WorldWideScience

Sample records for transims traffic simulation

  1. A comparative study of weaving sections in TRANSIMS and Highway Capacity Manual

    OpenAIRE

    Jillella, Srinivas

    2001-01-01

    Weaving is defined as the crossing of two or more traffic streams traveling in the same direction along a significant length of the highway without the aid of traffic control devices. The traditional methods used for the design and operational analysis of a highway is the Highway Capacity Manual (HCM). These traditional methods in the manual use road geometry and traffic volumes as input and provide an estimate of the speed as an output. TRANSIMS is a new computer simulation pa...

  2. Dynamic traffic assignment on parallel computers

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, K.; Frye, R.; Jakob, R.; Rickert, M.; Stretz, P.

    1998-12-01

    The authors describe part of the current framework of the TRANSIMS traffic research project at the Los Alamos National Laboratory. It includes parallel implementations of a route planner and a microscopic traffic simulation model. They present performance figures and results of an offline load-balancing scheme used in one of the iterative re-planning runs required for dynamic route assignment.

  3. 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...

  4. TRAFFIC SIMULATION FOR MIXED TRAFFIC SYSTEMS

    African Journals Online (AJOL)

    EGETE

    2012-05-04

    2002). Description of a microscopic traffic model of an urban district and the analysis and problem solving traffic congestion based on actual data is its objective. There suggested models for a vehicular traffic flow based on partial ...

  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. Simulation Model of Traffic Jam at Crossroads

    OpenAIRE

    Mladen Kalajžić; Katica Miloš; Mirela Muić

    2002-01-01

    Traffic congestion is one of the major problems in most cities.It is the consequence of unavoidable motorization, butalso, in many cases, of improper solutions considering constructionof roads or organisation of traffic.This paper deals with one problematic crossroad in thetown of Zadar in which traffic jams occur due to poor organisationof traffic. Using mathematical simulation, the first partproves that traffic jams will certainly occur, and in the secondpart, crossroads signalling is consi...

  7. Simulation Model of Traffic Jam at Crossroads

    Directory of Open Access Journals (Sweden)

    Mladen Kalajžić

    2002-11-01

    Full Text Available Traffic congestion is one of the major problems in most cities.It is the consequence of unavoidable motorization, butalso, in many cases, of improper solutions considering constructionof roads or organisation of traffic.This paper deals with one problematic crossroad in thetown of Zadar in which traffic jams occur due to poor organisationof traffic. Using mathematical simulation, the first partproves that traffic jams will certainly occur, and in the secondpart, crossroads signalling is considered as a possible solutionwhich, if combined with intelligent control could significantlyimprove the organisation of traffic at this crossroads.

  8. A queuing model for road traffic simulation

    International Nuclear Information System (INIS)

    Guerrouahane, N.; Aissani, D.; Bouallouche-Medjkoune, L.; Farhi, N.

    2015-01-01

    We present in this article a stochastic queuing model for the raod traffic. The model is based on the M/G/c/c state dependent queuing model, and is inspired from the deterministic Godunov scheme for the road traffic simulation. We first propose a variant of M/G/c/c state dependent model that works with density-flow fundamental diagrams rather than density-speed relationships. We then extend this model in order to consider upstream traffic demand as well as downstream traffic supply. Finally, we show how to model a whole raod by concatenating raod sections as in the deterministic Godunov scheme

  9. 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 ...

  10. Real-Time Microscopic Traffic Simulation and Optimization at Intersections with Video Traffic Detection

    OpenAIRE

    Liang, Zijun; Flötteröd, Yun-Pang; Chen, Hong; Sohr, Alexander; Bei, Xiaoxu; Bottazzi, Maximiliano; Trumpold, Jan

    2018-01-01

    In this paper, real-time vehicular data from video traffic detection (VTD) are used for minimizing the travel delay at intersections and a real-time traffic optimization model, based on the SUMO traffic simulation software, is established accordingly. The proposed model is implemented in a small industrial control computer which serves as the communication interface between the traffic signal control system, the traffic simulation and optimization model and the real-time video traffic detecti...

  11. Relaxing Synchronization in Parallel Agent-Based Road Traffic Simulation

    NARCIS (Netherlands)

    Xu, Y.; Cai, W.; Aydt, H.; Lees, M.; Zehe, D.

    Large-scale agent-based traffic simulation is computationally intensive. Parallel computing can help to speed up agent-based traffic simulation. Parallelization of agent-based traffic simulations is generally achieved by decomposing the road network into subregions. The agents in each subregion are

  12. Green supply chain: Simulating road traffic congestion

    Science.gov (United States)

    Jalal, Muhammad Zulqarnain Hakim Abd; Nawawi, Mohd Kamal Mohd; Laailatul Hanim Mat Desa, Wan; Khalid, Ruzelan; Khalid Abduljabbar, Waleed; Ramli, Razamin

    2017-09-01

    With the increasing awareness of the consumers about environmental issues, businesses, households and governments increasingly want use green products and services which lead to green supply chain. This paper discusses a simulation study of a selected road traffic system that will contribute to the air pollution if in the congestion state. Road traffic congestion (RTC) can be caused by a temporary obstruction, a permanent capacity bottleneck in the network itself, and stochastic fluctuation in demand within a particular sector of the network, leading to spillback and queue propagation. A discrete-event simulation model is developed to represent the real traffic light control (TLC) system condition during peak hours. Certain performance measures such as average waiting time and queue length were measured using the simulation model. Existing system uses pre-set cycle time to control the light changes which is fixed time cycle. In this research, we test several other combination of pre-set cycle time with the objective to find the best system. In addition, we plan to use a combination of the pre-set cycle time and a proximity sensor which have the authority to manipulate the cycle time of the lights. The sensors work in such situation when the street seems to have less occupied vehicles, obviously it may not need a normal cycle for green light, and automatically change the cycle to street where vehicle is present.

  13. Traffic and Driving Simulator Based on Architecture of Interactive Motion

    Science.gov (United States)

    Paz, Alexander; Veeramisti, Naveen; Khaddar, Romesh; de la Fuente-Mella, Hanns; Modorcea, Luiza

    2015-01-01

    This study proposes an architecture for an interactive motion-based traffic simulation environment. In order to enhance modeling realism involving actual human beings, the proposed architecture integrates multiple types of simulation, including: (i) motion-based driving simulation, (ii) pedestrian simulation, (iii) motorcycling and bicycling simulation, and (iv) traffic flow simulation. The architecture has been designed to enable the simulation of the entire network; as a result, the actual driver, pedestrian, and bike rider can navigate anywhere in the system. In addition, the background traffic interacts with the actual human beings. This is accomplished by using a hybrid mesomicroscopic traffic flow simulation modeling approach. The mesoscopic traffic flow simulation model loads the results of a user equilibrium traffic assignment solution and propagates the corresponding traffic through the entire system. The microscopic traffic flow simulation model provides background traffic around the vicinities where actual human beings are navigating the system. The two traffic flow simulation models interact continuously to update system conditions based on the interactions between actual humans and the fully simulated entities. Implementation efforts are currently in progress and some preliminary tests of individual components have been conducted. The implementation of the proposed architecture faces significant challenges ranging from multiplatform and multilanguage integration to multievent communication and coordination. PMID:26491711

  14. Traffic simulation for mixed traffic systems | Mbam | Global Journal of ...

    African Journals Online (AJOL)

    Traffic problem is classified into single and mixed, especially in most developing countries, where motorbikes are used as the most popular transportation system. The aim of this paper is to introduce the motorbike symbol into the traffic light control system to separate cars/lorries indicator from that of motorbike. This is likely ...

  15. GCA-w Algorithms for Traffic Simulation

    International Nuclear Information System (INIS)

    Hoffmann, R.

    2011-01-01

    The GCA-w model (Global Cellular Automata with write access) is an extension of the GCA (Global Cellular Automata) model, which is based on the cellular automata model (CA). Whereas the CA model uses static links to local neighbors, the GCA model uses dynamic links to potentially global neighbors. The GCA-w model is a further extension that allows modifying the neighbors' states. Thereby, neighbors can dynamically be activated or deactivated. Algorithms can be described more concisely and may execute more efficiently because redundant computations can be avoided. Modeling traffic flow is a good example showing the usefulness of the GCA-w model. The Nagel-Schreckenberg algorithm for traffic simulation is first described as CA and GCA, and then transformed into the GCA-w model. This algorithm is '' exclusive-write '', meaning that no write conflicts have to be resolved. Furthermore, this algorithm is extended, allowing to deactivate and to activate cars stuck in a traffic jam in order to save computation time and energy. (author)

  16. A Driver Behavior Learning Framework for Enhancing Traffic Simulation

    Directory of Open Access Journals (Sweden)

    Ramona Maria Paven

    2014-06-01

    Full Text Available Traffic simulation provides an essential support for developing intelligent transportation systems. It allows affordable validation of such systems using a large variety of scenarios that involves massive data input. However, realistic traffic models are hard to be implemented especially for microscopic traffic simulation. One of the hardest problems in this context is to model the behavior of drivers, due the complexity of human nature. The work presented in this paper proposes a framework for learning driver behavior based on a Hidden Markov Model technique. Moreover, we propose also a practical method to inject this behavior in a traffic model used by the SUMO traffic simulator. To demonstrate the effectiveness of this method we present a case study involving real traffic collected from Timisoara city area.

  17. Examining Road Traffic Mortality Status in China: A Simulation Study.

    Science.gov (United States)

    Huang, Helai; Yin, Qingyi; Schwebel, David C; Li, Li; Hu, Guoqing

    2016-01-01

    Data from the Chinese police service suggest substantial reductions in road traffic injuries since 2002, but critics have questioned the accuracy of those data, especially considering conflicting data reported by the health department. To address the gap between police and health department data and to determine which may be more accurate, we conducted a simulation study based on the modified Smeed equation, which delineates a non-linear relation between road traffic mortality and the level of motorization in a country or region. Our goal was to simulate trends in road traffic mortality in China and compare performances in road traffic safety management between China and 13 other countries. Chinese police data indicate a peak in road traffic mortalities in 2002 and a significant and a gradual decrease in population-based road traffic mortality since 2002. Health department data show the road traffic mortality peaked in 2012. In addition, police data suggest China's road traffic mortality peaked at a much lower motorization level (0.061 motor vehicles per person) in 2002, followed by a reduction in mortality to a level comparable to that of developed countries. Simulation results based on health department data suggest high road traffic mortality, with a mortality peak in 2012 at a moderate motorization level (0.174 motor vehicles per person). Comparisons to the other 13 countries suggest the health data from China may be more valid than the police data. Our simulation data indicate China is still at a stage of high road traffic mortality, as suggested by health data, rather than a stage of low road traffic mortality, as suggested by police data. More efforts are needed to integrate safety into road design, improve road traffic management, improve data quality, and alter unsafe behaviors of pedestrians, drivers and passengers in China.

  18. Nautical traffic simulation with multi-agent system

    NARCIS (Netherlands)

    Xiao, F.; Ligteringen, H.; Van Gulijk, C.; Ale, B.J.M.

    2013-01-01

    This paper describes a microscopic nautical traffic simulation model based on multi-agent system. The ship traffic is produced from the behavior of autonomous agents that represent ships. Especially, we look at the behaviors for collision avoidance in different encountering situations with different

  19. Use of agent based simulation for traffic safety assessment

    CSIR Research Space (South Africa)

    Conradie, Dirk CU

    2008-07-01

    Full Text Available This paper describes the development of an agent based Computational Building Simulation (CBS) tool, termed KRONOS that is being used to work on advanced research questions such as traffic safety assessment and user behaviour in buildings...

  20. Calibration of microscopic traffic simulation models using metaheuristic algorithms

    Directory of Open Access Journals (Sweden)

    Miao Yu

    2017-06-01

    Full Text Available This paper presents several metaheuristic algorithms to calibrate a microscopic traffic simulation model. The genetic algorithm (GA, Tabu Search (TS, and a combination of the GA and TS (i.e., warmed GA and warmed TS are implemented and compared. A set of traffic data collected from the I-5 Freeway, Los Angles, California, is used. Objective functions are defined to minimize the difference between simulated and field traffic data which are built based on the flow and speed. Several car-following parameters in VISSIM, which can significantly affect the simulation outputs, are selected to calibrate. A better match to the field measurements is reached with the GA, TS, and warmed GA and TS when comparing with that only using the default parameters in VISSIM. Overall, TS performs very well and can be used to calibrate parameters. Combining metaheuristic algorithms clearly performs better and therefore is highly recommended for calibrating microscopic traffic simulation models.

  1. Discrete event simulation of Maglev transport considering traffic waves

    OpenAIRE

    Cha, Moo Hyun; Mun, Duhwan

    2014-01-01

    A magnetically levitated vehicle (Maglev) system is under commercialization as a new transportation system in Korea. The Maglev is operated by an unmanned automatic control system. Therefore, the plan of train operation should be carefully established and validated in advance. In general, when making a train operation plan, statistically predicted traffic data is used. However, a traffic wave often occurs in real train service, and demand-driven simulation technology is required to review a t...

  2. Simulation Analysis on Driving Behavior during Traffic Sign Recognition

    Directory of Open Access Journals (Sweden)

    Lishan Sun

    2011-05-01

    Full Text Available The traffic signs transfer trip information to drivers through vectors like words, graphs and numbers. Traffic sign with excessive information often makes the drivers have no time to read and understand, leading to risky driving. It is still a problem of how to clarify the relationship between traffic sign recognition and risky driving behavior. This paper presents a study that is reflective of such an effort. Twenty volunteers participated in the dynamic visual recognition experiment in driving simulator, and the data of several key indicators are obtained, including visual cognition time, vehicle acceleration and the offset distance from middle lane, etc. Correlations between each indicator above are discussed in terms of risky driving. Research findings directly show that drivers' behavior changes a lot during their traffic sign recognition.

  3. Aircraft Performance for Open Air Traffic Simulations

    NARCIS (Netherlands)

    Metz, I.C.; Hoekstra, J.M.; Ellerbroek, J.; Kugler, D.

    2016-01-01

    The BlueSky Open Air Tra_c Simulator developed by the Control & Simulation section of TU Delft aims at supporting research for analysing Air Tra_c Management concepts by providing an open source simulation platform. The goal of this study was to complement BlueSky with aircraft performance

  4. Simulation of Road Traffic Applying Model-Driven Engineering

    Directory of Open Access Journals (Sweden)

    Alberto FERNÁNDEZ-ISABEL

    2016-05-01

    Full Text Available Road traffic is an important phenomenon in modern societies. The study of its different aspects in the multiple scenarios where it happens is relevant for a huge number of problems. At the same time, its scale and complexity make it hard to study. Traffic simulations can alleviate these difficulties, simplifying the scenarios to consider and controlling their variables. However, their development also presents difficulties. The main ones come from the need to integrate the way of working of researchers and developers from multiple fields. Model-Driven Engineering (MDE addresses these problems using Modelling Languages (MLs and semi-automatic transformations to organise and describe the development, from requirements to code. This paper presents a domain-specific MDE framework for simulations of road traffic. It comprises an extensible ML, support tools, and development guidelines. The ML adopts an agent-based approach, which is focused on the roles of individuals in road traffic and their decision-making. A case study shows the process to model a traffic theory with the ML, and how to specialise that specification for an existing target platform and its simulations. The results are the basis for comparison with related work.

  5. Dynamic Traffic Congestion Simulation and Dissipation Control Based on Traffic Flow Theory Model and Neural Network Data Calibration Algorithm

    Directory of Open Access Journals (Sweden)

    Li Wang

    2017-01-01

    Full Text Available Traffic congestion is a common problem in many countries, especially in big cities. At present, China’s urban road traffic accidents occur frequently, the occurrence frequency is high, the accident causes traffic congestion, and accidents cause traffic congestion and vice versa. The occurrence of traffic accidents usually leads to the reduction of road traffic capacity and the formation of traffic bottlenecks, causing the traffic congestion. In this paper, the formation and propagation of traffic congestion are simulated by using the improved medium traffic model, and the control strategy of congestion dissipation is studied. From the point of view of quantitative traffic congestion, the paper provides the fact that the simulation platform of urban traffic integration is constructed, and a feasible data analysis, learning, and parameter calibration method based on RBF neural network is proposed, which is used to determine the corresponding decision support system. The simulation results prove that the control strategy proposed in this paper is effective and feasible. According to the temporal and spatial evolution of the paper, we can see that the network has been improved on the whole.

  6. Highway traffic simulation on multi-processor computers

    Energy Technology Data Exchange (ETDEWEB)

    Hanebutte, U.R.; Doss, E.; Tentner, A.M.

    1997-04-01

    A computer model has been developed to simulate highway traffic for various degrees of automation with a high level of fidelity in regard to driver control and vehicle characteristics. The model simulates vehicle maneuvering in a multi-lane highway traffic system and allows for the use of Intelligent Transportation System (ITS) technologies such as an Automated Intelligent Cruise Control (AICC). The structure of the computer model facilitates the use of parallel computers for the highway traffic simulation, since domain decomposition techniques can be applied in a straight forward fashion. In this model, the highway system (i.e. a network of road links) is divided into multiple regions; each region is controlled by a separate link manager residing on an individual processor. A graphical user interface augments the computer model kv allowing for real-time interactive simulation control and interaction with each individual vehicle and road side infrastructure element on each link. Average speed and traffic volume data is collected at user-specified loop detector locations. Further, as a measure of safety the so- called Time To Collision (TTC) parameter is being recorded.

  7. Simulating Human Cognition in the Domain of Air Traffic Control

    Science.gov (United States)

    Freed, Michael; Johnston, James C.; Null, Cynthia H. (Technical Monitor)

    1995-01-01

    Experiments intended to assess performance in human-machine interactions are often prohibitively expensive, unethical or otherwise impractical to run. Approximations of experimental results can be obtained, in principle, by simulating the behavior of subjects using computer models of human mental behavior. Computer simulation technology has been developed for this purpose. Our goal is to produce a cognitive model suitable to guide the simulation machinery and enable it to closely approximate a human subject's performance in experimental conditions. The described model is designed to simulate a variety of cognitive behaviors involved in routine air traffic control. As the model is elaborated, our ability to predict the effects of novel circumstances on controller error rates and other performance characteristics should increase. This will enable the system to project the impact of proposed changes to air traffic control procedures and equipment on controller performance.

  8. Traffic

    International Nuclear Information System (INIS)

    Lichtblau, G.

    2001-01-01

    This chapter deals with passenger and freight traffic, public and private transportation, traffic related environmental impacts, future developments, traffic indicators, regional traffic planning, health costs due to road traffic related air pollution, noise pollution, measures and regulations for traffic control and fuels for traffic. In particular energy consumption, energy efficiency, pollutant emissions ( CO 2 , SO 2 , NO x , HC, CO, N 2 O, NH 3 and particulates) and environmental effects of the different types of traffic and different types of fuels are compared and studied. Legal regulations and measures for an effective traffic control are discussed. (a.n.)

  9. Upgrades to the Probabilistic NAS Platform Air Traffic Simulation Software

    Science.gov (United States)

    Hunter, George; Boisvert, Benjamin

    2013-01-01

    This document is the final report for the project entitled "Upgrades to the Probabilistic NAS Platform Air Traffic Simulation Software." This report consists of 17 sections which document the results of the several subtasks of this effort. The Probabilistic NAS Platform (PNP) is an air operations simulation platform developed and maintained by the Saab Sensis Corporation. The improvements made to the PNP simulation include the following: an airborne distributed separation assurance capability, a required time of arrival assignment and conformance capability, and a tactical and strategic weather avoidance capability.

  10. Discrete event simulation of Maglev transport considering traffic waves

    Directory of Open Access Journals (Sweden)

    Moo Hyun Cha

    2014-10-01

    Full Text Available A magnetically levitated vehicle (Maglev system is under commercialization as a new transportation system in Korea. The Maglev is operated by an unmanned automatic control system. Therefore, the plan of train operation should be carefully established and validated in advance. In general, when making a train operation plan, statistically predicted traffic data is used. However, a traffic wave often occurs in real train service, and demand-driven simulation technology is required to review a train operation plan and service quality considering traffic waves. We propose a method and model to simulate Maglev operation considering continuous demand changes. For this purpose, we employed a discrete event model that is suitable for modeling the behavior of railway passenger transportation. We modeled the system hierarchically using discrete event system specification (DEVS formalism. In addition, through implementation and an experiment using the DEVSim++ simulation environment, we tested the feasibility of the proposed model. Our experimental results also verified that our demand-driven simulation technology can be used for a priori review of train operation plans and strategies.

  11. Qualitative and Quantitative Analysis of Congested Marine Traffic Environment – An Application Using Marine Traffic Simulation System

    Directory of Open Access Journals (Sweden)

    Kazuhiko Hasegawa

    2013-06-01

    Full Text Available Difficulty of sailing is quite subjective matter. It depends on various factors. Using Marine Traffic Simulation System (MTSS developed by Osaka University this challenging subject is discussed. In this system realistic traffic flow including collision avoidance manoeuvres can be reproduced in a given area. Simulation is done for southward of Tokyo Bay, Strait of Singapore and off-Shanghai area changing traffic volume from 5 or 50 to 150 or 200% of the present volume. As a result, strong proportional relation between near-miss ratio and traffic density per hour per sailed area is found, independent on traffic volume, area size and configuration. The quantitative evaluation index of the difficulty of sailing, here called risk rate of the area is defined using thus defined traffic density and near-miss ratio.

  12. Simulation of load traffic and steeped speed control of conveyor

    Science.gov (United States)

    Reutov, A. A.

    2017-10-01

    The article examines the possibilities of the step control simulation of conveyor speed within Mathcad, Simulink, Stateflow software. To check the efficiency of the control algorithms and to more accurately determine the characteristics of the control system, it is necessary to simulate the process of speed control with real values of traffic for a work shift or for a day. For evaluating the belt workload and absence of spillage it is necessary to use empirical values of load flow in a shorter period of time. The analytical formulas for optimal speed step values were received using empirical values of load. The simulation checks acceptability of an algorithm, determines optimal parameters of regulation corresponding to load flow characteristics. The average speed and the number of speed switching during simulation are admitted as criteria of regulation efficiency. The simulation example within Mathcad software is implemented. The average conveyor speed decreases essentially by two-step and three-step control. A further increase in the number of regulatory steps decreases average speed insignificantly but considerably increases the intensity of the speed switching. Incremental algorithm of speed regulation uses different number of stages for growing and reducing load traffic. This algorithm allows smooth control of the conveyor speed changes with monotonic variation of the load flow. The load flow oscillation leads to an unjustified increase or decrease of speed. Work results can be applied at the design of belt conveyors with adjustable drives.

  13. A Cooperative Human-Adaptive Traffic Simulation (CHATS)

    Science.gov (United States)

    Phillips, Charles T.; Ballin, Mark G.

    1999-01-01

    NASA is considering the development of a Cooperative Human-Adaptive Traffic Simulation (CHATS), to examine and evaluate performance of the National Airspace System (NAS) as the aviation community moves toward free flight. CHATS will be specifically oriented toward simulating strategic decision-making by airspace users and by the service provider s traffic management personnel, within the context of different airspace and rules assumptions. It will use human teams to represent these interests and make decisions, and will rely on computer modeling and simulation to calculate the impacts of these decisions. The simulation objectives will be to examine: 1. evolution of airspace users and the service provider s strategies, through adaptation to new operational environments; 2. air carriers competitive and cooperative behavior; 3. expected benefits to airspace users and the service provider as compared to the current NAS; 4. operational limitations of free flight concepts due to congestion and safety concerns. This paper describes an operational concept for CHATS, and presents a high-level functional design which would utilize a combination of existing and new models and simulation capabilities.

  14. Proof of Concept for the Trajectory-Level Validation Framework for Traffic Simulation Models

    Science.gov (United States)

    2017-10-30

    Based on current practices, traffic simulation models are calibrated and validated using macroscopic measures such as 15-minute averages of traffic counts or average point-to-point travel times. For an emerging number of applications, including conne...

  15. Numerical simulation of vehicular traffic for non-ideal drivers.

    Science.gov (United States)

    Domínguez, Laura; Amador, Carlos

    2004-03-01

    Numerical simulations of vehicular traffic based on cellular automatae have provided a description of the more relevant experimentally observed properties of the system. Rules for drivers behaviour, though, are highly idealized. In this work we have included rules to mimic the different personalities of drivers: lane changers, passers, over-cautious drivers, tail-gaters, etc. Also we have adopted rules specific to the behaviour of drivers in Mexico City. The whole space of parameters is studied and conclusions are drawn for the effect of this variability on overall vehicular flow. As a further application of the model we study the effect of "shoulder of the road" drivers (who pass congested traffic and return to the main road afterwards) on overall vehicular flow.

  16. Modeling, Identification, Estimation, and Simulation of Urban Traffic Flow in Jakarta and Bandung

    Directory of Open Access Journals (Sweden)

    Herman Y. Sutarto

    2015-06-01

    Full Text Available This paper presents an overview of urban traffic flow from the perspective of system theory and stochastic control. The topics of modeling, identification, estimation and simulation techniques are evaluated and validated using actual traffic flow data from the city of Jakarta and Bandung, Indonesia, and synthetic data generated from traffic micro-simulator VISSIM. The results on particle filter (PF based state estimation and Expectation-Maximization (EM based parameter estimation (identification confirm the proposed model gives satisfactory results that capture the variation of urban traffic flow. The combination of the technique and the simulator platform assembles possibility to develop a real-time traffic light controller.  

  17. A Prototype System for Real Time Computer Animation of Slow Traffic in a Driving Simulator

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.; Delden, Mattijs J.B. van; Hin, Andrea J.S.; Wolffelaar, Peter C. van

    1997-01-01

    The Traffic Research Centre (TRC) of the University of Groningen in the Netherlands has developed a driving simulator with ‘intelligent’ computer-controlled traffic, consisting at the moment only of saloon cars. The range of possible applications would be greatly enhanced if other traffic

  18. Integrating meso- and micro-simulation models to evaluate traffic management strategies - year 1 : final report.

    Science.gov (United States)

    2016-06-01

    In this project the researchers developed a hierarchical multi-resolution traffic simulation system for metropolitan areas, referred to as MetroSim. Categorically, the focus is on integrating two types of simulation: microscopic simulation in which i...

  19. Toolbox for Urban Mobility Simulation: High Resolution Population Dynamics for Global Cities

    Science.gov (United States)

    Bhaduri, B. L.; Lu, W.; Liu, C.; Thakur, G.; Karthik, R.

    2015-12-01

    In this rapidly urbanizing world, unprecedented rate of population growth is not only mirrored by increasing demand for energy, food, water, and other natural resources, but has detrimental impacts on environmental and human security. Transportation simulations are frequently used for mobility assessment in urban planning, traffic operation, and emergency management. Previous research, involving purely analytical techniques to simulations capturing behavior, has investigated questions and scenarios regarding the relationships among energy, emissions, air quality, and transportation. Primary limitations of past attempts have been availability of input data, useful "energy and behavior focused" models, validation data, and adequate computational capability that allows adequate understanding of the interdependencies of our transportation system. With increasing availability and quality of traditional and crowdsourced data, we have utilized the OpenStreetMap roads network, and has integrated high resolution population data with traffic simulation to create a Toolbox for Urban Mobility Simulations (TUMS) at global scale. TUMS consists of three major components: data processing, traffic simulation models, and Internet-based visualizations. It integrates OpenStreetMap, LandScanTM population, and other open data (Census Transportation Planning Products, National household Travel Survey, etc.) to generate both normal traffic operation and emergency evacuation scenarios. TUMS integrates TRANSIMS and MITSIM as traffic simulation engines, which are open-source and widely-accepted for scalable traffic simulations. Consistent data and simulation platform allows quick adaption to various geographic areas that has been demonstrated for multiple cities across the world. We are combining the strengths of geospatial data sciences, high performance simulations, transportation planning, and emissions, vehicle and energy technology development to design and develop a simulation

  20. Traffic analysis toolbox volume XI : weather and traffic analysis, modeling and simulation.

    Science.gov (United States)

    2010-12-01

    This document presents a weather module for the traffic analysis tools program. It provides traffic engineers, transportation modelers and decisions makers with a guide that can incorporate weather impacts into transportation system analysis and mode...

  1. Integration of a driving simulator and a traffic simulator case study: Exploring drivers' behavior in response to variable message signs

    Directory of Open Access Journals (Sweden)

    Mansoureh Jeihani

    2017-12-01

    Full Text Available For the first time, a driving simulator has been integrated with a traffic simulator at the network level to allow subjects to drive in a fairly realistic environment with a realistic traffic flow and density. A 10 mi2 (25 km2 network was developed in a driving simulator and then exported to a traffic simulator. About 30 subjects drove the simulator under different traffic and driving conditions and variable message sign (VMS information, both with and without integration. Route guidance was available for the subjects. The challenges of the integration process are explained and its advantages investigated. The study concluded that traffic density, VMS reliability and compliance behavior are higher when driving and traffic simulators are integrated. To find factors affecting route diversion, researchers applied a binary logistic regression model. The results indicated that the original chosen route, displayed VMS information, subjects' attitude toward VMS information helpfulness, and their level of exposure to VMS affect route diversion. In addition, a multinomial logistic regression model was employed to investigate important factors in route choice. The results revealed that there is a significant correlation with driver route choice behavior and their actual travel time, the need for GPS, VMS exposure and also the designed scenarios. It should be noted that the paper was peer-reviewed by TRB and presented at the TRB Annual Meeting, Washington, D.C., January 2016. Keywords: Integration, Variable message sign, Compliance behavior, Driving simulator, Traffic simulator, Discrete choice analysis

  2. Simulation and analysis of traffic flow based on cellular automaton

    Science.gov (United States)

    Ren, Xianping; Liu, Xia

    2018-03-01

    In this paper, single-lane and two-lane traffic model are established based on cellular automaton. Different values of vehicle arrival rate at the entrance and vehicle departure rate at the exit are set to analyze their effects on density, average speed and traffic flow. If the road exit is unblocked, vehicles can pass through the road smoothly despite of the arrival rate at the entrance. If vehicles enter into the road continuously, the traffic condition is varied with the departure rate at the exit. To avoid traffic jam, reasonable vehicle departure rate should be adopted.

  3. Minimizing the Disruptive Effects of Prospective Memory in Simulated Air Traffic Control

    OpenAIRE

    Loft, Shayne; Smith, Rebekah E.; Remington, Roger

    2013-01-01

    Prospective memory refers to remembering to perform an intended action in the future. Failures of prospective memory can occur in air traffic control. In two experiments, we examined the utility of external aids for facilitating air traffic management in a simulated air traffic control task with prospective memory requirements. Participants accepted and handed-off aircraft and detected aircraft conflicts. The prospective memory task involved remembering to deviate from a routine operating pro...

  4. Comparision by Simulation of Different Approaches to the Urban Traffic Control

    Czech Academy of Sciences Publication Activity Database

    Přikryl, Jan; Tichý, T.; Bělinová, Z.; Kapitán, J.

    2012-01-01

    Roč. 5, č. 4 (2012), s. 26-30 ISSN 1899-8208 R&D Projects: GA TA ČR TA01030603 Institutional support: RVO:67985556 Keywords : traffic * ITS * telematics * urban traffic control Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2012/AS/prikryl-comparision by simulation of different approaches to the urban traffic control.pdf

  5. Simulating and evaluating an adaptive and integrated traffic lights control system for smart city application

    Science.gov (United States)

    Djuana, E.; Rahardjo, K.; Gozali, F.; Tan, S.; Rambung, R.; Adrian, D.

    2018-01-01

    A city could be categorized as a smart city when the information technology has been developed to the point that the administration could sense, understand, and control every resource to serve its people and sustain the development of the city. One of the smart city aspects is transportation and traffic management. This paper presents a research project to design an adaptive traffic lights control system as a part of the smart system for optimizing road utilization and reducing congestion. Research problems presented include: (1) Congestion in one direction toward an intersection due to dynamic traffic condition from time to time during the day, while the timing cycles in traffic lights system are mostly static; (2) No timing synchronization among traffic lights in adjacent intersections that is causing unsteady flows; (3) Difficulties in traffic condition monitoring on the intersection and the lack of facility for remotely controlling traffic lights. In this research, a simulator has been built to model the adaptivity and integration among different traffic lights controllers in adjacent intersections, and a case study consisting of three sets of intersections along Jalan K. H. Hasyim Ashari has been simulated. It can be concluded that timing slots synchronization among traffic lights is crucial for maintaining a steady traffic flow.

  6. Multiagent Systems: Introduction and Application in Traffic Control and Simulation and Emergency Situations Simulation

    Directory of Open Access Journals (Sweden)

    BAZZAN, A. L. C.

    2010-12-01

    Full Text Available The area of multiagent systems is new and challenging. From the moment a system includes more than one agent, artificial intelligence techniques become inadequate for they do not consider interactions with other agent, need for coordination and other factors. In this text those aspects are discussed, and an introduction to the area of autonomous agents and multiagent systems is offered. Afterwards, two application of this kind of systems are described, both in the area of transportation and emergency sistuations. In the former we discuss traffic control and simulation and in the latter, we focus on the simulation tool RoboCup Rescue

  7. Traffic simulation using distributed cellular automata in the Multi-agent system

    Directory of Open Access Journals (Sweden)

    Petr Fuks

    2007-04-01

    Full Text Available This article is aimed at the description of traffic simulation architecture based on a multi-agent system and cellular automata. This approach allows a better understanding of complexity of the real traffic and to build advanced dynamic navigation systems, which will be able to predict the traffic situation and to use an information based on current statistical data. In the future, such navigation systems will help us to prevent congestions and other problems, which are caused by increasing traffic intensity.

  8. Satellite Network Performance Measurements Using Simulated Multi-User Internet Traffic

    Science.gov (United States)

    Kruse, Hans; Allman, Mark; Griner, Jim; Ostermann, Shawn; Helvey, Eric

    1999-01-01

    As a number of diverse satellite systems (both Low Earth Orbit and Geostationary systems) are being designed and deployed, it becomes increasingly important to be able to test these systems under realistic traffic loads. While software simulations can provide valuable input into the system design process, it is crucial that the physical system be tested so that actual network devices can be employed and tuned. These tests need to utilize traffic patterns that closely mirror the expected user load, without the need to actually deploy an end-user network for the test. In this paper, we present trafgen. trafgen uses statistical information about the characteristics of sampled network traffic to emulate the same type of traffic over the test network. This paper compares sampled terrestrial network traffic with emulated satellite network traffic over the NASA ACTS satellite.

  9. Evaluation of traffic signal timing optimization methods using a stochastic and microscopic simulation program.

    Science.gov (United States)

    2003-01-01

    This study evaluated existing traffic signal optimization programs including Synchro,TRANSYT-7F, and genetic algorithm optimization using real-world data collected in Virginia. As a first step, a microscopic simulation model, VISSIM, was extensively ...

  10. Transforming GIS data into functional road models for large-scale traffic simulation.

    Science.gov (United States)

    Wilkie, David; Sewall, Jason; Lin, Ming C

    2012-06-01

    There exists a vast amount of geographic information system (GIS) data that model road networks around the world as polylines with attributes. In this form, the data are insufficient for applications such as simulation and 3D visualization-tools which will grow in power and demand as sensor data become more pervasive and as governments try to optimize their existing physical infrastructure. In this paper, we propose an efficient method for enhancing a road map from a GIS database to create a geometrically and topologically consistent 3D model to be used in real-time traffic simulation, interactive visualization of virtual worlds, and autonomous vehicle navigation. The resulting representation provides important road features for traffic simulations, including ramps, highways, overpasses, legal merge zones, and intersections with arbitrary states, and it is independent of the simulation methodologies. We test the 3D models of road networks generated by our algorithm on real-time traffic simulation using both macroscopic and microscopic techniques.

  11. Simulation of traffic capacity of inland waterway network

    NARCIS (Netherlands)

    Chen, L.; Mou, J.; Ligteringen, H.

    2013-01-01

    The inland waterborne transportation is viewed as an economic, safe and environmentally friendly alternative to the congested road network. The traffic capacity are the critical indicator of the inland shipping performance. Actually, interacted under the complicated factors, it is challenging to

  12. The Vehicles Traffic Flow Optimization in an Urban Transportation System by Using Simulation Modeling

    Directory of Open Access Journals (Sweden)

    Coman Marin-Marian

    2017-09-01

    Full Text Available The urban transportation system is characterized by the urban roads development and growth of road traffic, which leads, most of the time, to a series of congestions in the vehicles traffic. Consequently, due to a high time duration spent on the road traffic, the travel time from a location to another one could be very upsetting for any car drivers, or embarrassing for emergency services and vehicle convoys that carry goods or sensitive items. Those are mainly reasons for using simulation modeling to analyze and optimize the travel time of the road traffic actors in the an urban transportation system. This paper focuses on optimization vehicles flow in a crowded area of Sibiu city, by using agent-based modeling concept and AnyLogic simulation modeling software.

  13. TRACC_PB SOSS Integrated Traffic Simulation for CLT Ramp Operation

    Science.gov (United States)

    Okuniek, Nikolai; Zhu, Zhifan

    2017-01-01

    This presentation provides the current task under the NASA-DLR research collaboration for airport surface. It presents the effort done to adapt TRACC and SOSS software components to simulate airport (CLT) ramp area traffic management using TRACC's conflict free taxi trajectory optimization and SOSS's fast time simulation platform.

  14. 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...

  15. Efficient graph-based dynamic load-balancing for parallel large-scale agent-based traffic simulation

    NARCIS (Netherlands)

    Xu, Y.; Cai, W.; Aydt, H.; Lees, M.; Tolk, A.; Diallo, S.Y.; Ryzhov, I.O.; Yilmaz, L.; Buckley, S.; Miller, J.A.

    2014-01-01

    One of the issues of parallelizing large-scale agent-based traffic simulations is partitioning and load-balancing. Traffic simulations are dynamic applications where the distribution of workload in the spatial domain constantly changes. Dynamic load-balancing at run-time has shown better efficiency

  16. A Network Traffic Generator Model for Fast Network-on-Chip Simulation

    DEFF Research Database (Denmark)

    Mahadevan, Shankar; Angiolini, Frederico; Storgaard, Michael

    2005-01-01

    For Systems-on-Chip (SoCs) development, a predominant part of the design time is the simulation time. Performance evaluation and design space exploration of such systems in bit- and cycle-true fashion is becoming prohibitive. We propose a traffic generation (TG) model that provides a fast...

  17. Methods and measurements in real-time air traffic control system simulation.

    Science.gov (United States)

    1983-04-01

    The major purpose of this work was to asses dynamic simulation of air traffic control systems as a technique for evaluating such systems in a statistically sound and objective manner. A large set of customarily used measures based on the system missi...

  18. Integration of Linear Dynamic Emission and Climate Models with Air Traffic Simulations

    Science.gov (United States)

    Sridhar, Banavar; Ng, Hok K.; Chen, Neil Y.

    2012-01-01

    Future air traffic management systems are required to balance the conflicting objectives of maximizing safety and efficiency of traffic flows while minimizing the climate impact of aviation emissions and contrails. Integrating emission and climate models together with air traffic simulations improve the understanding of the complex interaction between the physical climate system, carbon and other greenhouse gas emissions and aviation activity. This paper integrates a national-level air traffic simulation and optimization capability with simple climate models and carbon cycle models, and climate metrics to assess the impact of aviation on climate. The capability can be used to make trade-offs between extra fuel cost and reduction in global surface temperature change. The parameters in the simulation can be used to evaluate the effect of various uncertainties in emission models and contrails and the impact of different decision horizons. Alternatively, the optimization results from the simulation can be used as inputs to other tools that monetize global climate impacts like the FAA s Aviation Environmental Portfolio Management Tool for Impacts.

