flight test

  1. Brake wear from vehicles as an important source of diffuse copper pollution

    NARCIS (Netherlands)

    Hulskotte, J.H.J.; Gon, H.A.C.D. van der; Visschedijk, A.J.H.; Schaap, M.

    2007-01-01

    In this article we show that brake wear from road traffic vehicles is an important source of atmospheric (participate) copper concentrations in Europe. Consequently, brake wear also contributes significantly to deposition fluxes of copper to surface waters. We estimated the copper emission due to

  2. assessment of traffic flow on enugu highways using speed density

    African Journals Online (AJOL)

    HOD

    effectively if traffic behaviours under all conditions are modeled accurately [2]. Traffic flow in engineering is the study of interaction between vehicles, commuters and infrastructure. (including the highways, signage and traffic control devices) with the aim of understanding and developing an optimal road network with efficient ...

  3. Efficiency of Roundabouts as Compared to Traffic Light Controlled ...

    African Journals Online (AJOL)

    Bheema

    light especially when the electric power consumption, fuel consumption and emission by the vehicles stopped by red light at the entrance of signalized intersection are taken into consideration. When traffic density exceeds this value, however, it is recommended for the traffic to be regulated with traffic light at a part time basis ...

  4. Impact of different vehicles for laser-assisted drug permeation via skin: full-surface versus fractional ablation.

    Science.gov (United States)

    Lee, Woan-Ruoh; Shen, Shing-Chuan; Aljuffali, Ibrahim A; Li, Yi-Ching; Fang, Jia-You

    2014-02-01

    This study aimed to assess impact of different vehicles for laser-assisted skin drug delivery. We also tried to uncover the mechanisms by which different vehicles affect laser-aided skin permeation. Full-surface ablative (conventional) and fractional lasers were used to irradiate nude mouse skin. Imiquimod and 5-aminolevulinic acid (ALA) were used as lipophilic and hydrophilic permeants. Vehicles employed included water with 40% polyethylene glycol 400 (PEG 400), propylene glycol (PG), and ethanol. Lipid nanoparticles were also utilized as carriers. In vitro permeation profiles showed improvement in imiquimod flux with conventional laser (2.5 J/cm2) producing a 12-, 9-, and 5-fold increase when loading imiquimod in 40% PEG400, PG, and ethanol, respectively, as compared with intact skin. Nanoparticulate delivery by laser produced a 6-fold enhancement in permeation. Fractional laser produced less enhancement of imiquimod delivery than conventional laser. Laser exposure increased follicular imiquimod accumulation from 0.80 to 5.81 μg/cm2. ALA permeation from aqueous buffer, PEG 400, and PG with conventional laser treatment was 641-, 445-, and 104-fold superior to passive control. In vivo skin deposition of topically applied ALA examined by confocal microscopy indicated the same trend as the in vitro experiment, with aqueous buffer showing the greatest proporphyllin IX signaling. Diffusion of cosolvent molecules into ablated skin and drug partitioning from vehicle to skin are two predominant factors controlling laser-assisted delivery. In contrast to conventional laser, lateral drug diffusion was anticipated for fractional laser. Our results suggest that different drug delivery vehicles substantially influence drug penetration enhanced by lasers.

  5. Vehicle Speed Estimation and Forecasting Methods Based on Cellular Floating Vehicle Data

    Directory of Open Access Journals (Sweden)

    Wei-Kuang Lai

    2016-02-01

    Full Text Available Traffic information estimation and forecasting methods based on cellular floating vehicle data (CFVD are proposed to analyze the signals (e.g., handovers (HOs, call arrivals (CAs, normal location updates (NLUs and periodic location updates (PLUs from cellular networks. For traffic information estimation, analytic models are proposed to estimate the traffic flow in accordance with the amounts of HOs and NLUs and to estimate the traffic density in accordance with the amounts of CAs and PLUs. Then, the vehicle speeds can be estimated in accordance with the estimated traffic flows and estimated traffic densities. For vehicle speed forecasting, a back-propagation neural network algorithm is considered to predict the future vehicle speed in accordance with the current traffic information (i.e., the estimated vehicle speeds from CFVD. In the experimental environment, this study adopted the practical traffic information (i.e., traffic flow and vehicle speed from Taiwan Area National Freeway Bureau as the input characteristics of the traffic simulation program and referred to the mobile station (MS communication behaviors from Chunghwa Telecom to simulate the traffic information and communication records. The experimental results illustrated that the average accuracy of the vehicle speed forecasting method is 95.72%. Therefore, the proposed methods based on CFVD are suitable for an intelligent transportation system.

  6. A new modelling approach for road traffic emissions: VERSIT+

    NARCIS (Netherlands)

    Smit, R.; Smokers, R.T.M.; Rabé, E.L.M.

    2007-01-01

    The objective of VERSIT+ LD is to predict traffic stream emissions for light-duty vehicles in any particular traffic situation. With respect to hot running emissions, VERSIT+ LD consists of a set of statistical models for detailed vehicle categories that have been constructed using multiple linear

  7. Vibration Analysis of 5-DOF Vehicle Model under Stochastic Road Surface Excitation

    Directory of Open Access Journals (Sweden)

    Zhang Yanlong

    2016-01-01

    Full Text Available Considering human body vertical motion, vehicle body vertical motion, pitch movement and vertical jump of front and rear wheels, a five-degree-of-freedom vehicle model is established to study basic driving characteristics of the vehicle. Using Fourier transform method, acceleration power spectral density of the seat and the mean square value curves of seat vertical weighted acceleration are obtained by numerical simulation. Combined with comfort provision standards, the influence of vehicle model parameters and speed on seat acceleration power spectral density and vertical root-mean-square value of seat weighted acceleration are analyzed. Results show that the stiffness and damping of the seat have no significant effect on seat acceleration power spectral density, and seat acceleration PSD increases with increasing front or rear suspension stiffness, but it decreases with increasing front or rear suspension damping. It should also be concluded that the model stiffness and the mean square value of seat vertical weighted acceleration present positive correlation in general, but seat vertical weighted acceleration decrease first and then increase when model damping increase. Such analysis results can provide reference for the parameter optimization design of the automobile.

  8. Fluctuations in Urban Traffic Networks

    Science.gov (United States)

    Chen, Yu-Dong; Li, Li; Zhang, Yi; Hu, Jian-Ming; Jin, Xue-Xiang

    Urban traffic network is a typical complex system, in which movements of tremendous microscopic traffic participants (pedestrians, bicyclists and vehicles) form complicated spatial and temporal dynamics. We collected flow volumes data on the time-dependent activity of a typical urban traffic network, finding that the coupling between the average flux and the fluctuation on individual links obeys a certain scaling law, with a wide variety of scaling exponents between 1/2 and 1. These scaling phenomena can explain the interaction between the nodes' internal dynamics (i.e. queuing at intersections, car-following in driving) and changes in the external (network-wide) traffic demand (i.e. the every day increase of traffic amount during peak hours and shocking caused by traffic accidents), allowing us to further understand the mechanisms governing the transportation system's collective behavior. Multiscaling and hotspot features are observed in the traffic flow data as well. But the reason why the separated internal dynamics are comparable to the external dynamics in magnitude is still unclear and needs further investigations.

  9. Rollover Mitigation Controller Development for Three-Wheeled Vehicle Using Active Front Steering

    Directory of Open Access Journals (Sweden)

    Raja Amer Azim

    2015-01-01

    Full Text Available Three-wheeled vehicles are agile, less complex, but relatively more prone to rollover. The current study focuses on the rollover mitigation control design using active front steering for such vehicles. A lateral load transfer ratio (LLTR adapted for a three-wheeled platform is presented. Sliding mode control design strategy has been devised which results in pseudo-direct control for roll dynamics of the vehicle. The lag in vehicle roll angle response has been managed using adaptive sliding surface. This concept can be extended for other vehicle configurations. The proposed control scheme is investigated for efficacy using a full vehicle simulation model of CarSim software and National Highway Traffic Safety Administration’s proposed Fishhook maneuver. The controller is able to limit the rollover propensity even with vehicle parameter uncertainties.

  10. A Sarsa(λ)-Based Control Model for Real-Time Traffic Light Coordination

    OpenAIRE

    Xiaoke Zhou; Fei Zhu; Quan Liu; Yuchen Fu; Wei Huang

    2014-01-01

    Traffic problems often occur due to the traffic demands by the outnumbered vehicles on road. Maximizing traffic flow and minimizing the average waiting time are the goals of intelligent traffic control. Each junction wants to get larger traffic flow. During the course, junctions form a policy of coordination as well as constraints for adjacent junctions to maximize their own interests. A good traffic signal timing policy is helpful to solve the problem. However, as there are so many factors t...

  11. Review on Driverless Traffic from Management Perspective

    Directory of Open Access Journals (Sweden)

    Chen Tingting

    2017-01-01

    Full Text Available The move towards automated driving is gaining ground. This paper reviews the development process of self-driving technology and discusses the safety and efficiency advantages of autonomous vehicles. The discussion shows that the existing traffic management system, including transport infrastructures and regulations, should be changed accordingly to maximize the advantages of autonomous driving. Thus, this paper subsequently gives an insight of the traffic management from three aspects: fully self-driving traffic infrastructures, mixed traffic infrastructures and regulations. First, it is summarized in detail what should be adjusted in intersections, parking lots, pedestrian crossings, ramps, signs and markings. With the transformation of traffic infrastructures, the advantages of driverless car will be more pronounced on account of increased capacity, reduced delay and land use. Also, this paper indicates that the implementations of strict product liability for self-driving car manufacturers and no-fault tort liability for users are applicable to automated vehicle accidents.

  12. Wave-Powered Unmanned Surface Vehicle as a Station-Keeping Gateway Node for Undersea Distributed Networks

    Science.gov (United States)

    2012-09-01

    Kinetic energy in the form of sea-surface wave oscillations is transformed into horizontal thrust of the vehicle using the flipper action of the lower body...similar to the Wave Glider design [17]. The resultant force Fmax is: Fmax =CD rV 2max 2 S0 (3.1) where CD is the drag coefficient of the thrust flippers , r...Efficiency of the design is also important to the overall operation of the Wave Glider propulsion system, and theory has shown that the flipper action is

  13. Modeling and Simulation of Vehicle Dynamics on the Surface of Phobos

    Science.gov (United States)

    Quadrelli, Marco B.; Balaram, J. Bob; Jain, Abhinandan; Cameron, Jonathan; Myint, Steven; Devalla, Avinash

    2015-01-01

    In this paper we analyze the dynamics of a spacecraft in proximity of Phobos by developing the equations of motion of a test mass in the Phobos rotating frame using a model based on circularly-restricted three body problem, and by analyzing the dynamics of a ATHLETE hopper vehicle interacting with the soil under different soil-interaction conditions. The main conclusion of the numerical studies is that the system response is dominated by the stiffness and damping parameters of the leg springs, with the soil characteristics having a much smaller effect. The system simulations identify ranges of parameters for which the vehicle emerges stably (relying only on the passive viscoelastic damper at each leg) or unstably (needing active attitude control) from the hop. The implication is that further experimental and possibly computational modeling work, as well as site characterization (from precursor missions) will be necessary to obtain validated performance models.

  14. Vehicle cabin cooling system for capturing and exhausting heated boundary layer air from inner surfaces of solar heated windows

    Science.gov (United States)

    Farrington, Robert B.; Anderson, Ren

    2001-01-01

    The cabin cooling system includes a cooling duct positioned proximate and above upper edges of one or more windows of a vehicle to exhaust hot air as the air is heated by inner surfaces of the windows and forms thin boundary layers of heated air adjacent the heated windows. The cabin cooling system includes at least one fan to draw the hot air into the cooling duct at a flow rate that captures the hot air in the boundary layer without capturing a significant portion of the cooler cabin interior air and to discharge the hot air at a point outside the vehicle cabin, such as the vehicle trunk. In a preferred embodiment, the cooling duct has a cross-sectional area that gradually increases from a distal point to a proximal point to the fan inlet to develop a substantially uniform pressure drop along the length of the cooling duct. Correspondingly, this cross-sectional configuration develops a uniform suction pressure and uniform flow rate at the upper edge of the window to capture the hot air in the boundary layer adjacent each window.

  15. Traffic camera system development

    Science.gov (United States)

    Hori, Toshi

    1997-04-01

    The intelligent transportation system has generated a strong need for the development of intelligent camera systems to meet the requirements of sophisticated applications, such as electronic toll collection (ETC), traffic violation detection and automatic parking lot control. In order to achieve the highest levels of accuracy in detection, these cameras must have high speed electronic shutters, high resolution, high frame rate, and communication capabilities. A progressive scan interline transfer CCD camera, with its high speed electronic shutter and resolution capabilities, provides the basic functions to meet the requirements of a traffic camera system. Unlike most industrial video imaging applications, traffic cameras must deal with harsh environmental conditions and an extremely wide range of light. Optical character recognition is a critical function of a modern traffic camera system, with detection and accuracy heavily dependent on the camera function. In order to operate under demanding conditions, communication and functional optimization is implemented to control cameras from a roadside computer. The camera operates with a shutter speed faster than 1/2000 sec. to capture highway traffic both day and night. Consequently camera gain, pedestal level, shutter speed and gamma functions are controlled by a look-up table containing various parameters based on environmental conditions, particularly lighting. Lighting conditions are studied carefully, to focus only on the critical license plate surface. A unique light sensor permits accurate reading under a variety of conditions, such as a sunny day, evening, twilight, storms, etc. These camera systems are being deployed successfully in major ETC projects throughout the world.

  16. Self-Organizing Traffic at a Malfunctioning Intersection

    OpenAIRE

    Sujai Kumar; Sugata Mitra

    2006-01-01

    Traffic signals and traffic flow models have been studied extensively in the past and have provided valuable insights on the design of signalling systems, congestion control, and punitive policies. This paper takes a slightly different tack and describes what happens at an intersection where the traffic signals are malfunctioning and stuck in some configuration. By modelling individual vehicles as agents, we were able to replicate the surprisingly organized traffic flow that we observed at a ...

  17. Electric and hybrid vehicles: power sources, models, sustainability, infrastructure and the market

    National Research Council Canada - National Science Library

    Pistoia, G

    2010-01-01

    ... for simulation studies Velocity scheduling using traffic preview Hybrid vehicles with telematics Optimal management of hybrid vehicles with telematics Conclusions and future opportunities 1. 2. 3...

  18. A statistical analysis of energy and power demand for the tractive purposes of an electric vehicle in urban traffic - an analysis of a short and long observation period

    Science.gov (United States)

    Slaski, G.; Ohde, B.

    2016-09-01

    The article presents the results of a statistical dispersion analysis of an energy and power demand for tractive purposes of a battery electric vehicle. The authors compare data distribution for different values of an average speed in two approaches, namely a short and long period of observation. The short period of observation (generally around several hundred meters) results from a previously proposed macroscopic energy consumption model based on an average speed per road section. This approach yielded high values of standard deviation and coefficient of variation (the ratio between standard deviation and the mean) around 0.7-1.2. The long period of observation (about several kilometers long) is similar in length to standardized speed cycles used in testing a vehicle energy consumption and available range. The data were analysed to determine the impact of observation length on the energy and power demand variation. The analysis was based on a simulation of electric power and energy consumption performed with speed profiles data recorded in Poznan agglomeration.

  19. A computerized traffic control algorithm to determine optimal traffic signal settings. Ph.D. Thesis - Toledo Univ.

    Science.gov (United States)

    Seldner, K.

    1977-01-01

    An algorithm was developed to optimally control the traffic signals at each intersection using a discrete time traffic model applicable to heavy or peak traffic. Off line optimization procedures were applied to compute the cycle splits required to minimize the lengths of the vehicle queues and delay at each intersection. The method was applied to an extensive traffic network in Toledo, Ohio. Results obtained with the derived optimal settings are compared with the control settings presently in use.

  20. Research of Off-Nominal Airport Traffic Management using a Surface Management System-Based Simulation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project is complimentary and directly beneficial to NASA's Safe and Efficient Surface Operations (SESO) research. NASA has previously developed a...

  1. Finite-time sliding mode attitude control for a reentry vehicle with blended aerodynamic surfaces and a reaction control system

    Directory of Open Access Journals (Sweden)

    Geng Jie

    2014-08-01

    Full Text Available This paper proposes a finite-time robust flight controller, targeting for a reentry vehicle with blended aerodynamic surfaces and a reaction control system (RCS. Firstly, a novel finite-time attitude controller is pointed out with the introduction of a nonsingular finite-time sliding mode manifold. The attitude tracking errors are mathematically proved to converge to zero within finite time which can be estimated. In order to improve the performance, a second-order finite-time sliding mode controller is further developed to effectively alleviate chattering without any deterioration of robustness and accuracy. Moreover, an optimization control allocation algorithm, using linear programming and a pulse-width pulse-frequency (PWPF modulator, is designed to allocate torque commands for all the aerodynamic surface deflections and on–off switching-states of RCS thrusters. Simulations are provided for the reentry vehicle considering uncertain parameters and external disturbances for practical purposes, and the results demonstrate the effectiveness and robustness of the attitude control system.

  2. Guidelines for developing a high-visibility enforcement campaign to reduce unsafe driving behaviors among drivers of passenger and commercial motor vehicles : a Selective Traffic Enforcement Program (STEP) based on the Ticketing Aggressive Cars and Trucks (TACT) pilot project

    Science.gov (United States)

    2007-10-01

    The goal of Selective Traffic Enforcement Programs (STEPs) is to induce motorists to drive safely. To achieve this goal, the STEP model combines intensive enforcement of a specific traffic safety law with extensive communication, education, and outre...

  3. Determination of an Optimal Control Strategy for a Generic Surface Vehicle

    Science.gov (United States)

    2014-06-18

    surge , sway , and yaw dynamics and neglects heave, roll, and pitch dynamics.’ The vehicle-fixed coordinate system is positioned at the center of mass with...centripetal matrix, D is the damping matrix, and / are the control forces and moments. The mass matrix M and Coriolis and centripetal matrix C can be...YyV — Y^r) -m (xgr + v) + Yi,v + Yi-r {-X^ + m)u m — X^u 0 (5) The damping matrix is composed of linear and nonlinear terms. The linear damping

  4. Effects of thermochemistry, nonequilibrium, and surface catalysis on the design of hypersonic vehicles

    Science.gov (United States)

    Scott, Carl D.

    1989-01-01

    An account is given of the function of physical aspects of a gas on the characteristics of the flow and of the heating associated with hypersonic flight. At the high temperatures encountered, the thermal and chemical characteristics of the air in a hypersonic vehicle's shock layer are altered in ways which depend on the atomic and molecular structure of N and O and their ions; similar effects exist in scramjet propulsion systems. These properties in turn influence the character of shock waves and expansions, and hence the pressure, temperature, and velocity distributions. Transport properties affecting the boundary-layer structure will also affect heat flux and shear stress.

  5. Traffic and Granular Flow '11

    CERN Document Server

    Buslaev, Alexander; Bugaev, Alexander; Yashina, Marina; Schadschneider, Andreas; Schreckenberg, Michael; TGF11

    2013-01-01

    This book continues the biannual series of conference proceedings, which has become a classical reference resource in traffic and granular research alike. It addresses new developments at the interface between physics, engineering and computational science. Complex systems, where many simple agents, be they vehicles or particles, give rise to surprising and fascinating phenomena.   The contributions collected in these proceedings cover several research fields, all of which deal with transport. Topics include highway, pedestrian and internet traffic, granular matter, biological transport, transport networks, data acquisition, data analysis and technological applications. Different perspectives, i.e. modeling, simulations, experiments and phenomenological observations, are considered.

  6. A Study on the Impact Coefficient of Traffic Flows on a Large Cable-Stayed Bridge in a Windy Environment

    Directory of Open Access Journals (Sweden)

    L. Ma

    2014-01-01

    Full Text Available By developing a wind-vehicle-bridge coupling dynamic analysis system, the impact coefficient of traffic flows on a cable-stayed bridge and its probabilistic distribution are studied in the paper. Some important influence factors of the impact coefficient, such as the vehicle-bridge coupling effect, traveling velocity, and traffic density, are analyzed. The influence of the coupling effect between a bridge deck’s buffeting and vehicles’ vibration on the impact coefficient of traffic flows on a cable-stayed bridge is paid due attention to. The results show that vehicle-bridge coupling effect and surface roughness exert important influence on the impact effect of a cable-stayed bridge. Considering that impact coefficient of traffic flows on a bridge bears the characteristics of randomness, the paper, on the basis of a large number of samples, interprets the influence of traveling velocity and traffic density in view of its probabilistic distribution. In view of results derived from the coupling dynamic analysis, it is suggested that the impact coefficient be 25% for all spans of a long cable-stayed bridge like the Sutong Yangtze Bridge.

  7. Connected variable speed limits control and vehicle acceleration control to resolve moving jams

    NARCIS (Netherlands)

    Wang, M.; Daamen, W.; Hoogendoorn, S.P.; Van Arem, B.

    2015-01-01

    The vision of intelligent vehicles traveling in road networks has prompted numerous concepts to control future traffic flow, one of which is the in-vehicle actuation of traffic control signals. The key of this concept is using intelligent vehicles as actuators for traffic control systems, replacing

  8. TRAFFIC SIGN DETECTION BASED ON BIOLOGICALLY VISUAL MECHANISM

    Directory of Open Access Journals (Sweden)

    X. Hu

    2012-07-01

    Full Text Available TSR (Traffic sign recognition is an important problem in ITS (intelligent traffic system, which is being paid more and more attention for realizing drivers assisting system and unmanned vehicle etc. TSR consists of two steps: detection and recognition, and this paper describe a new traffic sign detection method. The design principle of the traffic sign is comply with the visual attention mechanism of human, so we propose a method using visual attention mechanism to detect traffic sign ,which is reasonable. In our method, the whole scene will firstly be analyzed by visual attention model to acquire the area where traffic signs might be placed. And then, these candidate areas will be analyzed according to the shape characteristics of the traffic sign to detect traffic signs. In traffic sign detection experiments, the result shows the proposed method is effectively and robust than other existing saliency detection method.

  9. Use of mobile data for weather-responsive traffic management models.

    Science.gov (United States)

    2012-10-01

    The evolution of telecommunications and wireless technologies has brought in new sources of traffic data (particularly mobile data generated by vehicle probes), which could offer a breakthrough in the quality and extent of traffic data. This study re...

  10. Mining vehicle classifications from the Columbus Metropolitan Freeway Management System.

    Science.gov (United States)

    2015-01-01

    Vehicle classification data are used in many transportation applications, including: pavement design, : environmental impact studies, traffic control, and traffic safety. Ohio has over 200 permanent count stations, : supplemented by many more short-t...

  11. 32 CFR 636.38 - Impounding privately owned vehicles (POVs).

    Science.gov (United States)

    2010-07-01

    ... cleanup operations. (iii) The privately owned vehicle has been used in a crime or contains evidence of... present. This situation could arise during traffic and crime-related impoundments and abandoned vehicle... crime or serious traffic violation and sufficient probable cause exists to seize the vehicle. This...

  12. Traffic networks as information systems a viability approach

    CERN Document Server

    Aubin, Jean-Pierre

    2017-01-01

    This authored monograph covers a viability to approach to traffic management by advising to vehicles circulated on the network the velocity they should follow for satisfying global traffic conditions;. It presents an investigation of three structural innovations: The objective is to broadcast at each instant and at each position the advised celerity to vehicles, which could be read by auxiliary speedometers or used by cruise control devices. Namely, 1. Construct regulation feedback providing at each time and position advised velocities (celerities) for minimizing congestion or other requirements. 2. Taking into account traffic constraints of different type, the first one being to remain on the roads, to stop at junctions, etc. 3. Use information provided by the probe vehicles equipped with GPS to the traffic regulator; 4. Use other global traffic measures of vehicles provided by different types of sensors; These results are based on convex analysis, intertemporal optimization and viability theory as mathemati...

  13. Generation and Assessment of High Resolution Digital Surface Model by Using Unmanned Air Vehicle Based Multicopter

    Science.gov (United States)

    Gülci, S.; Dindaroğlu, T.; Gündoğan, R.

    2017-11-01

    Unmanned air vehicle systems (UAVSs), which are presently defined as effective measuring instruments, can be used for measurements and evaluation studies in fields. Furthermore, UAVs are effective tools that can produce high-precision and resolution data for use in geographic information system-based work. This study examined a multicopter (hexacopter) as an air platform to seek opportunity in generating DSM with high resolution. Flights were performed in Kahramanmaras Sutcu Imam University Campus area in Turkey. Pre-assessment of field works, mission, tests and installation were prepared by using a Laptop with an adaptive ground control station. Hand remote controller unit was also linked and activated during flight to interfere with emergency situations. Canon model IXSUS 160 was preferred as sensor. As a result of this study, as mentioned previous studies, .The orthophotos can be produced by RGB (Red-green-blue) images obtained with UAV, herewith information on terrain topography, land cover and soil erosion can be evaluated.

  14. Hydrogen storage on high-surface-area carbon monoliths for Adsorb hydrogen Gas Vehicle

    Science.gov (United States)

    Soo, Yuchoong; Pfeifer, Peter

    2014-03-01

    Carbon briquetting can increase hydrogen volumetric storage capacity by reducing the useless void volume resulting in a better packing density. It is a robust and efficient space-filling form for an adsorbed hydrogen gas vehicle storage tank. To optimize hydrogen storage capacity, we studied three fabrication process parameters: carbon-to-binder ratio, compaction temperature, and pyrolysis atmosphere. We found that carbon-to-binder ratio and pyrolysis atmosphere have influences on gravimetric excess adsorption. Compaction temperature has large influences on gravimetric and volumetric storage capacity. We have been able to optimize these parameters for high hydrogen storage. All monolith uptakes (up to 260 bar) were measured by a custom-built, volumetric, reservoir-type instrument.

  15. The preservation of quartz grain surface textures following vehicle fire and their use in forensic enquiry.

    Science.gov (United States)

    Morgan, R M; Little, M; Gibson, A; Hicks, L; Dunkerley, S; Bull, P A

    2008-09-01

    During a terrorist trial, dispute arose as to whether the temperature produced in a car fire was sufficient to destroy quartz grain surface textures. A series of seven sequential experiments showed that the temperature for quartz surface texture modification/destruction and the production of vugs, vesicles and glassy precipitation ('snowdrifting') occurred at 1200 degrees C under normal atmospheric conditions. By adding a number of man-made and natural substances, it was found that only the presence of salts depressed this modification temperature (to 900 degrees C). Experiments to determine the temperature of fire in a car indicated that the maximum temperature produced under natural conditions (810 degrees C) was insufficient to affect the quartz grain surface textures. These results confirm the use of surface texture analysis of quartz grains recovered from the remains of cars subjected to fire and their use as a forensic indicator.

  16. Simulation Study of Traffic Accidents in Bidirectional Traffic Models

    Science.gov (United States)

    Moussa, Najem

    Conditions for the occurrence of bidirectional collisions are developed based on the Simon-Gutowitz bidirectional traffic model. Three types of dangerous situations can occur in this model. We analyze those corresponding to head-on collision; rear-end collision and lane-changing collision. Using Monte Carlo simulations, we compute the probability of the occurrence of these collisions for different values of the oncoming cars' density. It is found that the risk of collisions is important when the density of cars in one lane is small and that of the other lane is high enough. The influence of different proportions of heavy vehicles is also studied. We found that heavy vehicles cause an important reduction of traffic flow on the home lane and provoke an increase of the risk of car accidents.

  17. Simultaneous Measurements of the Vehicle, Track, and Soil Vibrations at a Surface, Bridge, and Tunnel Railway Line

    Directory of Open Access Journals (Sweden)

    Lutz Auersch

    2017-01-01

    Full Text Available A complex measuring campaign has been performed including the simultaneous measurement of vehicle, track, and soil vibrations during train runs at 16, 25, 40, 63, 80, 100, 125, 140, and 160 km/h and impulse measurements of the passenger car, three track sections, and the soil. A ballast track on the soil surface and on a concrete bridge has been investigated as well as a slab track in a tunnel. The evaluation and comparison of all these data show a generally good agreement for all components if the strong low- and high-frequency cut-off characteristics of the layered and damped soil are incorporated. There is a strong causal correlation between the vehicle and the soil by the dynamic excitation forces and a weak relation between the track and the soil by the axle-sequence spectrum of the train. However, the similarity between the axle-impulse spectrum observed at the track and the spectra of the ground vibration leads to the special excitation component of “scattered axle impulses” which is predominant at the far field points of the soil.

  18. Traffic Monitor

    Science.gov (United States)

    1995-01-01

    Intelligent Vision Systems, Inc. (InVision) needed image acquisition technology that was reliable in bad weather for its TDS-200 Traffic Detection System. InVision researchers used information from NASA Tech Briefs and assistance from Johnson Space Center to finish the system. The NASA technology used was developed for Earth-observing imaging satellites: charge coupled devices, in which silicon chips convert light directly into electronic or digital images. The TDS-200 consists of sensors mounted above traffic on poles or span wires, enabling two sensors to view an intersection; a "swing and sway" feature to compensate for movement of the sensors; a combination of electronic shutter and gain control; and sensor output to an image digital signal processor, still frame video and optionally live video.

  19. Hydraulics and drones: observations of water level, bathymetry and water surface velocity from Unmanned Aerial Vehicles

    DEFF Research Database (Denmark)

    Bandini, Filippo

    extensive research and funding, they are far less expensive and therefore more important than disaster restoration and remediation. Thus, our research question was “Can we retrieve hydraulic observations of inland surface water bodies, whenever and wherever it is required, with (i) high accuracy, (ii) high...... in monitoring surface water bodies, at a limited cost and with high flexibility. This PhD project investigates and demonstrates how UAVs can enrich the set of available hydraulic observations in inland water bodies, including: 1. Orthometric water level. 2. Water depth (bathymetry). 3. Surface water speed...... to satellites, UAVs have several advantages: high spatial resolution, repeatability of the flight missions and good tracking of the water bodies. Nevertheless, UAVs face several constraints: vibrations, limited size, weight, and electric power available for the sensors. In this thesis, we present the first...

  20. A Sarsa(λ-Based Control Model for Real-Time Traffic Light Coordination

    Directory of Open Access Journals (Sweden)

    Xiaoke Zhou

    2014-01-01

    Full Text Available Traffic problems often occur due to the traffic demands by the outnumbered vehicles on road. Maximizing traffic flow and minimizing the average waiting time are the goals of intelligent traffic control. Each junction wants to get larger traffic flow. During the course, junctions form a policy of coordination as well as constraints for adjacent junctions to maximize their own interests. A good traffic signal timing policy is helpful to solve the problem. However, as there are so many factors that can affect the traffic control model, it is difficult to find the optimal solution. The disability of traffic light controllers to learn from past experiences caused them to be unable to adaptively fit dynamic changes of traffic flow. Considering dynamic characteristics of the actual traffic environment, reinforcement learning algorithm based traffic control approach can be applied to get optimal scheduling policy. The proposed Sarsa(λ-based real-time traffic control optimization model can maintain the traffic signal timing policy more effectively. The Sarsa(λ-based model gains traffic cost of the vehicle, which considers delay time, the number of waiting vehicles, and the integrated saturation from its experiences to learn and determine the optimal actions. The experiment results show an inspiring improvement in traffic control, indicating the proposed model is capable of facilitating real-time dynamic traffic control.