  19. Data-driven Travel Demand Modelling and Agent-based Traffic Simulation in Amsterdam Urban Area

    NARCIS (Netherlands)

    Melnikov, V.R.; Krzhizhanovskaya, V.V.; Lees, M.H.; Boukhanovsky, A.V.

    2016-01-01

    The goal of this project is the development of a large-scale agent-based traffic simulation system for Amsterdam urban area, validated on sensor data and adjusted for decision support in critical situations and for policy making in sustainable city development, emission control and electric car

  20. 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

  1. A new access density definition and its correlation with crash rates by microscopic traffic simulation method.

    Science.gov (United States)

    Huang, Bing; Zhang, Yu; Lu, Linjun; Lu, Jian John

    2014-03-01

    Better access management can improve highway safety by reducing potential crashes and conflicts. To make adequate access management decisions, it is essential to understand the impact of different access types on roadway safety, usually represented by the crash rate of a roadway segment. The objective of this paper is to propose a new access density definition reflecting the impact of traffic speed variation of different access types. The traffic speed variation was obtained from a microscopic traffic simulation software package TSIS-CORSIM. A sample roadway Temple Terrace Highway was selected to perform traffic simulation. Access Weight was obtained from traffic speed variation, and access density was obtained from access weight. The proposed access density was then compared with the existing definition by analyzing their correlations with crash rates on one suburban street in Temple Terrace, Florida. The comparison demonstrates that crash rates are more highly correlated with the proposed access density than that in the previous study, which is helpful for Federal Highway Administration (FHWA), United States Department of Transportation (USDOT), and transportation consulting companies to regulate the construction, management and design of roadway segments. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. DECISION WITH ARTIFICIAL NEURAL NETWORKS IN DISCRETE EVENT SIMULATION MODELS ON A TRAFFIC SYSTEM

    Directory of Open Access Journals (Sweden)

    Marília Gonçalves Dutra da Silva

    2016-04-01

    Full Text Available ABSTRACT This work aims to demonstrate the use of a mechanism to be applied in the development of the discrete-event simulation models that perform decision operations through the implementation of an artificial neural network. Actions that involve complex operations performed by a human agent in a process, for example, are often modeled in simplified form with the usual mechanisms of simulation software. Therefore, it was chosen a traffic system controlled by a traffic officer with a flow of vehicles and pedestrians to demonstrate the proposed solution. From a module built in simulation software itself, it was possible to connect the algorithm for intelligent decision to the simulation model. The results showed that the model elaborated responded as expected when it was submitted to actions, which required different decisions to maintain the operation of the system with changes in the flow of people and vehicles.

  3. An Iterative Algorithm to Determine the Dynamic User Equilibrium in a Traffic Simulation Model

    Science.gov (United States)

    Gawron, C.

    An iterative algorithm to determine the dynamic user equilibrium with respect to link costs defined by a traffic simulation model is presented. Each driver's route choice is modeled by a discrete probability distribution which is used to select a route in the simulation. After each simulation run, the probability distribution is adapted to minimize the travel costs. Although the algorithm does not depend on the simulation model, a queuing model is used for performance reasons. The stability of the algorithm is analyzed for a simple example network. As an application example, a dynamic version of Braess's paradox is studied.

  4. Development and Validation in Air Traffic Control by Means of Real-Time Simulations

    Directory of Open Access Journals (Sweden)

    Stephan Herr

    2009-02-01

    Full Text Available The airspace in Central Europe is already one of the busiest airspaces in the world and the forecasts predict further traffic increases. The current air transport system is reaching its capacity limits, not only at airports but also in parts of the en-route area. This is mainly due to the workload constraints of air traffic controllers. In the past, many technical system functionalities were developed with the aim of reducing controller workload and thus enabling the safe handling of the predicted traffic growth. But these new functionalities alone will not provide adequate relief to air traffic controllers. Their working procedures and the airspace structure will have to be adapted accordingly. In order to obtain real operational benefits, these technical innovations must be integrated into an overall concept which – in addition to the above-mentioned factors – also takes account of ergonomic aspects and human-machine interfaces. When developing such an overall concept, additional evaluation and validation measures are indispensable to ensure that the desired operational benefits are achieved. This is why DFS has for many years used fast- and real-time simulations to assess and optimise any changes to be made to the air traffic control system. The working methods of DFS in this context are in keeping with the European Operational Concept Validation Methodology of 2007, in short E-OCVM. This paper outlines the development and validation activities of DFS using the MSP D/L project as an example. The project deals with the introduction of the new role of air traffic controllers as multi-sector planners (MSP and new system functionalities, such as air/ground data link (D/L. The project included the development of an operational concept for using the new functionalities as well as for defining working procedures and the airspace structure. This concept was subsequently evaluated by means of a fast-time simulation and two real-time simulations

  5. Designing Scenarios for Controller-in-the-Loop Air Traffic Simulations

    Science.gov (United States)

    Kupfer, Michael; Mercer, Joey; Cabrall, Chris; Homola, Jeff; Callantine, Todd

    2013-01-01

    Within the Human Factors Division at NASA Ames Research Center the Airspace Operations Laboratory (AOL) is developing advanced automation concepts that help to transform the National Airspace System into NextGen, the Next Generation Air Transportation System. High-fidelity human-in-the-loop (HITL) simulations are used as a means to investigate and develop roles, responsibilities, support tools, and requirements for human operators and automation. This paper describes the traffic scenario design process and strategies as used by AOL researchers. Details are presented on building scenarios for specific simulation objectives using various design strategies. A focus is set on creating scenarios based on recorded real world traffic for terminal-area simulations.

  6. A simulation-based dynamic traffic assignment model with combined modes

    Directory of Open Access Journals (Sweden)

    Meng Meng

    2014-02-01

    Full Text Available This paper presents a dynamic traffic assignment (DTA model for urban multi-modal transportation network by con­structing a mesoscopic simulation model. Several traffic means such as private car, subway, bus and bicycle are con­sidered in the network. The mesoscopic simulator consists of a mesoscopic supply simulator based on MesoTS model and a time-dependent demand simulator. The mode choice is si­multaneously considered with the route choice based on the improved C-Logit model. The traffic assignment procedure is implemented by a time-dependent shortest path (TDSP al­gorithm in which travellers choose their modes and routes based on a range of choice criteria. The model is particularly suited for appraising a variety of transportation management measures, especially for the application of Intelligent Trans­port Systems (ITS. Five example cases including OD demand level, bus frequency, parking fee, information supply and car ownership rate are designed to test the proposed simulation model through a medium-scale case study in Beijing Chaoy­ang District in China. Computational results illustrate excel­lent performance and the application of the model to analy­sis of urban multi-modal transportation networks.

  7. Improving Precision and Reducing Runtime of Microscopic Traffic Simulators through Stratified Sampling

    Directory of Open Access Journals (Sweden)

    Khewal Bhupendra Kesur

    2013-01-01

    Full Text Available This paper examines the application of Latin Hypercube Sampling (LHS and Antithetic Variables (AVs to reduce the variance of estimated performance measures from microscopic traffic simulators. LHS and AV allow for a more representative coverage of input probability distributions through stratification, reducing the standard error of simulation outputs. Two methods of implementation are examined, one where stratification is applied to headways and routing decisions of individual vehicles and another where vehicle counts and entry times are more evenly sampled. The proposed methods have wider applicability in general queuing systems. LHS is found to outperform AV, and reductions of up to 71% in the standard error of estimates of traffic network performance relative to independent sampling are obtained. LHS allows for a reduction in the execution time of computationally expensive microscopic traffic simulators as fewer simulations are required to achieve a fixed level of precision with reductions of up to 84% in computing time noted on the test cases considered. The benefits of LHS are amplified for more congested networks and as the required level of precision increases.

  8. A comparative analysis of currently used microscopic and macroscopic traffic simulation software

    International Nuclear Information System (INIS)

    Ratrout Nedal T; Rahman Syed Masiur

    2009-01-01

    The significant advancements of information technology have contributed to increased development of traffic simulation models. These include microscopic models and broadening the areas of applications ranging from the modeling of specific components of the transportation system to a whole network having different kinds of intersections and links, even in a few cases combining travel demand models. This paper mainly reviews the features of traditionally used macroscopic and microscopic traffic simulation models along with a comparative analysis focusing on freeway operations, urban congested networks, project-level emission modeling, and variations in delay and capacity estimates. The models AIMSUN, CORSIM, and VISSIM are found to be suitable for congested arterials and freeways, and integrated networks of freeways and surface streets. The features of AIMSUN are favorable for creating large urban and regional networks. The models AIMSUN, PARAMICS, INTEGRATION, and CORSIM are potentially useful for Intelligent Transportation System (ITS). There are a few simulation models which are developed focusing on ITS such as MITSIMLab. The TRAF-family and HUTSIM models attempt a system-level simulation approach and develop open environments where several analysis models can be used interactively to solve traffic simulation problems. In Saudi Arabia, use of simulation software with the capability of analyzing an integrated system of freeways and surface streets has not been reported. Calibration and validation of simulation software either for freeways or surface streets has been reported. This paper suggests that researchers evaluate the state-of-the-art simulation tools and find out the suitable tools or approaches for the local conditions of Saudi Arabia. (author)

  9. Using spatial context to support prospective memory in simulated air traffic control.

    Science.gov (United States)

    Loft, Shayne; Finnerty, Dannielle; Remington, Roger W

    2011-12-01

    The aim was to examine whether prospective memory error and response costs to ongoing tasks in an air traffic control simulation could be reduced by providing spatial context. Prospective memory refers to remembering to perform an intended action at an appropriate point in the future. Failures of prospective memory can occur in air traffic control. For this study, three conditions of participants performed an air traffic control task that required them to accept and hand off aircraft and to prevent conflicts. The prospective memory task required participants to remember to press an alternative key rather than the routine key when accepting target aircraft. A red line separated the display into upper and lower regions. Participants in the context condition were told that the prospective memory instruction would apply only to aircraft approaching from one region (upper or lower). Those in the standard condition were not provided this information. In the control condition, participants did not have to perform the prospective memory task. In the context condition, participants made fewer prospective memory errors than did those in the standard condition and made faster acceptance decisions for aircraft approaching from irrelevant compared with relevant regions. Costs to hand-off decision time were also reduced in the context condition. Spatial context provided no benefit to conflict detection. Participants could partially localize their allocation of attentional resources to the prospective memory task to relevant display regions. The findings are potentially applicable to air traffic control, whereby regularities in airspace structure and standard traffic flows allow controllers to anticipate the location of specific air traffic events.

  10. Urban traffic simulated from the dual representation: Flow, crisis and congestion

    International Nuclear Information System (INIS)

    Hu Maobin; Jiang Rui; Wang Ruili; Wu Qingsong

    2009-01-01

    We propose a traffic simulation model for urban system based on the dual graph representation of a urban road network and with a random entering vehicle rate. To avoid the shortcoming of 'Space Syntax' of ignoring the road's metric distance, we consider both the motion of the vehicles along roads and the navigation of the vehicles in the network. Simulations have shown some basic properties of urban traffic system, such as flux fluctuation, crisis and dissipation, phase transition from a free flow to jams, overall capacity, the distribution of traveling time, and the fundamental diagram. The system's behavior greatly depends on the topology of the transportation network. A well-planned lattice grid can keep more vehicles travelling. The critical entering vehicle rate is much greater in lattice grid than in a self-organized network. The vehicles have to travel longer time in a self-organized urban system due to the navigation cost.

  11. UAS Air Traffic Controller Acceptability Study-2: Effects of Communications Delays and Winds in Simulation

    Science.gov (United States)

    Comstock, James R., Jr.; Ghatas, Rania W.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

    2016-01-01

    This study evaluated the effects of Communications Delays and Winds on Air Traffic Controller ratings of acceptability of horizontal miss distances (HMDs) for encounters between UAS and manned aircraft in a simulation of the Dallas-Ft. Worth East-side airspace. Fourteen encounters per hour were staged in the presence of moderate background traffic. Seven recently retired controllers with experience at DFW served as subjects. Guidance provided to the UAS pilots for maintaining a given HMD was provided by information from self-separation algorithms displayed on the Multi-Aircraft Simulation System. Winds tested did not affect the acceptability ratings. Communications delays tested included 0, 400, 1200, and 1800 msec. For longer communications delays, there were changes in strategy and communications flow that were observed and reported by the controllers. The aim of this work is to provide useful information for guiding future rules and regulations applicable to flying UAS in the NAS.

  12. Hyper-Spectral Networking Concept of Operations and Future Air Traffic Management Simulations

    Science.gov (United States)

    Davis, Paul; Boisvert, Benjamin

    2017-01-01

    The NASA sponsored Hyper-Spectral Communications and Networking for Air Traffic Management (ATM) (HSCNA) project is conducting research to improve the operational efficiency of the future National Airspace System (NAS) through diverse and secure multi-band, multi-mode, and millimeter-wave (mmWave) wireless links. Worldwide growth of air transportation and the coming of unmanned aircraft systems (UAS) will increase air traffic density and complexity. Safe coordination of aircraft will require more capable technologies for communications, navigation, and surveillance (CNS). The HSCNA project will provide a foundation for technology and operational concepts to accommodate a significantly greater number of networked aircraft. This paper describes two of the HSCNA projects technical challenges. The first technical challenge is to develop a multi-band networking concept of operations (ConOps) for use in multiple phases of flight and all communication link types. This ConOps will integrate the advanced technologies explored by the HSCNA project and future operational concepts into a harmonized vision of future NAS communications and networking. The second technical challenge discussed is to conduct simulations of future ATM operations using multi-bandmulti-mode networking and technologies. Large-scale simulations will assess the impact, compared to todays system, of the new and integrated networks and technologies under future air traffic demand.

  13. Initial Study of An Effective Fast-Time Simulation Platform for Unmanned Aircraft System Traffic Management

    Science.gov (United States)

    Xue, Min; Rios, Joseph

    2017-01-01

    Small Unmanned Aerial Vehicles (sUAVs), typically 55 lbs and below, are envisioned to play a major role in surveilling critical assets, collecting important information, and delivering goods. Large scale small UAV operations are expected to happen in low altitude airspace in the near future. Many static and dynamic constraints exist in low altitude airspace because of manned aircraft or helicopter activities, various wind conditions, restricted airspace, terrain and man-made buildings, and conflict-avoidance among sUAVs. High sensitivity and high maneuverability are unique characteristics of sUAVs that bring challenges to effective system evaluations and mandate such a simulation platform different from existing simulations that were built for manned air traffic system and large unmanned fixed aircraft. NASA's Unmanned aircraft system Traffic Management (UTM) research initiative focuses on enabling safe and efficient sUAV operations in the future. In order to help define requirements and policies for a safe and efficient UTM system to accommodate a large amount of sUAV operations, it is necessary to develop a fast-time simulation platform that can effectively evaluate requirements, policies, and concepts in a close-to-reality environment. This work analyzed the impacts of some key factors including aforementioned sUAV's characteristics and demonstrated the importance of these factors in a successful UTM fast-time simulation platform.

  14. Traffic signal design and simulation for vulnerable road users safety and bus preemption

    International Nuclear Information System (INIS)

    Lo, Shih-Ching; Huang, Hsieh-Chu

    2015-01-01

    Mostly, pedestrian car accidents occurred at a signalized interaction is because pedestrians cannot across the intersection safely within the green light. From the viewpoint of pedestrian, there might have two reasons. The first one is pedestrians cannot speed up to across the intersection, such as the elders. The other reason is pedestrians do not sense that the signal phase is going to change and their right-of-way is going to be lost. Developing signal logic to protect pedestrian, who is crossing an intersection is the first purpose of this study. In addition, to improve the reliability and reduce delay of public transportation service is the second purpose. Therefore, bus preemption is also considered in the designed signal logic. In this study, the traffic data of the intersection of Chong-Qing North Road and Min-Zu West Road, Taipei, Taiwan, is employed to calibrate and validate the signal logic by simulation. VISSIM 5.20, which is a microscopic traffic simulation software, is employed to simulate the signal logic. From the simulated results, the signal logic presented in this study can protect pedestrians crossing the intersection successfully. The design of bus preemption can reduce the average delay. However, the pedestrian safety and bus preemption signal will influence the average delay of cars largely. Thus, whether applying the pedestrian safety and bus preemption signal logic to an intersection or not should be evaluated carefully

  15. SIMULATION MODELS OF HEAVY TRUCKS TRAFFIC CONTROL WITH ELECTRIC DC DRIVE

    Directory of Open Access Journals (Sweden)

    N. N. Hurski

    2015-01-01

    Full Text Available A model of the straight course of movement of the mobile machine with a traction electric motor DC. Traffic management controller provides a closed classical scheme with feedback. The mathematical model of the electric DC motor with the energy dissipation in the rotor bearings. Design scheme of mobile machines include speed dial controller, traction electric motor, gearbox, transmission and progressively moving mass on the elastic­dissipative wheel. The results of the simulation of the machine in the form of temporary processes of change control signals, voltage and current in the windings of the motor and traction power developed on the wheel.

  16. A digital simulation of message traffic for natural disaster warning communications satellite

    Science.gov (United States)

    Hein, G. F.; Stevenson, S. M.

    1972-01-01

    Various types of weather communications are required to alert industries and the general public about the impending occurrence of tornados, hurricanes, snowstorms, floods, etc. A natural disaster warning satellite system has been proposed for meeting the communications requirements of the National Oceanic and Atmospheric Administration. Message traffic for a communications satellite was simulated with a digital computer in order to determine the number of communications channels to meet system requirements. Poisson inputs are used for arrivals and an exponential distribution is used for service.

  17. Trends in aircraft emissions. Simulation of two air traffic scenarios in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Larson, L.G.; Palsson, A. [The Aeronautical Research Inst. of Sweden, Bromma (Sweden). The Swedish Civil Aviation Administration

    1997-12-31

    The developing trends of emissions from aviation in Sweden have been studied by means of flight and emissions simulation. The objective was to investigate whether technical improvements will allow Swedish air traffic to increase, without exceeding national regulations for pollution in the future. It was found that, due to development of aircraft engines and, to some extent, improvement of aerodynamic designs, the fuel consumption and thus the emissions of carbon dioxide will decrease in the future. The decrease of nitrous oxides is predicted to be significant due to advances in engine technology. (author) 4 refs.

  18. Controlling Air Traffic (Simulated) in the Presence of Automation (CATS PAu) 1995: A Study of Measurement Techniques for Situation Awareness in Air Traffic Control

    Science.gov (United States)

    French, Jennifer R.

    1995-01-01

    As automated systems proliferate in aviation systems, human operators are taking on less and less of an active role in the jobs they once performed, often reducing what should be important jobs to tasks barely more complex than monitoring machines. When operators are forced into these roles, they risk slipping into hazardous states of awareness, which can lead to reduced skills, lack of vigilance, and the inability to react quickly and competently when there is a machine failure. Using Air Traffic Control (ATC) as a model, the present study developed tools for conducting tests focusing on levels of automation as they relate to situation awareness. Subjects participated in a two-and-a-half hour experiment that consisted of a training period followed by a simulation of air traffic control similar to the system presently used by the FAA, then an additional simulation employing automated assistance. Through an iterative design process utilizing numerous revisions and three experimental sessions, several measures for situational awareness in a simulated Air Traffic Control System were developed and are prepared for use in future experiments.

  19. IMPROVEMENT OF EXPERT ANALYSIS FOR ROAD TRAFFIC ACCIDENTS USING COMPUTER SIMULATION PROGRAMS

    Directory of Open Access Journals (Sweden)

    S. A. Azemsha

    2015-01-01

    Full Text Available The existing methods for auto-technical expertise presuppose selection of some parameters on the basis of the expert’s intuition and experience. Type of a vehicle and its loading rate, road conditions are not taken into account also in the case when deceleration is to be determined. While carrying out the analysis it has been established that an application of special software makes it possible to improve significantly efficiency of the executed works directed on solution of the assigned tasks, to speed up calculation processes, to decrease qualitatively probability of arithmetic errors and provides the possibility to visualize results of the conducted investigations. Possibility of using various models for dynamic motion simulation and collision of vehicles (in the form of 3D-models has been established in the paper. In such a case specific features of vehicle technical conditions, its loading rate and condition of roadway surface have been taken account in the paper. The given paper also permits to obtain a dynamic display of reconstructed accident mechanism in axonometric projection, to film video-clips when a camera is positioned at any spatial point: road, roadside, raised position, moving vehicle, driver's seat in the vehicle.The paper contains an analysis of possibilities of road traffic accident simulation programs, a statistical analysis that shows significance in differences between simulation results when various programs have been used. The paper presents initial data and results of vehicle speed calculation on the basis of braking track length which have been obtained with the help of road traffic accident express analysis (a classical approach and PC-Crash when additional influencing factors are taken into account. A number of shortcomings have been revealed while analyzing the simulation results of the applied software. The shortcomings must be removed in the analyzed software products.On the basis of the executed analysis in

  20. Numerical simulation of soliton and kink density waves in traffic flow with periodic boundaries

    Science.gov (United States)

    Zhu, H. B.; Dai, S. Q.

    2008-07-01

    The soliton and kink-antikink density waves are simulated with periodic boundaries, by adding perturbation in the initial condition on single-lane road based on a car-following model. They are reproduced in the form of the space-time evolution of headway, both of which propagate backwards. It is found that the solitons appear only near the neutral stability line regardless of the boundary conditions, and they exhibit upward form when the initial headway is smaller than the safety distance, otherwise they exhibit downward form. Comparison is made between the numerical and analytical results about the amplitude of kink-antikink wave, and the underlying mechanism is analyzed. Besides, it is indicated that the maximal current of traffic flow increases with decreasing safety distance. The numerical simulation shows a good agreement with the analytical results.

  1. Suitability of Synthetic Driving Profiles from Traffic Micro-Simulation for Real-World Energy Analysis: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Yunfei; Wood, Eric; Burton, Evan; Gonder, Jeffrey

    2015-10-14

    A shift towards increased levels of driving automation is generally expected to result in improved safety and traffic congestion outcomes. However, little empirical data exists to estimate the impact that automated driving could have on energy consumption and greenhouse gas emissions. In the absence of empirical data on differences between drive cycles from present day vehicles (primarily operated by humans) and future vehicles (partially or fully operated by computers) one approach is to model both situations over identical traffic conditions. Such an exercise requires traffic micro-simulation to not only accurately model vehicle operation under high levels of automation, but also (and potentially more challenging) vehicle operation under present day human drivers. This work seeks to quantify the ability of a commercial traffic micro-simulation program to accurately model real-world drive cycles in vehicles operated primarily by humans in terms of driving speed, acceleration, and simulated fuel economy. Synthetic profiles from models of freeway and arterial facilities near Atlanta, Georgia, are compared to empirical data collected from real-world drivers on the same facilities. Empirical and synthetic drive cycles are then simulated in a powertrain efficiency model to enable comparison on the basis of fuel economy. Synthetic profiles from traffic micro-simulation were found to exhibit low levels of transient behavior relative to the empirical data. Even with these differences, the synthetic and empirical data in this study agree well in terms of driving speed and simulated fuel economy. The differences in transient behavior between simulated and empirical data suggest that larger stochastic contributions in traffic micro-simulation (relative to those present in the traffic micro-simulation tool used in this study) are required to fully capture the arbitrary elements of human driving. Interestingly, the lack of stochastic contributions from models of human drivers

  2. Air Traffic Controller Performance and Acceptability of Multiple UAS in a Simulated NAS Environment

    Science.gov (United States)

    Vu, Kim-Phuong L.; Strybel, Thomas; Chiappe, Dan; Morales, Greg; Battiste, Vernol; Shively, Robert Jay

    2014-01-01

    Previously, we showed that air traffic controllers (ATCos) rated UAS pilot verbal response latencies as acceptable when a 1.5 s delay was added to the UAS pilot responses, but a 5 s delay was rated as mostly unacceptable. In the present study we determined whether a 1.5 s added delay in the UAS pilots' verbal communications would affect ATCos interactions with UAS and other conventional aircraft when the number and speed of the UAS were manipulated. Eight radar-certified ATCos participated in this simulation. The ATCos managed a medium altitude sector containing arrival aircraft, en route aircraft, and one to four UAS. The UAS were conducting a surveillance mission and flew at either a "slow" or "fast" speed. We measured both UAS and conventional pilots' verbal communication latencies, and obtained ATCos' acceptability ratings for these latencies. Although the UAS pilot response latencies were longer than those of conventional pilots, the ATCos rated UAS pilot verbal communication latencies to be as acceptable as those of conventional pilots. Because the overall traffic load within the sector was held constant, ATCos only performed slightly worse when multiple UAS were in their sector compared to when only one UAS was in the sector. Implications of these findings for UAS integration in the NAS are discussed.

  3. New Algorithms for Computing the Time-to-Collision in Freeway Traffic Simulation Models

    Directory of Open Access Journals (Sweden)

    Jia Hou

    2014-01-01

    Full Text Available Ways to estimate the time-to-collision are explored. In the context of traffic simulation models, classical lane-based notions of vehicle location are relaxed and new, fast, and efficient algorithms are examined. With trajectory conflicts being the main focus, computational procedures are explored which use a two-dimensional coordinate system to track the vehicle trajectories and assess conflicts. Vector-based kinematic variables are used to support the calculations. Algorithms based on boxes, circles, and ellipses are considered. Their performance is evaluated in the context of computational complexity and solution time. Results from these analyses suggest promise for effective and efficient analyses. A combined computation process is found to be very effective.

  4. COMPARISON OF THE MICRO-SIMULATION SOFTWARE AIMSUN & IHCM-1997 FOR HIGHWAY TRAFFIC PERFORMANCE ANALYSIS

    Directory of Open Access Journals (Sweden)

    Aji Ronaldo

    2015-02-01

    Full Text Available In order to make good decisions in transportation, decision-makers need some references to support it. One of the sources for such reference is by performing a micro-simulation; a model for representing real-world conditions including the behavior of travelers, vehicles and the infrastructure. This study examines and presents a comparison between AIMSUN (a commercial micro-simulation software and Indonesia Highway Capacity Manual 1997(IHCM-1997 in relation to the road traffic performance of the study object Södralänken, E266 and E75, in the southern part of Stockholm, Sweden. A calibration process was conducted in order to find the best value of a set of parameters in each software, selected based on the lowest value of a Root Mean Square Error (RMSE computed based on observed speed data and the model output. The parameters were then validated using evening peak-hour data. The comparisons were conducted in terms of flow, speed and density by AIMSUN, IHCM-1997 and the observation data on morning and evening peak-hour. The results are from the given experiments with the AIMSUN software with the best set of parameters being when the value of Maximum Desired Speed is at 100 km/h and Speed Acceptance is at 1,1. It shows that the significant difference between AIMSUN, IHCM-1997 and observation lays on the speed. IHCM-1997 gives relatively higher speed than both AIMSUN and observation data.

  5. Evolutionary Agent-Based Simulation of the Introduction of New Technologies in Air Traffic Management

    Science.gov (United States)

    Yliniemi, Logan; Agogino, Adrian K.; Tumer, Kagan

    2014-01-01

    Accurate simulation of the effects of integrating new technologies into a complex system is critical to the modernization of our antiquated air traffic system, where there exist many layers of interacting procedures, controls, and automation all designed to cooperate with human operators. Additions of even simple new technologies may result in unexpected emergent behavior due to complex human/ machine interactions. One approach is to create high-fidelity human models coming from the field of human factors that can simulate a rich set of behaviors. However, such models are difficult to produce, especially to show unexpected emergent behavior coming from many human operators interacting simultaneously within a complex system. Instead of engineering complex human models, we directly model the emergent behavior by evolving goal directed agents, representing human users. Using evolution we can predict how the agent representing the human user reacts given his/her goals. In this paradigm, each autonomous agent in a system pursues individual goals, and the behavior of the system emerges from the interactions, foreseen or unforeseen, between the agents/actors. We show that this method reflects the integration of new technologies in a historical case, and apply the same methodology for a possible future technology.

  6. Impact of Minimum Driveway Spacing Policies on Safety Performance: An Integrated Traffic Micro-Simulation and Automated Conflict Analysis

    Directory of Open Access Journals (Sweden)

    Chu C. Minh

    2014-09-01

    Full Text Available A key strategy for successful access management is the adoption of driveway spacing guidelines that consider both safety and operations. The goal is to provide sufficient distance from one driveway to the next so that drivers can perceive and react to the conditions at each potential conflict point in succession. State DOTs across the country have adopted different driveway spacing standards that vary according to the access class and characteristics of the adjacent roadway, such as type of roadway, posted speed limit, and traffic volume. Utilizing the VISSIM microscopic traffic simulation tool and FHWA's Surrogate Safety Assessment Model (SSAM, this research examined safety implications of four different driveway spacing policies representing 13 states. The analysis involved calibrating the VISSIM model for an arterial roadway corridor in West Columbia, SC, and then using the calibrated model to simulate various operational changes to the corridor, including speed limits, traffic volumes, and the associated minimum driveway spacing criteria for the four different policies. SSAM was used to analyze vehicle trajectories derived from VISSIM to determine the number of conflict points. Experimental results indicate that posted speed limit and traffic volume are the primary impact factors for driveway safety, and thus, these parameters should be considered in establishing minimum driveway spacing. Findings from this study indicate that there are significant differences in safety impacts between the different driveway spacing policies adopted by various state DOTs.

  7. Simulating the impacts of on-street vehicle parking on traffic operations on urban streets using cellular automation

    Science.gov (United States)

    Chen, Jingxu; Li, Zhibin; Jiang, Hang; Zhu, Senlai; Wang, Wei

    2017-02-01

    In recent years, many bicycle lanes on urban streets are replaced with vehicle parking places. Spaces for bicycle riding are reduced, resulting in changes in bicycle and vehicle operational features. The objective of this study is to estimate the impacts of on-street parking on heterogeneous traffic operation on urban streets. A cellular automaton (CA) model is developed and calibrated to simulate bicycle lane-changing on streets with on-street parking. Two types of street segments with different bicycle lane width are considered. From the simulation, two types of conflicts between bicycles and vehicles are identified which are frictional conflicts and blocking conflicts. Factors affecting the frequency of conflicts are also identified. Based on the results, vehicle delay is estimated for various traffic situations considering the range of occupancy levels for on-street parking. Later, a numerical network example is analyzed to estimate the network impact of on-street parking on traffic assignment and operation. Findings of the study are helpful to policies and design regarding on-street vehicle parking to improve the efficiency of traffic operations.

  8. The use of a transport simulation system (AIMSUN to determine the environmental effects of pedestrianization and traffic management in the center of Thessaloniki

    Directory of Open Access Journals (Sweden)

    Evangelos Mintsis

    2016-06-01

    Full Text Available Traffic congestion in urban areas results in increased energy consumption and vehicle emissions. Traffic management that alleviates traffic congestion also mitigates the environmental effects of vehicular traffic. This study uses the transport simulation model AIMSUN to evaluate the environmental effect of a set of traffic management and pedestrianization schemes. The effects of the pedestrianization of specific sections of roads, converting two-way roads into one-way roads for traffic and changing the direction of flow of traffic along one-way roads were simulated for different areas of Thessaloniki’s city centre network. The assessment of the environmental effect was done by determining the predicted fuel consumption and emissions of greenhouse gases (GHG and air pollutants. Fuel consumption and the environmental indicators were quantified directly using the fuel consumption and emissions model in AIMSUN. A typical weekday morning peak period, between 09:00am–10:00am, was simulated and the demand data obtained using a macroscopic traffic assignment model previously developed for the wider area of Thessaloniki. The results presented in this paper are for network-wide simulation statistics (i.e. fuel consumed, carbon dioxide (CO2, nitrogen oxides (NOx and particulate matter (PM.

  9. Evaluation of countermeasures for red light running by traffic simulator-based surrogate safety measures.

    Science.gov (United States)

    Lee, Changju; So, Jaehyun Jason; Ma, Jiaqi

    2018-01-02

    The conflicts among motorists entering a signalized intersection with the red light indication have become a national safety issue. Because of its sensitivity, efforts have been made to investigate the possible causes and effectiveness of countermeasures using comparison sites and/or before-and-after studies. Nevertheless, these approaches are ineffective when comparison sites cannot be found, or crash data sets are not readily available or not reliable for statistical analysis. Considering the random nature of red light running (RLR) crashes, an inventive approach regardless of data availability is necessary to evaluate the effectiveness of each countermeasure face to face. The aims of this research are to (1) review erstwhile literature related to red light running and traffic safety models; (2) propose a practical methodology for evaluation of RLR countermeasures with a microscopic traffic simulation model and surrogate safety assessment model (SSAM); (3) apply the proposed methodology to actual signalized intersection in Virginia, with the most prevalent scenarios-increasing the yellow signal interval duration, installing an advance warning sign, and an RLR camera; and (4) analyze the relative effectiveness by RLR frequency and the number of conflicts (rear-end and crossing). All scenarios show a reduction in RLR frequency (-7.8, -45.5, and -52.4%, respectively), but only increasing the yellow signal interval duration results in a reduced total number of conflicts (-11.3%; a surrogate safety measure of possible RLR-related crashes). An RLR camera makes the greatest reduction (-60.9%) in crossing conflicts (a surrogate safety measure of possible angle crashes), whereas increasing the yellow signal interval duration results in only a 12.8% reduction of rear-end conflicts (a surrogate safety measure of possible rear-end crash). Although increasing the yellow signal interval duration is advantageous because this reduces the total conflicts (a possibility of total

  10. Driving and traffic simulation for the evaluation of electronically coupled truck platoons; Kombinierte Fahr- und Verkehrsfluss-Simulation zur Untersuchung von elektronisch gekoppelten Lkw-Konvois

    Energy Technology Data Exchange (ETDEWEB)

    Friedrichs, A.; Petry, L.; Savelsberg, E. [RWTH Aachen (Germany). Zentrum fuer Lern- und Wissensmanagement]|[RWTH Aachen (Germany). Lehrstuhl Informatik im Maschinenbau

    2005-07-01

    The concept of creating trains on road (truck platoons) supported by advanced driver assistance systems is one possibility to manage the permanent increase of freight transportation and the utilisation of its capacities. An electronic coupling of trucks with short gaps will release the truck driver and therefore will also increase safety. Furthermore, the capacity of road will be used more efficient due to the short gaps between the trucks and the slip stream will save fuel. Regarding former research programs of the same topic, the practical use of such platoons shall be prepared with help of the InDriveS truck driving simulator. InDriveS is a combined driving and traffic flow simulation and gives the possibility to develop the driver assistance system and to investigate the stress of the truck driver during the platoon driving. It also allows an evaluation of the complete system in meaning of traffic flow, safety, environmental impacts and profitability. (orig.)

  11. Older People’s Perceptions of Pedestrian Friendliness and Traffic Safety: An Experiment Using Computer-Simulated Walking Environments

    Directory of Open Access Journals (Sweden)

    Daniela Kahlert

    2015-08-01

    Full Text Available Traffic safety and pedestrian friendliness are considered to be important conditions for older people’s motivation to walk through their environment. This study uses an experimental study design with computer-simulated living environments to investigate the effect of micro-scale environmental factors (parking spaces and green verges with trees on older people’s perceptions of both motivational antecedents (dependent variables. Seventy-four consecutively recruited older people were randomly assigned watching one of two scenarios (independent variable on a computer screen. The scenarios simulated a stroll on a sidewalk, as it is ‘typical’ for a German city. In version ‘A,’ the subjects take a fictive walk on a sidewalk where a number of cars are parked partially on it. In version ‘B’, cars are in parking spaces separated from the sidewalk by grass verges and trees. Subjects assessed their impressions of both dependent variables. A multivariate analysis of covariance showed that subjects’ ratings on perceived traffic safety and pedestrian friendliness were higher for Version ‘B’ compared to version ‘A’. Cohen’s d indicates medium (d = 0.73 and large (d = 1.23 effect sizes for traffic safety and pedestrian friendliness, respectively. The study suggests that elements of the built environment might affect motivational antecedents of older people’s walking behavior.

  12. Older People's Perceptions of Pedestrian Friendliness and Traffic Safety: An Experiment Using Computer-Simulated Walking Environments.

    Science.gov (United States)

    Kahlert, Daniela; Schlicht, Wolfgang

    2015-08-21

    Traffic safety and pedestrian friendliness are considered to be important conditions for older people's motivation to walk through their environment. This study uses an experimental study design with computer-simulated living environments to investigate the effect of micro-scale environmental factors (parking spaces and green verges with trees) on older people's perceptions of both motivational antecedents (dependent variables). Seventy-four consecutively recruited older people were randomly assigned watching one of two scenarios (independent variable) on a computer screen. The scenarios simulated a stroll on a sidewalk, as it is 'typical' for a German city. In version 'A,' the subjects take a fictive walk on a sidewalk where a number of cars are parked partially on it. In version 'B', cars are in parking spaces separated from the sidewalk by grass verges and trees. Subjects assessed their impressions of both dependent variables. A multivariate analysis of covariance showed that subjects' ratings on perceived traffic safety and pedestrian friendliness were higher for Version 'B' compared to version 'A'. Cohen's d indicates medium (d = 0.73) and large (d = 1.23) effect sizes for traffic safety and pedestrian friendliness, respectively. The study suggests that elements of the built environment might affect motivational antecedents of older people's walking behavior.

  13. Case Study: Influences of Uncertainties and Traffic Scenario Difficulties in a Human-in-the-Loop Simulation

    Science.gov (United States)

    Bienert, Nancy; Mercer, Joey; Homola, Jeffrey; Morey, Susan; Prevot, Thomas

    2014-01-01

    This paper presents a case study of how factors such as wind prediction errors and metering delays can influence controller performance and workload in Human-In-The-Loop simulations. Retired air traffic controllers worked two arrival sectors adjacent to the terminal area. The main tasks were to provide safe air traffic operations and deliver the aircraft to the metering fix within +/- 25 seconds of the scheduled arrival time with the help of provided decision support tools. Analyses explore the potential impact of metering delays and system uncertainties on controller workload and performance. The results suggest that trajectory prediction uncertainties impact safety performance, while metering fix accuracy and workload appear subject to the scenario difficulty.

  14. Solutions to Traffic Jam on East Road of Beijing Jiaotong University in Rush Hours Based on Analogue Simulation

    Directory of Open Access Journals (Sweden)

    Zou Yanwen

    2015-01-01

    Full Text Available Based on the simulation theory and method, this paper establishes a status analogue simulation model in peak hours, realizes an effective assessment on the road, finds out bottlenecks to improve the level of road services and puts forward the corresponding road improvement program. This paper simulates the improvement program by the use of VISSIM simulation model, and verifies the improvement effect of four programs and carries out promotion. The research obtains an effective method of solving the problem of jam on the sub-arterial road: It needs to set up by-pass and control over traffic flow of the by-pass, and give full play to the role of by-pass in city.