  1. A Sarsa(λ)-based control model for real-time traffic light coordination.

    Science.gov (United States)

    Zhou, Xiaoke; Zhu, Fei; Liu, Quan; Fu, Yuchen; Huang, Wei

    2014-01-01

    Traffic problems often occur due to the traffic demands by the outnumbered vehicles on road. Maximizing traffic flow and minimizing the average waiting time are the goals of intelligent traffic control. Each junction wants to get larger traffic flow. During the course, junctions form a policy of coordination as well as constraints for adjacent junctions to maximize their own interests. A good traffic signal timing policy is helpful to solve the problem. However, as there are so many factors that can affect the traffic control model, it is difficult to find the optimal solution. The disability of traffic light controllers to learn from past experiences caused them to be unable to adaptively fit dynamic changes of traffic flow. Considering dynamic characteristics of the actual traffic environment, reinforcement learning algorithm based traffic control approach can be applied to get optimal scheduling policy. The proposed Sarsa(λ)-based real-time traffic control optimization model can maintain the traffic signal timing policy more effectively. The Sarsa(λ)-based model gains traffic cost of the vehicle, which considers delay time, the number of waiting vehicles, and the integrated saturation from its experiences to learn and determine the optimal actions. The experiment results show an inspiring improvement in traffic control, indicating the proposed model is capable of facilitating real-time dynamic traffic control.

  2. Thermal and force loads on the vehicle surface in high-velocity motion in the earth's atmosphere

    Science.gov (United States)

    Tarnavskii, G. A.

    2008-03-01

    Consideration has been given to a number of aspects of mathematical modeling of a high-velocity flight in the earth’s atmosphere in a wide range of variation of the determining parameters. Super-and hypersonic gas flow past flying vehicles has been investigated based on computer-aided calculations with allowance for its actual properties. Data on the distribution of gasdynamic parameters in the flow field, including thermal and force loads on the surface, have been obtained and analyzed. The issues of applying today’s information technologies to archiving scientific knowledge obtained in electronic databases of a specialized Internet center and their dissemination via the Global Network have been discussed.

  3. Global neural dynamic surface tracking control of strict-feedback systems with application to hypersonic flight vehicle.

    Science.gov (United States)

    Xu, Bin; Yang, Chenguang; Pan, Yongping

    2015-10-01

    This paper studies both indirect and direct global neural control of strict-feedback systems in the presence of unknown dynamics, using the dynamic surface control (DSC) technique in a novel manner. A new switching mechanism is designed to combine an adaptive neural controller in the neural approximation domain, together with the robust controller that pulls the transient states back into the neural approximation domain from the outside. In comparison with the conventional control techniques, which could only achieve semiglobally uniformly ultimately bounded stability, the proposed control scheme guarantees all the signals in the closed-loop system are globally uniformly ultimately bounded, such that the conventional constraints on initial conditions of the neural control system can be relaxed. The simulation studies of hypersonic flight vehicle (HFV) are performed to demonstrate the effectiveness of the proposed global neural DSC design.

  4. Deadlock-free traffic control with geometrical critical sections

    NARCIS (Netherlands)

    Schoute, Albert L.; Bouwens, Peter J.; Bouwens, P.J.; De Backer, E.

    1994-01-01

    Traffic control of vehicles on pre-planned paths may be based on critical sections where vehicles have to control their velocity mutually in order to avoid collisions. By analysing the geometry of critical sections carefully deadlock situations can be recognised and situations where vehicles may

  5. Agent Based Individual Traffic Guidance

    DEFF Research Database (Denmark)

    Wanscher, Jørgen

    This thesis investigates the possibilities in applying Operations Research (OR) to autonomous vehicular traffic. The explicit difference to most other research today is that we presume that an agent is present in every vehicle - hence Agent Based Individual Traffic guidance (ABIT). The next...... evolutionary step for the in-vehicle route planners is the introduction of two-way communication. We presume that the agent is capable of exactly this. Based on this presumption we discuss the possibilities and define a taxonomy and use this to discuss the ABIT system. Based on a set of scenarios we conclude...... of the project were not previously considered. We define a special inseparable cost function and develop a solution complex capable of using this cost function. In relation to calibration and estimation of statistical models used for dynamic route guidance we worked with generating random number sequences...

  6. Land surface reflectance retrieval from hyperspectral data collected by an unmanned aerial vehicle over the Baotou test site.

    Science.gov (United States)

    Duan, Si-Bo; Li, Zhao-Liang; Tang, Bo-Hui; Wu, Hua; Ma, Lingling; Zhao, Enyu; Li, Chuanrong

    2013-01-01

    To evaluate the in-flight performance of a new hyperspectral sensor onboard an unmanned aerial vehicle (UAV-HYPER), a comprehensive field campaign was conducted over the Baotou test site in China on 3 September 2011. Several portable reference reflectance targets were deployed across the test site. The radiometric performance of the UAV-HYPER sensor was assessed in terms of signal-to-noise ratio (SNR) and the calibration accuracy. The SNR of the different bands of the UAV-HYPER sensor was estimated to be between approximately 5 and 120 over the homogeneous targets, and the linear response of the apparent reflectance ranged from approximately 0.05 to 0.45. The uniform and non-uniform Lambertian land surface reflectance was retrieved and validated using in situ measurements, with root mean square error (RMSE) of approximately 0.01-0.07 and relative RMSE of approximately 5%-12%. There were small discrepancies between the retrieved uniform and non-uniform Lambertian land surface reflectance over the homogeneous targets and under low aerosol optical depth (AOD) conditions (AOD = 0.18). However, these discrepancies must be taken into account when adjacent pixels had large land surface reflectance contrast and under high AOD conditions (e.g. AOD = 1.0).

  7. Land Surface Reflectance Retrieval from Hyperspectral Data Collected by an Unmanned Aerial Vehicle over the Baotou Test Site

    Science.gov (United States)

    Duan, Si-Bo; Li, Zhao-Liang; Tang, Bo-Hui; Wu, Hua; Ma, Lingling; Zhao, Enyu; Li, Chuanrong

    2013-01-01

    To evaluate the in-flight performance of a new hyperspectral sensor onboard an unmanned aerial vehicle (UAV-HYPER), a comprehensive field campaign was conducted over the Baotou test site in China on 3 September 2011. Several portable reference reflectance targets were deployed across the test site. The radiometric performance of the UAV-HYPER sensor was assessed in terms of signal-to-noise ratio (SNR) and the calibration accuracy. The SNR of the different bands of the UAV-HYPER sensor was estimated to be between approximately 5 and 120 over the homogeneous targets, and the linear response of the apparent reflectance ranged from approximately 0.05 to 0.45. The uniform and non-uniform Lambertian land surface reflectance was retrieved and validated using in situ measurements, with root mean square error (RMSE) of approximately 0.01–0.07 and relative RMSE of approximately 5%–12%. There were small discrepancies between the retrieved uniform and non-uniform Lambertian land surface reflectance over the homogeneous targets and under low aerosol optical depth (AOD) conditions (AOD = 0.18). However, these discrepancies must be taken into account when adjacent pixels had large land surface reflectance contrast and under high AOD conditions (e.g. AOD = 1.0). PMID:23785513

  8. Did Chile's traffic law reform push police enforcement? Understanding Chile's traffic fatalities and injuries reduction.

    Science.gov (United States)

    Nazif-Munoz, José Ignacio; Quesnel-Vallée, Amélie; van den Berg, Axel

    2015-06-01

    The objective of the current study is to determine to what extent the reduction of Chile's traffic fatalities and injuries during 2000-2012 was related to the police traffic enforcement increment registered after the introduction of its 2005 traffic law reform. A unique dataset with assembled information from public institutions and analyses based on ordinary least square and robust random effects models was carried out. Dependent variables were traffic fatality and severe injury rates per population and vehicle fleet. Independent variables were: (1) presence of new national traffic law; (2) police officers per population; (3) number of traffic tickets per police officer; and (4) interaction effect of number of traffic tickets per police officer with traffic law reform. Oil prices, alcohol consumption, proportion of male population 15-24 years old, unemployment, road infrastructure investment, years' effects and regions' effects represented control variables. Empirical estimates from instrumental variables suggest that the enactment of the traffic law reform in interaction with number of traffic tickets per police officer is significantly associated with a decrease of 8% in traffic fatalities and 7% in severe injuries. Piecewise regression model results for the 2007-2012 period suggest that police traffic enforcement reduced traffic fatalities by 59% and severe injuries by 37%. Findings suggest that traffic law reforms in order to have an effect on both traffic fatality and injury rates reduction require changes in police enforcement practices. Last, this case also illustrates how the diffusion of successful road safety practices globally promoted by WHO and World Bank can be an important influence for enhancing national road safety practices. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  9. Hydraulics and drones: observations of water level, bathymetry and water surface velocity from Unmanned Aerial Vehicles

    DEFF Research Database (Denmark)

    Bandini, Filippo

    profilers (ADCPs). For these reasons, water speed observations have been traditionally challenging, especially in difficult-to-access environments. Conversely, UAV-borne observations open up the possibility of measuring water speed over extended regions at a low cost. The 2D water surface velocity field...

  10. Evaluation of the Usefulness of Friction Tester Vehicles to Operate on Runway Pavement Surfaces

    Directory of Open Access Journals (Sweden)

    Wesołowski Mariusz

    2016-12-01

    Full Text Available The assessment correctness of runway pavement surfaces is a crucial element ensuring safety during flight operations. Foreign and national normative documents specify the required values of coefficients of friction both for designed (new and utilized runway pavement surfaces and/or those subject to planned renovation works. What is more, the above mentioned documents determine the minimum (limit values for operated runway pavement surfaces. Furthermore, they also describe the general requirements as regards measuring devices applied to specify the roughness of runway pavement surfaces. The accepted repeatability (Equipment Variation of coefficient of friction measurement is not sufficient to approve the device for roughness measurements of aerodrome functional elements. Due to this fact the device is authorized to take measurements of coefficient of friction under the condition that it is preceded by certain studies carried out in order to establish its usefulness. These research consist inter alia of the device evaluation in view of devices authorized to perform measurements, using statistical apparatus. Final evaluation of instrument usefulness includes additionally the whole gamut of technical problems associated with the operation process, its preparation, calibration (checking before taking measurements and the measurements themselves.

  11. Test Operation Procedure (TOP) 01-1-010A Vehicle Test Course Severity (Surface Roughness)

    Science.gov (United States)

    2017-12-12

    Paragraph 1. SCOPE ................................................................................... 2 2. FACILITIES...ATEC) Test Center facilities are provided in Section 5, in the following paragraphs : a. ATC courses, paragraph 5.1. b. YTC courses, paragraph ...5.2. c. TRTC courses, paragraph 5.3. 3. MONITORING TEST COURSE SURFACE ROUGHNESS. Test course roughness is monitored using several techniques

  12. String stability of vehicle platoons

    NARCIS (Netherlands)

    Ploeg, J.; Wouw, N. van de; Nijmeijer, H.

    2011-01-01

    In recent years, highway capacity has become a limiting factor, regularly causing traffic jams. Obviously, the road capacity can be increased by decreasing the inter-vehicle following distance di . As a consequence, however, vehicle automation in longitudinal direction is required in order to still

  13. Probabilistic description of traffic breakdowns

    Science.gov (United States)

    Kühne, Reinhart; Mahnke, Reinhard; Lubashevsky, Ihor; Kaupužs, Jevgenijs

    2002-06-01

    We analyze the characteristic features of traffic breakdown. To describe this phenomenon we apply the probabilistic model regarding the jam emergence as the formation of a large car cluster on a highway. In these terms, the breakdown occurs through the formation of a certain critical nucleus in the metastable vehicle flow, which enables us to confine ourselves to one cluster model. We assume that, first, the growth of the car cluster is governed by attachment of cars to the cluster whose rate is mainly determined by the mean headway distance between the car in the vehicle flow and, maybe, also by the headway distance in the cluster. Second, the cluster dissolution is determined by the car escape from the cluster whose rate depends on the cluster size directly. The latter is justified using the available experimental data for the correlation properties of the synchronized mode. We write the appropriate master equation converted then into the Fokker-Planck equation for the cluster distribution function and analyze the formation of the critical car cluster due to the climb over a certain potential barrier. The further cluster growth irreversibly causes jam formation. Numerical estimates of the obtained characteristics and the experimental data of the traffic breakdown are compared. In particular, we draw a conclusion that the characteristic intrinsic time scale of the breakdown phenomenon should be about 1 min and explain the case why the traffic volume interval inside which traffic breakdown is observed is sufficiently wide.

  14. Near-roadway monitoring of vehicle emissions as a function of mode of operation for light-duty vehicles.

    Science.gov (United States)

    Wen, Dongqi; Zhai, Wenjuan; Xiang, Sheng; Hu, Zhice; Wei, Tongchuan; Noll, Kenneth E

    2017-11-01

    Determination of the effect of vehicle emissions on air quality near roadways is important because vehicles are a major source of air pollution. A near-roadway monitoring program was undertaken in Chicago between August 4 and October 30, 2014, to measure ultrafine particles, carbon dioxide, carbon monoxide, traffic volume and speed, and wind direction and speed. The objective of this study was to develop a method to relate short-term changes in traffic mode of operation to air quality near roadways using data averaged over 5-min intervals to provide a better understanding of the processes controlling air pollution concentrations near roadways. Three different types of data analysis are provided to demonstrate the type of results that can be obtained from a near-roadway sampling program based on 5-min measurements: (1) development of vehicle emission factors (EFs) for ultrafine particles as a function of vehicle mode of operation, (2) comparison of measured and modeled CO2 concentrations, and (3) application of dispersion models to determine concentrations near roadways. EFs for ultrafine particles are developed that are a function of traffic volume and mode of operation (free flow and congestion) for light-duty vehicles (LDVs) under real-world conditions. Two air quality models-CALINE4 (California Line Source Dispersion Model, version 4) and AERMOD (American Meteorological Society/U.S. Environmental Protection Agency Regulatory Model)-are used to predict the ultrafine particulate concentrations near roadways for comparison with measured concentrations. When using CALINE4 to predict air quality levels in the mixing cell, changes in surface roughness and stability class have no effect on the predicted concentrations. However, when using AERMOD to predict air quality in the mixing cell, changes in surface roughness have a significant impact on the predicted concentrations. The paper provides emission factors (EFs) that are a function of traffic volume and mode of

  15. Visual Analysis of Air Traffic Data

    Science.gov (United States)

    Albrecht, George Hans; Pang, Alex

    2012-01-01

    In this paper, we present visual analysis tools to help study the impact of policy changes on air traffic congestion. The tools support visualization of time-varying air traffic density over an area of interest using different time granularity. We use this visual analysis platform to investigate how changing the aircraft separation volume can reduce congestion while maintaining key safety requirements. The same platform can also be used as a decision aid for processing requests for unmanned aerial vehicle operations.

  16. Auditory perception of motor vehicle travel paths.

    Science.gov (United States)

    Ashmead, Daniel H; Grantham, D Wesley; Maloff, Erin S; Hornsby, Benjamin; Nakamura, Takabun; Davis, Timothy J; Pampel, Faith; Rushing, Erin G

    2012-06-01

    These experiments address concerns that motor vehicles in electric engine mode are so quiet that they pose a risk to pedestrians, especially those with visual impairments. The "quiet car" issue has focused on hybrid and electric vehicles, although it also applies to internal combustion engine vehicles. Previous research has focused on detectability of vehicles, mostly in quiet settings. Instead, we focused on the functional ability to perceive vehicle motion paths. Participants judged whether simulated vehicles were traveling straight or turning, with emphasis on the impact of background traffic sound. In quiet, listeners made the straight-or-turn judgment soon enough in the vehicle's path to be useful for deciding whether to start crossing the street. This judgment is based largely on sound level cues rather than the spatial direction of the vehicle. With even moderate background traffic sound, the ability to tell straight from turn paths is severely compromised. The signal-to-noise ratio needed for the straight-or-turn judgment is much higher than that needed to detect a vehicle. Although a requirement for a minimum vehicle sound level might enhance detection of vehicles in quiet settings, it is unlikely that this requirement would contribute to pedestrian awareness of vehicle movements in typical traffic settings with many vehicles present. The findings are relevant to deliberations by government agencies and automobile manufacturers about standards for minimum automobile sounds and, more generally, for solutions to pedestrians' needs for information about traffic, especially for pedestrians with sensory impairments.