  15. UAS Air Traffic Controller Acceptability Study. 2; Evaluating Detect and Avoid Technology and Communication Delays in Simulation

    Science.gov (United States)

    Comstock, James R., Jr.; Ghatas, Rania W.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

    2015-01-01

    This study evaluated the effects of communications delays and winds on air traffic controller ratings of acceptability of horizontal miss distances (HMDs) for encounters between Unmanned Aircraft Systems (UAS) and manned aircraft in a simulation of the Dallas-Ft. Worth (DFW) airspace. Fourteen encounters per hour were staged in the presence of moderate background traffic. Seven recently retired controllers with experience at DFW served as subjects. Guidance provided to the UAS pilots for maintaining a given HMD was provided by information from Detect and Avoid (DAA) self-separation algorithms (Stratway+) displayed on the Multi-Aircraft Control System. This guidance consisted of amber "bands" on the heading scale of the UAS navigation display indicating headings that would result in a loss of well clear between the UAS and nearby traffic. Winds tested were successfully handled by the DAA algorithms and did not affect the controller acceptability ratings of the HMDs. Voice communications delays for the UAS were also tested and included one-way delay times of 0, 400, 1200, and 1800 msec. For longer communications delays, there were changes in strategy and communications flow that were observed and reported by the controllers. The aim of this work is to provide useful information for guiding future rules and regulations applicable to flying UAS in the NAS. Information from this study will also be of value to the Radio Technical Commission for Aeronautics (RTCA) Special Committee 228 - Minimum Performance Standards for UAS.

  16. Real-time monitoring of emissions with traffic data, simulation and air quality measurements

    NARCIS (Netherlands)

    Klunder, G.A.; Wilmink, I.R.

    2009-01-01

    This paper investigates the possibility to decide when to apply a (dynamic) traffic management measure to improve the air quality or reduce CO2 emissions, based on a limited set of (measured) data. It is expected that a combination of monitoring and modeling is needed for reliable air quality

  17. Assessment of safety levels and microscopic traffic simulation modeling tool under the IntelliDrive environment

    NARCIS (Netherlands)

    Roelofsen, M.; Bie, Jing; Lisheng, J.; van Arem, Bart

    2010-01-01

    In this paper we propose a novel design for the Lane Change Assistant (LCA). For drivers on the highway, LCA advises them on whether it is safe to change lanes under the current traffic conditions. We focus on how the LCA can provide a reliable advice in practice by considering the issues of

  18. Integrated Display and Simulation for Automatic Dependent Surveillance-Broadcast and Traffic Collision Avoidance System Data Fusion.

    Science.gov (United States)

    Wang, Yanran; Xiao, Gang; Dai, Zhouyun

    2017-11-13

    Automatic Dependent Surveillance-Broadcast (ADS-B) is the direction of airspace surveillance development. Research analyzing the benefits of Traffic Collision Avoidance System (TCAS) and ADS-B data fusion is almost absent. The paper proposes an ADS-B minimum system from ADS-B In and ADS-B Out. In ADS-B In, a fusion model with a variable sampling Variational Bayesian-Interacting Multiple Model (VSVB-IMM) algorithm is proposed for integrated display and an airspace traffic situation display is developed by using ADS-B information. ADS-B Out includes ADS-B Out transmission based on a simulator platform and an Unmanned Aerial Vehicle (UAV) platform. This paper describes the overall implementation of ADS-B minimum system, including theoretical model design, experimental simulation verification, engineering implementation, results analysis, etc. Simulation and implementation results show that the fused system has better performance than each independent subsystem and it can work well in engineering applications.

  19. Traffic theory

    National Research Council Canada - National Science Library

    Gazis, Denos C

    2002-01-01

    ... of traffic signal settings The vehicle-actuated traffic signal 87 89 77 CHAPTER 3. TRAFFIC CONTROL 101 Objectives of Traffic Control 103 Single, Isolated Intersection 105 Synchronization Scheme...

  20. Spatial variations in estimated chronic exposure to traffic-related air pollution in working populations: A simulation

    Directory of Open Access Journals (Sweden)

    Cloutier-Fisher Denise

    2008-07-01

    Full Text Available Abstract Background Chronic exposure to traffic-related air pollution is associated with a variety of health impacts in adults and recent studies show that exposure varies spatially, with some residents in a community more exposed than others. A spatial exposure simulation model (SESM which incorporates six microenvironments (home indoor, work indoor, other indoor, outdoor, in-vehicle to work and in-vehicle other is described and used to explore spatial variability in estimates of exposure to traffic-related nitrogen dioxide (not including indoor sources for working people. The study models spatial variability in estimated exposure aggregated at the census tracts level for 382 census tracts in the Greater Vancouver Regional District of British Columbia, Canada. Summary statistics relating to the distributions of the estimated exposures are compared visually through mapping. Observed variations are explored through analyses of model inputs. Results Two sources of spatial variability in exposure to traffic-related nitrogen dioxide were identified. Median estimates of total exposure ranged from 8 μg/m3 to 35 μg/m3 of annual average hourly NO2 for workers in different census tracts in the study area. Exposure estimates are highest where ambient pollution levels are highest. This reflects the regional gradient of pollution in the study area and the relatively high percentage of time spent at home locations. However, for workers within the same census tract, variations were observed in the partial exposure estimates associated with time spent outside the residential census tract. Simulation modeling shows that some workers may have exposures 1.3 times higher than other workers residing in the same census tract because of time spent away from the residential census tract, and that time spent in work census tracts contributes most to the differences in exposure. Exposure estimates associated with the activity of commuting by vehicle to work were

  1. Implementation of Controlled Traffic in the Canadian Prairies: Soil and Plant Dynamics under Simulated and Field Conditions

    Science.gov (United States)

    Guenette, Kris; Hernandez-Ramirez, Guillermo

    2017-04-01

    Achieving resiliency in agroecosystems may be accomplished through the incorporation of contemporary management systems and the diversification of crop rotations with pulse crops, such as controlled traffic farming (CTF) and faba beans (Vicia faba L.). As these practices become more common in the Canadian Prairies, it is imperative to have a well-rounded understanding of how faba beans interact with the soil-plant-atmosphere continuum in conditions found in contemporary management systems. Simulated field conditions emulated soil compaction found in both the trafficked and un-trafficked areas of a CTF system, in which the presence of high water availability was shown to offset the negative results of large applications of compactive effort. Furthermore, low water availability exacerbated differences in plant responses between compaction treatments. The simulated treatment of 1.2 gcm-3 coupled with high water content yielded the most optimal results for most measured parameters, with a contrasting detrimental treatment of 1.4 gcm-3 at low water availability. The simulated field conditions were further bridged through an analysis of two commercial sites in Alberta, Canada that compared both trafficked and un-trafficked soil properties. 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. The measured soil physical and hydraulic properties of bulk density, macroporosity, S-Index, PAWC and Km were shown to be heavily influenced by the CTF traffic regime, while soil nutrient properties of AN, pH, STN SOC were determined to be dependent on both management and landscape features.

  2. A 3D simulation case study of airport air traffic handling

    NARCIS (Netherlands)

    H. de Swaan Arons

    1996-01-01

    textabstractModern Windows-based simulation packages bring simulation within reach of decision-makers. The use of graphics enables the manager to observe an animation of the simulated reality, to focus on the essentials of the model without the need to bother about implementation details. In most

  3. The use of a simulation model to analyze the impact of heavy transport generated by the port to the city traffic.

    Directory of Open Access Journals (Sweden)

    Stasiak Natalia

    2017-06-01

    Full Text Available The article presents an analysis of the impact of transport on heavy urban traffic on Wharf Kwiatkowski using program PTV Vissim. The data for analysis were taken from the Road and Greenery in Gdynia from program PTV Visum. Attention has been focused on vehicle traffic in the afternoon the top of its intensity. Model of Kwiatkowskiego Wharf, made entirely in the PTV VISSIM, was used for microscopic simulation of traffic. With its help, it was possible to find and analyze the behavior of each autonomous vehicle and interactions on the Web. For the analysis was used as a program of traffic lights currency at these junctions. The analysis results of simulation in the PTV VISSIM are related to the movement of the two structures. The first assumes that the route will move cars and trucks, taking into account their share in the network based on the intensity of traffic during peak hours of the afternoon, the second consisted only of cars. The results presented are based on measuring the time of travel and delays on specific relationships and the average length of queues at selected inlets. The results of analysis and simulation tests were subjected to statistical analysis.

  4. Integration of Weather Data into Airspace and Traffic Operations Simulation (ATOS) for Trajectory- Based Operations Research

    Science.gov (United States)

    Peters, Mark; Boisvert, Ben; Escala, Diego

    2009-01-01

    Explicit integration of aviation weather forecasts with the National Airspace System (NAS) structure is needed to improve the development and execution of operationally effective weather impact mitigation plans and has become increasingly important due to NAS congestion and associated increases in delay. This article considers several contemporary weather-air traffic management (ATM) integration applications: the use of probabilistic forecasts of visibility at San Francisco, the Route Availability Planning Tool to facilitate departures from the New York airports during thunderstorms, the estimation of en route capacity in convective weather, and the application of mixed-integer optimization techniques to air traffic management when the en route and terminal capacities are varying with time because of convective weather impacts. Our operational experience at San Francisco and New York coupled with very promising initial results of traffic flow optimizations suggests that weather-ATM integrated systems warrant significant research and development investment. However, they will need to be refined through rapid prototyping at facilities with supportive operational users We have discussed key elements of an emerging aviation weather research area: the explicit integration of aviation weather forecasts with NAS structure to improve the effectiveness and timeliness of weather impact mitigation plans. Our insights are based on operational experiences with Lincoln Laboratory-developed integrated weather sensing and processing systems, and derivative early prototypes of explicit ATM decision support tools such as the RAPT in New York City. The technical components of this effort involve improving meteorological forecast skill, tailoring the forecast outputs to the problem of estimating airspace impacts, developing models to quantify airspace impacts, and prototyping automated tools that assist in the development of objective broad-area ATM strategies, given probabilistic

  5. Microscopic Car Modeling for Intelligent Traffic and Scenario Generation in the UCF Driving Simulator : Year 2

    Science.gov (United States)

    2000-01-01

    A multi-year project was initiated to introduce autonomous vehicles in the University of Central Florida (UCF) Driving Simulator for real-time interaction with the simulator vehicle. This report describes the progress during the second year. In the f...

  6. Effects of MDMA (ecstasy), and multiple drugs use on (simulated) driving performance and traffic safety

    NARCIS (Netherlands)

    Brookhuis, KA; de Waard, D; Samyn, N

    Rationale. The effects of MDMA on driving behaviour are not clear, since the direct effects of MDMA on cognitive performance are reported as not generally negative. Objectives. To assess in an advanced driving simulator acute effects on simulated driving behaviour and heart rate of MDMA, and effects

  7. Simulation of dynamic traffic loading based on accelerated pavement testing (APT)

    CSIR Research Space (South Africa)

    Steyn, WJvdM

    2004-03-01

    Full Text Available The objective of this paper is to introduce the latest Heavy Vehicle Simulator (HVS) technology as part of the South African Accelerated Pavement Testing (APT) efforts, its capabilities and expected impact on road pavement analysis....

  8. Real-Time Traffic Signal Control for Optimization of Traffic Jam Probability

    Science.gov (United States)

    Cui, Cheng-You; Shin, Ji-Sun; Miyazaki, Michio; Lee, Hee-Hyol

    Real-time traffic signal control is an integral part of urban traffic control system. It can control traffic signals online according to variation of traffic flow. In this paper, we propose a new method for the real-time traffic signal control system. The system uses a Cellular Automaton model and a Bayesian Network model to predict probabilistic distributions of standing vehicles, and uses a Particle Swarm Optimization method to calculate optimal traffic signals. A simulation based on real traffic data was carried out to show the effectiveness of the proposed real-time traffic signal control system CAPSOBN using a micro traffic simulator.

  9. Analysing the influence of different street vegetation on traffic-induced particle dispersion using microscale simulations.

    Science.gov (United States)

    Wania, Annett; Bruse, Michael; Blond, Nadège; Weber, Christiane

    2012-02-01

    Urban vegetation can be viewed as compensation to the environmental drawbacks of urbanisation. However, its ecosystem function is not well-known and, for urban planning, vegetation is mainly considered as an element of urban design. This article argues that planning practice needs to re-examine the impact of vegetation cover in the urban fabric given our evaluation of vegetation's effects on air quality, including the dispersion of traffic-induced particles at street level. Using the three-dimensional microclimate model ENVI-met®, we evaluate these effects regarding the height-to-width ratio of streets flanked by buildings and the vertical and horizontal density of street vegetation. Our results reveal vegetation's effect on particle dispersion through its influence on street ventilation. In general, vegetation was found to reduce wind speed, causing inhibition of canyon ventilation and, consequently, an increase in particle concentrations. Vegetation was also found to reduce wind speed at crown-height and to disrupt the flow field in close vicinity to the canopy. With increasing height-to-width ratio of street canyons, wind speed reduction increases and the disturbance of the flow impacts across a canyon's entire width. We also found that the effect is more pronounced in configurations with poor ventilation, such as the low wind speed, perpendicular inflow direction, and in deep canyons cases. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Visualizing Network Traffic to Understand the Performance of Massively Parallel Simulations

    KAUST Repository

    Landge, A. G.

    2012-12-01

    The performance of massively parallel applications is often heavily impacted by the cost of communication among compute nodes. However, determining how to best use the network is a formidable task, made challenging by the ever increasing size and complexity of modern supercomputers. This paper applies visualization techniques to aid parallel application developers in understanding the network activity by enabling a detailed exploration of the flow of packets through the hardware interconnect. In order to visualize this large and complex data, we employ two linked views of the hardware network. The first is a 2D view, that represents the network structure as one of several simplified planar projections. This view is designed to allow a user to easily identify trends and patterns in the network traffic. The second is a 3D view that augments the 2D view by preserving the physical network topology and providing a context that is familiar to the application developers. Using the massively parallel multi-physics code pF3D as a case study, we demonstrate that our tool provides valuable insight that we use to explain and optimize pF3D-s performance on an IBM Blue Gene/P system. © 1995-2012 IEEE.

  11. Air traffic simulation in chemistry-climate model EMAC 2.41: AirTraf 1.0

    Science.gov (United States)

    Yamashita, Hiroshi; Grewe, Volker; Jöckel, Patrick; Linke, Florian; Schaefer, Martin; Sasaki, Daisuke

    2016-09-01

    Mobility is becoming more and more important to society and hence air transportation is expected to grow further over the next decades. Reducing anthropogenic climate impact from aviation emissions and building a climate-friendly air transportation system are required for a sustainable development of commercial aviation. A climate optimized routing, which avoids climate-sensitive regions by re-routing horizontally and vertically, is an important measure for climate impact reduction. The idea includes a number of different routing strategies (routing options) and shows a great potential for the reduction. To evaluate this, the impact of not only CO2 but also non-CO2 emissions must be considered. CO2 is a long-lived gas, while non-CO2 emissions are short-lived and are inhomogeneously distributed. This study introduces AirTraf (version 1.0) that performs global air traffic simulations, including effects of local weather conditions on the emissions. AirTraf was developed as a new submodel of the ECHAM5/MESSy Atmospheric Chemistry (EMAC) model. Air traffic information comprises Eurocontrol's Base of Aircraft Data (BADA Revision 3.9) and International Civil Aviation Organization (ICAO) engine performance data. Fuel use and emissions are calculated by the total energy model based on the BADA methodology and Deutsches Zentrum für Luft- und Raumfahrt (DLR) fuel flow method. The flight trajectory optimization is performed by a genetic algorithm (GA) with respect to a selected routing option. In the model development phase, benchmark tests were performed for the great circle and flight time routing options. The first test showed that the great circle calculations were accurate to -0.004 %, compared to those calculated by the Movable Type script. The second test showed that the optimal solution found by the algorithm sufficiently converged to the theoretical true-optimal solution. The difference in flight time between the two solutions is less than 0.01 %. The dependence of

  12. Artificial force fields for multi-agent simulations of maritime traffic and risk estimation

    NARCIS (Netherlands)

    Xiao, F.; Ligteringen, H.; Van Gulijk, C.; Ale, B.J.M.

    2012-01-01

    A probabilistic risk model is designed to estimate probabilities of collisions for shipping accidents in busy waterways. We propose a method based on multi-agent simulation that uses an artificial force field to model ship maneuvers. The artificial force field is calibrated by AIS data (Automatic

  13. Impact of Automation Support on the Conflict Resolution Task in a Human-in-the-Loop Air Traffic Control Simulation

    Science.gov (United States)

    Mercer, Joey; Gomez, Ashley; Gabets, Cynthia; Bienert, Nancy; Edwards, Tamsyn; Martin, Lynne; Gujral, Vimmy; Homola, Jeffrey

    2016-01-01

    To determine the capabilities and limitations of human operators and automation in separation assurance roles, the second of three Human-in-the-Loop (HITL) part-task studies investigated air traffic controllers ability to detect and resolve conflicts under varying task sets, traffic densities, and run lengths. Operations remained within a single sector, staffed by a single controller, and explored, among other things, the controllers responsibility for conflict resolution with or without their involvement in the conflict detection task. Furthermore, these conditions were examined across two different traffic densities; 1x (current-day traffic) and a 20 increase above current-day traffic levels (1.2x). Analyses herein offer an examination of the conflict resolution strategies employed by controllers. In particular, data in the form of elapsed time between conflict detection and conflict resolution are used to assess if, and how, the controllers involvement in the conflict detection task affected the way in which they resolved traffic conflicts.

  14. Behaviour of dairy cows under free or forced cow traffic in a simulated automatic milking system environment.

    NARCIS (Netherlands)

    Lauwere, de C.C.K.; Hendriks, M.M.B.; Metz, J.H.M.; Schouten, W.G.P.

    1998-01-01

    The introduction of fully automatic milking systems (AMS) on dairy farms can only succeed if cows visit the system more or less voluntarily, at regular intervals. This can be arranged by either forced or free cow traffic. In the case of forced cow traffic, the AMS is the only route from the lying

  15. Reducing prospective memory error and costs in simulated air traffic control: External aids, extending practice, and removing perceived memory requirements.

    Science.gov (United States)

    Loft, Shayne; Chapman, Melissa; Smith, Rebekah E

    2016-09-01

    In air traffic control (ATC), forgetting to perform deferred actions-prospective memory (PM) errors-can have severe consequences. PM demands can also interfere with ongoing tasks (costs). We examined the extent to which PM errors and costs were reduced in simulated ATC by providing extended practice, or by providing external aids combined with extended practice, or by providing external aids combined with instructions that removed perceived memory requirements. Participants accepted/handed-off aircraft and detected conflicts. For the PM task, participants were required to substitute alternative actions for routine actions when accepting aircraft. In Experiment 1, when no aids were provided, PM errors and costs were not reduced by practice. When aids were provided, costs observed early in practice were eliminated with practice, but residual PM errors remained. Experiment 2 provided more limited practice with aids, but instructions that did not frame the PM task as a "memory" task led to high PM accuracy without costs. Attention-allocation policies that participants set based on expected PM demands were modified as individuals were increasingly exposed to reliable aids, or were given instructions that removed perceived memory requirements. These findings have implications for the design of aids for individuals who monitor multi-item dynamic displays. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  16. Effect of working memory load on electrophysiological markers of visuospatial orienting in a spatial cueing task simulating a traffic situation.

    Science.gov (United States)

    Vossen, Alexandra Y; Ross, Veerle; Jongen, Ellen M M; Ruiter, Robert A C; Smulders, Fren T Y

    2016-02-01

    Visuospatial attentional orienting has typically been studied in abstract tasks with low ecological validity. However, real-life tasks such as driving require allocation of working memory (WM) resources to several subtasks over and above orienting in a complex sensory environment. The aims of this study were twofold: firstly, to establish whether electrophysiological signatures of attentional orienting commonly observed under simplified task conditions generalize to a more naturalistic task situation with realistic-looking stimuli, and, secondly, to assess how these signatures are affected by increased WM load under such conditions. Sixteen healthy participants performed a dual task consisting of a spatial cueing paradigm and a concurrent verbal memory task that simulated aspects of an actual traffic situation. Behaviorally, we observed a load-induced detriment of sensitivity to targets. In the EEG, we replicated orienting-related alpha lateralization, the lateralized ERPs ADAN, EDAN, and LDAP, and the P1-N1 attention effect. When WM load was high (i.e., WM resources were reduced), lateralization of oscillatory activity in the lower alpha band was delayed. In the ERPs, we found that ADAN was also delayed, while EDAN was absent. Later ERP correlates were unaffected by load. Our results show that the findings in highly controlled artificial tasks can be generalized to spatial orienting in ecologically more valid tasks, and further suggest that the initiation of spatial orienting is delayed when WM demands of an unrelated secondary task are high. © 2015 Society for Psychophysiological Research.

  17. 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 ...

  18. Numerical Simulation for a Three-Dimensional Air Pollution Measurement Model in a Heavy Traffic Area under the Bangkok Sky Train Platform

    Directory of Open Access Journals (Sweden)

    Kewalee Suebyat

    2018-01-01

    Full Text Available Air pollutant levels in Bangkok are generally high in street tunnels. They are particularly elevated in almost closed street tunnels such as an area under the Bangkok sky train platform with high traffic volume where dispersion is limited. There are no air quality measurement stations in the vicinity, while the human population is high. In this research, the numerical simulation is used to measure the air pollutant levels. The three-dimensional air pollution measurement model in a heavy traffic area under the Bangkok sky train platform is proposed. The finite difference techniques are employed to approximate the modelled solutions. The vehicle air pollutant emission due to the high traffic volume is mathematically assumed by the pollutant sources term. The simulation is also considered in averaged and moving pollutant sources due to manner vehicle emission. The proposed approximated air pollutant concentration indicators can be replaced by user required gaseous pollutants indices such as NOx, SO2, CO, and PM2.5.

  19. 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

  20. Advanced Traffic Management Systems (ATMS) research analysis database system

    Science.gov (United States)

    2001-06-01

    The ATMS Research Analysis Database Systems (ARADS) consists of a Traffic Software Data Dictionary (TSDD) and a Traffic Software Object Model (TSOM) for application to microscopic traffic simulation and signal optimization domains. The purpose of thi...

  1. Accounting for anthropic energy flux of traffic in winter urban road surface temperature simulations with the TEB model

    Science.gov (United States)

    Khalifa, A.; Marchetti, M.; Bouilloud, L.; Martin, E.; Bues, M.; Chancibaut, K.

    2016-02-01

    Snowfall forecasts help winter maintenance of road networks, ensure better coordination between services, cost control, and a reduction in environmental impacts caused by an inappropriate use of de-icers. In order to determine the possible accumulation of snow on pavements, forecasting the road surface temperature (RST) is mandatory. Weather outstations are used along these networks to identify changes in pavement status, and to make forecasts by analyzing the data they provide. Physical numerical models provide such forecasts, and require an accurate description of the infrastructure along with meteorological parameters. The objective of this study was to build a reliable urban RST forecast with a detailed integration of traffic in the Town Energy Balance (TEB) numerical model for winter maintenance. The study first consisted in generating a physical and consistent description of traffic in the model with two approaches to evaluate traffic incidence on RST. Experiments were then conducted to measure the effect of traffic on RST increase with respect to non-circulated areas. These field data were then used for comparison with the forecast provided by this traffic-implemented TEB version.

  2. Accounting for anthropic energy flux of traffic in winter urban road surface temperature simulations with TEB model

    Science.gov (United States)

    Khalifa, A.; Marchetti, M.; Bouilloud, L.; Martin, E.; Bues, M.; Chancibaut, K.

    2015-06-01

    A forecast of the snowfall helps winter coordination operating services, reducing the cost of the maintenance actions, and the environmental impacts caused by an inappropriate use of de-icing. In order to determine the possible accumulation of snow on pavement, the forecast of the road surface temperature (RST) is mandatory. Physical numerical models provide such forecast, and do need an accurate description of the infrastructure along with meteorological parameters. The objective of this study was to build a reliable urban RST forecast with a detailed integration of traffic in the Town Energy Balance (TEB) numerical model for winter maintenance. The study first consisted in generating a physical and consistent description of traffic in the model with all the energy interactions, with two approaches to evaluate the traffic incidence on RST. Experiments were then conducted to measure the traffic effect on RST increase with respect to non circulated areas. These field data were then used for comparison with forecast provided by this traffic-implemented TEB version.

  3. UAS in the NAS Air Traffic Controller Acceptability Study-1: The Effects of Horizontal Miss Distances on Simulated UAS and Manned Aircraft Encounters

    Science.gov (United States)

    Ghatas, Rania W.; Comstock, James R., Jr.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

    2015-01-01

    This study examined air traffic controller acceptability ratings based on the effects of differing horizontal miss distances (HMDs) for encounters between UAS and manned aircraft. In a simulation of the Dallas/Fort Worth (DFW) East-side airspace, the CAS-1 experiment at NASA Langley Research Center enlisted fourteen recently retired DFW air traffic controllers to rate well-clear volumes based on differing HMDs that ranged from 0.5 NM to 3.0 NM. The controllers were tasked with rating these HMDs from "too small" to "too excessive" on a defined, 1-5, scale and whether these distances caused any disruptions to the controller and/or to the surrounding traffic flow. Results of the study indicated a clear favoring towards a particular HMD range. Controller workload was also measured. Data from this experiment and subsequent experiments will play a crucial role in the FAA's establishment of rules, regulations, and procedures to safely and efficiently integrate UAS into the NAS.

  4. A Simulation Based Analysis of The Impact of IEEE 802.15.4 MAC Parameters on the Performance Under Different Traffic Loads

    Directory of Open Access Journals (Sweden)

    D. Rohm

    2009-01-01

    Full Text Available IEEE 802.15.4, a MAC/PHY protocol for low power and low data rate wireless networks, is emerging as the popular choice for various monitoring and control applications. Depending on the application, the traffic load on an IEEE 802.15.4 network may vary over a wide range. The performance of the protocol, measured in terms of the packet loss probability and the packet latency, depends upon the prevailing traffic load among the nodes competing for channel access, the level of interference from the hidden nodes and the configuration of IEEE 802.15.4 MAC parameters. In this paper, we analyze via simulations the impact of different configurable MAC parameters on the performance of beaconless IEEE 802.15.4 networks under different traffic loads and under different levels of interference from the hidden nodes. Based on this analysis, we suggest the values of IEEE 802.15.4 MAC parameters that results in a good tradeoff between the packet loss probability and the packet latency under different conditions.

  5. Comparison of in situ observations of air traffic emission signatures in the North Atlantic flight corridor with simulations using a Gaussian plume model

    Energy Technology Data Exchange (ETDEWEB)

    Konopka, P.; Schlager, H.; Schulte, P.; Schumann, U.; Ziereis, H. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere; Hagen, D.; Whitefield, P. [Missouri Univ., Rolla, MO (United States). Lab. for Cloud and Aerosol Science

    1997-12-31

    Focussed aircraft measurements including NO, NO{sub 2}, O{sub 3}, and aerosols (CN) have been carried out over the Eastern North Atlantic as part of the POLINAT (Pollution from Aircraft Emissions in the North Atlantic Flight Corridor) project to search for small and large scale signals of air traffic emissions in the corridor region. Here, the experimental data measured at cruising altitudes on November, 6, 1994 close to peak traffic hours are considered. Observed peak concentrations in small scale NO{sub x} spikes exceed background level of about 50 pptv by up to two orders of magnitude. The measured NO{sub x} concentration field is compared with simulations obtained with a plume dispersion model using collected air traffic data and wind measurements. Additionally, the measured and calculated NO/NO{sub x} ratios are considered. The comparison with the model shows that the observed (multiple-)peaks can be understood as a superposition of several aircraft plumes with ages up to 3 hours. (author) 12 refs.

  6. 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.

  7. Traffic Games: Modeling Freeway Traffic with Game Theory.

    Science.gov (United States)

    Cortés-Berrueco, Luis E; Gershenson, Carlos; Stephens, Christopher R

    2016-01-01

    We apply game theory to a vehicular traffic model to study the effect of driver strategies on traffic flow. The resulting model inherits the realistic dynamics achieved by a two-lane traffic model and aims to incorporate phenomena caused by driver-driver interactions. To achieve this goal, a game-theoretic description of driver interaction was developed. This game-theoretic formalization allows one to model different lane-changing behaviors and to keep track of mobility performance. We simulate the evolution of cooperation, traffic flow, and mobility performance for different modeled behaviors. The analysis of these results indicates a mobility optimization process achieved by drivers' interactions.

  8. User’s Manual for the Simulation of Energy Consumption and Emissions from Rail Traffic Software Package

    DEFF Research Database (Denmark)

    Cordiero, Tiago M.; Lindgreen, Erik Bjørn Grønning; Sorenson, Spencer C

    2005-01-01

    The ARTEMIS rail emissions model was implemented in a Microsoft Excel software package that includes data from the GISCO database on railway traffic. This report is the user’s manual for the aforementioned software that includes information on how to run the program and an overview on how the pro...... of Excel Macros (Visual Basic) and database sheets included in one Excel file......The ARTEMIS rail emissions model was implemented in a Microsoft Excel software package that includes data from the GISCO database on railway traffic. This report is the user’s manual for the aforementioned software that includes information on how to run the program and an overview on how...

  9. 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

  10. The Classroom Traffic Jam

    Science.gov (United States)

    Edwards, Arthur W.

    1977-01-01

    The importance of energy conservation is developed in this simulation. Children draw an automobile and then are asked to drive it through the classroom roadways. When a traffic jam results, students offer ways to eliminate it. The importance of mass transportation and car pools is stressed by the teacher. (MA)

  11. DRONE - a tool for urban traffic noise abatement policy evaluation

    OpenAIRE

    Bhaskar, A.; Chung, E.; Kuwahara, M.

    2005-01-01

    Areawide Dynamic ROad traffic NoisE simulator-DRONE, been has developed by the integration of a road traffic noise prediction model (ASJ MODEL-1998) with road traffic simulator (AVENUE) which is further linked with GIS to provide areawide dynamic road traffic noise contour maps. This tool provides an engineering solution for the prediction of road traffic noise in urban network. Noise reduction in an urban area can be achieved by noise abatement policie...

  12. Modelling of H.264 MPEG2 TS Traffic Source

    Directory of Open Access Journals (Sweden)

    Stanislav Klucik

    2013-01-01

    Full Text Available This paper deals with IPTV traffic source modelling. Traffic sources are used for simulation, emulation and real network testing. This model is made as a derivation of known recorded traffic sources that are analysed and statistically processed. As the results show the proposed model causes in comparison to the known traffic source very similar network traffic parameters when used in a simulated network.

  13. Networked simulators: effects on the perceptual validity of traffic in driving simulators [Genetwerkte simulatoren: effecten op de perceptuele kwaliteit van verkeer in rijsimulatoren

    NARCIS (Netherlands)

    Kappé, B.; Vries, S.C. de

    2000-01-01

    Simulators have been used as a tool for training for many decades, and they are still gaining importance. Originally built for stand-alone use, the emergence of (global) network communication allowed these simulators to be connected with other simulators. This introduced the possibility of

  14. Spreading of Traffic Jam in a Traffic Flow Model

    Science.gov (United States)

    Nagatani, Takashi

    1993-04-01

    A cellular automaton (CA) model is presented to simulate the traffic jam induced by a traffic accident. The spreading of jamming cars induced by a car crash is investigated by computer simulation. An analogy is proposed between the crystal growth and the traffic-jam spreading. The scaling behavior of the traffic-jam spreading is studied. It is shown that the number N of jamming cars scales as N≈t2.34± 0.03 for p above the dynamical jamming transition pc{=}0.35 and N≈t1.07 below pc where t is the time and p is the density of cars. The time constant ts, which is the time required for all cars to stop, scales as ts≈p-1.07± 0.03 for p

  15. CFD SIMULATION OF THE DISPERSION OF EXHAUST GASES IN A TRAFFIC-LOADED STREET OF ASTANA, KAZAKHSTAN

    Directory of Open Access Journals (Sweden)

    A. Akhatova

    2015-01-01

    Full Text Available The aim of this paper is to consider one of the most traffic-loaded regions of Astana city(Kazakhstan and to determine the concentration of carbon-monoxide (CO in the airduring the peak hours. CFD analysis based on the SolidWorks-EFD platform was used tosimulate the dispersion of contaminants given the estimated emission rates and weatherconditions at the crossroad of Bogenbay Batyr and Zhenis Avenues in Astana.Turbulence prediction was based on k-ε model with wall functions. The governingequations were discretized using the finite volume method and a 2nd order spatialscheme. The mesh verification was based on 1% convergence criterion for a 50% ofmesh density increment; air pressure near the wall of a selected building was chosen asthe parameter to control the convergence. Numerical results are presented for prevailingconditions during all 4 seasons of the year, demonstrating that the highest levels of COare recorded in summer and reach the values up to 11.2 ppm which are still lower thanthe maximum level admitted for humans. Nevertheless, obtained results show thatAstana is gradually becoming a city that is likely to reach the critical levels of pollutantsin the nearest future if control measures are not taken with enough anticipation. As for afuture work, it is proposed to perform in-situ validation of specific scenarios to checkand support the results obtained with CFD and to develop then specific policies fortackling the problem before it becomes evident.

  16. The Stability of Multi-modal Traffic Network

    International Nuclear Information System (INIS)

    Han Linghui; Sun Huijun; Zhu Chengjuan; Jia Bin; Wu Jianjun

    2013-01-01

    There is an explicit and implicit assumption in multimodal traffic equilibrium models, that is, if the equilibrium exists, then it will also occur. The assumption is very idealized; in fact, it may be shown that the quite contrary could happen, because in multimodal traffic network, especially in mixed traffic conditions the interaction among traffic modes is asymmetric and the asymmetric interaction may result in the instability of traffic system. In this paper, to study the stability of multimodal traffic system, we respectively present the travel cost function in mixed traffic conditions and in traffic network with dedicated bus lanes. Based on a day-to-day dynamical model, we study the evolution of daily route choice of travelers in multimodal traffic network using 10000 random initial values for different cases. From the results of simulation, it can be concluded that the asymmetric interaction between the cars and buses in mixed traffic conditions can lead the traffic system to instability when traffic demand is larger. We also study the effect of travelers' perception error on the stability of multimodal traffic network. Although the larger perception error can alleviate the effect of interaction between cars and buses and improve the stability of traffic system in mixed traffic conditions, the traffic system also become instable when the traffic demand is larger than a number. For all cases simulated in this study, with the same parameters, traffic system with dedicated bus lane has better stability for traffic demand than that in mixed traffic conditions. We also find that the network with dedicated bus lane has higher portion of travelers by bus than it of mixed traffic network. So it can be concluded that building dedicated bus lane can improve the stability of traffic system and attract more travelers to choose bus reducing the traffic congestion. (general)

  17. 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.

  18. Modeling of Spacewire Traffic

    Science.gov (United States)

    Liebgott, Emmanuelle; Fourtier, Philippe; Jameux, David

    2011-08-01

    The Spacewire technology allows embarking high speed data networks on board spacecraft and become widely adopted by agencies and industries missions. Need for new tool to support conception, development and validation of such high speed data network has increased with Spacewire standard development. In that frame, MOST is a representative traffic spacewire simulator which presents great interests for both system engineers and spacewire experts:• It offers the possibility to build SpW network model, selecting and configuring SpW components, and to test defined design without waiting for HW,• It allows to keep control on traffic load and identify weak parts of the network topology,• It gives load margins and traffic performances,• It allows failures simulation and give the possibility to run various scenarios• MOST supports design risks decrease and secures planning thanks to early verification,• In addition, MOST is a progressive tool which allows testing of SpW standard evolutions.

  19. Analysis of vehicular traffic flow in the major areas of Kuala Lumpur utilizing open-traffic

    Science.gov (United States)

    Manogaran, Saargunawathy; Ali, Muhammad; Yusof, Kamaludin Mohamad; Suhaili, Ramdhan

    2017-09-01

    Vehicular traffic congestion occurs when a large number of drivers are overcrowded on the road and the traffic flow does not run smoothly. Traffic congestion causes chaos on the road and interruption to daily activities of users. Time consumed on road give lots of negative effects on productivity, social behavior, environmental and cost to economy. Congestion is worsens and leads to havoc during the emergency such as flood, accidents, road maintenance and etc., where behavior of traffic flow is always unpredictable and uncontrollable. Real-time and historical traffic data are critical inputs for most traffic flow analysis applications. Researcher attempt to predict traffic using simulations as there is no exact model of traffic flow exists due to its high complexity. Open Traffic is an open source platform available for traffic data analysis linked to Open Street Map (OSM). This research is aimed to study and understand the Open Traffic platform. The real-time traffic flow pattern in Kuala Lumpur area was successfully been extracted and analyzed using Open Traffic. It was observed that the congestion occurs on every major road in Kuala Lumpur and most of it owes to the offices and the economic and commercial centers during rush hours. At some roads the congestion occurs at night due to the tourism activities.

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

    Science.gov (United States)

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

    2016-04-28

    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.

  1. Traffic load effects in prestrssed concrete bridges

    NARCIS (Netherlands)

    Vrouwenvelder, A.C.W.M.; Allaix, D.L.; Courage, W.M.G.

    2007-01-01

    The traffic load effect of a two-span prestressed concrete bridge with two traffic lanes is analyzed in this paper. The design value of the result-ing bending moment in some prescribed sections is estimated by means of a Monte Carlo simulation. The model for the vehicular loads is derived from a set

  2. 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...

  3. Traffic and Granular Flow ’07

    CERN Document Server

    Chevoir, François; Gondret, Philippe; Lassarre, Sylvain; Lebacque, Jean-Patrick; Schreckenberg, Michael

    2009-01-01

    This book covers several research fields, all of which deal with transport. Three main topics are treated: road traffic, granular matter, and biological transport. Different points of view, i.e. modelling, simulations, experiments, and phenomenological observations, are considered. Sub-topics include: highway or urban vehicular traffic (dynamics of traffic, macro/micro modelling, measurements, data analysis, security issues, psychological issues), pedestrian traffic, animal traffic (e.g. social insects), collective motion in biological systems (molecular motors...), granular flow (dense flows, intermittent flows, solid/liquid transition, jamming, force networks, fluid and solid friction), networks (biological networks, urban traffic, the internet, vulnerability of networks, optimal transport networks) and cellular automata applied to the various aforementioned fields.

  4. 11th Traffic and Granular Flow Conference

    CERN Document Server

    Daamen, Winnie

    2016-01-01

    The Conference on Traffic and Granular Flow brings together international researchers from different fields ranging from physics to computer science and engineering to discuss the latest developments in traffic-related systems. Originally conceived to facilitate new ideas by considering the similarities of traffic and granular flow, TGF'15, organised by Delft University of Technology, now covers a broad range of topics related to driven particle and transport systems. Besides the classical topics of granular flow and highway traffic, its scope includes data transport (Internet traffic), pedestrian and evacuation dynamics, intercellular transport, swarm behaviour and the collective dynamics of other biological systems. Recent advances in modelling, computer simulation and phenomenology are presented, and prospects for applications, for example to traffic control, are discussed. The conference explores the interrelations between the above-mentioned fields and offers the opportunity to stimulate interdisciplinar...

  5. Traffic Flow Management Wrap-Up

    Science.gov (United States)

    Grabbe, Shon

    2011-01-01

    Traffic Flow Management involves the scheduling and routing of air traffic subject to airport and airspace capacity constraints, and the efficient use of available airspace. Significant challenges in this area include: (1) weather integration and forecasting, (2) accounting for user preferences in the Traffic Flow Management decision making process, and (3) understanding and mitigating the environmental impacts of air traffic on the environment. To address these challenges, researchers in the Traffic Flow Management area are developing modeling, simulation and optimization techniques to route and schedule air traffic flights and flows while accommodating user preferences, accounting for system uncertainties and considering the environmental impacts of aviation. This presentation will highlight some of the major challenges facing researchers in this domain, while also showcasing recent innovations designed to address these challenges.

  6. 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.

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

    African Journals Online (AJOL)

    Comparison is made between roundabouts with traffic light and without traffic light and signalized intersections on the basis of their performance to simplify traffic congestion. Computer simulations are used to propose critical arrival rates to separate between the three mentioned modes to decrease congestion at intersection ...

  8. Traffic modelling validation of advanced driver assistance systems

    NARCIS (Netherlands)

    Tongeren, R. van; Gietelink, O.J.; Schutter, B. de; Verhaegen, M.

    2007-01-01

    This paper presents a microscopic traffic model for the validation of advanced driver assistance systems. This model describes single-lane traffic and is calibrated with data from a field operational test. To illustrate the use of the model, a Monte Carlo simulation of single-lane traffic scenarios

  9. Traffic planning for non-homogeneous traffic

    Indian Academy of Sciences (India)

    2.3c Data summary The summarization of the density data based on videotape obser- vations is in table 1 which shows average, 30-second, sampled densities. Using the non- homogeneous traffic continuity equation of (2), the resultant traffic concentrations appear in table 2. Comparing the traffic concentrations in table 1 to ...

  10. Traffic jam induced by a crosscut road in a traffic-flow model

    Science.gov (United States)

    Nagatani, Takashi; Seno, Tadachika

    1994-06-01

    A deterministic cellular automaton model is presented to simulate the traffic jam induced by a crosscut road in a two-dimensional traffic flow. The effect of a crosscut road on the traffic flow is investigated by the use of a computer simulation. The traffic jam appears when a shock (discontinuous interface of different car densities) is formed. The condition for shock formation is derived for car densities p y and p x of the crosscut road and its crossing streets. The phase diagram and the dependence of the traffic flow on the car densities are shown. Also, we study the shock structure and the scaling of its width. The width Δ w of the shock scales with the system size L as Δ w ≈ L{1}/{2}. We present a self-consistent mean-field theory for the traffic flow.

  11. 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.

  12. 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

  13. 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…

  14. On vehicular traffic data analysis

    Energy Technology Data Exchange (ETDEWEB)

    Brics, Martins; Mahnke, Reinhard [Institute of Physics, Rostock University (Germany)

    2011-07-01

    This contribution consists of analysis of empirical vehicular traffic flow data. The main focus lies on the Next Generation Simulation (NGSIM) data. The first findings show that there are artificial structures within the data due to errors of monitoring as well as smoothing position measurement data. As a result speed data show discretisation in 5 feet per second. The aim of this investigation is to construct microscopic traffic flow models which are in agreement to the analysed empirical data. The ongoing work follows the subject of research summarized by Christof Liebe in his PhD thesis entitled ''Physics of traffic flow: Empirical data and dynamical models'' (Rostock, 2010).

  15. 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 ...

  16. Can Simulator Immersion Change Cognitive Style? Results from a Cross-Sectional Study of Field-Dependence--Independence in Air Traffic Control Students

    Science.gov (United States)

    Van Eck, Richard N.; Fu, Hongxia; Drechsel, Paul V. J.

    2015-01-01

    Air traffic control (ATC) operations are critical to the U.S. aviation infrastructure, making ATC training a critical area of study. Because ATC performance is heavily dependent on visual processing, it is important to understand how to screen for or promote relevant visual processing abilities. While conventional wisdom has maintained that such…

  17. CATCC/AATCC Simulator

    Data.gov (United States)

    Federal Laboratory Consortium — The 15G30 CATCC/AATCC simulator provides high fidelity training for Navy Air Traffic Control (ATC) trainees in a realistic shipboard air traffic control environment....

  18. 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.

  19. Distributed traffic signal control using fuzzy logic

    Science.gov (United States)

    Chiu, Stephen

    1992-01-01

    We present a distributed approach to traffic signal control, where the signal timing parameters at a given intersection are adjusted as functions of the local traffic condition and of the signal timing parameters at adjacent intersections. Thus, the signal timing parameters evolve dynamically using only local information to improve traffic flow. This distributed approach provides for a fault-tolerant, highly responsive traffic management system. The signal timing at an intersection is defined by three parameters: cycle time, phase split, and offset. We use fuzzy decision rules to adjust these three parameters based only on local information. The amount of change in the timing parameters during each cycle is limited to a small fraction of the current parameters to ensure smooth transition. We show the effectiveness of this method through simulation of the traffic flow in a network of controlled intersections.

  20. Traffic data reconstruction based on Markov random field modeling

    International Nuclear Information System (INIS)

    Kataoka, Shun; Tanaka, Kazuyuki; Yasuda, Muneki; Furtlehner, Cyril

    2014-01-01

    We consider the traffic data reconstruction problem. Suppose we have the traffic data of an entire city that are incomplete because some road data are unobserved. The problem is to reconstruct the unobserved parts of the data. In this paper, we propose a new method to reconstruct incomplete traffic data collected from various sensors. Our approach is based on Markov random field modeling of road traffic. The reconstruction is achieved by using a mean-field method and a machine learning method. We numerically verify the performance of our method using realistic simulated traffic data for the real road network of Sendai, Japan. (paper)

  1. 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.

  2. Does front-of-pack nutrition information improve consumer ability to make healthful choices? Performance of warnings and the traffic light system in a simulated shopping experiment.

    Science.gov (United States)

    Machín, Leandro; Aschemann-Witzel, Jessica; Curutchet, María Rosa; Giménez, Ana; Ares, Gastón

    2018-02-01

    The inclusion of more attention-grabbing and easily interpretable front-of-pack (FOP) nutrition information is one of the public policies that can be implemented to empower consumers to identify unhealthful food products and to make more informed food choices. The aim of the present work was to evaluate the influence of two FOP nutrition labelling schemes - the traffic light labelling and the warning scheme - on consumer food purchases when facing a health goal. The study was conducted with 1182 people from Montevideo (Uruguay), recruited using a Facebook advertisement. Participants were randomly allocated to one of three between-subjects experimental conditions: (i) a control condition with no FOP nutrition information, (ii) FOP nutrition information using a modified version of the traffic light system including information about calorie, saturated fat, sugars and sodium content per portion, and (iii) FOP nutrition information using the Chilean warning system including separate signs for high calorie, saturated fat, sugars and sodium content. Respondents were asked to imagine that they had to purchase food in order to prepare a healthy dinner for themselves and their family, using the website of an online grocery store. Results showed that FOP nutrition information effectively improved the average healthfulness of participants' choices compared to the control condition, both in terms of the average nutritional composition of the purchased products and expenditure in specific product categories. No relevant differences between the effect of the traffic light and the warning system were found. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. National guidelines for traffic calming

    CSIR Research Space (South Africa)

    Schermers, G

    1998-03-01

    Full Text Available This document serves as a comprehensive national traffic calming guideline, compiled to assist traffic engineering practitioners and road authorities with the implementation of traffic calming. It outlines the different objectives of traffic calming...

  4. Traffic signal timing manual

    Science.gov (United States)

    2008-06-01

    This report serves as a comprehensive guide to traffic signal timing and documents the tasks completed in association with its development. The focus of this document is on traffic signal control principles, practices, and procedures. It describes th...

  5. An intelligent traffic controller

    Science.gov (United States)

    1995-11-01

    Advances in computing sciences have not been applied to traffic control. This paper describes the development of an intelligent controller. A controller with advanced control logic can significantly improve traffic flows at intersections. In this vei...

  6. 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.

  7. Macroscopic Traffic State Estimation: Understanding Traffic Sensing Data-Based Estimation Errors

    Directory of Open Access Journals (Sweden)

    Paul B. C. van Erp

    2017-01-01

    Full Text Available Traffic state estimation is a crucial element in traffic management systems and in providing traffic information to road users. In this article, we evaluate traffic sensing data-based estimation error characteristics in macroscopic traffic state estimation. We consider two types of sensing data, that is, loop-detector data and probe speed data. These data are used to estimate the mean speed in a discrete space-time mesh. We assume that there are no errors in the sensing data. This allows us to study the errors resulting from the differences in characteristics between the sensing data and desired estimate together with the incomplete description of the relation between the two. The aim of the study is to evaluate the dependency of this estimation error on the traffic conditions and sensing data characteristics. For this purpose, we use microscopic traffic simulation, where we compare the estimates with the ground truth using Edie’s definitions. The study exposes a relation between the error distribution characteristics and traffic conditions. Furthermore, we find that it is important to account for the correlation between individual probe data-based estimation errors. Knowledge related to these estimation errors contributes to making better use of the available sensing data in traffic state estimation.

  8. 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.

  9. 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.

  10. Traffic Congestion Evaluation and Signal Control Optimization Based on Wireless Sensor Networks: Model and Algorithms

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2012-01-01

    Full Text Available This paper presents the model and algorithms for traffic flow data monitoring and optimal traffic light control based on wireless sensor networks. Given the scenario that sensor nodes are sparsely deployed along the segments between signalized intersections, an analytical model is built using continuum traffic equation and develops the method to estimate traffic parameter with the scattered sensor data. Based on the traffic data and principle of traffic congestion formation, we introduce the congestion factor which can be used to evaluate the real-time traffic congestion status along the segment and to predict the subcritical state of traffic jams. The result is expected to support the timing phase optimization of traffic light control for the purpose of avoiding traffic congestion before its formation. We simulate the traffic monitoring based on the Mobile Century dataset and analyze the performance of traffic light control on VISSIM platform when congestion factor is introduced into the signal timing optimization model. The simulation result shows that this method can improve the spatial-temporal resolution of traffic data monitoring and evaluate traffic congestion status with high precision. It is helpful to remarkably alleviate urban traffic congestion and decrease the average traffic delays and maximum queue length.

  11. Traffic Light Options

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte

    This paper introduces, prices, and analyzes traffic light options. The traffic light option is an innovative structured OTC derivative developed independently by several London-based investment banks to suit the needs of Danish life and pension (L&P) companies, which must comply with the traffic...... 2006, and supervisory authorities in many other European countries have implemented similar regulation. Traffic light options are therefore likely to attract the attention of a wider audience of pension fund managers in the future. Focusing on the valuation of the traffic light option we set up a Black...... light scenarios. These stress scenarios entail drops in interest rates as well as in stock prices, and traffic light options are thus designed to pay off and preserve sufficient capital when interest rates and stock prices fall simultaneously. Sweden's FSA implemented a traffic light system in January...

  12. A Marine Traffic Flow Model

    Directory of Open Access Journals (Sweden)

    Tsz Leung Yip

    2013-03-01

    Full Text Available A model is developed for studying marine traffic flow through classical traffic flow theories, which can provide us with a better understanding of the phenomenon of traffic flow of ships. On one hand, marine traffic has its special features and is fundamentally different from highway, air and pedestrian traffic. The existing traffic models cannot be simply extended to marine traffic without addressing marine traffic features. On the other hand, existing literature on marine traffic focuses on one ship or two ships but does not address the issues in marine traffic flow.

  13. Dynamic assessment of bridge deck performance considering realistic bridge-traffic interaction : research brief

    Science.gov (United States)

    2017-09-01

    This study is to develop simulation methodology to conduct the dynamic assessment of bridge deck performance subjected to traffic. Concrete bridge decks are exposed to daily traffic loads and may experience some surface cracking caused by excessive s...

  14. Integrating Human Performance Metrics into the Future Air Traffic Management Concepts Evaluation Tool, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's Future Air traffic management Concepts Evaluation Tool (FACET) is a simulation tool to evaluate next generation air traffic management (ATM) systems. FACET...

  15. Influence of Intra-cell Traffic on the Output Power of Base Station in GSM

    Directory of Open Access Journals (Sweden)

    M. Mileusnic

    2014-06-01

    Full Text Available In this paper we analyze the influence of intracell traffic in a GSM cell on the base station output power. It is proved that intracell traffic increases this power. If offered traffic is small, the increase of output power is equal to the part of intracell traffic. When the offered traffic and, as the result, call loss increase, the increase of output power becomes less. The results of calculation are verified by the computer simulation of traffic process in the GSM cell. The calculation and the simulation consider the uniform distribution of mobile users in the cell, but the conclusions are of a general nature.

  16. Evolution of Traffic Jam in Traffic Flow Model

    Science.gov (United States)

    Fukui, Minoru; Ishibashi, Yoshihiro

    1993-11-01

    Traffic flow is simulated in a three-state cellular automaton model. In a two-dimensional cell without a crashed car, the ensemble average of the velocity of the cars is enhanced by the self-organization in the low-density phase of cars. In the high-density phase above p{=}0.5 of car density, the velocity is decreased and the system then degenerates into a global jamming phase in which all cars are stopped. A crashed car provides the seed of a jamming cluster, which grows into a global traffic jam even in the low-density phase. The growth of the jamming cluster is studied, and the time dependence of the number of jamming cars and the scaling law for the cell sizes are discussed.

  17. Investigating Traffic Avoidance Maneuver Preferences of Unmanned Aircraft Operators

    Science.gov (United States)

    2016-06-13

    operations within the NAS can be conducted safely. Existing aviation regulations require that aviators “ see and avoid” nearby traffic . Without a...simulations to address the effectiveness of DAA with a pilot-in-the-loop, one must model how unmanned pilots respond when encountering other air traffic ... traffic with color-coded icons and, in some cases, an aural alert signal . Alert criteria are based on projected penetration of an alert region

  18. Fuzzy logic controller for a traffic signal

    Science.gov (United States)

    Janecek, J. J.; Zargham, Mehdi R.

    1995-08-01

    Automatic control of traffic signals in many cities are often based on a constant green-to-red cycle. The time period for green light (or red light) to be on is fixed, and is determined based on a stochastic model. In some situations, a human operator, or a fixed timer, may change the time period dyring time intervals where there is heavy traffic--typically during commuting times. Although in today's traffic controllers, the time period for green light can be changed in certain circumstances, in general they are not able to adjust dynamically to traffic changes. This paper presents the design of a controller that considers the intersection of two two-way streets and is able to adjust to environmental changes. Simulation of the proposed controller has produced results more in line with what we expected. In many cases, the proposed system has produced better results than systems that are based on a constant green-to-red cycle.

  19. Costs of traffic injuries

    DEFF Research Database (Denmark)

    Kruse, Marie

    2015-01-01

    OBJECTIVE: The aim of this study was to analyse the socioeconomic costs of traffic injuries in Denmark, notably the healthcare costs and the productivity costs related to traffic injuries, in a bottom-up, register-based perspective. METHOD: Traffic injury victims were identified using national...... emergency room data and police records. Victims were matched with five controls per case by means of propensity score, nearest-neighbour matching. In the cohort, consisting of the 52 526 individuals that experienced a traffic injury in 2000 and 262 630 matched controls, attributable healthcare costs were...... assessed using Danish national healthcare registers. Productivity costs were computed using duration analysis (Cox regression models). In a subanalysis, cost per severe traffic injury was computed for the 12 995 individuals that experienced a severe injury. RESULTS: The socioeconomic cost of a traffic...

  20. Traffic Signs Inventory System

    Directory of Open Access Journals (Sweden)

    J. Ružbarský

    2013-06-01

    Full Text Available The paper is focused on practical application of Cambridge Correlator. The goal is to propose a traffic signs inventory system by using excellent characteristics of correlator in the rapid optical correlation. The proposal of this inventory system includes obtaining of traffic signs to create the database either collecting the GPS coordinates. It is necessary to know the traffic signs position and also to document the entire surface route for later evaluation in offline mode.

  1. modified traffic s modified traffic signal phasing at traffic warden ...

    African Journals Online (AJOL)

    eobe

    obtained as being adequate for the critical approach. A 5 tained as being adequate for the critical approach. A 5 tained as being adequate for the critical approach. A 5-phase scheme is proposed with the fifth phase being an phase scheme is .... Other examples include traffic light signalized crossing with or without ...

  2. Online traffic flow model applying dynamic flow-density relation

    International Nuclear Information System (INIS)

    Kim, Y.

    2002-01-01

    This dissertation describes a new approach of the online traffic flow modelling based on the hydrodynamic traffic flow model and an online process to adapt the flow-density relation dynamically. The new modelling approach was tested based on the real traffic situations in various homogeneous motorway sections and a motorway section with ramps and gave encouraging simulation results. This work is composed of two parts: first the analysis of traffic flow characteristics and second the development of a new online traffic flow model applying these characteristics. For homogeneous motorway sections traffic flow is classified into six different traffic states with different characteristics. Delimitation criteria were developed to separate these states. The hysteresis phenomena were analysed during the transitions between these traffic states. The traffic states and the transitions are represented on a states diagram with the flow axis and the density axis. For motorway sections with ramps the complicated traffic flow is simplified and classified into three traffic states depending on the propagation of congestion. The traffic states are represented on a phase diagram with the upstream demand axis and the interaction strength axis which was defined in this research. The states diagram and the phase diagram provide a basis for the development of the dynamic flow-density relation. The first-order hydrodynamic traffic flow model was programmed according to the cell-transmission scheme extended by the modification of flow dependent sending/receiving functions, the classification of cells and the determination strategy for the flow-density relation in the cells. The unreasonable results of macroscopic traffic flow models, which may occur in the first and last cells in certain conditions are alleviated by applying buffer cells between the traffic data and the model. The sending/receiving functions of the cells are determined dynamically based on the classification of the

  3. Point Coordination Function WLAN Traffic Loadings | Ani | Nigerian ...

    African Journals Online (AJOL)

    WLAN's ability to provide high capacity links, mobility and low acquisition cost played considerable positive role in its popularity. The operation of WLAN in ... traffic loadings is presented. Influence of traffic loadings on WLAN quality of service (QoS) parameters was analyzed using computer simulation modeling technique.

  4. Integration of Weather Avoidance and Traffic Separation

    Science.gov (United States)

    Consiglio, Maria C.; Chamberlain, James P.; Wilson, Sara R.

    2011-01-01

    This paper describes a dynamic convective weather avoidance concept that compensates for weather motion uncertainties; the integration of this weather avoidance concept into a prototype 4-D trajectory-based Airborne Separation Assurance System (ASAS) application; and test results from a batch (non-piloted) simulation of the integrated application with high traffic densities and a dynamic convective weather model. The weather model can simulate a number of pseudo-random hazardous weather patterns, such as slow- or fast-moving cells and opening or closing weather gaps, and also allows for modeling of onboard weather radar limitations in range and azimuth. The weather avoidance concept employs nested "core" and "avoid" polygons around convective weather cells, and the simulations assess the effectiveness of various avoid polygon sizes in the presence of different weather patterns, using traffic scenarios representing approximately two times the current traffic density in en-route airspace. Results from the simulation experiment show that the weather avoidance concept is effective over a wide range of weather patterns and cell speeds. Avoid polygons that are only 2-3 miles larger than their core polygons are sufficient to account for weather uncertainties in almost all cases, and traffic separation performance does not appear to degrade with the addition of weather polygon avoidance. Additional "lessons learned" from the batch simulation study are discussed in the paper, along with insights for improving the weather avoidance concept. Introduction

  5. An extended lattice model accounting for traffic jerk

    Science.gov (United States)

    Redhu, Poonam; Siwach, Vikash

    2018-02-01

    In this paper, a flux difference lattice hydrodynamics model is extended by considering the traffic jerk effect which comes due to vehicular motion of non-motor automobiles. The effect of traffic jerk has been examined through linear stability analysis and shown that it can significantly enlarge the unstable region on the phase diagram. To describe the phase transition of traffic flow, mKdV equation near the critical point is derived through nonlinear stability analysis. The theoretical findings have been verified using numerical simulation which confirms that the jerk parameter plays an important role in stabilizing the traffic jam efficiently in sensing the flux difference of leading sites.

  6. Using Visual Simulation Tools And Learning Outcomes-Based Curriculum To Help Transportation Engineering Students And Practitioners To Better Understand And Design Traffic Signal Control Systems

    Science.gov (United States)

    2012-06-01

    The use of visual simulation tools to convey complex concepts has become a useful tool in education as well as in research. : This report describes a project that developed curriculum and visualization tools to train transportation engineering studen...

  7. Road Traffic in China

    NARCIS (Netherlands)

    Jie, L.; Van Zuylen, H.J.

    2014-01-01

    Traffic is tightly related to the social and economic development in a country. In China the development of the economy has been very fast in the past 30 years and this is still continuing. The transport infrastructure shows a similar pattern, while traffic is also rapidly growing. In urban areas

  8. Traffic Light Options

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte

    2007-01-01

    This paper introduces, prices, and analyzes traffic light options. The traffic light option is an innovative structured OTC derivative developed independently by several London-based investment banks to suit the needs of Danish life and pension (L&P) companies, which must comply with the traffic...... light solvency stress test system introduced by the Danish Financial Supervisory Authority (DFSA) in June 2001. This monitoring system requires L&P companies to submit regular reports documenting the sensitivity of the companies' base capital to certain pre-defined market shocks - the red and yellow...... light scenarios. These stress scenarios entail drops in interest rates as well as in stock prices, and traffic light options are thus designed to pay off and preserve sufficient capital when interest rates and stock prices fall simultaneously. Sweden's FSA implemented a traffic light system in January...

  9. Simulations

    CERN Document Server

    Ngada, Narcisse

    2015-06-15

    The complexity and cost of building and running high-power electrical systems make the use of simulations unavoidable. The simulations available today provide great understanding about how systems really operate. This paper helps the reader to gain an insight into simulation in the field of power converters for particle accelerators. Starting with the definition and basic principles of simulation, two simulation types, as well as their leading tools, are presented: analog and numerical simulations. Some practical applications of each simulation type are also considered. The final conclusion then summarizes the main important items to keep in mind before opting for a simulation tool or before performing a simulation.

  10. A Wavelet Analysis Approach for Categorizing Air Traffic Behavior

    Science.gov (United States)

    Drew, Michael; Sheth, Kapil

    2015-01-01

    In this paper two frequency domain techniques are applied to air traffic analysis. The Continuous Wavelet Transform (CWT), like the Fourier Transform, is shown to identify changes in historical traffic patterns caused by Traffic Management Initiatives (TMIs) and weather with the added benefit of detecting when in time those changes take place. Next, with the expectation that it could detect anomalies in the network and indicate the extent to which they affect traffic flows, the Spectral Graph Wavelet Transform (SGWT) is applied to a center based graph model of air traffic. When applied to simulations based on historical flight plans, it identified the traffic flows between centers that have the greatest impact on either neighboring flows, or flows between centers many centers away. Like the CWT, however, it can be difficult to interpret SGWT results and relate them to simulations where major TMIs are implemented, and more research may be warranted in this area. These frequency analysis techniques can detect off-nominal air traffic behavior, but due to the nature of air traffic time series data, so far they prove difficult to apply in a way that provides significant insight or specific identification of traffic patterns.

  11. Fine-Tuning ADAS Algorithm Parameters for Optimizing Traffic ...

    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 optimization at various highway facilities. To this end, the traffic management centers identify the optimal ADAS algorithm parameter set that enables the maximum improvement of the traffic safety and mobility performance, and broadcast the optimal parameter set wirelessly to individual ADAS-equipped vehicles. After adopting the optimal parameter set, the ADAS-equipped drivers become active agents in the traffic stream that work collectively and consistently to prevent traffic conflicts, lower the intensity of traffic disturbances, and suppress the development of traffic oscillations into heavy traffic jams. Successful implementation of this objective requires the analysis capability of capturing the impact of the ADAS on driving behaviors, and measuring traffic safety and mobility performance under the influence of the ADAS. To address this challenge, this research proposes a synthetic methodology that incorporates the ADAS-affected driving behavior modeling and state-of-the-art microscopic traffic flow modeling into a virtually simulated environment. Building on such an environment, the optimal ADAS algorithm parameter set is identified through an optimization programming framework to enable th

  12. 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.

  13. Providing resilience for carrier ethernet multicast traffic

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Wessing, Henrik; Zhang, Jiang

    2009-01-01

    This paper presents an overview of the Carrier Ethernet technology with specific focus on resilience. In particular, we detail how multicast traffic, which is essential for e.g. IPTV can be protected. We present Carrier Ethernet resilience methods for linear and ring networks and show by simulation...... that the availability of a multicast connection can be significantly increased by applying relevant resilience techniques....

  14. Traffic planning for non-homogeneous traffic

    Indian Academy of Sciences (India)

    Transport professionals can use these PCU values for accurate capacity, safety, and operational ... Most transportation engineering work depends on the use of continuity equations and pas- senger car units ...... of a service lane can serve slow and local traffic, as a capacity enhancement strategy would have higher benefit ...

  15. Numerical study of traffic flow considering the probability density distribution of the traffic density

    Science.gov (United States)

    Guo, L. M.; Zhu, H. B.; Zhang, N. X.

    The probability density distribution of the traffic density is analyzed based on the empirical data. It is found that the beta distribution can fit the result obtained from the measured traffic density perfectly. Then a modified traffic model is proposed to simulate the microscopic traffic flow, in which the probability density distribution of the traffic density is taken into account. The model also contains the behavior of drivers’ speed adaptation by taking into account the driving behavior difference and the dynamic headway. Accompanied by presenting the flux-density diagrams, the velocity evolution diagrams and the spatial-temporal profiles of vehicles are also given. The synchronized flow phase and the wide moving jam phase are indicated, which is the challenge for the cellular automata traffic model. Furthermore the phenomenon of the high speed car-following is exhibited, which has been observed in the measured data previously. The results set demonstrate the effectiveness of the proposed model in detecting the complicated dynamic phenomena of the traffic flow.

  16. A Wavelet Analysis-Based Dynamic Prediction Algorithm to Network Traffic

    Directory of Open Access Journals (Sweden)

    Meng Fan-Bo

    2016-01-01

    Full Text Available Network traffic is a significantly important parameter for network traffic engineering, while it holds highly dynamic nature in the network. Accordingly, it is difficult and impossible to directly predict traffic amount of end-to-end flows. This paper proposes a new prediction algorithm to network traffic using the wavelet analysis. Firstly, network traffic is converted into the time-frequency domain to capture time-frequency feature of network traffic. Secondly, in different frequency components, we model network traffic in the time-frequency domain. Finally, we build the prediction model about network traffic. At the same time, the corresponding prediction algorithm is presented to attain network traffic prediction. Simulation results indicates that our approach is promising.

  17. Calibration of CORSIM models under saturated traffic flow conditions.

    Science.gov (United States)

    2013-09-01

    This study proposes a methodology to calibrate microscopic traffic flow simulation models. : The proposed methodology has the capability to calibrate simultaneously all the calibration : parameters as well as demand patterns for any network topology....

  18. Agent-Based Collaborative Traffic Flow Management, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose agent-based game-theoretic approaches for simulation of strategies involved in multi-objective collaborative traffic flow management (CTFM). Intelligent...

  19. Expanding Regional Airport Usage to Accommodate Increased Air Traffic Demand

    Science.gov (United States)

    Russell, Carl R.

    2009-01-01

    Small regional airports present an underutilized source of capacity in the national air transportation system. This study sought to determine whether a 50 percent increase in national operations could be achieved by limiting demand growth at large hub airports and instead growing traffic levels at the surrounding regional airports. This demand scenario for future air traffic in the United States was generated and used as input to a 24-hour simulation of the national airspace system. Results of the demand generation process and metrics predicting the simulation results are presented, in addition to the actual simulation results. The demand generation process showed that sufficient runway capacity exists at regional airports to offload a significant portion of traffic from hub airports. Predictive metrics forecast a large reduction of delays at most major airports when demand is shifted. The simulation results then show that offloading hub traffic can significantly reduce nationwide delays.

  20. 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

  1. 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

  2. Impact of Road Bends on Traffic Flow in a Single-Lane Traffic System

    Directory of Open Access Journals (Sweden)

    Zeng Junwei

    2014-01-01

    Full Text Available Taking the characteristics of road bends as a research object, this work proposes the cellular model (CA with road bends based on the NaSch model, with which the traffic flow is examined under different conditions, such as bend radius, bend arc length, and road friction coefficiency. The simulation results show that, with the increase of the bend radius, the peak flow will be continuously increased, and the fundamental diagram will become more similar to that of the classic NaSch model; the smaller the bend radius is, the easier it is for the occurrence of blockage; for different bend lengths, all the corresponding traffic flows show that the phenomenon of go-and-stop and the bends exert slight inhibitory effect on traffic flow; under the same bend radius, the inhibition effect of the bends on the traffic flow will be weakened with the increase of the friction coefficiency.

  3. VBR video traffic models

    CERN Document Server

    Tanwir, Savera

    2014-01-01

    There has been a phenomenal growth in video applications over the past few years. An accurate traffic model of Variable Bit Rate (VBR) video is necessary for performance evaluation of a network design and for generating synthetic traffic that can be used for benchmarking a network. A large number of models for VBR video traffic have been proposed in the literature for different types of video in the past 20 years. Here, the authors have classified and surveyed these models and have also evaluated the models for H.264 AVC and MVC encoded video and discussed their findings.

  4. Comsat's TDMA traffic terminal

    Science.gov (United States)

    Benjamin, M. C.; Bogaert, W. M.

    1985-06-01

    Comsat has installed two traffic terminals in the Etam earth-station and is currently installing a third in the new Roaring Creek earth-station to access the Intelsat TDMA network. This paper describes the Comsat TDMA traffic terminal equipment from the supergroup interface to the antenna. Comsat's 1: N redundancy approach for terrestrial interface equipment and DSI unit back-up is described as well as electrical path length, amplitude and group delay equalization techniques, special on-line RF monitoring and failure reporting facilities and the operation and maintenance center which can operate and perform diagnostic testing on up to four traffic terminals from a central location.

  5. Network traffic behaviour near phase transition point

    Science.gov (United States)

    Lawniczak, A. T.; Tang, X.

    2006-03-01

    We explore packet traffic dynamics in a data network model near phase transition point from free flow to congestion. The model of data network is an abstraction of the Network Layer of the OSI (Open Systems Interconnect) Reference Model of packet switching networks. The Network Layer is responsible for routing packets across the network from their sources to their destinations and for control of congestion in data networks. Using the model we investigate spatio-temporal packets traffic dynamics near the phase transition point for various network connection topologies, and static and adaptive routing algorithms. We present selected simulation results and analyze them.

  6. Effect of changing driving conditions on driver behavior towards design of a safe and efficient traffic system.

    Science.gov (United States)

    2013-12-01

    This simulation-based study explores the effects of different work zone configurations, varying distances : between traffic signs, traffic density and individual differences on drivers behavior. Conventional Lane : Merge (CLM) and Joint Lane Merge...

  7. Excel simulations

    CERN Document Server

    Verschuuren, Gerard M

    2013-01-01

    Covering a variety of Excel simulations, from gambling to genetics, this introduction is for people interested in modeling future events, without the cost of an expensive textbook. The simulations covered offer a fun alternative to the usual Excel topics and include situations such as roulette, password cracking, sex determination, population growth, and traffic patterns, among many others.

  8. Tourism Traffic Management

    OpenAIRE

    Ioan Cosmescu

    2001-01-01

    Tourism traffic must be quantified through four observing units’ categories: custom houses; quartering units; internal and external travel agencies on home teritory; familiy budgets. These observing units allow to quantify the statistical observation’s object and its cyclicity.

  9. Driver behavior in traffic.

    Science.gov (United States)

    2012-02-01

    Existing traffic analysis and management tools do not model the ability of drivers to recognize their environment and respond to it with behaviors that vary according to the encountered driving situation. The small body of literature on characterizin...

  10. Non-Traffic Citations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Non-traffic citations (NTCs, also known as "summary offenses") document low-level criminal offenses where a law enforcement officer or other authorized official...

  11. 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...

  12. Traffic Signal Cycle Lengths

    Data.gov (United States)

    Town of Chapel Hill, North Carolina — Traffic signal location list for the town of Chapel Hill. This data set includes light cycle information as well as as intersection information.The Town of Chapel...

  13. 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.

  14. Traffic pollution and countermeasures of urban traffic environment

    Science.gov (United States)

    He, Yuhong; Zheng, Chaocheng

    2018-01-01

    Background: Traffic environment has become a serious social problem in China currently, therefore, urban traffic environment governance is the requirement to solve this issue because as an important place in people's social life, urban traffic environment shows a strong city's energy. Objective: Based on analysis on social function of city traffic environment and its influence of traffic on urban environment in this paper, the goal to establish a healthy urban traffic environment must be included under the aim of sustainable development eternally and feasible measures were put forward afterwards. Method, result, conclusion and possible applications.

  15. Effect of obstacles on formation of traffic jam in a two-dimensional traffic network

    Science.gov (United States)

    Sakakibara, Takehito; Honda, Yasushi; Horiguchi, Tsuyoshi

    2000-01-01

    We investigate the effect of obstacles on formation of a traffic jam for a traffic flow in a network of city roads. We consider a square lattice of two bonds between two nearest crossings as a network of city roads; we assume that there are three lattice sites in a crossing. We put five decorated sites on each bond between two nearest crossings. A car or an obstacle is assumed to be located on one of these decorated sites or one of the lattice sites. We assume only two types of cars; namely one type of cars move mainly in the positive x direction and change their direction to the positive y direction with a probability and the other type of cars move mainly in the positive y direction and change their direction to the positive x direction with the same probability. One of two lanes is assumed to be used mainly for passing the obstacles or jamming other cars. We set rules for car moving in order to make our traffic-flow model by taking into account all the possible situations. By using numerical simulations, we find that a phase transition from a free-moving phase to a traffic-jam phase is formed more easily for obstacles placed very close to traffic signals in the traffic direction than for those in the other cases.

  16. Effects of Car Accidents on Three-Lane Traffic Flow

    Directory of Open Access Journals (Sweden)

    Jianzhong Chen

    2014-01-01

    Full Text Available A three-lane traffic flow model is proposed to investigate the effect of car accidents on the traffic flow. The model is an extension of the full velocity difference (FVD model by taking into account the lane changing. The extended lane-changing rules are presented to model the lane-changing behaviour. The cases that the car accidents occupy the exterior or interior lane, the medium lane, and two lanes are studied by numerical simulations. The time-space diagrams and the current diagrams are presented, and the traffic jams are investigated. The results show that the car accident has a different effect on the traffic flow when it occupies different lanes. The car accidents have a more serious effect on the whole road when they occupy two lanes. The larger the density is, the greater the influence on the traffic flow becomes.

  17. Vehicle Modeling for Future Generation Transportation Simulation

    Science.gov (United States)

    2009-05-10

    Recent development of inter-vehicular wireless communication technologies have motivated many innovative applications aiming at significantly increasing traffic throughput and improving highway safety. Powerful traffic simulation is an indispensable ...

  18. Global impact of road traffic emissions on tropospheric ozone

    Directory of Open Access Journals (Sweden)

    S. Matthes

    2007-01-01

    Full Text Available Road traffic is one of the major anthropogenic emission sectors for NOx, CO and NMHCs (non-methane hydrocarbons. We applied ECHAM4/CBM, a general circulation model coupled to a chemistry module, which includes higher hydrocarbons, to investigate the global impact of 1990 road traffic emissions on the atmosphere. Improving over previous global modelling studies, which concentrated on road traffic NOx and CO emissions only, we assess the impact of NMHC emissions from road traffic. It is revealed that NMHC emissions from road traffic play a key role for the impact on ozone. They are responsible for (indirect long-range transport of NOx from road traffic via the formation of PAN, which is not found in a simulation without NMHC emissions from road traffic. Long-range transport of NMHC-induced PAN impacts on the ozone distribution in Northern Hemisphere regions far away from the sources, especially in arctic and remote maritime regions. In July total road traffic emissions (NOx, CO and NMHCs contribute to the zonally averaged ozone distribution by more than 12% near the surface in the Northern Hemisphere midlatitudes and arctic latitudes. In January road traffic emissions contribute near the surface in northern and southern extratropics more than 8%. Sensitivity studies for regional emission show that effective transport of road traffic emissions occurs mainly in the free troposphere. In tropical latitudes of America up to an altitude of 200 hPa, global road traffic emissions contribute about 8% to the ozone concentration. In arctic latitudes NMHC emissions from road transport are responsible for about 90% of PAN increase from road transport, leading to a contribution to ozone concentrations of up to 15%.

  19. Analysis of learning curves in the on-the-job training of air traffic controllers

    NARCIS (Netherlands)

    Oprins, E.A.P.B.; Bruggraaff, E.; Roe, R.

    2011-01-01

    This chapter describes a competence-based assessment system, called CBAS, for air traffic control (ATC) simulator and on-the-job training (OJT), developed at Air Traffic Control The Netherlands (LVNL). In contrast with simulator training, learning processes in OJT are difficult to assess, because

  20. Intelligent Traffic Quantification System

    Science.gov (United States)

    Mohanty, Anita; Bhanja, Urmila; Mahapatra, Sudipta

    2017-08-01

    Currently, city traffic monitoring and controlling is a big issue in almost all cities worldwide. Vehicular ad-hoc Network (VANET) technique is an efficient tool to minimize this problem. Usually, different types of on board sensors are installed in vehicles to generate messages characterized by different vehicle parameters. In this work, an intelligent system based on fuzzy clustering technique is developed to reduce the number of individual messages by extracting important features from the messages of a vehicle. Therefore, the proposed fuzzy clustering technique reduces the traffic load of the network. The technique also reduces congestion and quantifies congestion.

  1. 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.

  2. Forecasting of Congestion in Traffic Neural Network Modelling Using Duffing Holmes Oscillator

    Science.gov (United States)

    Mrgole, Anamarija L.; Čelan, Marko; Mesarec, Beno

    2017-10-01

    Forecasting of congestion in traffic with Neural Network is an innovative and new process of identification and detection of chaotic features in time series analysis. With the use of Duffing Holmes Oscillator, we estimate the emergence of traffic flow congestion when the traffic load on a specific section of the road and in a specific time period is close to exceeding the capacity of the road infrastructure. The orientated model is validated in six locations with a specific requirement. The paper points out the issue of importance of traffic flow forecasting and simulations for preventing or rerouting possible short term traffic flow congestions.

  3. Lane Changing Control to Reduce Traffic Load Effect on Long-Span Bridges

    OpenAIRE

    Caprani, Colin C; Enright, Bernard; Carey, Colm

    2012-01-01

    Long span bridges are critical parts of a nation’s infrastructure network and congested traffic loading is the governing form of traffic loading. Groups of trucks travelling in conveys are created when fast-er moving vehicles, such as cars, change lane. In this research the authors investigate how the control of these lane-changing events can help reduce the traffic load effects on long span bridges. Real traffic data is used to simulate a traffic stream on a virtual road and bridge using a m...

  4. A generic solution for unwanted traffic control through trust management

    Science.gov (United States)

    Yan, Zheng; Kantola, Raimo; Shen, Yue

    2014-01-01

    The Internet has dramatically changed our daily life. But it is also bogged down by unwanted traffic, which is malicious, harmful or unexpected for its receivers. In order to control the unwanted traffic over the Internet, especially the mobile Internet, in this paper, we propose a generic unwanted traffic control (UTC) solution through trust management. It can control unwanted traffic from its source to destinations in a personalized manner according to trust evaluation at a Global Trust Operator, traffic and behavior analysis at hosts and traffic observation in the Internet. Thus, it can conduct UTC by integrating distributed and centralized functions and supporting both defensive and offensive approaches. Simulation based evaluation shows that the solution is effective with regard to accuracy and efficiency for botnet intrusion and DDoS intrusion via reflectors. It is also robust against a number of malicious system attacks, such as hide evidence attack, bad mouthing attack, on-off attack, malicious attack by an Internet Service Provider and combinations of the above, playing in conjunction with traffic intrusions. Meanwhile, the solution can provide a personalized UTC based on unwanted traffic detection behaviors.