  17. Fuzzy Logic Based Autonomous Traffic Control System

    Directory of Open Access Journals (Sweden)

    Muhammad ABBAS

    2012-01-01

    Full Text Available The aim of this paper is to design and implement fuzzy logic based traffic light Control system to solve the traffic congestion issues. In this system four input parameters: Arrival, Queue, Pedestrian and Emergency Vehicle and two output parameters: Extension in Green and Pedestrian Signals are used. Using Fuzzy Rule Base, the system extends or terminates the Green Signal according to the Traffic situation at the junction. On the presence of emergency vehicle, the system decides which signal(s should be red and how much an extension should be given to Green Signal for Emergency Vehicle. The system also monitors the density of people and makes decisions accordingly. In order to verify the proposed design algorithm MATLAB simulation is adopted and results obtained show concurrency to the calculated values according to the Mamdani Model of the Fuzzy Control System.

  18. On Movement of Emergency Services amidst Urban Traffic

    Directory of Open Access Journals (Sweden)

    Manoj Bode

    2015-12-01

    Full Text Available Managing traffic in urban areas is a complex affair. The same becomes more challenging when one needs to take into account the prioritized movement of emergency vehicles along with the normal flow of traffic. Although, mechanisms have been proposed to model intelligent traffic management systems, a concentrated effort to facilitate the movement of emergency services amongst urban traffic is yet to be formalized. This paper proposes a distributed multi-agent based mechanism to create partial green corridors for the movement of emergency service vehicles such as ambulances, fire brigade and police vans, amidst urban traffic. The proposed approach makes se of a digital network of traffic signal nodes equipped with traffic sensors and an agent framework to autonomously extend, maintain and manage partial green corridors for such emergency vehicles. The approach was emulated using Tartarus, an agent framework over a LAN. The results gathered under varying traffic conditions and also several emergency vehicles, validate the performance of this approach and its effects on the movement of normal traffic. Comparisons with the non-prioritized and full green corridor approaches indicate that the proposed partial corridor approach outperforms the rest.

  19. Air pollution burden of illness from traffic in Toronto

    Energy Technology Data Exchange (ETDEWEB)

    McKeown, D.; Campbell, M.; Bassil, K.; Morgan, C.; Lalani, M.; Macfarlane, R.; Bienefeld, M. [Toronto Public Health, ON (Canada)

    2007-11-15

    This paper examined the health impacts of air pollution from traffic in Toronto. The paper provided a review of scientific studies on the health effects of vehicle pollution as well as a quantitative assessment of the economic costs and the burden of illness attributed to traffic pollution in Toronto. The report also assessed air pollution and traffic trends in the city, and outlined initiatives being conducted to reduce vehicle-related pollution. The study used the new air quality benefits tool (AQBAT) which determines the burden of illness and the economic impacts of traffic-related air pollution. Air modelling specialists were consulted in order to determine the contribution of traffic-related pollutants to overall pollution levels using data on traffic counts and vehicle emissions factors. The air model also considered dispersion, transport and and the transformation of compounds emitted from vehicles. Results of the study showed that traffic pollution caused approximately 440 premature deaths and 1700 hospitalizations per year. Children in the city experienced more than 1200 acute bronchitis episodes per year as a result of air pollution from traffic. Mortality-related costs associated with traffic pollution in Toronto were estimated at $2.2 billion. It was concluded that the city must pursue the implementation of sustainable transportation policies and programs which foster and enable the expansion and use of public transport. 47 refs., 8 tabs., 9 figs.

  20. SignalGuru: Leveraging mobile phones for collaborative traffic signal schedule advisory

    OpenAIRE

    Koukoumidis, Emmanouil; Peh, Li-Shiuan; Martonosi, Margaret

    2011-01-01

    While traffic signals are necessary to safely control competing flows of traffic, they inevitably enforce a stop-and-go movement pattern that increases fuel consumption, reduces traffic flow and causes traffic jams. These side effects can be alleviated by providing drivers and their onboard computational devices (e.g., vehicle computer, smartphone) with information about the schedule of the traffic signals ahead. Based on when the signal ahead will turn green, drivers can then adjust speed so...

  1. Urban road segment level of service based on bicycle users' perception under mixed traffic conditions

    National Research Council Canada - National Science Library

    Sambit Kumar Beura Haritha Chellapilla Prasanta Kumar Bhuyan

    2017-01-01

    .... However, these methodologies cannot be adopted under heterogeneous traffic where on-street bicyclists encounter a complex interaction with various types of vehicles and show divergent operational characteristics...

  2. Fixed Point Learning Based Intelligent Traffic Control System

    Science.gov (United States)

    Zongyao, Wang; Cong, Sui; Cheng, Shao

    2017-10-01

    Fixed point learning has become an important tool to analyse large scale distributed system such as urban traffic network. This paper presents a fixed point learning based intelligence traffic network control system. The system applies convergence property of fixed point theorem to optimize the traffic flow density. The intelligence traffic control system achieves maximum road resources usage by averaging traffic flow density among the traffic network. The intelligence traffic network control system is built based on decentralized structure and intelligence cooperation. No central control is needed to manage the system. The proposed system is simple, effective and feasible for practical use. The performance of the system is tested via theoretical proof and simulations. The results demonstrate that the system can effectively solve the traffic congestion problem and increase the vehicles average speed. It also proves that the system is flexible, reliable and feasible for practical use.

  3. Traffic flow dynamics data, models and simulation

    CERN Document Server

    Treiber, Martin

    2013-01-01

    This textbook provides a comprehensive and instructive coverage of vehicular traffic flow dynamics and modeling. It makes this fascinating interdisciplinary topic, which to date was only documented in parts by specialized monographs, accessible to a broad readership. Numerous figures and problems with solutions help the reader to quickly understand and practice the presented concepts. This book is targeted at students of physics and traffic engineering and, more generally, also at students and professionals in computer science, mathematics, and interdisciplinary topics. It also offers material for project work in programming and simulation at college and university level. The main part, after presenting different categories of traffic data, is devoted to a mathematical description of the dynamics of traffic flow, covering macroscopic models which describe traffic in terms of density, as well as microscopic many-particle models in which each particle corresponds to a vehicle and its driver. Focus chapters on ...

  4. Study on Reverse Reconstruction Method of Vehicle Group Situation in Urban Road Network Based on Driver-Vehicle Feature Evolution

    Directory of Open Access Journals (Sweden)

    Xiaoyuan Wang

    2017-01-01

    Full Text Available Vehicle group situation is the status and situation of dynamic permutation which is composed of target vehicle and neighboring traffic entities. It is a concept which is frequently involved in the research of traffic flow theory, especially the active vehicle security. Studying vehicle group situation in depth is of great significance for traffic safety. Three-lane condition was taken as an example; the characteristics of target vehicle and its neighboring vehicles were synthetically considered to restructure the vehicle group situation in this paper. The Gamma distribution theory was used to identify the vehicle group situation when target vehicle arrived at the end of the study area. From the perspective of driver-vehicle feature evolution, the reverse reconstruction method of vehicle group situation in the urban road network was proposed. Results of actual driving, virtual driving, and simulation experiments showed that the model established in this paper was reasonable and feasible.

  5. modified traffic s modified traffic signal phasing at traffic warden ...

    African Journals Online (AJOL)

    eobe

    centred' notion in traffic engineering is now being replaced by the new 'human centred' notion which takes all road users into consideration in its planning, design and operations and attaches more importance to vulnerable traffic participants such as the pedestrians [4]. Thus the pedestrian traffic safety management at TWC ...

  6. Probing Earth's conductivity structure beneath oceans by scalar geomagnetic data: autonomous surface vehicle solution

    Science.gov (United States)

    Kuvshinov, Alexey; Matzka, Jürgen; Poedjono, Benny; Samrock, Friedemann; Olsen, Nils; Pai, Sudhir

    2016-11-01

    The electric conductivity distribution of the Earth's crust and upper mantle provides a key to unraveling its structure. Information can be obtained from vector data time series of the natural variations of the magnetic and electric field in a directional stable reference frame. Applying this method, known as magnetotellurics, to oceanic regions is challenging since only vector instruments placed at the sea bottom can provide such data. Here, we discuss a concept of marine induction surveying which is based on sea-surface scalar magnetic field measurements from a modern position-keeping platform. The concept exploits scalar magnetic responses that relate variations of the scalar magnetic field at the survey sites with variations of the horizontal magnetic field at a reference site. A 3-D model study offshore Oahu Island (Hawaii) demonstrates that these responses are sensitive to the conductivity structure beneath the ocean. We conclude that the sensitivity, depending on the bathymetry gradient, is typically largest near the coast offshore. We show that such sea-surface marine induction surveys can be performed with the Wave Glider, an easy-to-deploy, autonomous, energy-harvesting floating platform with position-keeping capability.[Figure not available: see fulltext.

  7. 45 CFR 3.21 - Emergency vehicles.

    Science.gov (United States)

    2010-10-01

    ... THE NATIONAL INSTITUTES OF HEALTH FEDERAL ENCLAVE Traffic Regulations § 3.21 Emergency vehicles. A person must yield the right of way to an emergency vehicle operating its siren or flashing lights. ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Emergency vehicles. 3.21 Section 3.21 Public...

  8. Research on the Method of Traffic Organization and Optimization Based on Dynamic Traffic Flow Model

    Directory of Open Access Journals (Sweden)

    Shu-bin Li

    2017-01-01

    Full Text Available The modern transportation system is becoming sluggish by traffic jams, so much so that it can harm the economic and society in our country. One of the reasons is the surging vehicles day by day. Another reason is the shortage of the traffic supply seriously. But the most important reason is that the traffic organization and optimization hardly met the conditions of modern transport development. In this paper, the practical method of the traffic organization and optimization used in regional area is explored by the dynamic traffic network analysis method. Firstly, the operational states of the regional traffic network are obtained by simulation method based on the self-developed traffic simulation software DynaCHINA, in which the improved traffic flow simulation model was proposed in order to be more suitable for actual domestic urban transport situation. Then the appropriated optimization model and algorithm were proposed according to different optimized content and organization goals, and the traffic simulation processes more suitable to regional optimization were designed exactly. Finally, a regional network in Tai’an city was selected as an example. The simulation results show that the proposed method is effective and feasible. It can provide strong scientific and technological support for the traffic management department.

  9. TrafficTurk evaluation.

    Science.gov (United States)

    2014-04-01

    This report summarizes a project undertaken by the University of Illinois on behalf of the Illinois Department of : Transportation to evaluate a smartphone application called TrafficTurk for traffic safety and traffic monitoring : applications. Traff...

  10. Social dilemma structure hidden behind traffic flow with route selection

    Science.gov (United States)

    Tanimoto, Jun; Nakamura, Kousuke

    2016-10-01

    Several traffic flows contain social dilemma structures. Herein, we explored a route-selection problem using a cellular automaton simulation dovetailed with evolutionary game theory. In our model, two classes of driver-agents coexist: D agents (defective strategy), which refer to traffic information for route selection to move fast, and C agents (cooperative strategy), which are insensitive to information and less inclined to move fast. Although no evidence suggests that the social dilemma structure in low density causes vehicles to move freely and that in high density causes traffic jams, we found a structure that corresponds to an n-person (multiplayer) Chicken (n-Chicken) game if the provided traffic information is inappropriate. If appropriate traffic information is given to the agents, the n-Chicken game can be solved. The information delivered to vehicles is crucial for easing the social dilemma due to urban traffic congestion when developing technologies to support the intelligent transportation system (ITS).

  11. A Mobile System for Measuring Water Surface Velocities Using Unmanned Aerial Vehicle and Large-Scale Particle Image Velocimetry

    Science.gov (United States)

    Chen, Y. L.

    2015-12-01

    Measurement technologies for velocity of river flow are divided into intrusive and nonintrusive methods. Intrusive method requires infield operations. The measuring process of intrusive methods are time consuming, and likely to cause damages of operator and instrument. Nonintrusive methods require fewer operators and can reduce instrument damages from directly attaching to the flow. Nonintrusive measurements may use radar or image velocimetry to measure the velocities at the surface of water flow. The image velocimetry, such as large scale particle image velocimetry (LSPIV) accesses not only the point velocity but the flow velocities in an area simultaneously. Flow properties of an area hold the promise of providing spatially information of flow fields. This study attempts to construct a mobile system UAV-LSPIV by using an unmanned aerial vehicle (UAV) with LSPIV to measure flows in fields. The mobile system consists of a six-rotor UAV helicopter, a Sony nex5T camera, a gimbal, an image transfer device, a ground station and a remote control device. The activate gimbal helps maintain the camera lens orthogonal to the water surface and reduce the extent of images being distorted. The image transfer device can monitor the captured image instantly. The operator controls the UAV by remote control device through ground station and can achieve the flying data such as flying height and GPS coordinate of UAV. The mobile system was then applied to field experiments. The deviation of velocities measured by UAV-LSPIV of field experiments and handhold Acoustic Doppler Velocimeter (ADV) is under 8%. The results of the field experiments suggests that the application of UAV-LSPIV can be effectively applied to surface flow studies.

  12. Monitoring road traffic congestion using a macroscopic traffic model and a statistical monitoring scheme

    KAUST Repository

    Zeroual, Abdelhafid

    2017-08-19

    Monitoring vehicle traffic flow plays a central role in enhancing traffic management, transportation safety and cost savings. In this paper, we propose an innovative approach for detection of traffic congestion. Specifically, we combine the flexibility and simplicity of a piecewise switched linear (PWSL) macroscopic traffic model and the greater capacity of the exponentially-weighted moving average (EWMA) monitoring chart. Macroscopic models, which have few, easily calibrated parameters, are employed to describe a free traffic flow at the macroscopic level. Then, we apply the EWMA monitoring chart to the uncorrelated residuals obtained from the constructed PWSL model to detect congested situations. In this strategy, wavelet-based multiscale filtering of data has been used before the application of the EWMA scheme to improve further the robustness of this method to measurement noise and reduce the false alarms due to modeling errors. The performance of the PWSL-EWMA approach is successfully tested on traffic data from the three lane highway portion of the Interstate 210 (I-210) highway of the west of California and the four lane highway portion of the State Route 60 (SR60) highway from the east of California, provided by the Caltrans Performance Measurement System (PeMS). Results show the ability of the PWSL-EWMA approach to monitor vehicle traffic, confirming the promising application of this statistical tool to the supervision of traffic flow congestion.

  13. SOME EMPIRICAL RELATIONS BETWEEN TRAVEL SPEED, TRAFFIC VOLUME AND TRAFFIC COMPOSITION IN URBAN ARTERIALS

    Directory of Open Access Journals (Sweden)

    Eleni I. VLAHOGIANNI, Ph.D.

    2007-01-01

    Full Text Available The effects of traffic mix (the percentage of cars, trucks, buses and so on are of particular interest in the speed-volume relationship in urban signalized arterials under various geometric and control characteristics. The paper presents some empirical observations on the relation between travel speed, traffic volume and traffic composition in urban signalized arterials. A methodology based on emerging self-organizing structures of neural networks to identify regions in the speed-volume relationship with respect to traffic composition and Bayesian networks to evaluate the effect of different types of motorized vehicles on prevailing traffic conditions is proposed. Results based on data from a large urban network indicate that the variability in traffic conditions can be described by eight regions in speed-volume relationship with respect to traffic composition. Further evaluation of the effect of motorized vehicles in each region separately indicates that the effect of traffic composition decreases with the onset of congestion. Moreover, taxis and motorcycles are the primary affecting parameter of the form of the speed-volume relationship in urban arterials.

  14. Hydrogen Fuel Cell Vehicle Fuel System Integrity Research : Electrical Isolation Test Procedure Development and Verification

    Science.gov (United States)

    2012-03-01

    The Federal Motor Vehicle Safety Standards (FMVSS) establish minimum levels for vehicle safety, and manufacturers of motor vehicle and equipment items must comply with these standards. The National Highway Traffic Safety Administration (NHTSA) contra...

  15. Pocket facts 2008 : Swedish Road Administration, roads and traffic

    Science.gov (United States)

    2008-05-01

    Pocket Facts offers an overall picture of the road : transport system. Here you will find a selection of : brief facts about roads, road transports, vehicles and : people in traffic. In addition, it presents the functions : and organisation at the SR...

  16. Reducing local traffic emissions at urban intersection using ITS countermeasures

    NARCIS (Netherlands)

    Mahmod, M.; Arem, B. van; Pueboobpaphan, R.; Lange, R. de

    2013-01-01

    In many countries traffic emissions have significantly increased during the last two decades because of the increased number of vehicles. As such, traffic emissions have become the main source of air pollution in urban areas, where breaches of the EU limit values frequently occur. To reduce these

  17. Cooperative driving in mixed traffic networks - Optimizing for performance

    NARCIS (Netherlands)

    Calvert, S.C.; Broek, T.H.A. van den; Noort, M. van

    2012-01-01

    This paper discusses a cooperative adaptive cruise control application and its effects on the traffic system. In previous work this application has been tested on the road, and traffic simulation has been used to scale up the results of the field test to larger networks and more vehicles. The

  18. Road lighting and traffic safety : a functional approach.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1970-01-01

    Requirements to be made on the traffic facilities in order to reduce the number of night-time accidents are covered. Traffic facilities include apart from public lighting and road lighting by means of headlamps of vehicles, also road markings and signs, marker lights, catadioptric devices and

  19. Traffic and emission simulation in China based on statistical methodology

    Science.gov (United States)

    Liu, Huan; He, Kebin; Barth, Matthew

    2011-02-01

    To better understand how the traffic control can affect vehicle emissions, a novel TRaffic And Vehicle Emission Linkage (TRAVEL) approach was developed based on local traffic activity and emission data. This approach consists of a two-stage mapping from general traffic information to traffic flow patterns, and then to the aggregated emission rates. 39 traffic flow patterns and corresponding emission rates for light-duty and heavy-duty vehicles considering emission standards classification are generated. As a case study, vehicle activity and emissions during the Beijing Olympics were simulated and compared to BAU scenario. Approximately 42-65% of the gaseous pollutants and 24% of the particle pollutants from cars, taxies and buses were reduced. These results are validated by traffic and air quality monitoring data during the Olympics, as well as other emission inventory studies. This approach improves the ability to fast predict emission variation from traffic control measurements in several typical Chinese cities. Comments related to application of this approach with both advantages and limitations are included.

  20. Epidemiology of Traffic Accidents | Ferguson | South African Medical ...

    African Journals Online (AJOL)

    The epidemiology of traffic accidents is studied. Various factors include the nature of fatal injuries, the racial, sex and age distribution, the scene of accident, the weather and the time, the different categories of commuters and the trip purpose, the types of vehicles and motorways involved. The establishment of a traffic ...

  1. A Retrospective Study on the Unseen Epidemic of Road Traffic ...

    African Journals Online (AJOL)

    Conclusion and Recommendation: Among all RTAs the leading cause of injuries is Motor cycle traffic accidents followed by motor vehicle. RTAs are on increase particularly the motor cycle traffic accidents and has claimed a good number of innocent people's lives however most of them are preventable, therefore driving ...

  2. 75 FR 20935 - National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for...

    Science.gov (United States)

    2010-04-22

    .../nchrp/nchrp_webdoc_92.pdf . Finally, in anticipation of this NPA, the American Association of State...-way streets or highways that have three or more lanes for moving motor vehicle traffic. This includes...

  3. Automated Announcements of Approaching Emergency Vehicles

    Science.gov (United States)

    Bachelder, Aaron; Foster, Conrad

    2006-01-01

    Street intersections that are equipped with traffic lights would also be equipped with means for generating audible announcements of approaching emergency vehicles, according to a proposal. The means to generate the announcements would be implemented in the intersection- based subsystems of emergency traffic-light-preemption systems like those described in the two immediately preceding articles and in "Systems Would Preempt Traffic Lights for Emergency Vehicles" (NPO-30573), NASA Tech Briefs, Vol. 28, No. 10 (October 2004), page 36. Preempting traffic lights is not, by itself, sufficient to warn pedestrians at affected intersections that emergency vehicles are approaching. Automated visual displays that warn of approaching emergency vehicles can be helpful as a supplement to preemption of traffic lights, but experience teaches that for a variety of reasons, pedestrians often do not see such displays. Moreover, in noisy and crowded urban settings, the lights and sirens on emergency vehicles are often not noticed until a few seconds before the vehicles arrive. According to the proposal, the traffic-light preemption subsystem at each intersection would generate an audible announcement for example, emergency vehicle approaching, please clear intersection whenever a preemption was triggered. The subsystem would estimate the time of arrival of an approaching emergency vehicle by use of vehicle identity, position, and time data from one or more sources that could include units connected to traffic loops and/or transponders connected to diagnostic and navigation systems in participating emergency vehicles. The intersection-based subsystem would then start the announcement far enough in advance to enable pedestrians to leave the roadway before any emergency vehicles arrive.

  4. Active plasmonics in WDM traffic switching applications

    DEFF Research Database (Denmark)

    Papaioannou, S.; Kalavrouziotis, D.; Vyrsokinos, K.

    2012-01-01

    . The first active Dielectric-Loaded Surface Plasmon Polariton (DLSPP) thermo-optic (TO) switches with successful performance in single-channel 10 Gb/s data traffic environments have led the inroad towards bringing low-power active plasmonics in practical traffic applications. In this article, we introduce...

  5. Neural network system for traffic flow management

    Science.gov (United States)

    Gilmore, John F.; Elibiary, Khalid J.; Petersson, L. E. Rickard

    1992-09-01

    Atlanta will be the home of several special events during the next five years ranging from the 1996 Olympics to the 1994 Super Bowl. When combined with the existing special events (Braves, Falcons, and Hawks games, concerts, festivals, etc.), the need to effectively manage traffic flow from surface streets to interstate highways is apparent. This paper describes a system for traffic event response and management for intelligent navigation utilizing signals (TERMINUS) developed at Georgia Tech for adaptively managing special event traffic flows in the Atlanta, Georgia area. TERMINUS (the original name given Atlanta, Georgia based upon its role as a rail line terminating center) is an intelligent surface street signal control system designed to manage traffic flow in Metro Atlanta. The system consists of three components. The first is a traffic simulation of the downtown Atlanta area around Fulton County Stadium that models the flow of traffic when a stadium event lets out. Parameters for the surrounding area include modeling for events during various times of day (such as rush hour). The second component is a computer graphics interface with the simulation that shows the traffic flows achieved based upon intelligent control system execution. The final component is the intelligent control system that manages surface street light signals based upon feedback from control sensors that dynamically adapt the intelligent controller's decision making process. The intelligent controller is a neural network model that allows TERMINUS to control the configuration of surface street signals to optimize the flow of traffic away from special events.

  6. Road-rail vehicle

    NARCIS (Netherlands)

    Evers, J.J.M.

    2002-01-01

    A transport vehicle equipped with a number of first wheel sets, having wheels provided with tires, to which steering means and driving means, if any, are coupled to enable the transport vehicle to be moved over a road surface. The transport vehicle further comprises at least one second wheel set,

  7. Traffic and related self-driven many-particle systems

    Science.gov (United States)

    Helbing, Dirk

    2001-10-01

    Since the subject of traffic dynamics has captured the interest of physicists, many surprising effects have been revealed and explained. Some of the questions now understood are the following: Why are vehicles sometimes stopped by ``phantom traffic jams'' even though drivers all like to drive fast? What are the mechanisms behind stop-and-go traffic? Why are there several different kinds of congestion, and how are they related? Why do most traffic jams occur considerably before the road capacity is reached? Can a temporary reduction in the volume of traffic cause a lasting traffic jam? Under which conditions can speed limits speed up traffic? Why do pedestrians moving in opposite directions normally organize into lanes, while similar systems ``freeze by heating''? All of these questions have been answered by applying and extending methods from statistical physics and nonlinear dynamics to self-driven many-particle systems. This article considers the empirical data and then reviews the main approaches to modeling pedestrian and vehicle traffic. These include microscopic (particle-based), mesoscopic (gas-kinetic), and macroscopic (fluid-dynamic) models. Attention is also paid to the formulation of a micro-macro link, to aspects of universality, and to other unifying concepts, such as a general modeling framework for self-driven many-particle systems, including spin systems. While the primary focus is upon vehicle and pedestrian traffic, applications to biological or socio-economic systems such as bacterial colonies, flocks of birds, panics, and stock market dynamics are touched upon as well.

  8. Leader-follower formation control of underactuated surface vehicles based on sliding mode control and parameter estimation.

    Science.gov (United States)

    Sun, Zhijian; Zhang, Guoqing; Lu, Yu; Zhang, Weidong

    2017-12-05

    This paper studies the leader-follower formation control of underactuated surface vehicles with model uncertainties and environmental disturbances. A parameter estimation and upper bound estimation based sliding mode control scheme is proposed to solve the problem of the unknown plant parameters and environmental disturbances. For each of these leader-follower formation systems, the dynamic equations of position and attitude are analyzed using coordinate transformation with the aid of the backstepping technique. All the variables are guaranteed to be uniformly ultimately bounded stable in the closed-loop system, which is proven by the distribution design Lyapunov function synthesis. The main advantages of this approach are that: first, parameter estimation based sliding mode control can enhance the robustness of the closed-loop system in presence of model uncertainties and environmental disturbances; second, a continuous function is developed to replace the signum function in the design of sliding mode scheme, which devotes to reduce the chattering of the control system. Finally, numerical simulations are given to demonstrate the effectiveness of the proposed method. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  9. Tracking of a Fluorescent Dye in a Freshwater Lake with an Unmanned Surface Vehicle and an Unmanned Aircraft System

    Directory of Open Access Journals (Sweden)

    Craig Powers

    2018-01-01

    Full Text Available Recent catastrophic events in our oceans, including the spill of toxic oil from the explosion of the Deepwater Horizon drilling rig and the rapid dispersion of radioactive particulates from the meltdown of the Fukushima Daiichi nuclear plant, underscore the need for new tools and technologies to rapidly respond to hazardous agents. Our understanding of the movement and aerosolization of hazardous agents from natural aquatic systems can be expanded upon and used in prevention and tracking. New technologies with coordinated unmanned robotic systems could lead to faster identification and mitigation of hazardous agents in lakes, rivers, and oceans. In this study, we released a fluorescent dye (fluorescein into a freshwater lake from an anchored floating platform. A fluorometer (fluorescence sensor was mounted underneath an unmanned surface vehicle (USV, unmanned boat and was used to detect and track the released dye in situ in real-time. An unmanned aircraft system (UAS was used to visualize the dye and direct the USV to sample different areas of the dye plume. Image processing tools were used to map concentration profiles of the dye plume from aerial images acquired from the UAS, and these were associated with concentration measurements collected from the sensors onboard the USV. The results of this project have the potential to transform monitoring strategies for hazardous agents, enabling timely and accurate exposure assessment and response in affected areas. Fast response is essential in reacting to the introduction of hazardous agents, in order to quickly predict and contain their spread.

  10. Transportation, road and traffic; Yuso / doro / kotsu

    Energy Technology Data Exchange (ETDEWEB)

    Tsuneda, K.; Oshita, T.; Kimura, K.; Ishikura, T. [Ministry of Construction Ibaragi (Japan)

    1997-08-01

    Road transportation of cargos and passengers is increasing recently. Securing funds for road construction projects is under severe condition due to retrenchment in finance. The number of four-wheel vehicles possessed by users totaled to 65.18 million at the end of March, 1996, showing 3.0% increase compared with that of the previous year. The number of motorcycles increased by 40 thousand in the area of two-wheel vehicles. The number of light two-wheeled vehicles showed no marked fluctuations. No statistic was made public concerning motor-bicycles. Outlines of the budget for road construction and road maintenance situation are given. The traffic density was much heavier than the increasing rate of the road extension at the end of March, 1996. The advanced road traffic system is a new road traffic system which utilizes most advanced information communication technology to decrease traffic snarls and traffic accidents and to improve the riding comfort of users, and 9 development fields and 20 user service systems are being developed currently. 7 refs., 11 figs., 8 tabs.

  11. Electric vehicle and conventional vehicle. Urban air pollution assessment

    OpenAIRE

    Vale, Andreia; Silva, Lígia Torres; Rodrigues, Daniel Souto; Ramos, Rui A. R.

    2011-01-01

    Road traffic is the main source of air pollutant emissions in urban areas. Pollutant emissions can be evaluated and calculated using mathematical models based on the characteristics of traffic flowing in roads. This article aims to assess the air pollution produced by a fleet of vehicles with conventional (diesel and petrol) and electrical (hybrid and electric) motorization, in the city centre of Braga. The scientific toolbox adopted to develop the studies includes emission models to es...

  12. Apparatus, system, and method for traffic monitoring

    KAUST Repository

    Claudel, Christian G.

    2016-08-25

    An apparatus, system, and method for traffic monitory can have a Lagrangian inertial measurement unit. The Lagrangian inertial measurement unit can have a processor, an accelerometer, a gyroscope, and/or a wireless transmitter. The processor can have an integrated direction cosine matrix. The accelerometer can be configured to measure linear accelerations of a vehicle and/or can communicate measured linear acceleration to the processor. The gyroscope can be configured to measure rotational accelerations of the vehicle and/or can communicate measured rotational acceleration to the processor. The processor can be configured to calculate estimated vehicle speed and/or estimated vehicle attitude. The wireless transmitter can be configured to wirelessly transmit estimated vehicle speed and/or estimated vehicle attitude. The apparatus, system, and method can be integrated with a wireless sensor network.

  13. AN AUTOMATED RAILWAY STATION TRAFFIC CONTROL SYSTEM

    African Journals Online (AJOL)

    Majority of accidents experienced with railway transportation involve collision with automobiles or other vehicles and collision with other trains. These collisions can be averted by putting safety measures in place. Part of the measures can be achieved by using computerized railway station traffic control systems that use ...

  14. South Carolina traffic collision fact book, 2009

    Science.gov (United States)

    2010-01-01

    The number of traffic fatalities decreased from 921 in 2008 to 894 in : 2009, a 2.9% decrease. There was also a decrease in the mileage : death rate (MDR) as well. It fell to an all time low of 1.84 deaths per : hundred million vehicle miles of trave...

  15. Empirical findings with multi-criteria routing for Dynamic Traffic Management

    NARCIS (Netherlands)

    Chen, Y.; Zhang, F.

    2013-01-01

    Traffic simulation is conventionally based on travel time as input to the cost function. The new challenge in traffic management takes into account not only travel throughput but also vehicle emission and safety. The question is then whether the network traffic performance will change if

  16. 77 FR 46677 - Vehicle Certification; Contents of Certification Labels

    Science.gov (United States)

    2012-08-06

    ... TRANSPORTATION National Highway Traffic Safety Administration 49 CFR Part 567 RIN 2127-AL18 Vehicle Certification; Contents of Certification Labels AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT... Traffic Safety Administration (NHTSA) regulations that prescribe the format and contents of certification...

  17. 75 FR 67233 - Federal Motor Vehicle Safety Standards; Head Restraints

    Science.gov (United States)

    2010-11-02

    ... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AK39 Federal Motor Vehicle Safety... a set of common symptoms that occur in motor vehicle crashes and involve the soft tissues of the... organization of motor vehicle manufacturers. VSCI is a company that assists small volume vehicle manufacturers...

  18. 78 FR 2797 - Federal Motor Vehicle Safety Standards; Minimum Sound Requirements for Hybrid and Electric Vehicles

    Science.gov (United States)

    2013-01-14

    ... and Electric Vehicles; Draft Environmental Assessment for Rulemaking To Establish Minimum Sound Requirements for Hybrid and Electric Vehicles; Proposed Rules #0;#0;Federal Register / Vol. 78 , No. 9 / Monday... Requirements for Hybrid and Electric Vehicles AGENCY: National Highway Traffic Safety Administration (NHTSA...