  5. A SPATIOTEMPORAL APPROACH FOR HIGH RESOLUTION TRAFFIC FLOW IMPUTATION

    Energy Technology Data Exchange (ETDEWEB)

    Han, Lee [University of Tennessee, Knoxville (UTK); Chin, Shih-Miao [ORNL; Hwang, Ho-Ling [ORNL

    2016-01-01

    Along with the rapid development of Intelligent Transportation Systems (ITS), traffic data collection technologies have been evolving dramatically. The emergence of innovative data collection technologies such as Remote Traffic Microwave Sensor (RTMS), Bluetooth sensor, GPS-based Floating Car method, automated license plate recognition (ALPR) (1), etc., creates an explosion of traffic data, which brings transportation engineering into the new era of Big Data. However, despite the advance of technologies, the missing data issue is still inevitable and has posed great challenges for research such as traffic forecasting, real-time incident detection and management, dynamic route guidance, and massive evacuation optimization, because the degree of success of these endeavors depends on the timely availability of relatively complete and reasonably accurate traffic data. A thorough literature review suggests most current imputation models, if not all, focus largely on the temporal nature of the traffic data and fail to consider the fact that traffic stream characteristics at a certain location are closely related to those at neighboring locations and utilize these correlations for data imputation. To this end, this paper presents a Kriging based spatiotemporal data imputation approach that is able to fully utilize the spatiotemporal information underlying in traffic data. Imputation performance of the proposed approach was tested using simulated scenarios and achieved stable imputation accuracy. Moreover, the proposed Kriging imputation model is more flexible compared to current models.

  6. 2016 Traffic Safety Culture Index

    Science.gov (United States)

    ... SEARCH Driver Behavior & Performance 2016 Traffic Safety Culture Index This report presents the results of our annual Traffic Safety Culture Index survey, providing data on the attitudes and behaviors ...

  7. Texas traffic thermostat marketing package.

    Science.gov (United States)

    2013-04-01

    The traffic thermostat decision tool is built to help guide the user through a logical, step-wise, process of examining potential changes to their Manage Lane/toll facility. : **NOTE: Project Title: Application of the Traffic Thermostat Framework. Ap...

  8. Texas traffic thermostat software tool.

    Science.gov (United States)

    2013-04-01

    The traffic thermostat decision tool is built to help guide the user through a logical, step-wise, process of examining potential changes to their Manage Lane/toll facility. : **NOTE: Project Title: Application of the Traffic Thermostat Framework. Ap...

  9. Physical modeling of traffic with stochastic cellular automata

    Energy Technology Data Exchange (ETDEWEB)

    Schreckenberg, M. [Univ. Duisburg (Germany); Nagel, K. [Los Alamos National Lab., NM (United States)]|[Santa Fe Inst., NM (United States)

    1995-09-01

    A new type of probabilistic cellular automaton for the physical description of single and multilane traffic is presented. In this model space, time and the velocity of the cars are represented by integer numbers (as usual in cellular automata) with local update rules for the velocity. The model is very efficient for both numerical simulations and analytical investigations. The numerical results from extensive simulations reproduce very well data taken from real traffic (e.g. fundamental diagrams). Several analytical results for the model are presented as well as new approximation schemes for stationary traffic. In addition the relation to continuum hydrodynamic theory (Lighthill-Whitham) and the follow-the-leader models is discussed. The model is part of an interdisciplinary research program in Northrhine-Westfalia (``NRW Forschungsverbund Verkehrssimulation``) for the construction of a large scale microsimulation model for network traffic, supported by the government of NRW.

  10. Criterion for traffic phases in single vehicle data and empirical test of a microscopic three-phase traffic theory

    International Nuclear Information System (INIS)

    Kerner, Boris S; Klenov, Sergey L; Hiller, Andreas

    2006-01-01

    Based on empirical and numerical microscopic analyses, the physical nature of a qualitatively different behaviour of the wide moving jam phase in comparison with the synchronized flow phase-microscopic traffic flow interruption within the wide moving jam phase-is found. A microscopic criterion for distinguishing the synchronized flow and wide moving jam phases in single vehicle data measured at a single freeway location is presented. Based on this criterion, empirical microscopic classification of different local congested traffic states is performed. Simulations made show that the microscopic criterion and macroscopic spatiotemporal objective criteria lead to the same identification of the synchronized flow and wide moving jam phases in congested traffic. Microscopic models in the context of three-phase traffic theory have been tested based on the microscopic criterion for the phases in congested traffic. It is found that microscopic three-phase traffic models can explain both microscopic and macroscopic empirical congested pattern features. It is obtained that microscopic frequency distributions for vehicle speed difference as well as fundamental diagrams and speed correlation functions can depend on the spatial co-ordinate considerably. It turns out that microscopic optimal velocity (OV) functions and time headway distributions are not necessarily qualitatively different, even if local congested traffic states are qualitatively different. The reason for this is that important spatiotemporal features of congested traffic patterns are lost in these as well as in many other macroscopic and microscopic traffic characteristics, which are widely used as the empirical basis for a test of traffic flow models, specifically, cellular automata traffic flow models

  11. A Network Traffic Control Enhancement Approach over Bluetooth Networks

    DEFF Research Database (Denmark)

    Son, L.T.; Schiøler, Henrik; Madsen, Ole Brun

    2003-01-01

    This paper analyzes network traffic control issues in Bluetooth data networks as convex optimization problem. We formulate the problem of maximizing of total network flows and minimizing the costs of flows. An adaptive distributed network traffic control scheme is proposed as an approximated...... as capacity limitations and flow requirements in the network. Simulation shows that the performance of Bluetooth networks could be improved by applying the adaptive distributed network traffic control scheme...... solution of the stated optimization problem that satisfies quality of service requirements and topologically induced constraints in Bluetooth networks, such as link capacity and node resource limitations. The proposed scheme is decentralized and complies with frequent changes of topology as well...

  12. Multilane Traffic Flow Modeling Using Cellular Automata Theory

    Science.gov (United States)

    Chechina, Antonina; Churbanova, Natalia; Trapeznikova, Marina

    2018-02-01

    The paper deals with the mathematical modeling of traffic flows on urban road networks using microscopic approach. The model is based on the cellular automata theory and presents a generalization of the Nagel-Schreckenberg model to a multilane case. The created program package allows to simulate traffic on various types of road fragments (T or X type intersection, strait road elements, etc.) and on road networks that consist of these elements. Besides that, it allows to predict the consequences of various decisions regarding road infrastructure changes, such as: number of lanes increasing/decreasing, putting new traffic lights into operation, building new roads, entrances/exits, road junctions.

  13. Pricing of Traffic Light Options and other Correlation Derivatives

    DEFF Research Database (Denmark)

    Kokholm, Thomas

    companies stay solvent in the traffic light stress test system introduced by the Danish Financial Supervisory Authorities in 2001. Similar systems are now being implemented in several other European countries. A pricing approach for general payoffs is presented and illustrated with simulation via......This paper considers derivatives with payoffs that depend on a stock index and underlying LIBOR rates. A traffic light option pricing formula is derived under lognormality assumptions on the underlying processes. The traffic light option is aimed at the Danish life and pension sector to help...

  14. Pricing of Traffic Light Options and other Hybrid Products

    DEFF Research Database (Denmark)

    Kokholm, Thomas

    2009-01-01

    companies stay solvent in the traffic light stress test system introduced by the Danish Financial Supervisory Authorities in 2001. Similar systems are now being implemented in several other European countries. A pricing approach for general payoffs is presented and illustrated with simulation via......This paper considers derivatives with payoffs that depend on a stock index and underlying LIBOR rates. A traffic light option pricing formula is derived under lognormality assumptions on the underlying processes. The traffic light option is aimed at the Danish life and pension sector to help...

  15. Traffic Multiresolution Modeling and Consistency Analysis of Urban Expressway Based on Asynchronous Integration Strategy

    Directory of Open Access Journals (Sweden)

    Liyan Zhang

    2017-01-01

    Full Text Available The paper studies multiresolution traffic flow simulation model of urban expressway. Firstly, compared with two-level hybrid model, three-level multiresolution hybrid model has been chosen. Then, multiresolution simulation framework and integration strategies are introduced. Thirdly, the paper proposes an urban expressway multiresolution traffic simulation model by asynchronous integration strategy based on Set Theory, which includes three submodels: macromodel, mesomodel, and micromodel. After that, the applicable conditions and derivation process of the three submodels are discussed in detail. In addition, in order to simulate and evaluate the multiresolution model, “simple simulation scenario” of North-South Elevated Expressway in Shanghai has been established. The simulation results showed the following. (1 Volume-density relationships of three submodels are unanimous with detector data. (2 When traffic density is high, macromodel has a high precision and smaller error and the dispersion of results is smaller. Compared with macromodel, simulation accuracies of micromodel and mesomodel are lower but errors are bigger. (3 Multiresolution model can simulate characteristics of traffic flow, capture traffic wave, and keep the consistency of traffic state transition. Finally, the results showed that the novel multiresolution model can have higher simulation accuracy and it is feasible and effective in the real traffic simulation scenario.

  16. Traffic Engineering in Metro Ethernet

    OpenAIRE

    Padmaraj Nair; Suku Nair; Girish Chiruvolu

    2010-01-01

    Traffic engineering is one of the major issues that has to be addressed in Metro Ethernet networks for quality of service and efficient resource utilization. This paper aims at understanding the relevant issues and outlines novel algorithms for multipoint traffic engineering in Metro Ethernet. We present an algorithmic solution for traffic engineering in Metro Ethernet using optimal multiple spanning trees. This iterative approach distributes traffic across the network uniformly without overl...

  17. Framework for Traffic Congestion Prediction

    NARCIS (Netherlands)

    Zaki, J.F.W.; Ali-Eldin, A.M.T.; Hussein, S.E.; Saraya, S.F.; Areed, F.F.

    2016-01-01

    Traffic Congestion is a complex dilemma facing most major cities. It has undergone a lot of research since the early 80s in an attempt to predict traffic in the short-term. Recently, Intelligent Transportation Systems (ITS) became an integral part of traffic research which helped in modeling and

  18. Traffic light intensity meter, TIM®

    NARCIS (Netherlands)

    Leden, N. van der; Varkevisser, J.; Vroom, J. de; Oijen, T van

    2005-01-01

    The intensity of traffic lights decreases over time as a result of pollution and ageing. The Dutch Traffic Research Centre of the Ministry of Transport, Public Works and Water Management is searching for a convenient method for measuring the luminous intensity of traffic lights on the road, in order

  19. Traffic Flow Visualization and Control

    National Research Council Canada - National Science Library

    Larson, Robert

    1999-01-01

    .... Vehicle count, flow speed, headway, queue length and occupancy are some of the information that can be collected. The processed traffic data is then sent to a control center for further analysis and used by traffic operators attempting to analyze traffic on the highway.

  20. Traffic sign detection and analysis

    DEFF Research Database (Denmark)

    Møgelmose, Andreas; Trivedi, Mohan M.; Moeslund, Thomas B.

    2012-01-01

    Traffic sign recognition (TSR) is a research field that has seen much activity in the recent decade. This paper introduces the problem and presents 4 recent papers on traffic sign detection and 4 recent papers on traffic sign classification. It attempts to extract recent trends in the field and t...

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

    OpenAIRE

    C?rdenas-Ben?tez, N?stor; Aquino-Santos, Ra?l; Maga?a-Espinoza, Pedro; Aguilar-Velazco, Jos?; Edwards-Block, Arthur; Medina Cass, Aldo

    2016-01-01

    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 ...

  2. Inaccuracy in traffic forecasts

    DEFF Research Database (Denmark)

    Flyvbjerg, Bent; Holm, Mette K. Skamris; Buhl, Søren Ladegaard

    2006-01-01

    , the difference between actual and forecasted traffic is more than +-20%; for 25% of road projects, the difference is larger than +-40%. Forecasts for roads are more accurate and more balanced than for rail, with no significant difference between the frequency of inflated versus deflated forecasts. But for both...

  3. Alcohol and Traffic Safety.

    Science.gov (United States)

    Dickman, Frances Baker, Ed.

    1988-01-01

    Seven papers discuss current issues and applied social research concerning alcohol traffic safety. Prevention, policy input, methodology, planning strategies, anti-drinking/driving programs, social-programmatic orientations of Mothers Against Drunk Driving, Kansas Driving Under the Influence Law, New Jersey Driving While Impaired Programs,…

  4. Impact of traffic noise on railway traffic safety

    Directory of Open Access Journals (Sweden)

    Zdravko TOŠ

    2008-01-01

    Full Text Available Traffic noise is one of the dominant factors of ergo-assessment. The harmful impact of traffic noise on the engine driver as target group can be studied in isolation from other ergo-assessment factors only in the initial phase of research. The simultaneous action of several related factors in the system of ergo-assessment factors has cumulative effect on the perception and psychomotoric status of the railway traffic participants in the appropriate traffic situation. The initial partial research of traffic noise by a combination of several scientific methods needs to be eventually upgraded by studying the relations among several concurrent important or dominant ergo-assessment factors.

  5. Simulation

    DEFF Research Database (Denmark)

    Gould, Derek A; Chalmers, Nicholas; Johnson, Sheena J

    2012-01-01

    Recognition of the many limitations of traditional apprenticeship training is driving new approaches to learning medical procedural skills. Among simulation technologies and methods available today, computer-based systems are topical and bring the benefits of automated, repeatable, and reliable...... performance assessments. Human factors research is central to simulator model development that is relevant to real-world imaging-guided interventional tasks and to the credentialing programs in which it would be used....

  6. Modelling of road traffic for traffic flow optimization of modern regional center as an example of Odessa

    Directory of Open Access Journals (Sweden)

    S.V. Myronenko

    2016-12-01

    Full Text Available At present sharply there is a problem of traffic management especially in big cities. The increase in the number of vehicles, both personal and public, led to congestion of city roads, many hours of traffic jams, difficulty of movement of pedestrians, increase the number of accidents, etc. Aim: The aim of the study is to evaluate the possibility of using simulation models to solve problems of analysis and optimization of traffic flows. To achieve this goal in a simulation environment the data base of the transport network will be developed. Materials and Methods: The problem of analysis and optimization of traffic flow is considered by the example of the city of Odessa (Ukraine, the results and recommendations can be easily adapted for other cities of Ukraine, and for the cities of most countries of the former socialist bloc. Features of transport systems make it impossible to build an adequate analytical model to explore options for the management of the system and its characteristic in different conditions. At the same time simulation modelling as a method to study such objects is a promising for the solution to this problem. As a simulation environment an OmniTRANS package as a universal tool for modeling of discrete, continuous and hybrid systems. Results: With OmniTRANS programs the model of traffic in Odessa was derived and the intensity of the traffic flow. B first approximation the transport network of the central district of the city was considered and built; without calibration and simulation it was developed a database of elements of the transport network and shown how it can be used to solve problems of analysis and optimization of traffic flows. Models constructed from elements of created database, allows you to change the level of detail of the simulated objects and phenomena, thereby obtaining models as macro and micro level.

  7. An Intelligent Vehicular Traffic Signal Control System with State Flow Chart Design and FPGA Prototyping

    Directory of Open Access Journals (Sweden)

    UMAIR SAEEDSOLANGI

    2017-04-01

    Full Text Available The problem of vehicular traffic congestion is a persistent constraint in the socio-economic development of Pakistan. This paper presents design and implementation of an intelligent traffic controller based on FPGA (Field Programmable Gate Array to provide an efficient traffic management by optimizing functioning of traffic lights which will result in minimizing traffic congestion at intersections. The existent Traffic Signal system in Pakistan is fixed-time based and offers only Open Loop method for Traffic Control. The Intelligent Traffic Controller presented here uses feedback sensors to read the Traffic density present at a four way intersection to provide an efficient alternative for better supervisory Control of Traffic flow. The traffic density based control logic has been developed in a State Flow Chart for improved visualization of State Machine based operation, and implemented as a Subsystem in Simulink and transferred into VHDL (Hardware Description Language code using HDL Coder for reducing development time and time to market, which are essential to capitalize Embedded Systems Market. The VHDL code is synthesized with Altera QUARTUS, simulated timing waveform is obtained to verify correctness of the algorithm for different Traffic Scenarios. For implementation purpose estimations were obtained for Cyclone-III and Stratix-III.

  8. An intelligent vehicular traffic signal control system with state flow chart design and fpga prototyping

    International Nuclear Information System (INIS)

    Solangi, U.S.; Memon, T.D.; Noonari, A.S.; Ansari, O.A.

    2017-01-01

    The problem of vehicular traffic congestion is a persistent constraint in the socio-economic development of Pakistan. This paper presents design and implementation of an intelligent traffic controller based on FPGA (Field Programmable Gate Array) to provide an efficient traffic management by optimizing functioning of traffic lights which will result in minimizing traffic congestion at intersections. The existent Traffic Signal system in Pakistan is fixed-time based and offers only Open Loop method for Traffic Control. The Intelligent Traffic Controller presented here uses feedback sensors to read the Traffic density present at a four way intersection to provide an efficient alternative for better supervisory Control of Traffic flow. The traffic density based control logic has been developed in a State Flow Chart for improved visualization of State Machine based operation, and implemented as a Subsystem in Simulink and transferred into VHDL (Hardware Description Language) code using HDL Coder for reducing development time and time to market, which are essential to capitalize Embedded Systems Market. The VHDL code is synthesized with Altera QUARTUS, simulated timing waveform is obtained to verify correctness of the algorithm for different Traffic Scenarios. For implementation purpose estimations were obtained for Cyclone-III and Stratix-III. (author)

  9. Traffic Accident Propagation Properties and Control Measures for Urban Links Based on Cellular Automata

    Directory of Open Access Journals (Sweden)

    Xian-sheng Li

    2013-01-01

    Full Text Available With the rapid development of urban transport and the sharp increase in vehicle population, traffic accidents form one of the most important causes of urban traffic congestion other than the imbalance between traffic supply and demand. Traffic congestion causes severe problems, such as environment contamination and energy dissipation. Therefore, it would be useful to analyze the congestion propagation characteristics after traffic accidents. Numerical analysis and computer simulation were two of the typical methods used at present to study the traffic congestion propagation properties. The latter was more widespread as it is more consistent with the actual traffic flow and more visual than the former. In this paper, an improved cellular automata (CA model was presented to analyze traffic congestion propagation properties and to evaluate control strategies. In order to apply them to urban traffic flow simulation, the CA models have been improved and expanded on. Computer simulations were built for congestion not only extending to the upstream intersection, but also the upstream intersection and the entire road network, respectively. Congestion propagation characteristics after road traffic accidents were obtained, and controls of different severities and durations were analyzed. The results provide the theoretical foundation and practical means for the control of congestion.

  10. City traffic jam relief by stochastic resonance

    Science.gov (United States)

    Castillo, F.; Toledo, B. A.; Muñoz, V.; Rogan, J.; Zarama, R.; Kiwi, M.; Valdivia, J. A.

    2014-06-01

    We simulate traffic in a city by means of the evolution of a row of interacting cars, using a cellular automaton model, in a sequence of traffic lights synchronized by a "green wave". When our initial condition is a small density jammed state, its evolution shows the expected scaling laws close to the synchronization resonance, with a uniform car density along the street. However, for an initial large density jammed state, we observe density variations along the streets, which results in the breakdown of the scaling laws. This spatial disorder corresponds to a different attractor of the system. As we include velocity perturbations in the dynamics of the cars, all these attractors converge to a statistically equivalent system for all initial jammed densities. However, this emergent state shows a stochastic resonance-like behavior in which the average traffic velocity increases with respect to that of the system without noise, for several initial jammed densities. This result may help in the understanding of dynamics of traffic jams in cities.

  11. Virtual Reality Game Education to Learn Traffic Regulation

    Directory of Open Access Journals (Sweden)

    Andru Deva Lukito

    2017-10-01

    Full Text Available Abstract – Traffic accident has become number 3 of children death cause in the world according to WHO[1]. Traffic accident that involve children often caused by their own by breaking the law or regulation. Therefor education about traffic regulation and law including traffic sign and its meaning must be given to children early. Because education means process to change a person or a group attitude and behavior in order to make them mature through teaching and training [2]. One of them that can be used is digital media.  One of interactive digital media is digital game, various form of digital game start from 2D, 2.5D, 3D with many point of view and new technology. VR (Virtual Reality as new digital media where alternate reality exist to test various theory without any real consequences, according to Greenbaum “Virtual Reality is an alternate world filled with computer-generated images that respond to human movements. These simulated environments are usually visited with the aid of an expensive data suit which features stereophonic video goggles and fiber-optic data gloves”[3]. Greenbaum statement before were make VR suitable to test traffic law and regulation and educate kid to obey the traffic sign and regulation without real consequences from real world. This Journal contain the result of using virtual reality as traffic regulation education media. Education material that arranged consisting traffic sign that appear on the road and safety riding gear. Keywords – Virtual Reality, Traffic sign, Road traffic, children, education

  12. Simulation

    CERN Document Server

    Ross, Sheldon

    2006-01-01

    Ross's Simulation, Fourth Edition introduces aspiring and practicing actuaries, engineers, computer scientists and others to the practical aspects of constructing computerized simulation studies to analyze and interpret real phenomena. Readers learn to apply results of these analyses to problems in a wide variety of fields to obtain effective, accurate solutions and make predictions about future outcomes. This text explains how a computer can be used to generate random numbers, and how to use these random numbers to generate the behavior of a stochastic model over time. It presents the statist

  13. An Approach to Modeling the Impact of Traffic Incident on Urban Expressway

    Directory of Open Access Journals (Sweden)

    Yaping Li

    2015-01-01

    Full Text Available To identify network bottlenecks of urban expressway effectively is a foundational work for improving network traffic condition and preventing traffic congestion. This study proposes a methodology to estimate the impact of traffic incident on urban expressway on the basis of modified cell transmission model. The metastable state was taken into account in the proposed method to reflect the actual operating state of traffic flow on urban expressway as much as possible. Regarding the location of traffic incident, the method of cell restructuring settings was discussed. We then proceed to introduce a new concept of the effected length in a given time period as the evaluation indicator to directly depict the influence of traffic incident. The proposed method was tested on a 6516-meter urban expressway section of west second ring road in Beijing. The simulation results indicated that the proposed methodology performs well to predict the impact of traffic incident on urban expressway.

  14. Delay-feedback control strategy for reducing CO2 emission of traffic flow system

    Science.gov (United States)

    Zhang, Li-Dong; Zhu, Wen-Xing

    2015-06-01

    To study the signal control strategy for reducing traffic emission theoretically, we first presented a kind of discrete traffic flow model with relative speed term based on traditional coupled map car-following model. In the model, the relative speed difference between two successive running cars is incorporated into following vehicle's acceleration running equation. Then we analyzed its stability condition with discrete control system stability theory. Third, we designed a delay-feedback controller to suppress traffic jam and decrease traffic emission based on modern controller theory. Last, numerical simulations are made to support our theoretical results, including the comparison of models' stability analysis, the influence of model type and signal control on CO2 emissions. The results show that the temporal behavior of our model is superior to other models, and the traffic signal controller has good effect on traffic jam suppression and traffic CO2 emission, which fully supports the theoretical conclusions.

  15. Development of a Gridded Maritime Traffic DB for e-Navigation

    Directory of Open Access Journals (Sweden)

    Kwang-Il Kim

    2014-12-01

    Full Text Available In the era of e-Navigation, it is important to deliver maritime traffic information from a shore based station to all navigating vessels. However, in a vessel boarding system, there is a limit to the amount of raw traffic data that can be processed. In this paper, we used the Automatic Identification System (AIS data as metadata to build up the maritime traffic gridded database by projecting traffic data on a geographic coordinate system. In order to apply this database to the image layer for transferring to the ship efficiently, we have developed a maritime traffic display layer and route traffic information layer. All simulated data was collected and analyzed with the AIS in a Vessel Traffic Service(VTS center.

  16. 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...... have not yet been seen for the detection sub-problem of TLR, where detection is dominated by methods based on heuristic models. Evaluation of existing systems is currently limited primarily to small local datasets. In order to provide a common basis for comparing future TLR research an extensive public...... 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...

  17. Assessing Road Traffic Expression

    Directory of Open Access Journals (Sweden)

    Fábio Silva

    2014-12-01

    Full Text Available Road traffic is a problem which is increasing in cities with large population. Unrelated to this fact the number of portable and wearable devices has also been increasing throughout the population of most countries. With this advent, the capacity to monitor and register data about people habits and locations as well as more complex data such as intensity and strength of movements has created an opportunity to contribute to the general wealth and comfort within these environments. Ambient Intelligence and Intelligent Decision Making processes can benefit from the knowledge gathered by these devices to improve decisions on everyday tasks such as deciding navigation routes by car, bicycle or other means of transportation and avoiding route perils. The concept of computational sustainability may also be applied to this problem. Current applications in this area demonstrate the usefulness of real time system that inform the user of certain conditions in the surrounding area. On the other hand, the approach presented in this work aims to describe models and approaches to automatically identify current states of traffic inside cities and use methods from computer science to improve overall comfort and the sustainability of road traffic both with the user and the environment in mind. Such objective is delivered by analyzing real time contributions from those mobile ubiquitous devices to identifying problematic situations and areas under a defined criteria that have significant influence towards a sustainable use of the road transport infrastructure.

  18. Effects of traffic noise

    Energy Technology Data Exchange (ETDEWEB)

    Gottlob, D.

    1986-02-01

    One of the main sources of noise is road traffic. In 1984 there were over 25 million cars, 1.2 million lorries, 1.3 million motor cycles and 1.6 million mopeds using our roads. Opinion polls showed that 21% of the population felt that they were affected by traffic noise as a nuisance factor. An outline of the effects of this noise on the affected population is given, illustrated by diagrams. Details about noise emissions (drive-past level) of the different types of vehicles in city traffic are stated and the effects of noise described. The author goes into the nuisance effect (noise is not a physical factor, but a psychosocial one), changes in behaviour (ways of speaking, reduction of stress on households in proportion to rising income and higher educational levels) and the consequences for health (the reaction of the body to noise is primarily a consequence of the psychosomatic organisation of ow bodies). In conclusion, the author deals with the subjective efficiency of noise protection measures. (HWJ).

  19. Traffic Dynamics of Computer Networks

    Science.gov (United States)

    Fekete, Attila

    2008-10-01

    Two important aspects of the Internet, namely the properties of its topology and the characteristics of its data traffic, have attracted growing attention of the physics community. My thesis has considered problems of both aspects. First I studied the stochastic behavior of TCP, the primary algorithm governing traffic in the current Internet, in an elementary network scenario consisting of a standalone infinite-sized buffer and an access link. The effect of the fast recovery and fast retransmission (FR/FR) algorithms is also considered. I showed that my model can be extended further to involve the effect of link propagation delay, characteristic of WAN. I continued my thesis with the investigation of finite-sized semi-bottleneck buffers, where packets can be dropped not only at the link, but also at the buffer. I demonstrated that the behavior of the system depends only on a certain combination of the parameters. Moreover, an analytic formula was derived that gives the ratio of packet loss rate at the buffer to the total packet loss rate. This formula makes it possible to treat buffer-losses as if they were link-losses. Finally, I studied computer networks from a structural perspective. I demonstrated through fluid simulations that the distribution of resources, specifically the link bandwidth, has a serious impact on the global performance of the network. Then I analyzed the distribution of edge betweenness in a growing scale-free tree under the condition that a local property, the in-degree of the "younger" node of an arbitrary edge, is known in order to find an optimum distribution of link capacity. The derived formula is exact even for finite-sized networks. I also calculated the conditional expectation of edge betweenness, rescaled for infinite networks.

  20. Effect of current vehicle’s interruption on traffic stability in cooperative car-following theory

    Science.gov (United States)

    Zhang, Geng; Liu, Hui

    2017-12-01

    To reveal the impact of the current vehicle’s interruption information on traffic flow, a new car-following model with consideration of the current vehicle’s interruption is proposed and the influence of the current vehicle’s interruption on traffic stability is investigated through theoretical analysis and numerical simulation. By linear analysis, the linear stability condition of the new model is obtained and the negative influence of the current vehicle’s interruption on traffic stability is shown in the headway-sensitivity space. Through nonlinear analysis, the modified Korteweg-de Vries (mKdV) equation of the new model near the critical point is derived and it can be used to describe the propagating behavior of the traffic density wave. Finally, numerical simulation confirms the analytical results, which shows that the current vehicle’s interruption information can destabilize traffic flow and should be considered in real traffic.

  1. Modeling the Environmental Impact of Air Traffic Operations

    Science.gov (United States)

    Chen, Neil

    2011-01-01

    There is increased interest to understand and mitigate the impacts of air traffic on the climate, since greenhouse gases, nitrogen oxides, and contrails generated by air traffic can have adverse impacts on the climate. The models described in this presentation are useful for quantifying these impacts and for studying alternative environmentally aware operational concepts. These models have been developed by leveraging and building upon existing simulation and optimization techniques developed for the design of efficient traffic flow management strategies. Specific enhancements to the existing simulation and optimization techniques include new models that simulate aircraft fuel flow, emissions and contrails. To ensure that these new models are beneficial to the larger climate research community, the outputs of these new models are compatible with existing global climate modeling tools like the FAA's Aviation Environmental Design Tool.

  2. Compliance with traffic laws by traffic police officers, non-traffic police officers, and civilian drivers.

    Science.gov (United States)

    Rosenbloom, Tova; Pereg, Avihu; Perlman, Amotz

    2014-01-01

    The policy of a public organization, such as police, may shape the norms and the behavior of the citizens. In line with this, police officers are expected by the public to comply with traffic laws and serve as an example for the citizenry. This study used on-site observations of civilian and police driver, comparing police officers' compliance with traffic laws to that of civilians. We compared driver compliance with traffic laws for drivers in 3 groups of vehicles: traffic police cars, non-traffic police cars, and civilian cars. Four hundred sixty-six vehicles were observed and compared by vehicle type and whether a uniform was worn by the driver. We observed safety belt usage, signaling before turning, cellular phone usage, and giving way to traffic (measured by merging time). We found evidence that generally drivers in police cars use seat belts while driving more that drivers in civilian cars do. In particular, more traffic police car drivers used seat belts than non-traffic police car drivers do. In addition, drivers in civilian cars and non-traffic police cars waited longer periods of time before merging right into traffic compared to traffic police car drivers. Our findings supported the notion that on-duty police officers, and traffic police officers in particular, adhere more closely to traffic laws compared to civilian drivers. As the general public compliance with traffic laws is affected by the police perceived legitimacy, the publication of these results can both boost public cooperation with the police and encourage police officers to continue providing positive role models to the public.

  3. Model for Detection and Classification of DDoS Traffic Based on Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    D. Peraković

    2017-06-01

    Full Text Available Detection of DDoS (Distributed Denial of Service traffic is of great importance for the availability protection of services and other information and communication resources. The research presented in this paper shows the application of artificial neural networks in the development of detection and classification model for three types of DDoS attacks and legitimate network traffic. Simulation results of developed model showed accuracy of 95.6% in classification of pre-defined classes of traffic.

  4. An Adaptive Fuzzy-Logic Traffic Control System in Conditions of Saturated Transport Stream

    Science.gov (United States)

    Marakhimov, A. R.; Igamberdiev, H. Z.; Umarov, Sh. X.

    2016-01-01

    This paper considers the problem of building adaptive fuzzy-logic traffic control systems (AFLTCS) to deal with information fuzziness and uncertainty in case of heavy traffic streams. Methods of formal description of traffic control on the crossroads based on fuzzy sets and fuzzy logic are proposed. This paper also provides efficient algorithms for implementing AFLTCS and develops the appropriate simulation models to test the efficiency of suggested approach. PMID:27517081

  5. Networks and their traffic in multiplayer games

    Directory of Open Access Journals (Sweden)

    Cristian Andrés Melo López

    2016-06-01

    Full Text Available Computer games called multiplayer real-time, or (MCG are at the forefront of the use of the possibilities of the network. Research on this subject have been made for military simulations, virtual reality systems, computer support teamwork, the solutions diverge on the problems posed by MCG. With this in mind, this document provides an overview of the four issues affecting networking at the MCG. First, network resources (bandwidth, latency and computing capacity, together with the technical limits within which the MCG must operate. Second, the distribution concepts include communication architectures (peer-to-peer, client / server, server / network, and data and control architectures (centralized, distributed and reproduced .Thirdly, scalability allows the MCG to adapt to changes in parameterization resources. Finally, security is intended to fend off the traps and vandalism, which are common in online games; to check traffic, particularly these games we decided to take the massively multiplayer game League of Legends, a scene corresponding to a situation of real life in a network of ADSL access network is deployed has been simulated by using NS2 Three variants of TCP, it means SACK TCP, New Reno TCP, and TCP Vegas, have been considered for the cross traffic. The results show that TCP Vegas is able to maintain a constant speed while racing against the game traffic, since it avoids the packet loss and the delays in the tail caused by high peaks, without increasing the size of the sender window. SACK TCP and TCP New Reno, on the other hand, tend to increase continuously the sender window size, which could allow a greater loss of packages and also to cause unwanted delays for the game traffic.

  6. Multicast traffic grooming in flexible optical WDM networks

    Science.gov (United States)

    Patel, Ankitkumar N.; Ji, Philip N.; Jue, Jason P.; Wang, Ting

    2012-12-01

    In Metropolitan Area Networks (MANs), point-to-multipoint applications, such as IPTV, video-on-demand, distance learning, and content distribution, can be efficiently supported through light-tree-based multicastcommunications instead of lightpath-based unicast-communications. The application of multicasting for such traffic is justified by its inherent benefits of reduced control and management overhead and elimination of redundant resource provisioning. Supporting such multicast traffic in Flexible optical WDM (FWDM) networks that can provision light-trees using optimum amount of spectrum within flexible channel spacing leads to higher wavelength and spectral efficiencies compared to the conventional ITU-T fixed grid networks. However, in spite of such flexibility, the residual channel capacity of stranded channels may not be utilized if the network does not offer channels with arbitrary line rates. Additionally, the spectrum allocated to guard bands used to isolate finer granularity channels remains unutilized. These limitations can be addressed by using traffic grooming in which low-rate multicast connections are aggregated and switched over high capacity light-trees. In this paper, we address the multicast traffic grooming problem in FWDM networks, and propose a novel auxiliary graph-based algorithm for the first time. The performance of multicast traffic grooming is evaluated in terms of spectral, cost, and energy efficiencies compared to lightpath-based transparent FWDM networks, lightpathbased traffic grooming-capable FWDM networks, multicast-enabled transparent FWDM networks, and multicast traffic grooming-capable fixed grid networks. Simulation results demonstrate that multicast traffic grooming in FWDM networks not only improves spectral efficiency, but also cost, and energy efficiencies compared to other multicast traffic provisioning approaches of FWDM and fixed grid networks.

  7. Simulating the Risk of Bird Strikes

    NARCIS (Netherlands)

    Metz, I.C.; Ellerbroek, J.; Muhlhausen, Thorsten; Kügler, D.; Hoekstra, J.M.

    2017-01-01

    This paper presents a fast-time simulation environment for assessing the risk of bird strikes in aviation. An existing air traffic simulator was enhanced in order to simulate air and bird traffic simultaneously and to recognize collisions between birds and aircraft. Furthermore, a method was

  8. OPTIMASI BANDWITH MENGGUNAKAN TRAFFIC SHAPPING

    Directory of Open Access Journals (Sweden)

    Imam Riadi

    2010-01-01

    Full Text Available Perkembangan layanan komunikasi telah berkembang sangat pesat. Salah satunya adalah pemanfaatan penggunaan bandwith untuk mengakases jaringan Internet. Traffic shapping bandwidth dapat memberikan efesiensi dalam hal pemanfaatan bandwidth pada instansi yang melakukan manajemen dalam lalulintas jaringannya. Metode yang digunakan dalam penelitian ini adalah metode literatur yaitu metode pengumpulan data yang dilakukan dengan mengumpulkan sumber- sumber data yang terkait dan metode eksperimen yaitu melakukan penelitian dengan mengkonfigurasi Mikrotik RouterOS untuk melakukan traffic shapping bandwidth. Hasil penelitian ini adalah router yang dapat melakukan traffic shapping sehingga kualitas koneksi menjadi lebih baik untuk mengakses dan mengambil data dari sebuah website. Kata kunci : Optimasi, Bandwith, Traffic Shapping, MikroTik. 

  9. Bicycle traffic in urban areas

    Directory of Open Access Journals (Sweden)

    Anđelković Zorica

    2015-01-01

    Full Text Available Cycling is a term describing the use of bicycles, but also any mean of transport driven solely by human power. Development of bicycle traffic in urban areas involves construction of cycling infrastructure, adapting streets and other traffic infrastructure to a form suitable for cycling and other means of transport (individual motorized traffic, public transport, walking, ensuring the adequate budget and systematic planning and development of sustainable transport in cities. The paper presents basic settings and conditions as input elements to plan bicycle traffic in urban areas, as well as program- design conditions which lead the activities of planners and designers of urban roads in connection with cyclists.

  10. MoTiV - Mobility and transport in intermodal traffic. Mobility in urban areas. 'SIM-simulation models'. Final report; Mobilitaet und Transport im intermodalen Verkehr (MoTiV). Mobilitaet im Ballungsraum. 'SIM-Simulationsmodell'. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Konhaeuser, P.

    2000-11-23

    Today, modelling and simulation of traffic flow is used for the design and investigation of new systems, in particular for driver assistance and especially for on-line applications for the reconstruction of traffic state. In the project existing software tools were improved, refined and adapted for special applications in the joined project MoTiV. An emphasis was the development, provision and application of robust techniques for the traffic state estimation at existing line control equipment, where measured traffic data have been used as input. A further emphasis was the development of a model for the traffic in urban areas and the application of this model for the design and optimisation of co-ordinated control of light signal units. In this application modern control techniques and also agent-based techniques were used. Significant results are the design of controllers for ACC systems, the sensor simulations for the project ASA (turning and lane changing assistance) and the methods of the model coupling for applications of the incident detection. A highlight was the on-line application of different methods and techniques for the reconstruction of speed and density profiles and the tools for the incident detection in the context of the COMPANION system which was installed at the German highway A92. For the final demonstration in Goettingen, single vehicle data were collected with help of induction loops at the test site A92. These data were transmitted to the demonstration site, where the processing and visualisation was conducted. To get a good visual impression about the traffic states and to compare the results, a transmission of video images was transmitted parallel to the traffic data. (orig.) [German] Die Modellierung und Simulation von Verkehrsablaeufen wird heute zur Auslegung und Untersuchung von neuen Systemen, insbesondere auch Fahrerassistenzsystemen und speziell fuer On-Line-Anwendungen zur Rekonstruktion von Verkehrszustaenden (Verkehrslagen

  11. Calibration of a microscopic simulation model for emission calculation

    NARCIS (Netherlands)

    Jie, L.; Zuylen, H. van; Chen, Y.; Viti, F.; Wilmink, I.