  19. The social dilemma of autonomous vehicles

    National Research Council Canada - National Science Library

    Bonnefon, Jean-François; Shariff, Azim; Rahwan, Iyad

    2016-01-01

    Autonomous vehicles (AVs) should reduce traffic accidents, but they will sometimes have to choose between two evils, such as running over pedestrians or sacrificing themselves and their passenger to save the pedestrians...

  20. Arizona motor vehicle crash facts, 2010

    Science.gov (United States)

    2010-08-22

    This publication is an annual statistical review of the motor vehicle crashes in the State of Arizona for the calendar year 2010. The results are compiled from Arizona Traffic Accident Reports submitted to the Arizona Department of Transportation by ...

  1. Arizona motor vehicle crash facts, 2008

    Science.gov (United States)

    2009-06-25

    This publication is an annual statistical review of the motor vehicle crashes in the State of Arizona for the calendar year 2008. : The results are compiled from Arizona Traffic Accident Reports submitted to the Arizona Department of Transportation b...

  2. 2006 motor vehicle occupant protection facts

    Science.gov (United States)

    2008-08-01

    The National Highway Traffic Safety Administration has produced this booklet to explain the need for legislation, enforcement, education, and public awareness campaigns about protecting children, youth, and young adults in motor vehicles. collectivel...

  3. Arizona motor vehicle crash facts, 2007

    Science.gov (United States)

    2009-02-17

    This publication is an annual statistical review of the motor vehicle crashes in the State of Arizona for the calendar year 2007. : The results are compiled from Arizona Traffic Accident Reports submitted to the Arizona Department of Transportation b...

  4. Arizona motor vehicle crash facts, 2014.

    Science.gov (United States)

    2015-06-01

    This publication is an annual statistical review of the motor vehicle crashes in the State of Arizona for the calendar year 2014. The : results are compiled from Arizona Traffic Accident Reports submitted to the Arizona Department of Transportation b...

  5. Arizona motor vehicle crash facts, 2009

    Science.gov (United States)

    2009-09-29

    This publication is a statistical review of the motor vehicle crashes in the State of Arizona for calendar year 2009. The results are compiled from Arizona Traffic Accident Reports submitted to the Arizona Department of Transportation by state, count...

  6. Torsion vehicle model test for automotive vehicle

    Science.gov (United States)

    Nor, M. K. Mohd; Ho, C. S.; Ma'at, N.

    2017-04-01

    Torsion vehicle model test of Simple Structural Surfaces (SSS) model for automotive vehicle sedan is proposed in this paper to demonstrate the importance of providing continuous load path within the vehicle structures. The proposed approach is relatively easy to understand as compared to Finite Element Method (FEM). The results prove that the proposed vehicle model test is capable to show that a satisfactory load paths can five a sufficient structural stiffness within the vehicle structure. It is clearly observed that the global torsion stiffness reduces significantly when only one panel is removed from the complete SSS model. The results also five a food agreement with respect to the theoretical hypothesis as the structure is less stiff in torsion in an open section condition. The SSS model and the corresponding torsion test is obviously useful to give an overview of vehicle structural integrity. It can be potentially integrated with FEM to speed up the design process of automotive vehicle.

  7. New Zealand traffic and local air quality.

    Science.gov (United States)

    Irving, Paul; Moncrieff, Ian

    2004-12-01

    Since 1996 the New Zealand Ministry of Transport (MOT) has been investigating the effects of road transport on local air quality. The outcome has been the government's Vehicle Fleet Emissions Control Strategy (VFECS). This is a programme of measures designed to assist with the improvement in local air quality, and especially in the appropriate management of transport sector emissions. Key to the VFECS has been the development of tools to assess and predict the contribution of vehicle emissions to local air pollution, in a given urban situation. Determining how vehicles behave as an emissions source, and more importantly, how the combined traffic flows contribute to the total emissions within a given airshed location was an important element of the programme. The actual emissions output of a vehicle is more than that determined by a certified emission standard, at the point of manufacture. It is the engine technology's general performance capability, in conjunction with the local driving conditions, that determines its actual emissions output. As vehicles are a mobile emissions source, to understand the effect of vehicle technology, it is necessary to work with the average fleet performance, or "fleet-weighted average emissions rate". This is the unit measure of performance of the general traffic flow that could be passing through a given road corridor or network, as an average, over time. The flow composition can be representative of the national fleet population, but also may feature particular vehicle types in a given locality, thereby have a different emissions 'signature'. A summary of the range of work that has been completed as part of the VFECS programme is provided. The NZ Vehicle Fleet Emissions Model and the derived data set available in the NZ Traffic Emission Rates provide a significant step forward in the consistent analysis of practical, sustainable vehicle emissions policy and air-quality management in New Zealand.

  8. Impacts of Traffic Noise and Traffic Volume on Birds of Roadside Habitats

    Directory of Open Access Journals (Sweden)

    Kirsten M. Parris

    2009-06-01

    Full Text Available Roadside habitats are important for a range of taxa including plants, insects, mammals, and birds, particularly in developed countries in which large expanses of native vegetation have been cleared for agriculture or urban development. Although roadside vegetation may provide suitable habitat for many species, resident animals can be exposed to high levels of traffic noise, visual disturbance from passing vehicles, and the risk of collision with cars and trucks. Traffic noise can reduce the distance over which acoustic signals such as song can be detected, an effect known as acoustic interference or masking. Studies from the northern hemisphere show that the singing behavior of birds changes in the presence of traffic noise. We investigated the impact of traffic noise and traffic volume on two species of birds, the Grey Shrike-thrush (Colluricincla harmonica and the Grey Fantail (Rhipidura fuliginosa, at 58 roadside sites on the Mornington Peninsula, southeastern Australia. The lower singing Grey Shrike-thrush sang at a higher frequency in the presence of traffic noise, with a predicted increase in dominant frequency of 5.8 Hz/dB of traffic noise, and a total effect size of 209 Hz. In contrast, the higher singing Grey Fantail did not appear to change its song in traffic noise. The probability of detecting each species on a visit to a site declined substantially with increasing traffic noise and traffic volume, with several lines of evidence supporting a larger effect of traffic noise. Traffic noise could hamper detection of song by conspecifics, making it more difficult for birds to establish and maintain territories, attract mates and maintain pair bonds, and possibly leading to reduced breeding success in noisy roadside habitats. Closing key roads during the breeding season is a potential, but untested, management strategy to protect threatened bird species from traffic noise and collision with vehicles at the time of year when they are most

  9. Integrating axle weight restrictions in a two-dimensional vehicle routing problem with sequence based loading

    OpenAIRE

    Pollaris, H.; Braekers, K.; Caris, A.; Janssens, G.K.; S Limbourg

    2014-01-01

    A mixed integer linear programming model for a two-dimensional capacitated vehicle routing problem (2L-CVRP) with sequence based loading and axle weight restrictions is provided. To the authors’ knowledge, it is the first time that axle weight restrictions are incorporated in a VRP. Axle weight limits impose a great challenge for transportation companies. Trucks with overloaded axles represent a significant threat for traffic safety and may cause serious damage to the road surface. Transpor...

  10. Stochastic stability of traffic maps

    Science.gov (United States)

    Blank, Michael

    2012-12-01

    We study the ergodic properties of a family of traffic maps acting in the space of bi-infinite sequences of real numbers. The corresponding dynamics mimics the motion of vehicles in a simple traffic flow, which explains the name. Using connections to topological Markov chains we obtain nontrivial invariant measures, prove their stochastic stability and calculate the topological entropy. Technically these results in the deterministic setting are related to the construction of measures of maximal entropy via measures uniformly distributed on periodic points of a given period, while in the random setting we construct (spatially) Markov invariant measures directly. In distinction to conventional results the limiting measures in the non-lattice case are non-ergodic. The average velocity of individual ‘vehicles’ as a function of their density and its stochastic stability is studied as well.

  11. Crowding effects in vehicular traffic.

    Directory of Open Access Journals (Sweden)

    Jay Samuel L Combinido

    Full Text Available While the impact of crowding on the diffusive transport of molecules within a cell is widely studied in biology, it has thus far been neglected in traffic systems where bulk behavior is the main concern. Here, we study the effects of crowding due to car density and driving fluctuations on the transport of vehicles. Using a microscopic model for traffic, we found that crowding can push car movement from a superballistic down to a subdiffusive state. The transition is also associated with a change in the shape of the probability distribution of positions from a negatively-skewed normal to an exponential distribution. Moreover, crowding broadens the distribution of cars' trap times and cluster sizes. At steady state, the subdiffusive state persists only when there is a large variability in car speeds. We further relate our work to prior findings from random walk models of transport in cellular systems.

  12. Management of Traffic Congestion in Urban Areas

    Directory of Open Access Journals (Sweden)

    Vilibald Premzl

    2012-10-01

    Full Text Available The use of road vehicles is increasing, the benefits they affordhave been progressively diminished by external costs.Whereas traffic increases as we approach the centre, the roadand open space decreases. The greater specialisation allows thecity growth in size and in traffic attraction. In this way urbangrowth feeds itself !mer-urban transp011 facilities also becomemore extensive. Growth in size of the city generates greateramounts of traffic and can eventually give rise to agglomerationdiseconomies. Higher transport costs, offices and shops, attractedby the accessibility of central locations, gradually replaceresidential uses, people being forced to seek housing inthe suburbs. As the urban area expands and offices in the citycentre are built denser and highe1; traffic congestion increases.This may result in the fall in centra/land values, since accessibilitydiminishes with the saturation of transport network. Increasedpollution takes various forms as noise, smoke andovercrowded housing in the centre, urban decay in the transitionalzone as commercial development is anticipated.

  13. IRVIN - Intelligent Road and Vehicle test INfrastructure

    NARCIS (Netherlands)

    Bakker, R.T.; Hogema, J.A.; Huiskamp, W.; Papp, Z.

    2005-01-01

    Simulation, or rather virtual testing, is a good instrument for study and design of traffic management concepts, traffic safety, vehicle safety and ergonomics. Simulation facilitates the evaluation of the design at an early stage and reduces the costs of making prototypes. The Dutch research

  14. Control of Networked Traffic Flow Distribution - A Stochastic Distribution System Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hong [Pacific Northwest National Laboratory (PNNL); Aziz, H M Abdul [ORNL; Young, Stan [National Renewable Energy Laboratory (NREL); Patil, Sagar [Pacific Northwest National Laboratory (PNNL)

    2017-10-01

    Networked traffic flow is a common scenario for urban transportation, where the distribution of vehicle queues either at controlled intersections or highway segments reflect the smoothness of the traffic flow in the network. At signalized intersections, the traffic queues are controlled by traffic signal control settings and effective traffic lights control would realize both smooth traffic flow and minimize fuel consumption. Funded by the Energy Efficient Mobility Systems (EEMS) program of the Vehicle Technologies Office of the US Department of Energy, we performed a preliminary investigation on the modelling and control framework in context of urban network of signalized intersections. In specific, we developed a recursive input-output traffic queueing models. The queue formation can be modeled as a stochastic process where the number of vehicles entering each intersection is a random number. Further, we proposed a preliminary B-Spline stochastic model for a one-way single-lane corridor traffic system based on theory of stochastic distribution control.. It has been shown that the developed stochastic model would provide the optimal probability density function (PDF) of the traffic queueing length as a dynamic function of the traffic signal setting parameters. Based upon such a stochastic distribution model, we have proposed a preliminary closed loop framework on stochastic distribution control for the traffic queueing system to make the traffic queueing length PDF follow a target PDF that potentially realizes the smooth traffic flow distribution in a concerned corridor.

  15. Hydrogen-bonding layer-by-layer-assembled biodegradable polymeric micelles as drug delivery vehicles from surfaces.

    Science.gov (United States)

    Kim, Byeong-Su; Park, Sang Wook; Hammond, Paula T

    2008-02-01

    We present the integration of amphiphilic block copolymer micelles as nanometer-sized vehicles for hydrophobic drugs within layer-by-layer (LbL) films using alternating hydrogen bond interactions as the driving force for assembly for the first time, thus enabling the incorporation of drugs and pH-sensitive release. The film was constructed based on the hydrogen bonding between poly(acrylic acid) (PAA) as an H-bond donor and biodegradable poly(ethylene oxide)-block-poly(epsilon-caprolactone) (PEO-b-PCL) micelles as the H-bond acceptor when assembled under acidic conditions. By taking advantage of the weak interactions of the hydrogen-bonded film on hydrophobic surfaces, it is possible to generate flexible free-standing films of these materials. A free-standing micelle LbL film of (PEO-b-PCL/PAA)60 with a thickness of 3.1 microm was isolated, allowing further characterization of the bulk film properties, including morphology and phase transitions, using transmission electron microscopy and differential scanning calorimetry. Because of the sensitive nature of the hydrogen bonding employed to build the multilayers, the film can be rapidly deconstructed to release micelles upon exposure to physiological conditions. However, we could also successfully control the rate of film deconstruction by cross-linking carboxylic acid groups in PAA through thermally induced anhydride linkages, which retard the drug release to the surrounding medium to enable sustained release over multiple days. To demonstrate efficacy in delivering active therapeutics, in vitro Kirby-Bauer assays against Staphylococcus aureus were used to illustrate that the drug-loaded micelle LbL film can release significant amounts of an active antibacterial drug, triclosan, to inhibit the growth of bacteria. Because the micellar encapsulation of hydrophobic therapeutics does not require specific chemical interactions, we believe this noncovalent approach provides a new route to integrating active small

  16. Impact analysis of traffic-related air pollution based on real-time traffic and basic meteorological information.

    Science.gov (United States)

    Pan, Long; Yao, Enjian; Yang, Yang

    2016-12-01

    With the rapid development of urbanization and motorization in China, traffic-related air pollution has become a major component of air pollution which constantly jeopardizes public health. This study proposes an integrated framework for estimating the concentration of traffic-related air pollution with real-time traffic and basic meteorological information and also for further evaluating the impact of traffic-related air pollution. First, based on the vehicle emission factor models sensitive to traffic status, traffic emissions are calculated according to the real-time link-based average traffic speed, traffic volume, and vehicular fleet composition. Then, based on differences in meteorological conditions, traffic pollution sources are divided into line sources and point sources, and the corresponding methods to determine the dynamic affecting areas are also proposed. Subsequently, with basic meteorological data, Gaussian dispersion model and puff integration model are applied respectively to estimate the concentration of traffic-related air pollution. Finally, the proposed estimating framework is applied to calculate the distribution of CO concentration in the main area of Beijing, and the population exposure is also calculated to evaluate the impact of traffic-related air pollution on public health. Results show that there is a certain correlation between traffic indicators (i.e., traffic speed and traffic intensity) of the affecting area and traffic-related CO concentration of the target grid, which indicates the methods to determine the affecting areas are reliable. Furthermore, the reliability of the proposed estimating framework is verified by comparing the predicted and the observed ambient CO concentration. In addition, results also show that the traffic-related CO concentration is higher in morning and evening peak hours, and has a heavier impact on public health within the Fourth Ring Road of Beijing due to higher population density and higher CO

  17. System And Method For Monitoring Traffic While Preserving Personal Privacy

    KAUST Repository

    Canepa, Edward

    2015-08-06

    A traffic monitoring system and method for mapping traffic speed and density while preserving privacy. The system can include fixed stations that make up a network and mobile probes that are associated with vehicles. The system and method do not gather, store, or transmit any unique or identifying information, and thereby preserves the privacy of members of traffic. The system and method provide real-time traffic density and speed mapping. The system and method can further be integrated with a complementary flood monitoring system and method.

  18. Long-Life, Oil-Free, Light-Weight, Multi-Roller Traction Drives for Planetary Vehicle Surface Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A multi-roller "oil free" traction drive is under development for use on vehicles used in hostile environments like those that will be encountered on planetary...

  19. Connected variable speed limits control and car-following control with vehicle-infrastructure communication to resolve stop-and-go waves

    NARCIS (Netherlands)

    Wang, M.; Daamen, W.; Hoogendoorn, S.P.; van Arem, B.

    2016-01-01

    The vision of intelligent vehicles traveling in road networks has prompted numerous concepts to control future traffic flow, one of which is the in-vehicle actuation of traffic control commands. The key of this concept is using intelligent vehicles as actuators for traffic control systems. Under

  20. Psychoactive Medication and Traffic Safety

    Directory of Open Access Journals (Sweden)

    Joris C. Verster

    2009-03-01

    Full Text Available Driving a car is important to maintain independence and participate in society. Many of those who use psychoactive medication are outpatients and are thus likely to drive a vehicle. Most common adverse effects that impair driving are reduced alertness, affected psychomotor functioning and impaired vision. This review discusses the effects on driving ability of most commonly prescribed psychoactive drugs, including hypnotics, antidepressants, antihistamines, analgesics and stimulant drugs. Within these categories of medicines significant differences concerning their impact on driving ability are evident. The International Council on Alcohol, Drugs and Traffic Safety (ICADTS categorization can help physicians to make a choice between treatments when patients want to drive a car.

  1. a Modified Cellular Automaton Model for Ring Road Traffic with Velocity Guidance

    Science.gov (United States)

    Mei, C. Q.; Huang, H. J.; Tang, T. Q.

    We present a modified cellular automaton model to study the traffic flow on a signal controlled ring road with velocity guidance. The velocity guidance is such a strategy that when vehicles approach the traffic light, suggested velocities are provided for avoiding the vehicles' sharp brakes in front of red light. Simulation results show that this strategy may significantly reduce the vehicles' stopping rate and the effect size is dependent upon the traffic density, the detector position, the signal's cycle time and the obedience rate of vehicles to the guidance.

  2. 77 FR 65769 - Petition for Exemption From the Vehicle Theft Prevention Standard; Volkswagen Group of America, Inc.

    Science.gov (United States)

    2012-10-30

    ... corporate requirements for electrical and electronic assemblies in motor vehicles related to performance... unauthorized persons; preventing operation of the vehicle by unauthorized entrants; and ensuring the... National Highway Traffic Safety Administration Petition for Exemption From the Vehicle Theft Prevention...

  3. Development of a mobile application for manual traffic counts

    Directory of Open Access Journals (Sweden)

    Ghanim Mohammad

    2017-01-01

    Full Text Available The use of technology in performing traffic counts has become widely used by many transportation agencies and private sectors. Different technologies have been employed to perform such counts, such as inductive loops, image processing, Bluetooth technologies, and laser and infrared technologies. However, the use of these advanced technologies come with extra cost to develop, install, and maintain. While the use of advanced technologies provide reliable traffic counts and vehicle classifications data, the use of manual traffic is an inevitable task. Manual traffic counts can serve different purposes, such as performing quality control or conducting short-term traffic survey. Manual traffic counts are usually conducted with the use of the traditional paper-and-pencil approach or the use of hand-held devices that are specifically developed to assess performing manual traffic counts. In this paper, the development of a mobile app that can be used to assist those who need to perform manual traffic counts. The app can be used by many public agencies, private sectors, and college students to collect their traffic data. It also provides users with the capabilities of sharing their traffic counts instantly, where traffic counts can be extracted and processed quickly by other parties.

  4. Mobile agent based online integration modeling for traffic information services

    Science.gov (United States)

    Li, Qingquan; Gao, Dequan; Fang, Zhixiang; Li, Lianying

    2007-06-01

    With the rapid development of urban economy and urbanization construction in China, traffic load rises sharply because of the larger vehicle occupancy within many urban areas, which has already led to serious traffic congestion problem. GIS-T is an efficient technological solution and core information infrastructure for solving modern urban transportation problems. High-level traffic systems must integrate real-time traffic information and spatial data of road to supply timely and efficient public services and guarantee a better orderly transportation. However, for traffic information is multisource, complex and massive, traffic information service must have fast, powerful capabilities for online integration processing. Online integration of traffic information emphasizes the traffic resources share and services optimization, and solve assignment, scheduling, monitoring and feedback of integration computing tasks in dynamic and distributed network. This paper firstly analyzes traffic data and existing problems of online integration, and then discusses mobile agent technology, and finally proposes a mobile agent based unified online integration model of traffic information. This model will achieve cooperative computing and more accessible, flexible and reliable traffic information services.

  5. Consensus-Based Cooperative Control Based on Pollution Sensing and Traffic Information for Urban Traffic Networks

    Directory of Open Access Journals (Sweden)

    Antonio Artuñedo

    2017-04-01

    Full Text Available Nowadays many studies are being conducted to develop solutions for improving the performance of urban traffic networks. One of the main challenges is the necessary cooperation among different entities such as vehicles or infrastructure systems and how to exploit the information available through networks of sensors deployed as infrastructures for smart cities. In this work an algorithm for cooperative control of urban subsystems is proposed to provide a solution for mobility problems in cities. The interconnected traffic lights controller (TLC network adapts traffic lights cycles, based on traffic and air pollution sensory information, in order to improve the performance of urban traffic networks. The presence of air pollution in cities is not only caused by road traffic but there are other pollution sources that contribute to increase or decrease the pollution level. Due to the distributed and heterogeneous nature of the different components involved, a system of systems engineering approach is applied to design a consensus-based control algorithm. The designed control strategy contains a consensus-based component that uses the information shared in the network for reaching a consensus in the state of TLC network components. Discrete event systems specification is applied for modelling and simulation. The proposed solution is assessed by simulation studies with very promising results to deal with simultaneous responses to both pollution levels and traffic flows in urban traffic networks.

  6. Consensus-Based Cooperative Control Based on Pollution Sensing and Traffic Information for Urban Traffic Networks.

    Science.gov (United States)

    Artuñedo, Antonio; Del Toro, Raúl M; Haber, Rodolfo E

    2017-04-26

    Nowadays many studies are being conducted to develop solutions for improving the performance of urban traffic networks. One of the main challenges is the necessary cooperation among different entities such as vehicles or infrastructure systems and how to exploit the information available through networks of sensors deployed as infrastructures for smart cities. In this work an algorithm for cooperative control of urban subsystems is proposed to provide a solution for mobility problems in cities. The interconnected traffic lights controller (TLC) network adapts traffic lights cycles, based on traffic and air pollution sensory information, in order to improve the performance of urban traffic networks. The presence of air pollution in cities is not only caused by road traffic but there are other pollution sources that contribute to increase or decrease the pollution level. Due to the distributed and heterogeneous nature of the different components involved, a system of systems engineering approach is applied to design a consensus-based control algorithm. The designed control strategy contains a consensus-based component that uses the information shared in the network for reaching a consensus in the state of TLC network components. Discrete event systems specification is applied for modelling and simulation. The proposed solution is assessed by simulation studies with very promising results to deal with simultaneous responses to both pollution levels and traffic flows in urban traffic networks.

  7. Mining vehicle classifications from the Columbus Metropolitan Freeway Management System : [summary].

    Science.gov (United States)

    2015-01-01

    Vehicle classification data are used in many transportation applications, including: pavement design, : environmental impact studies, traffic control, and traffic safety. Ohio has over 200 permanent count : stations, supplemented by many more short-t...

  8. 75 FR 62482 - List of Nonconforming Vehicles Decided To Be Eligible for Importation

    Science.gov (United States)

    2010-10-12

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF TRANSPORTATION National Highway Traffic Safety Administration 49 CFR Part 593 List of Nonconforming Vehicles Decided To Be Eligible for Importation AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT...

  9. New Evidence on the Casual Effect of Traffic safety Laws on Drunk Driving and Traffic Fatalities

    OpenAIRE

    Wright, Nicholas Anthony; Lee, La-troy

    2017-01-01

    In the United States, about 28 lives are lost daily in motor vehicle accidents that involve an alcohol-impaired driver. The conventional wisdom is that these accidents can be prevented through the use of strict traffic laws that are robustly enforced, though no consensus exists on the causal impact of these laws in reducing motor vehicle-related fatalities. This paper exploits quasi-random variation in state-level driving and road safety restrictions to estimate the causal effect of select ...

  10. 76 FR 55829 - Federal Motor Vehicle Safety Standards; Electronic Stability Control Systems

    Science.gov (United States)

    2011-09-09

    ... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AL02 Federal Motor Vehicle Safety Standards; Electronic Stability Control Systems AGENCY: National Highway Traffic Safety Administration... changes to a new Federal motor vehicle safety standard requiring light vehicles to be equipped with...

  11. Short Paper: Towards Data-similarity-based Clustering for Inter-vehicle Communication

    NARCIS (Netherlands)

    Dietzel, Stefan; Balanici, Mihail; Kargl, Frank

    2013-01-01

    Many applications of inter-vehicle communication networks (IVC) rely on multi-hop dissemination of information using vehicle-to-vehicle communication. An example are traffic information systems, which aim to provide up-to-date information about traffic jams to drivers. Due to the large amount of

  12. FPGA Based Efficient Design of Traffic Light Controller using Frequency Scaling for Family of HSTL

    DEFF Research Database (Denmark)

    Sharma, Shivani; Khan, Sadiq; Das, Bhagwan

    2016-01-01

    Traffic blockage is one of the major issues faced by world today. That can be road traffic or air traffic or even water traffic .Traffic Controllers provide the right direction by providing a rule for any kind of Vehicles. The idea goes around designing traffic light controller system which...... utilizes least amount of power and is well tested in hardware using Xilinx Virtex6 Field Programmable gate array. FPGA designs are not only cheaper than ASIC designs but have many positive features like speed and performance. So the factors that contribute to power consumption for family of HSTL...

  13. A Survey on Urban Traffic Management System Using Wireless Sensor Networks.

    Science.gov (United States)

    Nellore, Kapileswar; Hancke, Gerhard P

    2016-01-27

    Nowadays, the number of vehicles has increased exponentially, but the bedrock capacities of roads and transportation systems have not developed in an equivalent way to efficiently cope with the number of vehicles traveling on them. Due to this, road jamming and traffic correlated pollution have increased with the associated adverse societal and financial effect on different markets worldwide. A static control system may block emergency vehicles due to traffic jams. Wireless Sensor networks (WSNs) have gained increasing attention in traffic detection and avoiding road congestion. WSNs are very trendy due to their faster transfer of information, easy installation, less maintenance, compactness and for being less expensive compared to other network options. There has been significant research on Traffic Management Systems using WSNs to avoid congestion, ensure priority for emergency vehicles and cut the Average Waiting Time (AWT) of vehicles at intersections. In recent decades, researchers have started to monitor real-time traffic using WSNs, RFIDs, ZigBee, VANETs, Bluetooth devices, cameras and infrared signals. This paper presents a survey of current urban traffic management schemes for priority-based signalling, and reducing congestion and the AWT of vehicles. The main objective of this survey is to provide a taxonomy of different traffic management schemes used for avoiding congestion. Existing urban traffic management schemes for the avoidance of congestion and providing priority to emergency vehicles are considered and set the foundation for further research.

  14. A Survey on Urban Traffic Management System Using Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Kapileswar Nellore

    2016-01-01

    Full Text Available Nowadays, the number of vehicles has increased exponentially, but the bedrock capacities of roads and transportation systems have not developed in an equivalent way to efficiently cope with the number of vehicles traveling on them. Due to this, road jamming and traffic correlated pollution have increased with the associated adverse societal and financial effect on different markets worldwide. A static control system may block emergency vehicles due to traffic jams. Wireless Sensor networks (WSNs have gained increasing attention in traffic detection and avoiding road congestion. WSNs are very trendy due to their faster transfer of information, easy installation, less maintenance, compactness and for being less expensive compared to other network options. There has been significant research on Traffic Management Systems using WSNs to avoid congestion, ensure priority for emergency vehicles and cut the Average Waiting Time (AWT of vehicles at intersections. In recent decades, researchers have started to monitor real-time traffic using WSNs, RFIDs, ZigBee, VANETs, Bluetooth devices, cameras and infrared signals. This paper presents a survey of current urban traffic management schemes for priority-based signalling, and reducing congestion and the AWT of vehicles. The main objective of this survey is to provide a taxonomy of different traffic management schemes used for avoiding congestion. Existing urban traffic management schemes for the avoidance of congestion and providing priority to emergency vehicles are considered and set the foundation for further research.

  15. Synchronization of Traffic Light Systems for Maximum Efficiency along Jalan Bukit Gambier, Penang, Malaysia

    Directory of Open Access Journals (Sweden)

    Ahmad Rafidi M.A.

    2014-01-01

    Full Text Available The synchronization of traffic light systems is one of the best solutions in order to avoid problematic traffic jams. Traffic timing is a major concern when it comes to traffic management. One of the common causes of traffic jams is because of nonsynchronized traffic light systems. Once a light turns green, traffic begins to move, but by the time the moving traffic reaches the next light, the signal is still red. This will disrupt the continuity of the traffic flow, especially for large main roads. The smooth flow of traffic on main routes is important to clear dense traffic in a given time. This study examined the density of vehicles on Jalan Bukit Gambier and also the traffic timing was documented in order to plan out proper re-timing for traffic lights along the studied road. The outcomes of this study support the hypothesis that retiming traffic lights to create a synchronized traffic light system for main roads will greatly improve traffic flow.

  16. Surface generation and editing operations applied to structural support of aerospace vehicle fuselages. M.S. Thesis

    Science.gov (United States)

    Schwartz, Susan K.

    1992-01-01

    The Solid Modeling Aerospace Research Tool (SMART) is a computer aided design tool used in aerospace vehicle design. Modeling of structural components using SMART includes the representation of the transverse or cross-wise elements of a vehicle's fuselage, ringframes, and bulkheads. Ringframes are placed along a vehicle's fuselage to provide structural support and maintain the shape of the fuselage. Bulkheads are also used to maintain shape, but are placed at locations where substantial structural support is required. Given a Bezier curve representation of a cross sectional cut through a vehicle's fuselage and/or an internal tank, this project produces a first-guess Bezier patch representation of a ringframe or bulkhead at the cross-sectional position. The grid produced is later used in the structural analysis of the vehicle. The graphical display of the generated patches allows the user to edit patch control points in real time. Constraints considered in the patch generation include maintaining 'square-like' patches and placement of longitudinal, or lengthwise along the fuselage, structural elements called longerons.

  17. Vision-based traffic data collection sensor for automotive applications.

    Science.gov (United States)

    Llorca, David F; Sánchez, Sergio; Ocaña, Manuel; Sotelo, Miguel A

    2010-01-01

    This paper presents a complete vision sensor onboard a moving vehicle which collects the traffic data in its local area in daytime conditions. The sensor comprises a rear looking and a forward looking camera. Thus, a representative description of the traffic conditions in the local area of the host vehicle can be computed. The proposed sensor detects the number of vehicles (traffic load), their relative positions and their relative velocities in a four-stage process: lane detection, candidates selection, vehicles classification and tracking. Absolute velocities (average road speed) and global positioning are obtained after combining the outputs provided by the vision sensor with the data supplied by the CAN Bus and a GPS sensor. The presented experiments are promising in terms of detection performance and accuracy in order to be validated for applications in the context of the automotive industry.

  18. Vision-Based Traffic Data Collection Sensor for Automotive Applications

    Science.gov (United States)

    Llorca, David F.; Sánchez, Sergio; Ocaña, Manuel; Sotelo, Miguel. A.