    2013-01-01

    Emissions by road traffic can be reduced by optimising traffic control. The impact of this optimisation on emission can be analysed ex ante by simulation. The simulation programs used for this analysis should be valid with respect to the traffic characteristics that determine the emissions. Thus

  12. Inaccuracy in traffic forecasts

    DEFF Research Database (Denmark)

    Flyvbjerg, Bent; Holm, Mette K. Skamris; Buhl, Søren Ladegaard

    2006-01-01

    that forecasters generally do a poor job of estimating the demand for transportation infrastructure projects. The result is substantial downside financial and economic risk. Forecasts have not become more accurate over the 30-year period studied. If techniques and skills for arriving at accurate demand forecasts...... forecasting. Highly inaccurate traffic forecasts combined with large standard deviations translate into large financial and economic risks. But such risks are typically ignored or downplayed by planners and decision-makers, to the detriment of social and economic welfare. The paper presents the data...

  13. Real time traffic models, decision support for traffic management

    NARCIS (Netherlands)

    Wismans, Luc Johannes Josephus; de Romph, E.; Friso, K.; Zantema, K.

    2014-01-01

    Reliable and accurate short-term traffic state prediction can improve the performance of real-time traffic management systems significantly. Using this short-time prediction based on current measurements delivered by advanced surveillance systems will support decision-making processes on various

  14. Real Time Traffic Models, Decision Support for Traffic Management

    NARCIS (Netherlands)

    Wismans, L.; De Romph, E.; Friso, K.; Zantema, K.

    2014-01-01

    Reliable and accurate short-term traffic state prediction can improve the performance of real-time traffic management systems significantly. Using this short-time prediction based on current measurements delivered by advanced surveillance systems will support decision-making processes on various

  15. Traffic Infrastructure in the Development of the Croatian Traffic System

    Directory of Open Access Journals (Sweden)

    Damir Šimulčik

    2012-10-01

    Full Text Available The absence of a long-term traffic policy and of the policyof financing the constntction and maintenance of traffic infrastructurefacilities, represents a synthesis of numerous unresolvedrelations whose negative effects are felt in the overalleconomic and traffic development and consequently theevaluation of national potentials in the field. Adverse aspectcaused by the lack of a clear and feasible policy of financing thetraffic infrastructure facilities, is also a result of not having definedan adequate traffic policy, programme and strategiccourses of development, nor financing models that would be inaccordance with the market and economy system.This indicates that it is necessary to determine a policy forfinancing the constntction and maintenance of traffic infrastntcture,which has to be based on scientific development,team work, availability of plans and programmes to scientistsand experts, determined methodology based on marketing andeconomic logic in defining the programme and strategic tasksand assignments so as to make them feasible.In the near future, intensive preparations for investments inthe overall traffic sysiem are necessary, especially regarding thetraffic infrastntcture facilities - the pivotal points in the processof evaluating the traffic in our national tenitory. Croatia needsto define clearly its strategy in constructing and maintaining thegeneral traffic infrastructure, appointing at the same time thosewho will carry out the given tasks.

  16. Using Tensor Completion Method to Achieving Better Coverage of Traffic State Estimation from Sparse Floating Car Data.

    Science.gov (United States)

    Ran, Bin; Song, Li; Zhang, Jian; Cheng, Yang; Tan, Huachun

    2016-01-01

    Traffic state estimation from the floating car system is a challenging problem. The low penetration rate and random distribution make available floating car samples usually cover part space and time points of the road networks. To obtain a wide range of traffic state from the floating car system, many methods have been proposed to estimate the traffic state for the uncovered links. However, these methods cannot provide traffic state of the entire road networks. In this paper, the traffic state estimation is transformed to solve a missing data imputation problem, and the tensor completion framework is proposed to estimate missing traffic state. A tensor is constructed to model traffic state in which observed entries are directly derived from floating car system and unobserved traffic states are modeled as missing entries of constructed tensor. The constructed traffic state tensor can represent spatial and temporal correlations of traffic data and encode the multi-way properties of traffic state. The advantage of the proposed approach is that it can fully mine and utilize the multi-dimensional inherent correlations of traffic state. We tested the proposed approach on a well calibrated simulation network. Experimental results demonstrated that the proposed approach yield reliable traffic state estimation from very sparse floating car data, particularly when dealing with the floating car penetration rate is below 1%.

  17. Driver behavior analysis during ACC activation and deactivation in a real traffic environment

    NARCIS (Netherlands)

    Pauwelussen, J.; Feenstra, P.J.

    2010-01-01

    For the development of a traffic-simulation model to estimate the effect of adaptive cruise control (ACC) systems on traffic safety, throughput, and environment, data of a field operational test (FOT) were analyzed, in which vehicles were equipped with ACC and lane-departure warning (LDW) systems.

  18. European Traffic Connections and Croatia

    Directory of Open Access Journals (Sweden)

    Ivan Vuković

    2012-10-01

    Full Text Available The overall traffic connections within Europe are particularlyimportant from the economic point of view of eve1y Europeancountry. Therefore, the development of traffic and trafficinfrastructure in the European Union are considered with specialattention. The main aim of traffic development in the EuropeanUnion is full possible freedom of movement both fromthe technical and organisational aspect, with continuous improvementin traffic safety and environmental protection.Traffic development and connections are one of the essentieddevelopment factors of eve1y modem counlly. Every COU/1-try tends to organise traffic system in the way that suits her best.The same holds for the European Union as well. The leadingbodies in the European Union agree that the EU traffic systemneeds to be set upon such fundamentals that it can follow furtherdevelopment of the community. EU connects 15 membercountries into a single community, and it also plans soon to expandonto new members.The aims set by the Maastricht Agreement have been realisedby announcing the traffic guidelines on infrastructure projectsthat should be realised. In the Commission's proposal tothe Council and the Parliament in 1994, on the development ofTrans-European traffic networks, a ve1y efficient plan was presentedof connecting national traffic networks into a singleTrans-European network, to be realised until 2010.Overall economic and political connections of the EuropeanUnion and the countries in transition are becoming strongereve1y day. Several countries in transition are already preparingfor joining the European Union. This brings to the fore theneed for better traffic connections of EU and the countries intransition.In some sections the adopted Crete corridors pass alsothrough Croatia. Moreover, Croatia is located on the main Europeantraffic routes from the North to the South, and from theEast to the West.

  19. Reports on internet traffic statistics

    NARCIS (Netherlands)

    Hoogesteger, Martijn; de Oliveira Schmidt, R.; Sperotto, Anna; Pras, Aiko

    2013-01-01

    Internet traffic statistics can provide valuable information to network analysts and researchers about the way nowadays networks are used. In the past, such information was provided by Internet2 in a public website called Internet2 NetFlow: Weekly Reports. The website reported traffic statistics

  20. Probabilistic description of traffic flow

    International Nuclear Information System (INIS)

    Mahnke, R.; Kaupuzs, J.; Lubashevsky, I.

    2005-01-01

    A stochastic description of traffic flow, called probabilistic traffic flow theory, is developed. The general master equation is applied to relatively simple models to describe the formation and dissolution of traffic congestions. Our approach is mainly based on spatially homogeneous systems like periodically closed circular rings without on- and off-ramps. We consider a stochastic one-step process of growth or shrinkage of a car cluster (jam). As generalization we discuss the coexistence of several car clusters of different sizes. The basic problem is to find a physically motivated ansatz for the transition rates of the attachment and detachment of individual cars to a car cluster consistent with the empirical observations in real traffic. The emphasis is put on the analogy with first-order phase transitions and nucleation phenomena in physical systems like supersaturated vapour. The results are summarized in the flux-density relation, the so-called fundamental diagram of traffic flow, and compared with empirical data. Different regimes of traffic flow are discussed: free flow, congested mode as stop-and-go regime, and heavy viscous traffic. The traffic breakdown is studied based on the master equation as well as the Fokker-Planck approximation to calculate mean first passage times or escape rates. Generalizations are developed to allow for on-ramp effects. The calculated flux-density relation and characteristic breakdown times coincide with empirical data measured on highways. Finally, a brief summary of the stochastic cellular automata approach is given

  1. Steering Kids to Traffic Safety.

    Science.gov (United States)

    PTA Today, 1991

    1991-01-01

    Guidelines to help parents explain traffic safety to children cover the following: school bus safety (e.g., remain seated, do not shout); walking (e.g., obey traffic signals, cross at crosswalks); driving (e.g., wear seatbelts, enter and exit from the curb side); and biking (e.g., wear helmets, do not ride at night). (SM)

  2. Road traffic noise and stroke

    DEFF Research Database (Denmark)

    Sørensen, Mette; Hvidberg, Martin; Andersen, Zorana J

    2011-01-01

    Epidemiological studies suggest that long-term exposure to road traffic noise increases the risk of cardiovascular disorders. The aim of this study was to investigate the relation between exposure to road traffic noise and risk for stroke, which has not been studied before....

  3. Web traffic and firm performance

    DEFF Research Database (Denmark)

    Farooq, Omar; Aguenaou, Samir

    2013-01-01

    -traffic on firm performance in civil law countries, firms with concentrated ownership, and firms with more intangible assets. All of these groups are characterized by higher agency problems. Our results, therefore, indicate that web-traffic can play a substitute for traditional governance mechanisms in the MENA...

  4. Impact of Flooding on Traffic Route Choices

    Directory of Open Access Journals (Sweden)

    Othman M.H.

    2014-01-01

    Full Text Available Traffic route choice using road network modelling can play a key role in preventing and minimizing traffic problems during disasters. Using road network modelling, real road conditions during flooding are simulated in order to produce a response plan for road users to evacuate based on the roads' real risks and situation. Using a Geographical Information System (GIS we can forecast and provide road users with available alternatives when certain access roads or links need to be closed due to catastrophic hazards such as floods. This study focuses on floods as it is the most common form of natural disaster occurring in Malaysia, and due to the fact that the chance and risk of a flood occurring cannot be accurately predicted nor measured. Therefore, as a response to this problem, the outcome of this study is highly useful for the retrieval of information on flooded roads and the impacts on road users. Using GIS's capability to display both spatial and attributive information, we have provided an attractive alternative to conventional methods in order to show available traffic route choices and a transportation network plan.

  5. Cubesat Constellation Design for Air Traffic Monitoring

    Science.gov (United States)

    Nag, Sreeja; Rios, Joseph Lucio; Gerhardt, David; Pham, Camvu

    2015-01-01

    Suitably equipped global and local air traffic can be tracked. The tracking information may then be used for control from ground-based stations by receiving the Automatic Dependent Surveillance-Broadcast (ADS-B) signal. The ADS-B signal, emitted from the aircraft's Mode-S transponder, is currently tracked by terrestrial based receivers but not over remote oceans or sparsely populated regions such as Alaska or the Pacific Ocean. Lack of real-time aircraft time/location information in remote areas significantly hinders optimal planning and control because bigger "safety bubbles" (lateral and vertical separation) are required around the aircraft until they reach radar-controlled airspace. Moreover, it presents a search-and-rescue bottleneck. Aircraft in distress, e.g. Air France AF449 that crashed in 2009, take days to be located or cannot be located at all, e.g. Malaysia Airlines MH370 in 2014. In this paper, we describe a tool for designing a constellation of small satellites which demonstrates, through high-fidelity modeling based on simulated air traffic data, the value of space-based ADS-B monitoring and provides recommendations for cost-efficient deployment of a constellation of small satellites to increase safety and situational awareness in the currently poorly-served surveillance area of Alaska. Air traffic data has been obtained from the Future ATM Concepts Evaluation Tool (FACET), developed at NASA Ames Research Center, simulated over the Alaskan airspace over a period of one day. The simulation is driven by MATLAB with satellites propagated and coverage calculated using AGI's Satellite ToolKit(STK10).

  6. Towards Scalable Distributed Framework for Urban Congestion Traffic Patterns Warehousing

    Directory of Open Access Journals (Sweden)

    A. Boulmakoul

    2015-01-01

    Full Text Available We put forward architecture of a framework for integration of data from moving objects related to urban transportation network. Most of this research refers to the GPS outdoor geolocation technology and uses distributed cloud infrastructure with big data NoSQL database. A network of intelligent mobile sensors, distributed on urban network, produces congestion traffic patterns. Congestion predictions are based on extended simulation model. This model provides traffic indicators calculations, which fuse with the GPS data for allowing estimation of traffic states across the whole network. The discovery process of congestion patterns uses semantic trajectories metamodel given in our previous works. The challenge of the proposed solution is to store patterns of traffic, which aims to ensure the surveillance and intelligent real-time control network to reduce congestion and avoid its consequences. The fusion of real-time data from GPS-enabled smartphones integrated with those provided by existing traffic systems improves traffic congestion knowledge, as well as generating new information for a soft operational control and providing intelligent added value for transportation systems deployment.

  7. Traffic Congestion Detection and Avoidance using Vehicular Communication

    Directory of Open Access Journals (Sweden)

    Ajay Narendrabhai Upadhyaya

    2015-01-01

    Full Text Available Traffic congestion is a serious problem in big cities. With the number of vehicles increasing rapidly, especially in cities whose economy is booming, the situation is getting even worse. Drivers, unaware of congestion ahead eventually join it and increase the severity of it. The ability of a driver to know the traffic conditions on the roads ahead enables him/her to seek alternate routes through which time and fuel can be saved. Due to recent advancements in vehicular technologies, vehicular communication has emerged. The objective of this work is to check feasibility of using infrastructure based vehicular communication for detecting and avoiding traffic congestion. In this paper we propose a Signal Agent (SA and Car Agent(CAbased approach for detecting and avoiding traffic congestion. We analyze performance of the proposed approach for two different road network scenarios using simulations: structured grid network (like Gandhinagar City of Gujarat, India and apart of typical city road network ( Tiwan city. With the proposed approach we get reduction of 10.05% in trip duration of vehicles, reduction of 10.08% in number of vehicles in entire traffic road network and 9.82% in heavy traffic area. In an accident scenario, about 72.63% vehicles changed their route due to awareness of congestion. Error in trip time estimation and vehicle count estimation is observed to be less than 1%.

  8. A theory of traffic congestion at heavy bottlenecks

    International Nuclear Information System (INIS)

    Kerner, Boris S

    2008-01-01

    Spatiotemporal features and physics of vehicular traffic congestion occurring due to heavy highway bottlenecks caused for example by bad weather conditions or accidents are found based on simulations in the framework of three-phase traffic theory. A model of a heavy bottleneck is presented. Under a continuous non-limited increase in bottleneck strength, i.e., when the average flow rate within a congested pattern allowed by the heavy bottleneck decreases continuously up to zero, the evolution of the traffic phases in congested traffic, synchronized flow and wide moving jams, is studied. It is found that at a small enough flow rate within the congested pattern, the pattern exhibits a non-regular structure: a pinch region of synchronized flow within the pattern disappears and appears randomly over time; wide moving jams upstream of the pinch region exhibit a complex non-regular dynamics in which the jams appear and disappear randomly. At greater bottleneck strengths, wide moving jams merge onto a mega-wide moving jam (mega-jam) within which low-speed patterns with a complex non-regular spatiotemporal dynamics occur. We show that when the bottleneck strength is great enough, only the mega-jam survives and synchronized flow remains only within its downstream front separating free flow and congested traffic. Theoretical results presented can explain why no sequence of wide moving jams can often be distinguished in non-homogeneous traffic congestion measured at very heavy bottlenecks caused by bad weather conditions or accidents

  9. Particle hopping vs. fluid-dynamical models for traffic flow

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, K.

    1995-12-31

    Although particle hopping models have been introduced into traffic science in the 19509, their systematic use has only started recently. Two reasons for this are, that they are advantageous on modem computers, and that recent theoretical developments allow analytical understanding of their properties and therefore more confidence for their use. In principle, particle hopping models fit between microscopic models for driving and fluiddynamical models for traffic flow. In this sense, they also help closing the conceptual gap between these two. This paper shows connections between particle hopping models and traffic flow theory. It shows that the hydrodynamical limits of certain particle hopping models correspond to the Lighthill-Whitham theory for traffic flow, and that only slightly more complex particle hopping models produce already the correct traffic jam dynamics, consistent with recent fluid-dynamical models for traffic flow. By doing so, this paper establishes that, on the macroscopic level, particle hopping models are at least as good as fluid-dynamical models. Yet, particle hopping models have at least two advantages over fluid-dynamical models: they straightforwardly allow microscopic simulations, and they include stochasticity.

  10. A theory of traffic congestion at heavy bottlenecks

    Energy Technology Data Exchange (ETDEWEB)

    Kerner, Boris S [Daimler AG, GR/ETI, HPC: G021, 71059 Sindelfingen (Germany)

    2008-05-30

    Spatiotemporal features and physics of vehicular traffic congestion occurring due to heavy highway bottlenecks caused for example by bad weather conditions or accidents are found based on simulations in the framework of three-phase traffic theory. A model of a heavy bottleneck is presented. Under a continuous non-limited increase in bottleneck strength, i.e., when the average flow rate within a congested pattern allowed by the heavy bottleneck decreases continuously up to zero, the evolution of the traffic phases in congested traffic, synchronized flow and wide moving jams, is studied. It is found that at a small enough flow rate within the congested pattern, the pattern exhibits a non-regular structure: a pinch region of synchronized flow within the pattern disappears and appears randomly over time; wide moving jams upstream of the pinch region exhibit a complex non-regular dynamics in which the jams appear and disappear randomly. At greater bottleneck strengths, wide moving jams merge onto a mega-wide moving jam (mega-jam) within which low-speed patterns with a complex non-regular spatiotemporal dynamics occur. We show that when the bottleneck strength is great enough, only the mega-jam survives and synchronized flow remains only within its downstream front separating free flow and congested traffic. Theoretical results presented can explain why no sequence of wide moving jams can often be distinguished in non-homogeneous traffic congestion measured at very heavy bottlenecks caused by bad weather conditions or accidents.

  11. Dissociative Tendencies and Traffic Incidents

    Directory of Open Access Journals (Sweden)

    Valle, Virginia

    2012-01-01

    Full Text Available This paper analyses the relationship between dissociative experiences and road traffic incidents (crashes and traffic tickets in drivers (n=295 from Mar del Plata (Argentina city. A self-report questionnaire was applied to assess traffic crash involvement and sociodemographic variables. Dissociative tendencies were assessed by a modified version of the DES scale. To examine differences in DES scores tests of the difference of means were applied. Drivers who reported to be previously involved in traffic incidents obtained higher puntuations in the dissociative experiences scale than drivers who did not report such events. This result is observed for the total scale and for the three sub-scales (absorption, amnesia and depersonalization. However, differences appeared mainly for minor damage collisions. Further studies are needed to evaluate the role of dissociative tendencies as a risk factor in road traffic safety.

  12. Gas Kinetics of Traffic Jam

    Science.gov (United States)

    Nagatani, Takashi

    1997-04-01

    The kinetics of one-dimensional traffic flow is descibed in terms of Boltzmann-like gas kinetic equation. Paveri-Fontana's gas kinetic equation is modified to take into account the desired velocity depending on the car density. A discrete version of the gas kinetic equation is derived to numerically solve the equation. The velocity distributions are calculated by a numerical method. It is found that the traffic jam is formed in the congested traffic flow when the car density is higher than the critical value. The traffic jam propagates backward, its propagation velocity increases with the accerelation and the density within the jam decreases with increasing accerelation. It is shown that the velocity distributions change significantly before and after the traffic jam.

  13. Model for traffic emissions estimation

    Science.gov (United States)

    Alexopoulos, A.; Assimacopoulos, D.; Mitsoulis, E.

    A model is developed for the spatial and temporal evaluation of traffic emissions in metropolitan areas based on sparse measurements. All traffic data available are fully employed and the pollutant emissions are determined with the highest precision possible. The main roads are regarded as line sources of constant traffic parameters in the time interval considered. The method is flexible and allows for the estimation of distributed small traffic sources (non-line/area sources). The emissions from the latter are assumed to be proportional to the local population density as well as to the traffic density leading to local main arteries. The contribution of moving vehicles to air pollution in the Greater Athens Area for the period 1986-1988 is analyzed using the proposed model. Emissions and other related parameters are evaluated. Emissions from area sources were found to have a noticeable share of the overall air pollution.

  14. Analyzing the Influence of Mobile Phone Use of Drivers on Traffic Flow Based on an Improved Cellular Automaton Model

    Directory of Open Access Journals (Sweden)

    Yao Xiao

    2015-01-01

    Full Text Available This paper aimed to analyze the influence of drivers’ behavior of phone use while driving on traffic flow, including both traffic efficiency and traffic safety. An improved cellular automaton model was proposed to simulate traffic flow with distracted drivers based on the Nagel-Schreckenberg model. The driving characters of drivers using a phone were first discussed and a value representing the probability to use a phone while driving was put into the CA model. Simulation results showed that traffic flow rate was significantly reduced if some drivers used a phone compared to no phone use. The flow rate and velocity decreased as the proportion of drivers using a phone increased. While, under low density, the risk of traffic decreased first and then increased as the distracted drivers increased, the distracted behavior of drivers, like using a phone, could reduce the flow rate by 5 percent according to the simulation.

  15. The NASA Air Traffic Management Ontology (atmonto)

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA ATM (Air Traffic Management) Ontology describes classes, properties, and relationships relevant to the domain of air traffic management, and represents...

  16. Traffic information computing platform for big data

    Science.gov (United States)

    Duan, Zongtao; Li, Ying; Zheng, Xibin; Liu, Yan; Dai, Jiting; Kang, Jun

    2014-10-01

    Big data environment create data conditions for improving the quality of traffic information service. The target of this article is to construct a traffic information computing platform for big data environment. Through in-depth analysis the connotation and technology characteristics of big data and traffic information service, a distributed traffic atomic information computing platform architecture is proposed. Under the big data environment, this type of traffic atomic information computing architecture helps to guarantee the traffic safety and efficient operation, more intelligent and personalized traffic information service can be used for the traffic information users.

  17. Traffic information computing platform for big data

    International Nuclear Information System (INIS)

    Duan, Zongtao; Li, Ying; Zheng, Xibin; Liu, Yan; Dai, Jiting; Kang, Jun

    2014-01-01

    Big data environment create data conditions for improving the quality of traffic information service. The target of this article is to construct a traffic information computing platform for big data environment. Through in-depth analysis the connotation and technology characteristics of big data and traffic information service, a distributed traffic atomic information computing platform architecture is proposed. Under the big data environment, this type of traffic atomic information computing architecture helps to guarantee the traffic safety and efficient operation, more intelligent and personalized traffic information service can be used for the traffic information users

  18. A new cellular automata model of traffic flow with negative exponential weighted look-ahead potential

    Science.gov (United States)

    Ma, Xiao; Zheng, Wei-Fan; Jiang, Bao-Shan; Zhang, Ji-Ye

    2016-10-01

    With the development of traffic systems, some issues such as traffic jams become more and more serious. Efficient traffic flow theory is needed to guide the overall controlling, organizing and management of traffic systems. On the basis of the cellular automata model and the traffic flow model with look-ahead potential, a new cellular automata traffic flow model with negative exponential weighted look-ahead potential is presented in this paper. By introducing the negative exponential weighting coefficient into the look-ahead potential and endowing the potential of vehicles closer to the driver with a greater coefficient, the modeling process is more suitable for the driver’s random decision-making process which is based on the traffic environment that the driver is facing. The fundamental diagrams for different weighting parameters are obtained by using numerical simulations which show that the negative exponential weighting coefficient has an obvious effect on high density traffic flux. The complex high density non-linear traffic behavior is also reproduced by numerical simulations. Project supported by the National Natural Science Foundation of China (Grant Nos. 11572264, 11172247, 11402214, and 61373009).

  19. Modeling Left-Turn Driving Behavior at Signalized Intersections with Mixed Traffic Conditions

    Directory of Open Access Journals (Sweden)

    Hong Li

    2016-01-01

    Full Text Available In many developing countries, mixed traffic is the most common type of urban transportation; traffic of this type faces many major problems in traffic engineering, such as conflicts, inefficiency, and security issues. This paper focuses on the traffic engineering concerns on the driving behavior of left-turning vehicles caused by different degrees of pedestrian violations. The traffic characteristics of left-turning vehicles and pedestrians in the affected region at a signalized intersection were analyzed and a cellular-automata-based “following-conflict” driving behavior model that mainly addresses four basic behavior modes was proposed to study the conflict and behavior mechanisms of left-turning vehicles by mathematic methodologies. Four basic driving behavior modes were reproduced in computer simulations, and a logit model of the behavior mode choice was also developed to analyze the relative share of each behavior mode. Finally, the microscopic characteristics of driving behaviors and the macroscopic parameters of traffic flow in the affected region were all determined. These data are important reference for geometry and capacity design for signalized intersections. The simulation results show that the proposed models are valid and can be used to represent the behavior of left-turning vehicles in the case of conflicts with illegally crossing pedestrians. These results will have potential applications on improving traffic safety and traffic capacity at signalized intersections with mixed traffic conditions.

  20. Variable speed limit strategies analysis with mesoscopic traffic flow model based on complex networks

    Science.gov (United States)

    Li, Shu-Bin; Cao, Dan-Ni; Dang, Wen-Xiu; Zhang, Lin

    As a new cross-discipline, the complexity science has penetrated into every field of economy and society. With the arrival of big data, the research of the complexity science has reached its summit again. In recent years, it offers a new perspective for traffic control by using complex networks theory. The interaction course of various kinds of information in traffic system forms a huge complex system. A new mesoscopic traffic flow model is improved with variable speed limit (VSL), and the simulation process is designed, which is based on the complex networks theory combined with the proposed model. This paper studies effect of VSL on the dynamic traffic flow, and then analyzes the optimal control strategy of VSL in different network topologies. The conclusion of this research is meaningful to put forward some reasonable transportation plan and develop effective traffic management and control measures to help the department of traffic management.

  1. Reducing the noise pollution level along main roads in Sibiu, Romania by optimizing the traffic flow

    Directory of Open Access Journals (Sweden)

    Deac Cristian

    2017-01-01

    Full Text Available Noise pollution is one of the most important negative effects of road traffic, especially in cities. The current paper presents an attempt to reduce the noise level created by the road traffic along some main roads in the city of Sibiu, Romania by suggesting ways to optimize the traffic flow. The number of cars and the resulting noise levels were recorded in a key area of Sibiu. The noise levels were compared to standards and to measurements taken in areas with less traffic. Then, they were fed, together with road geometry data, into a specialized simulation software that allowed the computer-aided reproduction of the traffic flow, but also the modifying of conditions such as the road geometry to achieve, coupled with a multicriterial analysis, an optimization of the pedestrian and road traffic flow in view of a reduced noise pollution.

  2. A Cellular Automata Traffic Flow Model considering Bus Lane Changing Behavior with Scheduling Parameters

    Directory of Open Access Journals (Sweden)

    Zun-dong Zhang

    2015-01-01

    Full Text Available According to different driving behavioral characteristics of bus drivers, a cellular automata traffic model considering the bus lane changing behavior with scheduling parameters is proposed in this paper. Traffic bottleneck problems caused by bus stops are simulated in multiple lanes roads with no-bay bus stations. With the mixed traffic flow composed of different bus arrival rate, flow-density graph, density distribution graph, and temporal-spatial graph are presented. Furthermore, the mixed traffic flow characteristics are analyzed. Numerical experiment results show that the proposed model can generate a variety of complicated realistic phenomena in the traffic system with bus stops and provide theoretical basis for better using of traffic flow model.

  3. A cellular automata model of traffic flow with variable probability of randomization

    International Nuclear Information System (INIS)

    Zheng Wei-Fan; Zhang Ji-Ye

    2015-01-01

    Research on the stochastic behavior of traffic flow is important to understand the intrinsic evolution rules of a traffic system. By introducing an interactional potential of vehicles into the randomization step, an improved cellular automata traffic flow model with variable probability of randomization is proposed in this paper. In the proposed model, the driver is affected by the interactional potential of vehicles before him, and his decision-making process is related to the interactional potential. Compared with the traditional cellular automata model, the modeling is more suitable for the driver’s random decision-making process based on the vehicle and traffic situations in front of him in actual traffic. From the improved model, the fundamental diagram (flow–density relationship) is obtained, and the detailed high-density traffic phenomenon is reproduced through numerical simulation. (paper)

  4. Impacts of Large Vehicles on Traffic Safety in Freeway Interchange Merging Areas and Improvement Measures

    Directory of Open Access Journals (Sweden)

    Guo Yifan

    2017-01-01

    Full Text Available In order to work out the characteristics of traffic operation on freeway interchange merging areas under different ratio of large vehicles, aerial photography technique based on unmanned aircraft and other observation device were used to investigate the merge section traffic data firstly. Based on survey data and actual traffic characteristics, the paper then established simulation models with VI SSIM with calibrated car-following and lane changing behaviour models. Next, the paper analysed the influence of traffic volume and acceleration lane length under various traffic compositions to evaluate safety status of interchange merge sections by traffic conflict technique and speed consistency index. Finally, two kinds of safety promotion strategies, speed limit and setting forbidden line, were evaluated and the results indicated these measures can raise safety level by about 10%∼15% under certain conditions, which were determined as the best applicable conditions.

  5. Failure of classical traffic flow theories: Stochastic highway capacity and automatic driving

    Science.gov (United States)

    Kerner, Boris S.

    2016-05-01

    In a mini-review Kerner (2013) it has been shown that classical traffic flow theories and models failed to explain empirical traffic breakdown - a phase transition from metastable free flow to synchronized flow at highway bottlenecks. The main objective of this mini-review is to study the consequence of this failure of classical traffic-flow theories for an analysis of empirical stochastic highway capacity as well as for the effect of automatic driving vehicles and cooperative driving on traffic flow. To reach this goal, we show a deep connection between the understanding of empirical stochastic highway capacity and a reliable analysis of automatic driving vehicles in traffic flow. With the use of simulations in the framework of three-phase traffic theory, a probabilistic analysis of the effect of automatic driving vehicles on a mixture traffic flow consisting of a random distribution of automatic driving and manual driving vehicles has been made. We have found that the parameters of automatic driving vehicles can either decrease or increase the probability of the breakdown. The increase in the probability of traffic breakdown, i.e., the deterioration of the performance of the traffic system can occur already at a small percentage (about 5%) of automatic driving vehicles. The increase in the probability of traffic breakdown through automatic driving vehicles can be realized, even if any platoon of automatic driving vehicles satisfies condition for string stability.

  6. Traffic Signal Synchronization in the Saturated High-Density Grid Road Network

    Directory of Open Access Journals (Sweden)

    Xiaojian Hu

    2015-01-01

    Full Text Available Most existing traffic signal synchronization strategies do not perform well in the saturated high-density grid road network (HGRN. Traffic congestion often occurs in the saturated HGRN, and the mobility of the network is difficult to restore. In order to alleviate traffic congestion and to improve traffic efficiency in the network, the study proposes a regional traffic signal synchronization strategy, named the long green and long red (LGLR traffic signal synchronization strategy. The essence of the strategy is to control the formation and dissipation of queues and to maximize the efficiency of traffic flows at signalized intersections in the saturated HGRN. With this strategy, the same signal control timing plan is used at all signalized intersections in the HGRN, and the straight phase of the control timing plan has a long green time and a long red time. Therefore, continuous traffic flows can be maintained when vehicles travel, and traffic congestion can be alleviated when vehicles stop. Using the strategy, the LGLR traffic signal synchronization model is developed, with the objective of minimizing the number of stops. Finally, the simulation is executed to analyze the performance of the model by comparing it to other models, and the superiority of the LGLR model is evident in terms of delay, number of stops, queue length, and overall performance in the saturated HGRN.

  7. Traffic Signal Synchronization in the Saturated High-Density Grid Road Network

    Science.gov (United States)

    Hu, Xiaojian; Lu, Jian; Wang, Wei; Zhirui, Ye

    2015-01-01

    Most existing traffic signal synchronization strategies do not perform well in the saturated high-density grid road network (HGRN). Traffic congestion often occurs in the saturated HGRN, and the mobility of the network is difficult to restore. In order to alleviate traffic congestion and to improve traffic efficiency in the network, the study proposes a regional traffic signal synchronization strategy, named the long green and long red (LGLR) traffic signal synchronization strategy. The essence of the strategy is to control the formation and dissipation of queues and to maximize the efficiency of traffic flows at signalized intersections in the saturated HGRN. With this strategy, the same signal control timing plan is used at all signalized intersections in the HGRN, and the straight phase of the control timing plan has a long green time and a long red time. Therefore, continuous traffic flows can be maintained when vehicles travel, and traffic congestion can be alleviated when vehicles stop. Using the strategy, the LGLR traffic signal synchronization model is developed, with the objective of minimizing the number of stops. Finally, the simulation is executed to analyze the performance of the model by comparing it to other models, and the superiority of the LGLR model is evident in terms of delay, number of stops, queue length, and overall performance in the saturated HGRN. PMID:25663835

  8. Integrated Traffic Flow Management Decision Making

    Science.gov (United States)

    Grabbe, Shon R.; Sridhar, Banavar; Mukherjee, Avijit

    2009-01-01

    A generalized approach is proposed to support integrated traffic flow management decision making studies at both the U.S. national and regional levels. It can consider tradeoffs between alternative optimization and heuristic based models, strategic versus tactical flight controls, and system versus fleet preferences. Preliminary testing was accomplished by implementing thirteen unique traffic flow management models, which included all of the key components of the system and conducting 85, six-hour fast-time simulation experiments. These experiments considered variations in the strategic planning look-ahead times, the replanning intervals, and the types of traffic flow management control strategies. Initial testing indicates that longer strategic planning look-ahead times and re-planning intervals result in steadily decreasing levels of sector congestion for a fixed delay level. This applies when accurate estimates of the air traffic demand, airport capacities and airspace capacities are available. In general, the distribution of the delays amongst the users was found to be most equitable when scheduling flights using a heuristic scheduling algorithm, such as ration-by-distance. On the other hand, equity was the worst when using scheduling algorithms that took into account the number of seats aboard each flight. Though the scheduling algorithms were effective at alleviating sector congestion, the tactical rerouting algorithm was the primary control for avoiding en route weather hazards. Finally, the modeled levels of sector congestion, the number of weather incursions, and the total system delays, were found to be in fair agreement with the values that were operationally observed on both good and bad weather days.

  9. Optimized Sensor Network and Multi-Agent Decision Support for Smart Traffic Light Management.

    Science.gov (United States)

    Cruz-Piris, Luis; Rivera, Diego; Fernandez, Susel; Marsa-Maestre, Ivan

    2018-02-02

    One of the biggest challenges in modern societies is to solve vehicular traffic problems. Sensor networks in traffic environments have contributed to improving the decision-making process of Intelligent Transportation Systems. However, one of the limiting factors for the effectiveness of these systems is in the deployment of sensors to provide accurate information about the traffic. Our proposal is using the centrality measurement of a graph as a base to locate the best locations for sensor installation in a traffic network. After integrating these sensors in a simulation scenario, we define a Multi-Agent Systems composed of three types of agents: traffic light management agents, traffic jam detection agents, and agents that control the traffic lights at an intersection. The ultimate goal of these Multi-Agent Systems is to improve the trip duration for vehicles in the network. To validate our solution, we have developed the needed elements for modelling the sensors and agents in the simulation environment. We have carried out experiments using the Simulation of Urban MObility (SUMO) traffic simulator and the Travel and Activity PAtterns Simulation (TAPAS) Cologne traffic scenario. The obtained results show that our proposal allows to reduce the sensor network while still obtaining relevant information to have a global view of the environment. Finally, regarding the Multi-Agent Systems, we have carried out experiments that show that our proposal is able to improve other existing solutions such as conventional traffic light management systems (static or dynamic) in terms of reduction of vehicle trip duration and reduction of the message exchange overhead in the sensor network.

  10. Optimized Sensor Network and Multi-Agent Decision Support for Smart Traffic Light Management

    Directory of Open Access Journals (Sweden)

    Luis Cruz-Piris

    2018-02-01

    Full Text Available One of the biggest challenges in modern societies is to solve vehicular traffic problems. Sensor networks in traffic environments have contributed to improving the decision-making process of Intelligent Transportation Systems. However, one of the limiting factors for the effectiveness of these systems is in the deployment of sensors to provide accurate information about the traffic. Our proposal is using the centrality measurement of a graph as a base to locate the best locations for sensor installation in a traffic network. After integrating these sensors in a simulation scenario, we define a Multi-Agent Systems composed of three types of agents: traffic light management agents, traffic jam detection agents, and agents that control the traffic lights at an intersection. The ultimate goal of these Multi-Agent Systems is to improve the trip duration for vehicles in the network. To validate our solution, we have developed the needed elements for modelling the sensors and agents in the simulation environment. We have carried out experiments using the Simulation of Urban MObility (SUMO traffic simulator and the Travel and Activity PAtterns Simulation (TAPAS Cologne traffic scenario. The obtained results show that our proposal allows to reduce the sensor network while still obtaining relevant information to have a global view of the environment. Finally, regarding the Multi-Agent Systems, we have carried out experiments that show that our proposal is able to improve other existing solutions such as conventional traffic light management systems (static or dynamic in terms of reduction of vehicle trip duration and reduction of the message exchange overhead in the sensor network.

  11. A Cooperative Traffic Control of Vehicle–Intersection (CTCVI) for the Reduction of Traffic Delays and Fuel Consumption

    Science.gov (United States)

    Li, Jinjian; Dridi, Mahjoub; El-Moudni, Abdellah

    2016-01-01

    The problem of reducing traffic delays and decreasing fuel consumption simultaneously in a network of intersections without traffic lights is solved by a cooperative traffic control algorithm, where the cooperation is executed based on the connection of Vehicle-to-Infrastructure (V2I). This resolution of the problem contains two main steps. The first step concerns the itinerary of which intersections are chosen by vehicles to arrive at their destination from their starting point. Based on the principle of minimal travel distance, each vehicle chooses its itinerary dynamically based on the traffic loads in the adjacent intersections. The second step is related to the following proposed cooperative procedures to allow vehicles to pass through each intersection rapidly and economically: on one hand, according to the real-time information sent by vehicles via V2I in the edge of the communication zone, each intersection applies Dynamic Programming (DP) to cooperatively optimize the vehicle passing sequence with minimal traffic delays so that the vehicles may rapidly pass the intersection under the relevant safety constraints; on the other hand, after receiving this sequence, each vehicle finds the optimal speed profiles with the minimal fuel consumption by an exhaustive search. The simulation results reveal that the proposed algorithm can significantly reduce both travel delays and fuel consumption compared with other papers under different traffic volumes. PMID:27999333

  12. Effect of Mixed Traffic Flow on Control Delay at Signalized ...

    African Journals Online (AJOL)

    The operational conditions of such intersections profoundly affect the well being of the transportation of goods and passengers in cities. There are several methods available for operational analysis including mathematical models and traffic simulation models; however the Highway Capacity Manual (HCM) has been widely

  13. Theory of traffic jam in a one-lane model

    Science.gov (United States)

    Hayakawa, Hisao; Nakanishi, Ken

    1998-04-01

    We propose a generalized optimal velocity model to describe one-lane traffic flows. We carry out a weakly nonlinear analysis based on the technique of soliton perturbations and determine the selected propagating velocity, amplitude, and width of the interface between a jam state and a nonjam state. From the direct simulation of the model, we have confirmed the validity of our theoretical analysis.

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

    African Journals Online (AJOL)

    Bheema

    ABSTRACT. Evaluating the performance of a multi-lane intersection is important to identify the best scheme as congestion is becoming a worldwide serious problem. A Multi-stream Minimum Acceptable. Space (MMAS) Cellular Automata (CA) model is used for the simulation of vehicular traffic at double-lane roundabouts ...

  15. Multiple curved descending approaches and the air traffic control problem

    Science.gov (United States)

    Hart, S. G.; Mcpherson, D.; Kreifeldt, J.; Wemple, T. E.

    1977-01-01

    A terminal area air traffic control simulation was designed to study ways of accommodating increased air traffic density. The concepts that were investigated assumed the availability of the microwave landing system and data link and included: (1) multiple curved descending final approaches; (2) parallel runways certified for independent and simultaneous operation under IFR conditions; (3) closer spacing between successive aircraft; and (4) a distributed management system between the air and ground. Three groups each consisting of three pilots and two air traffic controllers flew a combined total of 350 approaches. Piloted simulators were supplied with computer generated traffic situation displays and flight instruments. The controllers were supplied with a terminal area map and digital status information. Pilots and controllers also reported that the distributed management procedure was somewhat more safe and orderly than the centralized management procedure. Flying precision increased as the amount of turn required to intersect the outer mark decreased. Pilots reported that they preferred the alternative of multiple curved descending approaches with wider spacing between aircraft to closer spacing on single, straight in finals while controllers preferred the latter option. Both pilots and controllers felt that parallel runways are an acceptable way to accommodate increased traffic density safely and expeditiously.

  16. An Improved Response Surface Methodology Algorithm with an Application to Traffic Signal Optimization for Urban Networks

    Science.gov (United States)

    1995-01-01

    Prepared ca. 1995. This paper illustrates the use of the simulation-optimization technique of response surface methodology (RSM) in traffic signal optimization of urban networks. It also quantifies the gains of using the common random number (CRN) va...

  17. Framework for multi-resolution analyses of advanced traffic management strategies [summary].

    Science.gov (United States)

    2017-01-01

    Transportation planning relies extensively on software that can simulate and predict travel behavior in response to alternative transportation networks. However, different software packages view traffic at different scales. Some programs are based on...

  18. Nonlinear analysis of an extended traffic flow model in ITS environment

    International Nuclear Information System (INIS)

    Yu Lei; Shi Zhongke

    2008-01-01

    An extended traffic flow model is proposed by introducing the relative velocity of arbitrary number of cars that precede and that follow into the Newell-Whitham-type car-following model. The stability condition of this model is obtained by using the linear stability theory. The results show that the stability of traffic flow is improved by taking into account the relative velocity of cars ahead and backward. By applying the nonlinear analysis the modified Korteweg-de Vries (mKdV) equation is derived to describe the traffic behavior near the critical point. The kink-antikink soliton, the solution of the mKdV equation, is obtained to describe the traffic jams. From the numerical simulation, it is shown that the traffic jams are suppressed efficiently by taking into account the relative velocity of cars ahead and backward. The analytical results are consistent with the simulation one

  19. Design and Construction of Intelligent Traffic Light Control System Using Fuzzy Logic

    Science.gov (United States)

    Lin, Htin; Aye, Khin Muyar; Tun, Hla Myo; Theingi, Naing, Zaw Min

    2008-10-01

    Vehicular travel is increasing throughout the world, particularly in large urban areas. Therefore the need arises for simulation and optimizing traffic control algorithms to better accommodate this increasing demand. This paper presents a microcontroller simulation of intelligent traffic light controller using fuzzy logic that is used to change the traffic signal cycles adaptively at a two-way intersection. This paper is an attempt to design an intelligent traffic light control systems using microcontrollers such as PIC 16F84A and PIC 16F877A. And then traffic signal can be controlled depending upon the densities of cars behind green and red lights of the two-way intersection by using sensors and detectors circuits.

  20. Framework for Traffic Congestion Management

    Directory of Open Access Journals (Sweden)

    Mahmud Hassan TALUKDAR

    2013-06-01

    Full Text Available Traffic Congestion is one of many serious global problems in all great cities resulted from rapid urbanization which always exert negative externalities upon society. The solution of traffic congestion is highly geocentric and due to its heterogeneous nature, curbing congestion is one of the hard tasks for transport planners. It is not possible to suggest unique traffic congestion management framework which could be absolutely applied for every great cities. Conversely, it is quite feasible to develop a framework which could be used with or without minor adjustment to deal with congestion problem. So, the main aim of this paper is to prepare a traffic congestion mitigation framework which will be useful for urban planners, transport planners, civil engineers, transport policy makers, congestion management researchers who are directly or indirectly involved or willing to involve in the task of traffic congestion management. Literature review is the main source of information of this study. In this paper, firstly, traffic congestion is defined on the theoretical point of view and then the causes of traffic congestion are briefly described. After describing the causes, common management measures, using world- wide, are described and framework for supply side and demand side congestion management measures are prepared.

  1. Impact of distracted driving on safety and traffic flow.

    Science.gov (United States)

    Stavrinos, Despina; Jones, Jennifer L; Garner, Annie A; Griffin, Russell; Franklin, Crystal A; Ball, David; Welburn, Sharon C; Ball, Karlene K; Sisiopiku, Virginia P; Fine, Philip R

    2013-12-01

    Studies have documented a link between distracted driving and diminished safety; however, an association between distracted driving and traffic congestion has not been investigated in depth. The present study examined the behavior of teens and young adults operating a driving simulator while engaged in various distractions (i.e., cell phone, texting, and undistracted) and driving conditions (i.e., free flow, stable flow, and oversaturation). Seventy five participants 16-25 years of age (split into 2 groups: novice drivers and young adults) drove a STISIM simulator three times, each time with one of three randomly presented distractions. Each drive was designed to represent daytime scenery on a 4 lane divided roadway and included three equal roadway portions representing Levels of Service (LOS) A, C, and E as defined in the 2000 Highway Capacity Manual. Participants also completed questionnaires documenting demographics and driving history. Both safety and traffic flow related driving outcomes were considered. A Repeated Measures Multivariate Analysis of Variance was employed to analyze continuous outcome variables and a Generalized Estimate Equation (GEE) Poisson model was used to analyze count variables. Results revealed that, in general more lane deviations and crashes occurred during texting. Distraction (in most cases, text messaging) had a significantly negative impact on traffic flow, such that participants exhibited greater fluctuation in speed, changed lanes significantly fewer times, and took longer to complete the scenario. In turn, more simulated vehicles passed the participant drivers while they were texting or talking on a cell phone than while undistracted. The results indicate that distracted driving, particularly texting, may lead to reduced safety and traffic flow, thus having a negative impact on traffic operations. No significant differences were detected between age groups, suggesting that all drivers, regardless of age, may drive in a manner

  2. Traffic jams: dynamics and control.

    Science.gov (United States)

    Orosz, Gábor; Wilson, R Eddie; Stépán, Gábor

    2010-10-13

    This introductory paper reviews the current state-of-the-art scientific methods used for modelling, analysing and controlling the dynamics of vehicular traffic. Possible mechanisms underlying traffic jam formation and propagation are presented from a dynamical viewpoint. Stable and unstable motions are described that may give the skeleton of traffic dynamics, and the effects of driver behaviour are emphasized in determining the emergent state in a vehicular system. At appropriate points, references are provided to the papers published in the corresponding Theme Issue.

  3. OPTIMASI BANDWITH MENGGUNAKAN TRAFFIC SHAPPING

    Directory of Open Access Journals (Sweden)

    Imam Riadi

    2012-05-01

    Full Text Available Perkembangan layanan komunikasi telah berkembang sangat pesat. Salah satunya adalah pemanfaatan penggunaan bandwith untuk mengakases jaringan Internet. Traffic shapping bandwidth dapat memberikan efesiensi dalam hal pemanfaatan bandwidth pada instansi yang melakukan manajemen dalam lalulintas jaringannya. Metode yang digunakan dalam penelitian ini adalah metode literatur yaitu metode pengumpulan data yang dilakukan dengan mengumpulkan sumber-sumber data yang terkait dan metode eksperimen yaitu melakukan penelitian dengan mengkonfigurasi Mikrotik RouterOS untuk melakukan traffic shapping bandwidth. Hasil penelitian ini adalah router yang dapat melakukan traffic shapping sehingga kualitas koneksi menjadi lebih baik untuk mengakses dan mengambil data dari sebuah website.

  4. Traffic Light Detection at Night

    DEFF Research Database (Denmark)

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

    2015-01-01

    of three detectors based on heuristic models and one learning-based detector. Evaluation is done on night-time data from the public LISA Traffic Light Dataset. The learning-based detector out- performs the model-based detectors in both precision and recall. The learning-based detector achieves an average......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...

  5. [Comics for traffic education: evaluation of a traffic safety campaign].

    Science.gov (United States)

    Bonfadelli, H

    1989-01-01

    Traffic safety campaigns often are ineffective to change driving behavior because they don't reach the target group or are recognized only by people who are already interested or concerned. The evaluation of a traffic safety campaign called "Leo Lässig", addressed to young new drivers, shows that recognition and acceptance by the target group were stimulated by the age-conform means of comic-strips.

  6. The Pricing of Traffic Light Options and other Correlation Derivatives

    DEFF Research Database (Denmark)

    Kokholm, Thomas

    for the price of the correlation derivative known as the traffic light option under lognormality assumptions for the underlying processes. A pricing approach for more general payoffs is presented, and an illustration is performed with Monte Carlo simulation by the pricing of a specific hybrid derivative...... with payoff depending on the performance of a stock index and the spread between two LIBOR rates. Further, it is briefly described how the traffic light option can be used for hedging interest rate risk and stock price risk....

  7. 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.

  8. 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.

  9. 49 CFR 1139.2 - Traffic study.

    Science.gov (United States)

    2010-10-01

    ... “base-calendar year—actual.” The study shall include a probability sampling of the actual traffic... 49 Transportation 8 2010-10-01 2010-10-01 false Traffic study. 1139.2 Section 1139.2... of General Commodities § 1139.2 Traffic study. (a) The respondents shall submit a traffic study for...

  10. Traffic Aware Strategic Aircrew Requests (TASAR)

    Science.gov (United States)

    Wing, David J.

    2014-01-01

    The Traffic Aware Strategic Aircrew Request (TASAR) concept offers onboard automation for the purpose of advising the pilot of traffic compatible trajectory changes that would be beneficial to the flight. A fast-time simulation study was conducted to assess the benefits of TASAR to Alaska Airlines. The simulation compares historical trajectories without TASAR to trajectories developed with TASAR and evaluated by controllers against their objectives. It was estimated that between 8,000 and 12,000 gallons of fuel and 900 to 1,300 minutes could be saved annually per aircraft. These savings were applied fleet-wide to produce an estimated annual cost savings to Alaska Airlines in excess of $5 million due to fuel, maintenance, and depreciation cost savings. Switching to a more wind-optimal trajectory was found to be the use case that generated the highest benefits out of the three TASAR use cases analyzed. Alaska TASAR requests peaked at four to eight requests per hour in high-altitude Seattle center sectors south of Seattle-Tacoma airport..

  11. Self-Adapting Routing Overlay Network for Frequently Changing Application Traffic in Content-Based Publish/Subscribe System

    Directory of Open Access Journals (Sweden)

    Meng Chi

    2014-01-01

    Full Text Available In the large-scale distributed simulation area, the topology of the overlay network cannot always rapidly adapt to frequently changing application traffic to reduce the overall traffic cost. In this paper, we propose a self-adapting routing strategy for frequently changing application traffic in content-based publish/subscribe system. The strategy firstly trains the traffic information and then uses this training information to predict the application traffic in the future. Finally, the strategy reconfigures the topology of the overlay network based on this predicting information to reduce the overall traffic cost. A predicting path is also introduced in this paper to reduce the reconfiguration numbers in the process of the reconfigurations. Compared to other strategies, the experimental results show that the strategy proposed in this paper could reduce the overall traffic cost of the publish/subscribe system in less reconfigurations.

  12. Characterization and Modeling of Network Traffic

    DEFF Research Database (Denmark)

    Shawky, Ahmed; Bergheim, Hans; Ragnarsson, Olafur

    2011-01-01

    This paper attempts to characterize and model backbone network traffic, using a small number of statistics. In order to reduce cost and processing power associated with traffic analysis. The parameters affecting the behaviour of network traffic are investigated and the choice is that inter......-arrival time, IP addresses, port numbers and transport protocol are the only necessary parameters to model network traffic behaviour. In order to recreate this behaviour, a complex model is needed which is able to recreate traffic behaviour based on a set of statistics calculated from the parameters values....... The model investigates the traffic generation mechanisms, and grouping traffic into flows and applications....

  13. Automatic Traffic Recorder (ATR) Stations

    Data.gov (United States)

    Department of Homeland Security — The data included in the GIS Traffic Stations Version database have been assimilated from station description files provided by FHWA for Weigh-in-Motion (WIM), and...

  14. Traffic safety in the future

    OpenAIRE

    EKKEHARD, Brühning; OKAMURA, Kazuko; FLEURY, Dominique; BRILON, Werner; DINGES, David F.; ABE, Takashi

    2013-01-01

    This booklet is divided in 4 parts : Traffic Safety in Japan and Germany - Success, Deficiencies, Future Potentials. Research on the Territorial Approach to Safety. Reliability of Motorway Operation. Transportation Safety and Operator Sleepiness: Where Biology Needs Technology.

  15. 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...

  16. Traffic behavior at freeway bottlenecks.

    Science.gov (United States)

    2014-09-01

    This study examines traffic behavior in the vicinity of a freeway bottleneck, revisiting commonly held : assumptions and uncovering systematic biases that likely have distorted empirical studies of bottleneck : formation, capacity drop, and the funda...

  17. Assessment of Traffic Noise Impacts

    DEFF Research Database (Denmark)

    Rich, Jeppe Husted; Nielsen, Otto Anker

    2004-01-01

    A steady growth in traffic intensities in most urban areas throughout the world has forced planners and politicians to seriously consider the resulting environmental impact, such as traffic noise, accidents and air pollution. The assessment of such negative factors is needed in order to reveal...... the true social benefit of infrastructure plans. The paper presents a noise assessment model for the Copenhagen region, which brings together GIS technology and non-linear hedonic regression models to reveal the implicit costs of traffic noise measured as the marginal percentage loss in property values...... with respect to the decibel traffic noise. The model distinguishes between houses and apartments and shows that the ability to include refined accessibility variables have significant impact on estimated prices....

  18. Estimating Emissions from Railway Traffic

    DEFF Research Database (Denmark)

    Jørgensen, Morten W.; Sorenson, Spencer C.

    1998-01-01

    Several parameters of importance for estimating emissions from railway traffic are discussed, and typical results presented. Typical emissions factors from diesel engines and electrical power generation are presented, and the effect of differences in national electrical generation sources illustr...

  19. Game theory and traffic assignment.

    Science.gov (United States)

    2013-09-01

    Traffic assignment is used to determine the number of users on roadway links in a network. While this problem has : been widely studied in transportation literature, its use of the concept of equilibrium has attracted considerable interest : in the f...

  20. Traffic by multiple species of molecular motors.

    Science.gov (United States)

    Chai, Yan; Klumpp, Stefan; Müller, Melanie J I; Lipowsky, Reinhard

    2009-10-01

    We study the traffic of two types of molecular motors using the two-species asymmetric simple exclusion process (ASEP) with periodic boundary conditions and with attachment and detachment of particles. We determine characteristic properties such as motor densities and currents by simulations and analytical calculations. For motors with different unbinding probabilities, mean-field theory gives the correct bound density and total current of the motors, as shown by numerical simulations. For motors differing in their stepping probabilities, the particle-hole symmetry of the current-density relationship is broken and mean-field theory fails drastically. The total motor current exhibits exponential finite-size scaling, which we use to extrapolate the total current to the thermodynamic limit. Finally, we also study the motion of a single motor in the background of many nonmoving motors.

  1. Stochastic control of traffic patterns

    DEFF Research Database (Denmark)

    Gaididei, Yuri B.; Gorria, Carlos; Berkemer, Rainer

    2013-01-01

    A stochastic modulation of the safety distance can reduce traffic jams. It is found that the effect of random modulation on congestive flow formation depends on the spatial correlation of the noise. Jam creation is suppressed for highly correlated noise. The results demonstrate the advantage...... of heterogeneous performance of the drivers in time as well as individually. This opens the possibility for the construction of technical tools to control traffic jam formation....

  2. Estimating emissions from railway traffic

    Energy Technology Data Exchange (ETDEWEB)

    Joergensen, M.W.; Sorenson, C.

    1997-07-01

    The report discusses methods that can be used to estimate the emissions from various kinds of railway traffic. The methods are based on the estimation of the energy consumption of the train, so that comparisons can be made between electric and diesel driven trains. Typical values are given for the necessary traffic parameters, emission factors, and train loading. Detailed models for train energy consumption are presented, as well as empirically based methods using average train speed and distance between stop. (au)

  3. Future Emissions from Railway Traffic

    DEFF Research Database (Denmark)

    Sorenson, Spencer C.

    1998-01-01

    In investigation of the expected development in factors which influence railway energy consumption and emissions. Traffic factors such as train speed, load, an occupancy were considered. Tehcnical factors such an emissions factors, fleet composition and train weight were also considered. An estim......In investigation of the expected development in factors which influence railway energy consumption and emissions. Traffic factors such as train speed, load, an occupancy were considered. Tehcnical factors such an emissions factors, fleet composition and train weight were also considered...

  4. Analysis of mixed traffic flow with human-driving and autonomous cars based on car-following model

    Science.gov (United States)

    Zhu, Wen-Xing; Zhang, H. M.

    2018-04-01

    We investigated the mixed traffic flow with human-driving and autonomous cars. A new mathematical model with adjustable sensitivity and smooth factor was proposed to describe the autonomous car's moving behavior in which smooth factor is used to balance the front and back headway in a flow. A lemma and a theorem were proved to support the stability criteria in traffic flow. A series of simulations were carried out to analyze the mixed traffic flow. The fundamental diagrams were obtained from the numerical simulation results. The varying sensitivity and smooth factor of autonomous cars affect traffic flux, which exhibits opposite varying tendency with increasing parameters before and after the critical density. Moreover, the sensitivity of sensors and smooth factors play an important role in stabilizing the mixed traffic flow and suppressing the traffic jam.

  5. An analysis of the traffic safety phenomenon.

    OpenAIRE

    Asmussen, E. & Kranenburg, A.

    1982-01-01

    The lack of traffic safety is a combination of the critical coincidence of circumstances in the traffic of incidents (near-accidents) and accidents with unwanted (permanent) consequences, such as fatalities, injured and disabled persons and material damage. This definition covers the whole of the critical coincidence of circumstances in traffic. In order to elucidate the phenomenon of traffic safety or the lack of traffic safety, accidents and incidents can be analysed.

  6. Economic Efficacy of Road Traffic Safety Measures

    OpenAIRE

    Gul, Ejaz

    2013-01-01

    The number of road traffic casualties is still very lofty and the trend shows a boost with each passing day. The road traffic accidents involve fatalities due to which economic resources are damaged and the productivity of the economy is correspondingly impaired. Costs resulting from traffic accidents represent the largest single part of the overall cost of traffic to the economy. Knowledge about the harm of these traffic accidents to the economy is essential if measures to reduce road traffi...

  7. Economic Evaluation of Road Traffic Safety Measures

    OpenAIRE

    Gul, Ejaz

    2013-01-01

    The number of road traffic casualties is still very lofty and the trend shows a boost with each passing day. The road traffic accidents involve fatalities due to which economic resources are damaged and the productivity of the economy is correspondingly impaired. Costs resulting from traffic accidents represent the largest single part of the overall cost of traffic to the economy. Knowledge about the harm of these traffic accidents to the economy is essential if measures to reduce road traffi...

  8. Regulatory measures for traffic safety

    International Nuclear Information System (INIS)

    Veerapur, R.D.; Bharambe, S.D.; Patnaik, S.K.; Tandle, A.K.; Sonawane, K.A.; Kumar, Rajesh; Venkat Subramanian, K.

    2017-01-01

    Traffic safety is an issue related to occupational safety not restricted alone to the transportation but extends beyond. BARC has many facilities spread across large area in Mumbai and outside Mumbai. BARC deploys large number of buses, mini buses, jeeps and cars for commuting its employees to reach BARC and for commuting within BARC premises. Additionally, trucks, fire tenders, trailers etc. are also deployed for transportation of materials. No moving vehicle is ever free of the possibility of involvement in an accident. Vehicular accidents and the fatalities on road are the result of inter-play of a number of factors. The vehicle population has been steadily increasing with the pace picking up significantly in recent past. Increase in vehicle population in the face of limited road space used by a large variety of traffic has heightened the need and urgency for a well-thought-out road safety. Therefore, existence of regulatory authority to regulate traffic and vehicles to ensure safety of its employees and vehicles is very essential. BARC Traffic Safety Committee (BTSC), which is the regulating body for traffic safety is responsible for ensuring overall traffic safety. (author)

  9. 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.

  10. Piezoelectric materials involved in road traffic applications test system

    International Nuclear Information System (INIS)

    Vazquez Rodriguez, M.; Jimenez Martinez, F.; Frutos, J. de

    2011-01-01

    The test bench system described in this paper performs experiments on piezoelectric materials used in road traffic applications, covering a range between 14 and 170 km/h, which is considered enough for testing under standard traffic conditions. A software has been developed to control the three phase induction motor driver and to acquire all the measurement data of the piezoelectric materials. The mass over each systems axis can be selected, with a limit of 60 kg over each wheel. The test bench is used to simulate the real behaviour of buried piezoelectric cables in road traffic applications for both light and heavy vehicles. This new test bed system is a powerful research tool and can be applied to determine the optimal installation and configuration of the piezoelectric cable sensors and opens a new field of research: the study of energy harvesting techniques based on piezoelectric materials. (Author) 10 refs.

  11. Obtaining traffic information by urban air quality inspection

    International Nuclear Information System (INIS)

    Federico, G; Simone, A.; Simone, A.; Traverso, M.; Nicolosi, S.

    2006-01-01

    Transportation and its environmental impacts are a major component of urban environmental management. At the same time, transportation and mobility are an important part of urban economics and quality of life. To analyze urban transportation and its environmental impacts, a comprehensive, interdisciplinary approach is needed. Unfortunately, theoretical works about traffic flow and pollutant dynamic have independently evolved, rarely meeting contact points. Our works aims to provide a contribution in linking traffic flow and pollutant dynamic by proponing a new traffic model, able to calculate the number of running vehicles, once the ground level of an arbitrary pollutant concentration is know. The validation and simulation of this model is made possible by the training of an adaptive.(Author)

  12. Modeling Erlang's Ideal Grading with Multirate BPP Traffic

    Directory of Open Access Journals (Sweden)

    Mariusz Glabowski

    2012-01-01

    Full Text Available This paper presents a complete methodology for modeling gradings (also called non-full-availability groups servicing single-service and multi-service traffic streams. The methodology worked out by the authors makes it possible to determine traffic characteristics of various types of gradings with state-dependent call arrival processes, including a new proposed structure of the Erlang’s Ideal Grading with the multirate links. The elaborated models of the gradings can be used for modeling different systems of modern networks, for example, the radio interfaces of the UMTS system, switching networks carrying a mixture of different multirate traffic streams, and video-on-demand systems. The results of the analytical calculations are compared with the results of the simulation data for selected gradings, which confirm high accuracy of the proposed methodology.

  13. Performance Evaluation of 100 Gigabit Ethernet Switches under Bursty Traffic

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Rytlig, A.; Manolova, Anna Vasileva

    2011-01-01

    Switch fabrics for 100 Gigabit Ethernet systems pose high demands in terms of delay and scalability. In this paper we analyze the performance of a Clos-based switch fabric under uniform and bursty traffic, and compare its performance to a crossbar-based switch design for benchmarking. In particular......) fashion. Simulation results show that for uniform Bernoulli traffic, the DSRR scheme outperforms the others. Under bursty traffic, the DSRR scheme and the random scheme achieve similar performance. The static scheme performs the worst for both cases. Comparing the SMM design to an Output Queued crossbar...... switch only reveals a minor performance penalty, which can be compensated by the high scalability, robustness and low complexity of the Clos-based design for high speed switching systems....

  14. Airport Network Flow Simulator

    Science.gov (United States)

    1978-10-01

    The Airport Network Flow Simulator is a FORTRAN IV simulation of the flow of air traffic in the nation's 600 commercial airports. It calculates for any group of selected airports: (a) the landing and take-off (Type A) delays; and (b) the gate departu...

  15. Accurate and fast replication on the generation of fractal network traffic using alternative probability models

    Science.gov (United States)

    Fernandes, Stenio; Kamienski, Carlos; Sadok, Djamel

    2003-08-01

    Synthetic self-similar traffic in computer networks simulation is of imperative significance for the capturing and reproducing of actual Internet data traffic behavior. A universally used procedure for generating self-similar traffic is achieved by aggregating On/Off sources where the active (On) and idle (Off) periods exhibit heavy tailed distributions. This work analyzes the balance between accuracy and computational efficiency in generating self-similar traffic and presents important results that can be useful to parameterize existing heavy tailed distributions such as Pareto, Weibull and Lognormal in a simulation analysis. Our results were obtained through the simulation of various scenarios and were evaluated by estimating the Hurst (H) parameter, which measures the self-similarity level, using several methods.

  16. A Multi-Agent Traffic Control Model Based on Distributed System

    Directory of Open Access Journals (Sweden)

    Qian WU

    2014-06-01

    Full Text Available With the development of urbanization construction, urban travel has become a quite thorny and imminent problem. Some previous researches on the large urban traffic systems easily change into NPC problems. We purpose a multi-agent inductive control model based on the distributed approach. To describe the real traffic scene, this model designs four different types of intelligent agents, i.e. we regard each lane, route, intersection and traffic region as different types of intelligent agents. Each agent can achieve the real-time traffic data from its neighbor agents, and decision-making agents establish real-time traffic signal plans through the communication between local agents and their neighbor agents. To evaluate the traffic system, this paper takes the average delay, the stopped time and the average speed as performance parameters. Finally, the distributed multi-agent is simulated on the VISSIM simulation platform, the simulation results show that the multi-agent system is more effective than the adaptive control system in solving the traffic congestion.

  17. Traffic behavior of mixed traffic flow with two kinds of different self-stabilizing control vehicles

    Science.gov (United States)

    Li, Zhipeng; Li, Wenzhong; Xu, Shangzhi; Qian, Yeqing; Sun, Jian

    2015-10-01

    In this paper, we propose a heterogeneous car following model in terms of an extension to the original optimal velocity model characterizing two classes of different self-stabilizing control vehicles. Linear stability analysis method is utilized to the extended model, for purpose to explore how the varying percentages of the vehicles with short-duration self-stabilizing control influence the stability of the heterogeneous traffic flow. We obtain the neutral stability lines for different percentages of two classes of vehicles, with finding that the traffic flow trends to stable with the decrease of the percentage for short-duration self-stabilizing control vehicles. Moreover, we explore a special case that the same numbers of two different classes of vehicles with self-stabilizing control. We theoretically derive the stability condition of the special case, and conclude the effect of the average value and the standard deviation of two time gaps, on the heterogeneous traffic stability. At last, direct simulations are conducted to verify the conclusion of theoretical analysis.

  18. 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.

  19. Traffic analysis and control using image processing

    Science.gov (United States)

    Senthilkumar, K.; Ellappan, Vijayan; Arun, A. R.

    2017-11-01

    This paper shows the work on traffic analysis and control till date. It shows an approach to regulate traffic the use of image processing and MATLAB systems. This concept uses computational images that are to be compared with original images of the street taken in order to determine the traffic level percentage and set the timing for the traffic signal accordingly which are used to reduce the traffic stoppage on traffic lights. They concept proposes to solve real life scenarios in the streets, thus enriching the traffic lights by adding image receivers like HD cameras and image processors. The input is then imported into MATLAB to be used. as a method for calculating the traffic on roads. Their results would be computed in order to adjust the traffic light timings on a particular street, and also with respect to other similar proposals but with the added value of solving a real, big instance.

  20. Analysis of the influence of occupation rate of public transit vehicles on mixing traffic flow in a two-lane system

    Science.gov (United States)

    Qian, Yong-Sheng; Shi, Pei-Ji; Zeng, Qiong; Ma, Chang-Xi; Lin, Fang; Sun, Peng; Yin, Xiao-Ting

    2009-09-01

    Based on the existing classical cellular automaton model of traffic flow, a cellular automaton traffic model with different-maximum-speed vehicles mixed on a single lane is proposed, in which public transit and harbour-shaped bus stops are taken into consideration. Parameters such as length of cellular automaton, operation speed and random slow mechanism are re-demarcated. A harbour-shaped bus stop is set up and the vehicle changing lane regulation is changed. Through computer simulation, the influence of occupation rate of public transit vehicles on mixed traffic flow and traffic capacity is analysed. The results show that a public transport system can ease urban traffic congestion but creates new jams at the same time, and that the influence of occupation rate of public transit vehicles on traffic capacity is considerable. To develop urban traffic, attention should be paid to the occupation rate of public transit vehicles and traffic development in a haphazard way should be strictly avoided.

  1. The physics of traffic jams

    Science.gov (United States)

    Nagatani, Takashi

    2002-09-01

    Traffic flow is a kind of many-body system of strongly interacting vehicles. Traffic jams are a typical signature of the complex behaviour of vehicular traffic. Various models are presented to understand the rich variety of physical phenomena exhibited by traffic. Analytical and numerical techniques are applied to study these models. Particularly, we present detailed results obtained mainly from the microscopic car-following models. A typical phenomenon is the dynamical jamming transition from the free traffic (FT) at low density to the congested traffic at high density. The jamming transition exhibits the phase diagram similar to a conventional gas-liquid phase transition: the FT and congested traffic correspond to the gas and liquid phases, respectively. The dynamical transition is described by the time-dependent Ginzburg-Landau equation for the phase transition. The jamming transition curve is given by the spinodal line. The metastability exists in the region between the spinodal and phase separation lines. The jams in the congested traffic reveal various density waves. Some of these density waves show typical nonlinear waves such as soliton, triangular shock and kink. The density waves are described by the nonlinear wave equations: the Korteweg-de-Vries (KdV) equation, the Burgers equation and the Modified KdV equation. Subjects like the traffic flow such as bus-route system and pedestrian flow are touched as well. The bus-route system with many buses exhibits the bunching transition where buses bunch together with proceeding ahead. Such dynamic models as the car-following model are proposed to investigate the bunching transition and bus delay. A recurrent bus exhibits the dynamical transition between the delay and schedule-time phases. The delay transition is described in terms of the nonlinear map. The pedestrian flow also reveals the jamming transition from the free flow at low density to the clogging at high density. Some models are presented to study the

  2. 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.

  3. Engineering Education Tool for Distance Telephone Traffic Learning Through Web

    Directory of Open Access Journals (Sweden)

    Leonimer Flávio de Melo

    2012-11-01

    Full Text Available This work subject focuses in distance learning (DL modality by the Internet. The use of calculators and simulators software introduces a high level of interactivity in DL systems, such as Matlab software proposed by using in this work. The use of efficient mathematical packages and hypermedia technologies opens the door to a new paradigm of teaching and learning in the dawn of this new millennium. The use of hypertext, graphics, animation, audio, video, efficient calculators and simulators incorporating artificial intelligence techniques and the advance in the broadband networks will pave the way to this new horizon. The contribution of this work, besides the Matlab Web integration, is the developing of an introductory course in traffic engineering in hypertext format. Also, calculators to the most employed expressions of traffic analysis were developed to the Matlab server environment. By the use of the telephone traffic calculator, the user inputs data on his or her Internet browser and the systems returns numerical data, graphics and tables in HTML pages. The system is also very useful for Professional traffic calculations, replacing with advantages the use of the traditional methods by means of static tables and graphics in paper format.

  4. Cellular automata model for traffic flow with safe driving conditions

    International Nuclear Information System (INIS)

    Lárraga María Elena; Alvarez-Icaza Luis

    2014-01-01

    In this paper, a recently introduced cellular automata (CA) model is used for a statistical analysis of the inner microscopic structure of synchronized traffic flow. The analysis focuses on the formation and dissolution of clusters or platoons of vehicles, as the mechanism that causes the presence of this synchronized traffic state with a high flow. This platoon formation is one of the most interesting phenomena observed in traffic flows and plays an important role both in manual and automated highway systems (AHS). Simulation results, obtained from a single-lane system under periodic boundary conditions indicate that in the density region where the synchronized state is observed, most vehicles travel together in platoons with approximately the same speed and small spatial distances. The examination of velocity variations and individual vehicle gaps shows that the flow corresponding to the synchronized state is stable, safe and highly correlated. Moreover, results indicate that the observed platoon formation in real traffic is reproduced in simulations by the relation between vehicle headway and velocity that is embedded in the dynamics definition of the CA model. (general)

  5. Road traffic injuries in Colombia.

    Science.gov (United States)

    Rodríguez, Deysi Yasmin; Fernández, Francisco José; Acero Velásquez, Hugo

    2003-01-01

    Road traffic injuries are a leading public health problem in Colombia. Pedestrians are the most vulnerable road users, especially in the main urban centers of Bogotá, Medellin and Cali. Data analyzed in this report include official statistics from the National Police and the National Institute of Legal Medicine and Forensic Sciences for 1996-2000, and results of a study conducted at the National University of Colombia in 2000. Methods from the Highway Capacity Manual were used for determining physical and technical variables, and a Geographical Information System tool was used for the location and spatial analysis of the road traffic crashes. Pedestrians accounted for close to 32% of injuries and 40% of the deaths from road traffic crashes. The problem of road traffic crashes existed predominately in urban areas. In the main urban centers, pedestrians constituted nearly 68% of road traffic crash victims. The high level of risky road use behaviors demonstrated by pedestrians and drivers, and inadequate infrastructure for safe mobility of pedestrians in some sections of the road network were the main contributing factors. Major improvements were achieved in Bogotá following enhancements to the municipal transport system and other policies introduced since 1995. In conclusion, policies and programs for improving road safety, in particular pedestrian safety, and strengthening urban planning are top priority.

  6. 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.

  7. A cellular automata traffic flow model considering the heterogeneity of acceleration and delay probability

    Science.gov (United States)

    Li, Qi-Lang; Wong, S. C.; Min, Jie; Tian, Shuo; Wang, Bing-Hong

    2016-08-01

    This study examines the cellular automata traffic flow model, which considers the heterogeneity of vehicle acceleration and the delay probability of vehicles. Computer simulations are used to identify three typical phases in the model: free-flow, synchronized flow, and wide moving traffic jam. In the synchronized flow region of the fundamental diagram, the low and high velocity vehicles compete with each other and play an important role in the evolution of the system. The analysis shows that there are two types of bistable phases. However, in the original Nagel and Schreckenberg cellular automata traffic model, there are only two kinds of traffic conditions, namely, free-flow and traffic jams. The synchronized flow phase and bistable phase have not been found.

  8. Dimensional reduction of web traffic data

    Science.gov (United States)

    Nikulin, Vladimir

    2006-04-01

    Dimensional reduction may be effective in order to compress data without loss of essential information. Also, it may be useful in order to smooth data and reduce random noise. The model presented in this paper was motivated by the structure of the msweb web-traffic dataset from the UCI archive. It is proposed to reduce dimension (number of the used web-areas or vroots) as a result of the unsupervised learning process maximizing specially defined average log-likelihood divergence. Two different web-areas will be merged in the case if these areas appear together frequently during the same sessions. Essentially, roles of the web-areas are not symmetrical in the merging process. The web-area or cluster with bigger weight will act as an attractor and will stimulate merging. In difference, the smaller cluster will try to keep independence. In both cases the powers of attraction or resistance will depend on the weights of the corresponding clusters. Above strategy will prevent creation of one super-big cluster, and will help to reduce number of non-significant clusters. The proposed method was illustrated using two synthetic examples. The first example is based on an ideal vlink matrix which characterizes weights of the vroots and relations between them. The vlink matrix for the second example was generated using specially designed web-traffic simulator.

  9. Data-driven modeling of transportation systems and traffic data analysis during a major power outage in the Netherlands

    NARCIS (Netherlands)

    Melnikov, V.R.; Krzhizhanovskaya, V.V.; Boukhanovsky, A.V.; Sloot, P.M.A.

    2015-01-01

    Efficient methods and tools for road network planning and traffic management are critically important in the ever more urbanized world. The goal of our research is the development of a data-driven multiscale modeling approach for accurate simulation of road traffic in real-life transportation

  10. Exact results of 1D traffic cellular automata: The low-density behavior of the Fukui-Ishibashi model

    Science.gov (United States)

    Salcido, Alejandro; Hernández-Zapata, Ernesto; Carreón-Sierra, Susana

    2018-03-01

    The maximum entropy states of the cellular automata models for traffic flow in a single-lane with no anticipation are presented and discussed. The exact analytical solutions for the low-density behavior of the stochastic Fukui-Ishibashi traffic model were obtained and compared with computer simulations of the model. An excellent agreement was found.

  11. Air traffic security act unconstitutional

    International Nuclear Information System (INIS)

    Heller, W.

    2006-01-01

    In the interest of more effective protective measures against terrorist attacks, the German federal parliament inter alia added a clause to the Air Traffic Security Act (Sec. 14, Para. 3, Air Traffic Security Act) empowering the armed forces to shoot down aircraft to be used as a weapon against human lives. In Germany, this defense possibility has been discussed also in connection with deliberate crashes of hijacked aircraft on nuclear power plants. The 1 st Division of the German Federal Constitutional Court, in its decision of February 15, 2006, ruled that Sec. 14, Para. 3, Air Traffic Security Act was incompatible with the Basic Law and thus was null and void (file No. 1 BvR 357/05) for two reasons: - There was no legislative authority on the part of the federal government. - The provision was incompatible with the basic right of life and the guarantee of human dignity as enshrined in the Basic Law. (orig.)

  12. Traffic Jam and Shock Formation in Stochastic Traffic-Flow Model of a Two-Lane Roadway

    Science.gov (United States)

    Nagatani, Takashi

    1994-01-01

    We present a stochastic cellular automaton (CA) model to simulate the traffic jam induced by a car accident in the traffic flow of a two-lane roadway. The CA model is an extended version of the one-dimensional asymmetric exclusion model to take into account the stochastic exchange of cars between the first and second lanes. We study the traffic flow of the system when the translation invariance is broken by the insertion of a blockage which is induced by a car accident on the first lane. Using the computer simulation, it is found that the dynamical jamming transions occur successively from the phase 1, through the phase 2, to the phase 3 with increasing the density of cars. The phase 1 is characterized by the property such that no cars exist in the first lane and the cars on the second lane move with the maximal velocity. The phase 2 is characterized by the shock formation (a discontinuity of density) and the maximal current. In the phase 3, the discontinuity disappears and the traffic flow is not affected by the car accident.

  13. Agent Based Individual Traffic guidance

    DEFF Research Database (Denmark)

    Wanscher, Jørgen Bundgaard

    2004-01-01

    can be obtained through cellular phone tracking or GPS systems. This information can then be used to provide individual traffic guidance as opposed to the mass information systems of today -- dynamic roadsigns and trafficradio. The goal is to achieve better usage of road and time. The main topic......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...

  14. Intelligent Ambulance Traffic Assistance System

    OpenAIRE

    RONOJOY GHOSH; VIVEK SHAH; HITESH AGARWAL; ASHUTOSH BHUSHAN; PRASUN KANTI GHOSH

    2013-01-01

    With the increase in traffic road density, several causalities occur due to delay in taking a patient to the hospital in an ambulance. In this paper, we have developed an algorithm to find the shortest path to reach the required destination. As required the software will identify the present location of the vehicle and ask the user for the destination. Then it will show all the available paths, highlighting the shortest one or in several cases the most optimum one. Further we made the traffic...