    2010-01-01

    This paper presents a complete vision sensor onboard a moving vehicle which collects the traffic data in its local area in daytime conditions. The sensor comprises a rear looking and a forward looking camera. Thus, a representative description of the traffic conditions in the local area of the host vehicle can be computed. The proposed sensor detects the number of vehicles (traffic load), their relative positions and their relative velocities in a four-stage process: lane detection, candidates selection, vehicles classification and tracking. Absolute velocities (average road speed) and global positioning are obtained after combining the outputs provided by the vision sensor with the data supplied by the CAN Bus and a GPS sensor. The presented experiments are promising in terms of detection performance and accuracy in order to be validated for applications in the context of the automotive industry. PMID:22315572

  19. An extended macro traffic flow model accounting for multiple optimal velocity functions with different probabilities

    Science.gov (United States)

    Cheng, Rongjun; Ge, Hongxia; Wang, Jufeng

    2017-08-01

    Due to the maximum velocity and safe headway distance of the different vehicles are not exactly the same, an extended macro model of traffic flow with the consideration of multiple optimal velocity functions with probabilities is proposed in this paper. By means of linear stability theory, the new model's linear stability condition considering multiple probabilities optimal velocity is obtained. The KdV-Burgers equation is derived to describe the propagating behavior of traffic density wave near the neutral stability line through nonlinear analysis. The numerical simulations of influences of multiple maximum velocities and multiple safety distances on model's stability and traffic capacity are carried out. The cases of two different kinds of maximum speeds with same safe headway distance, two different types of safe headway distances with same maximum speed and two different max velocities and two different time-gaps are all explored by numerical simulations. First cases demonstrate that when the proportion of vehicles with a larger vmax increase, the traffic tends to unstable, which also means that jerk and brakes is not conducive to traffic stability and easier to result in stop and go phenomenon. Second cases show that when the proportion of vehicles with greater safety spacing increases, the traffic tends to be unstable, which also means that too cautious assumptions or weak driving skill is not conducive to traffic stability. Last cases indicate that increase of maximum speed is not conducive to traffic stability, while reduction of the safe headway distance is conducive to traffic stability. Numerical simulation manifests that the mixed driving and traffic diversion does not have effect on the traffic capacity when traffic density is low or heavy. Numerical results also show that mixed driving should be chosen to increase the traffic capacity when the traffic density is lower, while the traffic diversion should be chosen to increase the traffic capacity when

  20. Connected commercial vehicles-integrated truck project : vehicle build and build test plan, final technical report.

    Science.gov (United States)

    2014-01-01

    Connected vehicle wireless data communications can enable safety applications that may reduce injuries and : fatalities suffered on our roads and highways, as well as enabling reductions in traffic congestion and impacts on : the environment. As a cr...

  1. Connected commercial vehicles-integrated truck project : vehicle build test report.

    Science.gov (United States)

    2014-01-01

    Connected vehicle wireless data communications can enable safety applications that may reduce injuries and fatalities : suffered on our roads and highways, as well as enabling reductions in traffic congestion and effects on the : environment. As a cr...

  2. Public transportation development and traffic accident prevention in Indonesia

    Directory of Open Access Journals (Sweden)

    Sutanto Soehodho

    2017-03-01

    Full Text Available Traffic accidents have long been known as an iceberg for comprehending the discrepancies of traffic management and entire transportation systems. Figures detailing traffic accidents in Indonesia, as is the case in many other countries, show significantly high numbers and severity levels; these types of totals are also evident in Jakarta, the highest-populated city in the country. While the common consensus recognizes that traffic accidents are the results of three different factor types, namely, human factors, vehicle factors, and external factors (including road conditions, human factors have the strongest influence—and figures on a worldwide scale corroborate that assertion. We, however, try to pinpoint the issues of non-human factors in light of increasing traffic accidents in Indonesia, where motorbike accidents account for the majority of incidents. We then consider three important pillars of action: the development of public transportation, improvement of the road ratio, and traffic management measures.

  3. Open traffic : A toolbox for traffic research

    NARCIS (Netherlands)

    Tamminga, G.F.; Knoppers, P.; Van Lint, J.W.C.

    2014-01-01

    Open Traffic is an open source software project that provides a transport modeling software environment. While most transport model packages offer ready-to-use modules for end-users, Open Traffic provides open access to a modelling environment for the (further) development of methods and algorithms

  4. Traffic management simulation development.

    Science.gov (United States)

    2011-01-03

    Microscopic simulation can provide significant support to traffic management center (TMC) operations. However, traffic simulation applications require data that are expensive and time-consuming to collect. Data collected by TMCs can be used as a prim...

  5. Traffic management simulation development : summary.

    Science.gov (United States)

    2011-01-01

    Increasingly, Florida traffic is monitored electronically by components of the Intelligent Traffic System (ITS), which send data to regional traffic management centers and assist management of traffic flows and incident response using software called...

  6. Awareness and Detection of Traffic and Obstacles Using Synthetic and Enhanced Vision Systems

    Science.gov (United States)

    Bailey, Randall E.

    2012-01-01

    Research literature are reviewed and summarized to evaluate the awareness and detection of traffic and obstacles when using Synthetic Vision Systems (SVS) and Enhanced Vision Systems (EVS). The study identifies the critical issues influencing the time required, accuracy, and pilot workload associated with recognizing and reacting to potential collisions or conflicts with other aircraft, vehicles and obstructions during approach, landing, and surface operations. This work considers the effect of head-down display and head-up display implementations of SVS and EVS as well as the influence of single and dual pilot operations. The influences and strategies of adding traffic information and cockpit alerting with SVS and EVS were also included. Based on this review, a knowledge gap assessment was made with recommendations for ground and flight testing to fill these gaps and hence, promote the safe and effective implementation of SVS/EVS technologies for the Next Generation Air Transportation System

  7. Road traffic safety on the roundabouts

    Directory of Open Access Journals (Sweden)

    О. В. Степанчук

    2013-07-01

    Full Text Available The growth of automobilization and the noncompliance of the city central parts with the modern vehicles requirements create the preconditions for the increase of the road traffic accidents. the intersections, of the main streets of the district value are the most accidental. It is noted that to develop a set of measures to improve road safety at the intersections it is necessary to know the degree of their security. it is found that that the intersections of highways significantly reduce the capacity, creating significant delay of traffic flows, as a result of which they become places of high concentration of automobile emissions, noise and other adverse effects on the environment

  8. 78 FR 74225 - Decision That Certain Nonconforming Motor Vehicles Are Eligible for Importation

    Science.gov (United States)

    2013-12-10

    ... National Highway Traffic Safety Administration Decision That Certain Nonconforming Motor Vehicles Are... vehicle, 49 U.S.C. 30141(a)(1)(B) permits a nonconforming motor vehicle to be admitted into the United.... Claude H. Harris, Director, Office of Vehicle Safety Compliance. Annex A--Nonconforming Motor Vehicles...

  9. Traffic jam driving with NMV avoidance

    Science.gov (United States)

    Milanés, Vicente; Alonso, Luciano; Villagrá, Jorge; Godoy, Jorge; de Pedro, Teresa; Oria, Juan P.

    2012-08-01

    In recent years, the development of advanced driver assistance systems (ADAS) - mainly based on lidar and cameras - has considerably improved the safety of driving in urban environments. These systems provide warning signals for the driver in the case that any unexpected traffic circumstance is detected. The next step is to develop systems capable not only of warning the driver but also of taking over control of the car to avoid a potential collision. In the present communication, a system capable of autonomously avoiding collisions in traffic jam situations is presented. First, a perception system was developed for urban situations—in which not only vehicles have to be considered, but also pedestrians and other non-motor-vehicles (NMV). It comprises a differential global positioning system (DGPS) and wireless communication for vehicle detection, and an ultrasound sensor for NMV detection. Then, the vehicle's actuators - brake and throttle pedals - were modified to permit autonomous control. Finally, a fuzzy logic controller was implemented capable of analyzing the information provided by the perception system and of sending control commands to the vehicle's actuators so as to avoid accidents. The feasibility of the integrated system was tested by mounting it in a commercial vehicle, with the results being encouraging.

  10. The SYOEKSY research project. Electrically-powered vehicles in ring rail line feeder traffic and short-distance travel; Saehkoeiset ajoneuvot kehaeradan syoettoe- ja asiointiliikenteessae. SYOEKSY-tutkimushankkeen loppuraportti 21.9.2011

    Energy Technology Data Exchange (ETDEWEB)

    2011-07-01

    The research report is divided into three sections: a general description of the project, separate reports on each of the themes investigated and a summary of the research results and recommendations. Section 2 deals with themes such as: Low-emissions-technology solutions for traffic and their technical prerequisites in an urban environment and the results obtained from pilot projects. New service models based on electrically-powered traffic technology with an assessment of their feasibility and their effect on urban infrastructure and levels of CO{sub 2} emissions. User needs in new feeder traffic, short-distance travel and other journeys on personal business together with proposals for planning measures which will promote sustainable mobility in new residential areas. The prerequisites for electrically-powered feeder traffic and short-distance travel are therefore handled in a wide-ranging manner. A condensed version of the project conclusions and recommendations is provided in Section 3. A list of the data sources and publications resulting from project work can be found at the end of the report

  11. Vehicle Powertrain Connected Route Optimization for Conventional, Hybrid and Plug-in Electric Vehicles

    OpenAIRE

    Qiao, Zhiqian; Karabasoglu, Orkun

    2016-01-01

    Most navigation systems use data from satellites to provide drivers with the shortest-distance, shortest-time or highway-preferred paths. However, when the routing decisions are made for advanced vehicles, there are other factors affecting cost, such as vehicle powertrain type, battery state of charge (SOC) and the change of component efficiencies under traffic conditions, which are not considered by traditional routing systems. The impact of the trade-off between distance and traffic on the ...

  12. Subjective safety in traffic.

    NARCIS (Netherlands)

    2012-01-01

    The term ‘subjective safety in traffic’ refers to people feeling unsafe in traffic or, more generally, to anxiety regarding being unsafe in traffic for oneself and/or others. Subjective safety in traffic can lead to road users limiting their mobility and social activities, which is one of the

  13. Trajectory Based Traffic Analysis

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Andersen, Ove; Lewis-Kelham, Edwin

    2013-01-01

    We present the INTRA system for interactive path-based traffic analysis. The analyses are developed in collaboration with traffic researchers and provide novel insights into conditions such as congestion, travel-time, choice of route, and traffic-flow. INTRA supports interactive point...

  14. Gaussian traffic everywhere?

    NARCIS (Netherlands)

    van de Meent, R.; Mandjes, M.R.H.; Pras, Aiko

    2006-01-01

    It is often assumed that Internet traffic exhibits Gaussian characteristics, and this assumption has been validated in various studies of real Internet traffic. Less is known, however, about possible boundaries: at what timescales is traffic Gaussian and how much user aggregation is required for

  15. Effect of adaptive cruise control systems on traffic flow

    Science.gov (United States)

    Davis, L. C.

    2004-06-01

    The flow of traffic composed of vehicles that are equipped with adaptive cruise control (ACC) is studied using simulations. The ACC vehicles are modeled by a linear dynamical equation that has string stability. In platoons of all ACC vehicles, perturbations due to changes in the lead vehicle’s velocity do not cause jams. Simulations of merging flows near an onramp show that if the total incoming rate does not exceed the capacity of the single outgoing lane, free flow is maintained. With larger incoming flows, a state closely related to the synchronized flow phase found in manually driven vehicular traffic has been observed. This state, however, should not be considered congested because the flow is maximal for the density. Traffic composed of random sequences of ACC vehicles and manual vehicles has also been studied. At high speeds ( ˜30 m/s ) jamming occurs for concentrations of ACC vehicles of 10% or less. At 20% no jams are formed. The formation of jams is sensitive to the sequence of vehicles (ACC or manual). At lower speeds ( ˜15 m/s ) , no critical concentration for complete jam suppression is found. Rather, the average velocity in the pseudojam region increases with increasing ACC concentration. Mixing 50% ACC vehicles randomly with manually driven vehicles on the primary lane in onramp simulations shows only modestly reduced travel times and larger flow rates.

  16. 49 CFR 575.105 - Vehicle rollover.

    Science.gov (United States)

    2010-10-01

    ... Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY... are passenger car derivatives) which have a wheelbase of 110 inches or less and special features for... vehicle design features which cause this type of vehicles to be more likely to rollover (e.g., higher...

  17. Optimizing Traffic Operation in Designing Specific Upgrades

    Directory of Open Access Journals (Sweden)

    Ebrahim Sangsefidi

    2015-01-01

    Full Text Available Transport forms one of the primary needs in all categories of the population in modern society; it is of paramount concern for traffic engineers, transport planners, and policy makers to understand and evaluate the quality of service being provided by the transport facilities designed by them. This paper presents an investigation in profile geometric design and traffic flow operation on two-lane two-way highways and provides analyses that will help in a better understanding of traffic operation on these facilities to select the optimum profile configuration. The effects of influencing parameters consisting of grade, length of grade, traffic composition, and traffic volume are evaluated and finally a systematic procedure to evaluate flow rate under the base condition is presented. Finally, based on these achievements an algorithm is introduced to select optimum Finished Ground of profile view. Results show that the percentage of heavy vehicles has a contributing effect on traffic operation so that the optimum profile configuration is incredibly affected by this factor. Source data have been obtained from Highway Capacity Manual (HCM as a pioneer document in respect of quantifying the concept of capacity for a transport facility.

  18. Traffic Flow Wide-Area Surveillance system

    Energy Technology Data Exchange (ETDEWEB)

    Allgood, G.O.; Ferrell, R.K.; Kercel, S.W.; Abston, R.A.

    1994-09-01

    Traffic management can be thought of as a stochastic queuing process where the serving time at one of its control points is dynamically linked to the global traffic pattern, which is, in turn, dynamically linked to the control point. For this closed-loop system to be effective, the traffic management system must sense and interpret a large spatial projection of data originating from multiple sensor suites. This concept is the basis for the development of a Traffic Flow Wide-Area Surveillance (TFWAS) system. This paper presents the results of a study by Oak Ridge National Laboratory to define the operational specifications and characteristics, to determine the constraints, and to examine the state of technology of a TFWAS system in terms of traffic management and control. In doing so, the functions and attributes of a TFWAS system are mapped into an operational structure consistent with the Intelligent Vehicle Highway System (IVHS) concept and the existing highway infrastructure. This mapping includes identifying candidate sensor suites and establishing criteria, requirements, and performance measures by which these systems can be graded in their ability and practicality to meet the operational requirements of a TFWAS system. In light of this, issues such as system integration, applicable technologies, impact on traffic management and control, and public acceptance are addressed.

  19. Competitive Traffic Assignment in Road Networks

    Directory of Open Access Journals (Sweden)

    Krylatov Alexander Y.

    2016-09-01

    Full Text Available Recently in-vehicle route guidance and information systems are rapidly developing. Such systems are expected to reduce congestion in an urban traffic area. This social benefit is believed to be reached by imposing the route choices on the network users that lead to the system optimum traffic assignment. However, guidance service could be offered by different competitive business companies. Then route choices of different mutually independent groups of users may reject traffic assignment from the system optimum state. In this paper, a game theoretic approach is shown to be very efficient to formalize competitive traffic assignment problem with various groups of users in the form of non-cooperative network game with the Nash equilibrium search. The relationships between the Wardrop’s system optimum associated with the traffic assignment problem and the Nash equilibrium associated with the competitive traffic assignment problem are investigated. Moreover, some related aspects of the Nash equilibrium and the Wardrop’s user equilibrium assignments are also discussed.

  20. Traffic flow wide-area surveillance system

    Science.gov (United States)

    Allgood, Glenn O.; Ferrell, Regina K.; Kercel, Stephen W.; Abston, Ruth A.

    1995-01-01

    Traffic management can be thought of as a stochastic queuing process where the serving time at one of its control points is dynamically linked to the global traffic pattern, which is, in turn, dynamically linked to the control point. For this closed-loop system to be effective, the traffic management system must sense and interpret a large spatial projection of data originating from multiple sensor suites. This concept is the basis for the development of a traffic flow wide-area surveillance (TFWAS) system. This paper presents the results of a study by Oak Ridge National Laboratory to define the operational specifications and characteristics, to determine the constraints, and to examine the state of technology of a TFWAS system in terms of traffic management and control. In doing so, the functions and attributes of a TFWAS system are mapped into an operational structure consistent with the Intelligent Vehicle Highway System (IVHS) concept and the existing highway infrastructure. This mapping includes identifying candidate sensor suites and establishing criteria, requirements, and performance measures by which these systems can be graded in their ability and practicality to meet the operational requirements of a TFWAS system. In light of this, issues such as system integration, applicable technologies, impact on traffic management and control, and public acceptance are addressed.