  15. Traffic conflict assessment for non-lane-based movements of motorcycles under congested conditions

    Directory of Open Access Journals (Sweden)

    Long Xuan Nguyen

    2014-03-01

    Full Text Available Traffic conflict under congested conditions is one of the main safety issues of motorcycle traffic in developing countries. Unlike cars, motorcycles often display non-lane-based movements such as swerving or oblique following of a lead vehicle when traffic becomes congested. Very few studies have quantitatively evaluated the effects of such non-lane-based movements on traffic conflict. Therefore, in this study we aim to develop an integrated model to assess the traffic conflict of motorcycles under congested conditions. The proposed model includes a concept of safety space to describe the non-lane-based movements unique to motorcycles, new features developed for traffic conflict assessment such as parameters of acceleration and deceleration, and the conditions for choosing a lead vehicle. Calibration data were extracted from video clips taken at two road segments in Ho Chi Minh City. A simulation based on the model was developed to verify the dynamic non-lane-based movements of motorcycles. Subsequently, the assessment of traffic conflict was validated by calculating the probability of sudden braking at each time interval according to the change in the density of motorcycle flow. Our findings underscore the fact that higher flow density may lead to conflicts associated with a greater probability of sudden breaking. Three types of motorcycle traffic conflicts were confirmed, and the proportions of each type were calculated and discussed.

  16. Anomalous Traffic Detection and Self-Similarity Analysis in the Environment of ATMSim

    Directory of Open Access Journals (Sweden)

    Hae-Duck J. Jeong

    2017-12-01

    Full Text Available Internet utilisation has steadily increased, predominantly due to the rapid recent development of information and communication networks and the widespread distribution of smartphones. As a result of this increase in Internet consumption, various types of services, including web services, social networking services (SNS, Internet banking, and remote processing systems have been created. These services have significantly enhanced global quality of life. However, as a negative side-effect of this rapid development, serious information security problems have also surfaced, which has led to serious to Internet privacy invasions and network attacks. In an attempt to contribute to the process of addressing these problems, this paper proposes a process to detect anomalous traffic using self-similarity analysis in the Anomaly Teletraffic detection Measurement analysis Simulator (ATMSim environment as a research method. Simulations were performed to measure normal and anomalous traffic. First, normal traffic for each attack, including the Address Resolution Protocol (ARP and distributed denial-of-service (DDoS was measured for 48 h over 10 iterations. Hadoop was used to facilitate processing of the large amount of collected data, after which MapReduce was utilised after storing the data in the Hadoop Distributed File System (HDFS. A new platform on Hadoop, the detection system ATMSim, was used to identify anomalous traffic after which a comparative analysis of the normal and anomalous traffic was performed through a self-similarity analysis. There were four categories of collected traffic that were divided according to the attack methods used: normal local area network (LAN traffic, DDoS attack, and ARP spoofing, as well as DDoS and ARP attack. ATMSim, the anomaly traffic detection system, was used to determine if real attacks could be identified effectively. To achieve this, the ATMSim was used in simulations for each scenario to test its ability to

  17. Wireless traffic steering for green cellular networks

    CERN Document Server

    Zhang, Shan; Zhou, Sheng; Niu, Zhisheng; Shen, Xuemin (Sherman)

    2016-01-01

    This book introduces wireless traffic steering as a paradigm to realize green communication in multi-tier heterogeneous cellular networks. By matching network resources and dynamic mobile traffic demand, traffic steering helps to reduce on-grid power consumption with on-demand services provided. This book reviews existing solutions from the perspectives of energy consumption reduction and renewable energy harvesting. Specifically, it explains how traffic steering can improve energy efficiency through intelligent traffic-resource matching. Several promising traffic steering approaches for dynamic network planning and renewable energy demand-supply balancing are discussed. This book presents an energy-aware traffic steering method for networks with energy harvesting, which optimizes the traffic allocated to each cell based on the renewable energy status. Renewable energy demand-supply balancing is a key factor in energy dynamics, aimed at enhancing renewable energy sustainability to reduce on-grid energy consum...

  18. Highway and traffic engineering in developing countries

    DEFF Research Database (Denmark)

    Jørgensen, N O

    1996-01-01

    Describes road and traffic engineering methods and problems in developing countries as opposed to similar problems in industrialized countries......Describes road and traffic engineering methods and problems in developing countries as opposed to similar problems in industrialized countries...

  19. Active Traffic Capture for Network Forensics

    Science.gov (United States)

    Slaviero, Marco; Granova, Anna; Olivier, Martin

    Network traffic capture is an integral part of network forensics, but current traffic capture techniques are typically passive in nature. Under heavy loads, it is possible for a sniffer to miss packets, which affects the quality of forensic evidence.

  20. Genetic algorithms for air traffic assignment

    OpenAIRE

    Delahaye , Daniel; Alliot , Jean-Marc; Schoenauer , Marc; Farges , Jean-Loup

    1994-01-01

    International audience; In this paper, we show how genetic algorithms can be used to compute automatically a traffic assignment of aircraft on the air network to increase Air Traffic Control capacity in high density areas.

  1. Towards reducing traffic congestion using cooperative adaptive cruise control on a freeway with a ramp

    Directory of Open Access Journals (Sweden)

    Georges Arnaout

    2011-12-01

    Full Text Available Purpose: In this paper, the impact of Cooperative Adaptive Cruise Control (CACC systems on traffic performance is examined using microscopic agent-based simulation. Using a developed traffic simulation model of a freeway with an on-ramp - created to induce perturbations and to trigger stop-and-go traffic, the CACC system’s effect on the traffic performance is studied. The previously proposed traffic simulation model is extended and validated. By embedding CACC vehicles in different penetration levels, the results show significance and indicate the potential of CACC systems to improve traffic characteristics and therefore can be used to reduce traffic congestion. The study shows that the impact of CACC is positive but is highly dependent on the CACC market penetration. The flow rate of the traffic using CACC is proportional to the market penetration rate of CACC equipped vehicles and the density of the traffic.Design/methodology/approach: This paper uses microscopic simulation experiments followed by a quantitative statistical analysis. Simulation enables researchers manipulating the system variables to straightforwardly predict the outcome on the overall system, giving researchers the unique opportunity to interfere and make improvements to performance. Thus with simulation, changes to variables that might require excessive time, or be unfeasible to carry on real systems, are often completed within seconds.Findings: The findings of this paper are summarized as follow:•\tProvide and validate a platform (agent-based microscopic traffic simulator in which any CACC algorithm (current or future may be evaluated.•\tProvide detailed analysis associated with implementation of CACC vehicles on freeways.•\tInvestigate whether embedding CACC vehicles on freeways has a significant positive impact or not.Research limitations/implications: The main limitation of this research is that it has been conducted solely in a computer laboratory. Laboratory

  2. A new traffic model on compulsive lane-changing caused by off-ramp

    Science.gov (United States)

    Xiao-He, Liu; Hung-Tang, Ko; Ming-Min, Guo; Zheng, Wu

    2016-04-01

    In the field of traffic flow studies, compulsive lane-changing refers to lane-changing (LC) behaviors due to traffic rules or bad road conditions, while free LC happens when drivers change lanes to drive on a faster or less crowded lane. LC studies based on differential equation models accurately reveal LC influence on traffic environment. This paper presents a second-order partial differential equation (PDE) model that simulates both compulsive LC behavior and free LC behavior, with lane-changing source terms in the continuity equation and a lane-changing viscosity term in the momentum equation. A specific form of this model focusing on a typical compulsive LC behavior, the ‘off-ramp problem’, is derived. Numerical simulations are given in several cases, which are consistent with real traffic phenomenon. Project supported by the National Natural Science Foundation of China (Grant Nos. 11002035 and 11372147).

  3. Highway carbon footprinting.

    Science.gov (United States)

    2011-09-01

    An effort was undertaken to engage an under-used technology, the TRANSIMS and the MOVES traffic models, in order to advance the utilization of this technology within the state of New York and to examine the value of carbon-footprinting as a metric fo...

  4. Developing Concept Learning Capabilities in the COGNET/IGEN Integrative architecture and Associated Agent-based Modeling and Behavioral Representation (AMBR) Air Traffic Control

    National Research Council Canada - National Science Library

    Zachary, Wayne; Ryder, Joan; Stokes, James; Glenn, Floyd; Le Mentec, Jean-Christophe; Santarelli, Thomas

    2004-01-01

    ...) program conducted by the Air Force Research Laboratory. Phases III and IV focused on modeling and simulating concept learning within the context of a simulated Air Traffic Control (ATC) work environment...

  5. Downlink Performance of a Multi-Carrier MIMO System in a Bursty Traffic Cellular Network

    DEFF Research Database (Denmark)

    Nguyen, Hung Tuan; Kovacs, Istvan; Wang, Yuanye

    2011-01-01

    In this paper we analyse the downlink performance of a rank adaptive multiple input multiple output (MIMO) system in a busty traffic cellular network. A LTE-Advanced system with multiple component carriers was selected as a study case. To highlight the advantage of using MIMO techniques, we used...... a single input multiple output (SIMO) system as a baseline for performance comparison. The gain mechanisms of the MIMO system over the SIMO system are investigated and their characteristic at different traffic load conditions are highlighted. The simulation results are used to verified our proposed model...... to predict the performance of the SIMO and MIMO systems in a bursty traffic network....

  6. Theoretical Considerations of Interdisciplinary Expertise in Traffic

    Directory of Open Access Journals (Sweden)

    Zdravko Peran

    2012-10-01

    Full Text Available Jnterdisciplinwy traffic expertise is being increasingly appliedin road traffic. It is not possible to determine whether anaccident had been intentionally set up without such expertise.The interdisciplinary expertise is the result of mutual work ofseveral different interdisciplinary experts. The paper analysesthe basic characteristics of interdisciplinary investigation ofset-up traffic accidents. Special attention has been paid to interdisciplinwyexpertise of set-up traffic accidents involving injuredpersons or fatalities.

  7. Holonic Models for Traffic Control Systems

    Science.gov (United States)

    Ciufudean, Calin; Filote, Constantin

    This paper proposes a new time-placed net model for traffic control systems, respectively railway control traffic systems. This model can be interpreted as a holonic one, and contains three modules: Transport Planning Module, Transport Control Module and Priority Control Module. For railway traffic systems we introduce a strategy in a timed-place Petri net model to solve collision and traffic jam problems.

  8. Spacelab system analysis: The modified free access protocol: An access protocol for communication systems with periodic and Poisson traffic

    Science.gov (United States)

    Ingels, Frank; Owens, John; Daniel, Steven

    1989-01-01

    The protocol definition and terminal hardware for the modified free access protocol, a communications protocol similar to Ethernet, are developed. A MFA protocol simulator and a CSMA/CD math model are also developed. The protocol is tailored to communication systems where the total traffic may be divided into scheduled traffic and Poisson traffic. The scheduled traffic should occur on a periodic basis but may occur after a given event such as a request for data from a large number of stations. The Poisson traffic will include alarms and other random traffic. The purpose of the protocol is to guarantee that scheduled packets will be delivered without collision. This is required in many control and data collection systems. The protocol uses standard Ethernet hardware and software requiring minimum modifications to an existing system. The modification to the protocol only affects the Ethernet transmission privileges and does not effect the Ethernet receiver.

  9. 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...

  10. User Interface for the SMAC Traffic Accident Reconstruction Program

    Directory of Open Access Journals (Sweden)

    Rok Krulec

    2003-11-01

    Full Text Available This paper describes the development of the user interfacefor the traffic accident reconstruction program SMAC. Threebasic modules of software will be presented. Initial parametersinput and visualization, using graphics library for simulation of3D space, which form a graphical user interface, will be explainedin more detail. The modules have been developed usingdifferent technologies and programming approaches to increaseflexibility in further development and to take maximumadvantage of the currently accessible computer hardware, sothat module to module communication is also mentioned.

  11. Some random models in traffic science

    Energy Technology Data Exchange (ETDEWEB)

    Hjorth, U.

    1996-06-01

    We give an overview of stochastic models for the following traffic phenomena. Models for traffic flow including gaps and capacities for lanes, crossings and roundabouts. Models for wanted and achieved speed distributions. Mode selection models including dispersed equilibrium models and traffic accident models. Also some statistical questions are discussed. 60 refs, 1 tab

  12. Predicting Information Flows in Network Traffic.

    Science.gov (United States)

    Hinich, Melvin J.; Molyneux, Robert E.

    2003-01-01

    Discusses information flow in networks and predicting network traffic and describes a study that uses time series analysis on a day's worth of Internet log data. Examines nonlinearity and traffic invariants, and suggests that prediction of network traffic may not be possible with current techniques. (Author/LRW)

  13. 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

  14. Models for Predictive Railway Traffic Management

    NARCIS (Netherlands)

    Kecman, P.

    2014-01-01

    The potential growth in transport demand in the next decade and beyond requires a change from reactive to proactive traffic control to maintain and improve the reliability of railway traffic. In order to enable an anticipative approach to traffic management, it is necessary to develop the tools for

  15. NEW POSSIBILITIES OF RAILWAY TRAFFIC CONTROL SYSTEMS

    Directory of Open Access Journals (Sweden)

    Lionginas LIUDVINAVIČIUS

    2016-06-01

    Full Text Available This article analyses the train traffic control systems in 1435 mm and 1520 mm gauge railways. The article analyses the aspects of train traffic control and locomotive energy saving by using the coordinates of track profile change that have been received from GPS. In the article, achievements of Lithuanian railways (LG in the area of train traffic control optimisation are presented.

  16. Light signals for road traffic control.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1981-01-01

    Signals for road traffic control are a major constituent of the modern traffic scene, particularly in built-up areas. A vast amount of research has been executed in the last two decennia, resulting in a fairly generally accepted view on what the requirements for effective traffic lights are. For the

  17. 30 CFR 56.9100 - Traffic control.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Traffic control. 56.9100 Section 56.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 56.9100 Traffic control. To provide for the safe movement of self-propelled...

  18. ReFlow: Reports on Internet Traffic

    NARCIS (Netherlands)

    Hoogesteger, Martijn; de Oliveira Schmidt, R.; Sperotto, Anna; Pras, Aiko

    Internet traffic statistics can provide valuable information to network analysts and researchers about the traffic, technologies and main characteristics of today’s networks. For many years Internet2 maintained a public website with statistics about the traffic in the Abilene network. This site was

  19. TRAFFIC SIGN RECOGNATION WITH VIDEO PROCESSING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Musa AYDIN

    2013-01-01

    Full Text Available In this study, traffic signs are aimed to be recognized and identified from a video image which is taken through a video camera. To accomplish our aim, a traffic sign recognition program has been developed in MATLAB/Simulink environment. The target traffic sign are recognized in the video image with the developed program.

  20. Phase diagram distortion from traffic parameter averaging.

    NARCIS (Netherlands)

    Stipdonk, H. Toorenburg, J. van & Postema, M.

    2010-01-01

    Motorway traffic congestion is a major bottleneck for economic growth. Therefore, research of traffic behaviour is carried out in many countries. Although well describing the undersaturated free flow phase as an almost straight line in a (k,q)-phase diagram, congested traffic observations and

  1. Capturing Internet Traffic Dynamics through Graph Distances

    NARCIS (Netherlands)

    Uhlig, S.; Fu, B.; Jamakovic, A.

    2009-01-01

    Studies of the Internet have typically focused either on the routing system, i.e. the paths chosen to reach a given destination, or on the evolution of traffic on a physical link. In this paper, we combine routing and traffic, and study for the first time the evolution of the traffic on the Internet

  2. Effects of a traffic noise background on judgements of aircraft noise

    Science.gov (United States)

    Powell, C. A.; Rice, C. G.

    1974-01-01

    A study was conducted in which subjects judged aircraft noises in the presence of road traffic background noise. Two different techniques for presenting the background noises were evaluated. For one technique, the background noise was continuous over the whole of a test session. For the other, the background noise was changed with each aircraft noise. A range of aircraft noise levels and traffic noise levels were presented to simulate typical indoor levels.

  3. 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.

  4. Multi-Layer Traffic Steering

    DEFF Research Database (Denmark)

    Fotiadis, Panagiotis; Polignano, Michele; Gimenez, Lucas Chavarria

    2013-01-01

    This paper investigates the potentials of traffic steering in the Radio Resource Control (RRC) Idle state by evaluating the Absolute Priorities (AP) framework in a multilayer Long Term Evolution (LTE) macrocell scenario. Frequency priorities are broadcast on the system information and RRC Idle...

  5. Next generation traffic management centers.

    Science.gov (United States)

    2013-05-01

    Traffic management centers (TMCs) are critical to providing mobility to millions of people travelling on high-volume roadways. In Virginia, as with most regions of the United States, TMCs were aggressively deployed in the late 1990s and early 2000s. ...

  6. Traffic at risk in Mediterranean

    International Nuclear Information System (INIS)

    Bilardo, U.; Mureddu, G.

    1993-01-01

    The Mediterranean Sea represents only about 0.7% of the planet's total water surface area, yet it is host to as much as one-quarter of the world's total maritime oil traffic. Statistics indicate that from 47 to 77,000 tonnes of crude oil are now being released annually into the Sea through accidental spills; and over the last decade, its tourism dependent coastlines have been fouled by the highest levels of tar contamination in the world. Oil carrier traffic, routed within the Sea's already overcrowded shipping lanes, is intense and this traffic is expected to increase, as a result of rises in world energy demand, to levels of from 7 to 8 million barrels a day. It has been estimated that, at the end of 1992, 90% of all large tankers operating in this area, will have reached a service life of 15-16 years which is very close to the average recommended life cycle limit of 15-20 years. Only 20% of the world's 3,000 tankers are currently equipped with double bottomed hulls. This paper uses these and other facts and figures to argue that the risks of future severe oil tanker accidents in the Mediterranean Sea are high, and that these must be countered with the development of a new set of stricter marine traffic safety regulations at the Italian, national, as well as, European level

  7. Statistical variances in traffic data

    OpenAIRE

    Krbalek, Milan; Seba, Petr

    2006-01-01

    We perform statistical analysis of the single-vehicle data measured on the Dutch freeway A9 and discussed in Ref. [2]. Using tools originating from the Random Matrix Theory we show that the significant changes in the statistics of the traffic data can be explained applying equilibrium statistical physics of interacting particles.

  8. Learning to Detect Traffic Signs

    DEFF Research Database (Denmark)

    Møgelmose, Andreas; Trivedi, Mohan M.; Moeslund, Thomas B.

    2012-01-01

    This study compares the performance of sign detection based on synthetic training data to the performance of detection based on real-world training images. Viola-Jones detectors are created for 4 different traffic signs with both synthetic and real data, and varying numbers of training samples. T...

  9. 2008 Michigan traffic crash facts

    Science.gov (United States)

    2009-03-18

    In keeping with recent trends, traffic fatalities in 2008 were down to 980, a 9.6 : percent decrease from last year. The total number of persons injured also declined : 7.5 percent to 74,568 and total crashes dropped 2.5 percent to 316,057. Most : no...

  10. 2009 Michigan traffic crash facts

    Science.gov (United States)

    2010-01-01

    In keeping with recent trends, traffic fatalities in 2009 were down to 871, a 11.1 : percent decrease from last year. The total number of persons injured also declined : 4.9 percent to 70,931 and total crashes dropped 7.9 percent to 290,978. Most : n...

  11. Variations in urban traffic volumes

    NARCIS (Netherlands)

    Thomas, Tom; Weijermars, Wendy; van Berkum, Eric C.

    2008-01-01

    Over the past few decades passenger transport has grown rapidly resulting in a multitude of problems including severe traffic congestion and pollution. It is expected that passenger transport will continue to grow rapidly in the future, which will worsen the situation even further. The traditional

  12. Effect of Data Traffic Patterns on QoS Parameters | Ani | Nigerian ...

    African Journals Online (AJOL)

    Object oriented computer simulation modeling technique provided the general platform necessary for such level of comparison. In this work MATLAB simulink simevent simulation environment was employed. The results present exponential distribution as the traffic model to be employed for worst-case analysis while ...

  13. A latency analysis for M2M and OG-like traffic patterns in different HSPA core network configurations

    Directory of Open Access Journals (Sweden)

    M. V. Popović

    2014-11-01

    Full Text Available In this paper we present an analysis intended to reveal possible impacts of core network features on latency for modelled M2M and Online Gaming traffic. Simulations were performed in a live 3G/HSPA network. Test traffic simulating multiplayer real-time games and M2M applications was generated on 10 mobile phones in parallel, sending data to a remote server. APNs with different combinations of hardware and features (proxy server, different GGSNs and firewalls, usage of Service Awareness feature were chosen. The traffic was recorded on the Gn interface in the mobile core. The goal of experiments was to evaluate any eventually significant variation of average recorded RTTs in the core part of mobile network that would clearly indicate either the impact of used APN on delay for a specific traffic pattern, or selectivity of the APN towards different traffic patterns.

  14. Price of anarchy on heterogeneous traffic-flow networks

    Science.gov (United States)

    Rose, A.; O'Dea, R.; Hopcraft, K. I.

    2016-09-01

    The efficiency of routing traffic through a network, comprising nodes connected by links whose cost of traversal is either fixed or varies in proportion to volume of usage, can be measured by the "price of anarchy." This is the ratio of the cost incurred by agents who act to minimize their individual expenditure to the optimal cost borne by the entire system. As the total traffic load and the network variability—parameterized by the proportion of variable-cost links in the network—changes, the behaviors that the system presents can be understood with the introduction of a network of simpler structure. This is constructed from classes of nonoverlapping paths connecting source to destination nodes that are characterized by the number of variable-cost edges they contain. It is shown that localized peaks in the price of anarchy occur at critical traffic volumes at which it becomes beneficial to exploit ostensibly more expensive paths as the network becomes more congested. Simulation results verifying these findings are presented for the variation of the price of anarchy with the network's size, aspect ratio, variability, and traffic load.

  15. Price of anarchy on heterogeneous traffic-flow networks.

    Science.gov (United States)

    Rose, A; O'Dea, R; Hopcraft, K I

    2016-09-01

    The efficiency of routing traffic through a network, comprising nodes connected by links whose cost of traversal is either fixed or varies in proportion to volume of usage, can be measured by the "price of anarchy." This is the ratio of the cost incurred by agents who act to minimize their individual expenditure to the optimal cost borne by the entire system. As the total traffic load and the network variability-parameterized by the proportion of variable-cost links in the network-changes, the behaviors that the system presents can be understood with the introduction of a network of simpler structure. This is constructed from classes of nonoverlapping paths connecting source to destination nodes that are characterized by the number of variable-cost edges they contain. It is shown that localized peaks in the price of anarchy occur at critical traffic volumes at which it becomes beneficial to exploit ostensibly more expensive paths as the network becomes more congested. Simulation results verifying these findings are presented for the variation of the price of anarchy with the network's size, aspect ratio, variability, and traffic load.

  16. The car following model considering traffic jerk

    Science.gov (United States)

    Ge, Hong-Xia; Zheng, Peng-jun; Wang, Wei; Cheng, Rong-Jun

    2015-09-01

    Based on optimal velocity car following model, a new model considering traffic jerk is proposed to describe the jamming transition in traffic flow on a highway. Traffic jerk means the sudden braking and acceleration of vehicles, which has a significant impact on traffic movement. The nature of the model is researched by using linear and nonlinear analysis method. A thermodynamic theory is formulated to describe the phase transition and critical phenomenon in traffic flow. The time-dependent Ginzburg-Landau (TDGL) equation and the modified Korteweg-de Vries (mKdV) equation are derived to describe the traffic flow near the critical point and the traffic jam. In addition, the connection between the TDGL and the mKdV equations are also given.

  17. Simulator justifications

    International Nuclear Information System (INIS)

    Fairchild, B.T.

    1990-01-01

    For several years, the authors have been convinced by overwhelming evidence that dynamic simulators are justified for many applications where acceptance has been slow. They speculate as to why this situation has existed and list many benefits that accrue to those who use simulators for training and other purposes. This paper along may be sufficient to convince a receptive approval chain of the value of simulator ownership. It is intended primarily as an aid and supporting document for those who find it necessary to build a detailed justification for a specific simulator acquisition. The purchase of a simulator requires justification. For new military aircraft and for spacecraft, a simulator for training and performance evaluation is virtually assumed, value having been proven many times over. for commercial aircraft, safety is the overwhelming justification. For nuclear power plants, government regulations require operators to be licensed by examination on a certified simulator. For other applications, including air traffic control, biomedical, communications, electronic power transmission and distribution, emergency engineering and management, fossil power plants, gaming land vehicles, manufacturing, maintenance, marine vehicles, process plants, weapons, etc

  18. Modeling DNP3 Traffic Characteristics of Field Devices in SCADA Systems of the Smart Grid

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Huan [Lehigh Univ., Bethlehem, PA (United States); Cheng, Liang [Lehigh Univ., Bethlehem, PA (United States); Chuah, Mooi Choo [Lehigh Univ., Bethlehem, PA (United States)

    2017-03-08

    In the generation, transmission, and distribution sectors of the smart grid, intelligence of field devices is realized by programmable logic controllers (PLCs). Many smart-grid subsystems are essentially cyber-physical energy systems (CPES): For instance, the power system process (i.e., the physical part) within a substation is monitored and controlled by a SCADA network with hosts running miscellaneous applications (i.e., the cyber part). To study the interactions between the cyber and physical components of a CPES, several co-simulation platforms have been proposed. However, the network simulators/emulators of these platforms do not include a detailed traffic model that takes into account the impacts of the execution model of PLCs on traffic characteristics. As a result, network traces generated by co-simulation only reveal the impacts of the physical process on the contents of the traffic generated by SCADA hosts, whereas the distinction between PLCs and computing nodes (e.g., a hardened computer running a process visualization application) has been overlooked. To generate realistic network traces using co-simulation for the design and evaluation of applications relying on accurate traffic profiles, it is necessary to establish a traffic model for PLCs. In this work, we propose a parameterized model for PLCs that can be incorporated into existing co-simulation platforms. We focus on the DNP3 subsystem of slave PLCs, which automates the processing of packets from the DNP3 master. To validate our approach, we extract model parameters from both the configuration and network traces of real PLCs. Simulated network traces are generated and compared against those from PLCs. Our evaluation shows that our proposed model captures the essential traffic characteristics of DNP3 slave PLCs, which can be used to extend existing co-simulation platforms and gain further insights into the behaviors of CPES.

  19. 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...... that the system can be divided into two separate constituents. The immediate dispersion, which is used for small areas and quick response, and the individual alleviation, which considers the longer distance decision support. Both of these require intrinsicate models and cost functions which at the beginning...

  20. Modelling traffic pollution in streets

    Energy Technology Data Exchange (ETDEWEB)

    Berkowicz, R.; Hertel, O. [National Environmental Research Inst., Dept. of Atmospheric Environment, Roskilde (Denmark); Larsen, S.E.; Soerensen, N.N.; Nielsen, M. [Risoe National Lab., Dept. of Meteorology and Wind Energy, Roskilde (Denmark)

    1997-01-01

    This report concerns mainly the subject related to modelling air pollution from traffic in urban streets. A short overview is presented over the theoretical aspects and examples of most commonly used methods and models are given. Flow and dispersion conditions in street canyons are discussed and the presentation is substantiated with the analysis of the experimental data. The main emphasis is on the modelling methods that are suitable for routine applications and a more detailed presentation is given of the Operational Street Pollution Model (OSPM), which was developed by the National Environmental Research Institute. The model is used for surveillance of air pollution from traffic in Danish cities and also for special air pollution studies. (au) 76 refs.

  1. Container Traffic In European Ports

    Directory of Open Access Journals (Sweden)

    Elen Twrdy

    2004-03-01

    Full Text Available Over the last fifteen years the European transport markethas witnessed a growth of container traffic which today reachesapproximately 50 million TEU per year. From 1997 to 2002,container traffic in the northern European ports increased from14 to 20.6 million TEU per year, in the ports of the westernMedite"anean from 6 to 10 million TEU per year, and in thenorthern Adriatic ports from 0. 69 to 0. 74 million TEU per year.The ports of the northern Adriatic are located in three states(Slovenia, Croatia and Italy with different statuses in relationto the common European market. In addition, different developmentlevels of these states are reflected in different levels ofinternational commercial exchange, the development of the existinginfrastructure and plans for the construction of new infrastructures.However, all three countries share a common goaltoincrease their competitiveness in comparison with the westemEuropean ports.

  2. 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.

  3. Traffic control: nursing practice calendar.

    Science.gov (United States)

    Rus, Linda; Cheesebro, Kathy; Nagra, Erica; Neff, Alaina

    2013-01-01

    Educating nurses on the multitude of new and updated best practices, changes in regulatory standards, new equipment, and enhanced technology creates an "information traffic jam." Multiple practice changes occurring simultaneously pose challenges for nurses to retain information to practice safely and effectively. An absence of coordination between various nursing and allied health teaching initiatives compounds this problem. A nursing practice calendar was developed to facilitate the prioritization, communication, and education of hospital-wide initiatives affecting nursing practice.

  4. Active Traffic Management in Michigan

    OpenAIRE

    Johnson, Pat

    2018-01-01

    The US 23 Flex Route is the first active traffic management (ATM) project in the state of Michigan. This route utilizes overhead lane control gantries equipped with various intelligent transportation system (ITS) equipment to facilitate the following ATM strategies: dynamic shoulder use, dynamic lane control, variable speed advisories, and queue warning. The focus of this presentation is how the project team overcame several challenges during the planning, design, and system management phases...

  5. Traffic Aware Planner (TAP) Flight Evaluation

    Science.gov (United States)

    Maris, John M.; Haynes, Mark A.; Wing, David J.; Burke, Kelly A.; Henderson, Jeff; Woods, Sharon E.

    2014-01-01

    NASA's Traffic Aware Planner (TAP) is a cockpit decision support tool that has the potential to achieve significant fuel and time savings when it is embedded in the data-rich Next Generation Air Transportation System (NextGen) airspace. To address a key step towards the operational deployment of TAP and the NASA concept of Traffic Aware Strategic Aircrew Requests (TASAR), a system evaluation was conducted in a representative flight environment in November, 2013. Numerous challenges were overcome to achieve this goal, including the porting of the foundational Autonomous Operations Planner (AOP) software from its original simulation-based, avionics-embedded environment to an Electronic Flight Bag (EFB) platform. A flight-test aircraft was modified to host the EFB, the TAP application, an Automatic Dependent Surveillance Broadcast (ADS-B) processor, and a satellite broadband datalink. Nine Evaluation Pilots conducted 26 hours of TAP assessments using four route profiles in the complex eastern and north-eastern United States airspace. Extensive avionics and video data were collected, supplemented by comprehensive inflight and post-flight questionnaires. TAP was verified to function properly in the live avionics and ADS-B environment, characterized by recorded data dropouts, latency, and ADS-B message fluctuations. Twelve TAP-generated optimization requests were submitted to ATC, of which nine were approved, and all of which resulted in fuel and/or time savings. Analysis of subjective workload data indicated that pilot interaction with TAP during flight operations did not induce additional cognitive loading. Additionally, analyses of post-flight questionnaire data showed that the pilots perceived TAP to be useful, understandable, intuitive, and easy to use. All program objectives were met, and the next phase of TAP development and evaluations with partner airlines is in planning for 2015.

  6. Investigation of the impact of additional traffic volumes on existing arterials

    Energy Technology Data Exchange (ETDEWEB)

    Selman, W.A.

    1986-01-01

    New developments attract a large number of additional vehicular trips to the areas in which they are located. An assessment of the impact of these additional trips on surrounding street systems is often needed. The objective of this study is the development of a regression model that would assess this impact. The model predicts increases in average vehicular delay due to specific increases in traffic volumes. It should be very useful since it requires less data than computerized simulation models, it does not require the use of a computer, and it is expected to give reasonably accurate estimates of delays. To develop the proposed model, traffic flow characteristics on six arterials were simulated. The traffic flow model TRANSYT-7F was used to simulate traffic operations on the arterials for four values of increased volumes. These simulations generated the necessary data for the development of the prediction model. Using existing traffic characteristics as predictors, four regression equations were developed and validated. The equations predict the increase in average delay in seconds per vehicle, corresponding to increases in volume of 200, 300, 500, and 700 vehicles per hour.

  7. Cross-Layer Scheduling and Resource Allocation for Heterogeneous Traffic in 3G LTE

    Directory of Open Access Journals (Sweden)

    Richard Musabe

    2014-01-01

    Full Text Available 3G long term evolution (LTE introduces stringent needs in order to provide different kinds of traffic with Quality of Service (QoS characteristics. The major problem with this nature of LTE is that it does not have any paradigm scheduling algorithm that will ideally control the assignment of resources which in turn will improve the user satisfaction. This has become an open subject and different scheduling algorithms have been proposed which are quite challenging and complex. To address this issue, in this paper, we investigate how our proposed algorithm improves the user satisfaction for heterogeneous traffic, that is, best-effort traffic such as file transfer protocol (FTP and real-time traffic such as voice over internet protocol (VoIP. Our proposed algorithm is formulated using the cross-layer technique. The goal of our proposed algorithm is to maximize the expected total user satisfaction (total-utility under different constraints. We compared our proposed algorithm with proportional fair (PF, exponential proportional fair (EXP-PF, and U-delay. Using simulations, our proposed algorithm improved the performance of real-time traffic based on throughput, VoIP delay, and VoIP packet loss ratio metrics while PF improved the performance of best-effort traffic based on FTP traffic received, FTP packet loss ratio, and FTP throughput metrics.

  8. Developing a stochastic traffic volume prediction model for public-private partnership projects

    Science.gov (United States)

    Phong, Nguyen Thanh; Likhitruangsilp, Veerasak; Onishi, Masamitsu

    2017-11-01

    Transportation projects require an enormous amount of capital investment resulting from their tremendous size, complexity, and risk. Due to the limitation of public finances, the private sector is invited to participate in transportation project development. The private sector can entirely or partially invest in transportation projects in the form of Public-Private Partnership (PPP) scheme, which has been an attractive option for several developing countries, including Vietnam. There are many factors affecting the success of PPP projects. The accurate prediction of traffic volume is considered one of the key success factors of PPP transportation projects. However, only few research works investigated how to predict traffic volume over a long period of time. Moreover, conventional traffic volume forecasting methods are usually based on deterministic models which predict a single value of traffic volume but do not consider risk and uncertainty. This knowledge gap makes it difficult for concessionaires to estimate PPP transportation project revenues accurately. The objective of this paper is to develop a probabilistic traffic volume prediction model. First, traffic volumes were estimated following the Geometric Brownian Motion (GBM) process. Monte Carlo technique is then applied to simulate different scenarios. The results show that this stochastic approach can systematically analyze variations in the traffic volume and yield more reliable estimates for PPP projects.

  9. Principled negotiation and distributed optimization for advanced air traffic management

    Science.gov (United States)

    Wangermann, John Paul

    Today's aircraft/airspace system faces complex challenges. Congestion and delays are widespread as air traffic continues to grow. Airlines want to better optimize their operations, and general aviation wants easier access to the system. Additionally, the accident rate must decline just to keep the number of accidents each year constant. New technology provides an opportunity to rethink the air traffic management process. Faster computers, new sensors, and high-bandwidth communications can be used to create new operating models. The choice is no longer between "inflexible" strategic separation assurance and "flexible" tactical conflict resolution. With suitable operating procedures, it is possible to have strategic, four-dimensional separation assurance that is flexible and allows system users maximum freedom to optimize operations. This thesis describes an operating model based on principled negotiation between agents. Many multi-agent systems have agents that have different, competing interests but have a shared interest in coordinating their actions. Principled negotiation is a method of finding agreement between agents with different interests. By focusing on fundamental interests and searching for options for mutual gain, agents with different interests reach agreements that provide benefits for both sides. Using principled negotiation, distributed optimization by each agent can be coordinated leading to iterative optimization of the system. Principled negotiation is well-suited to aircraft/airspace systems. It allows aircraft and operators to propose changes to air traffic control. Air traffic managers check the proposal maintains required aircraft separation. If it does, the proposal is either accepted or passed to agents whose trajectories change as part of the proposal for approval. Aircraft and operators can use all the data at hand to develop proposals that optimize their operations, while traffic managers can focus on their primary duty of ensuring

  10. Traffic Conflict Detection and Resolution (CDR) in ERTMS System

    OpenAIRE

    Zhu, Taomei

    2016-01-01

    This thesis addresses the conflict problem in railway traffic. Although the railway traffic management nowadays can partly be carried out by a traffic control system (or a traffic management system), the control system is insufficient to make operational decisions once the occurrence of disturbance gets frequent, particularly at the junctions with dense traffic. Traffic conflicts may arise along with the disturbances. The traffic controllers (and dispatchers) are often required to handle thes...

  11. Studies of vehicle lane-changing dynamics and its effect on traffic efficiency, safety and environmental impact

    Science.gov (United States)

    Li, Xiang; Sun, Jian-Qiao

    2017-02-01

    Drivers often change lanes on the road to maintain desired speed and to avoid slow vehicles, pedestrians, obstacles and lane closure. Understanding the effect of lane-changing on the traffic is an important topic in designing optimal traffic control systems. This paper presents a comprehensive study of this topic. We review the theory of microscopic dynamic car-following models and the lane-changing models, propose additional lane-changing rules to deal with moving bottleneck and lane reduction, and investigate the effects of lane-changing on the traffic efficiency, traffic safety and fuel consumption as a function of different variables including the distance of the emergency sign ahead of the lane closure, speed limit, traffic density, etc. Extensive simulations of the traffic system have been carried out in different scenarios. A number of important findings of the effect of various factors on the traffic are reported. These findings provide guidance on the traffic management and are important to the designers and engineers of modern highway or inner city roads to achieve high traffic efficiency and safety with minimum environmental impact.

  12. Integrated coding-aware intra-ONU scheduling for passive optical networks with inter-ONU traffic

    Science.gov (United States)

    Li, Yan; Dai, Shifang; Wu, Weiwei

    2016-12-01

    Recently, with the soaring of traffic among optical network units (ONUs), network coding (NC) is becoming an appealing technique for improving the performance of passive optical networks (PONs) with such inter-ONU traffic. However, in the existed NC-based PONs, NC can only be implemented by buffering inter-ONU traffic at the optical line terminal (OLT) to wait for the establishment of coding condition, such passive uncertain waiting severely limits the effect of NC technique. In this paper, we will study integrated coding-aware intra-ONU scheduling in which the scheduling of inter-ONU traffic within each ONU will be undertaken by the OLT to actively facilitate the forming of coding inter-ONU traffic based on the global inter-ONU traffic distribution, and then the performance of PONs with inter-ONU traffic can be significantly improved. We firstly design two report message patterns and an inter-ONU traffic transmission framework as the basis for the integrated coding-aware intra-ONU scheduling. Three specific scheduling strategies are then proposed for adapting diverse global inter-ONU traffic distributions. The effectiveness of the work is finally evaluated by both theoretical analysis and simulations.

  13. A modified two-lane traffic model considering drivers' personality

    Science.gov (United States)

    Zhu, H. B.; Zhang, N. X.; Wu, W. J.

    2015-06-01

    Based on the two-lane traffic model proposed by Chowdhury et al., a modified traffic model (R-STCA model, for short) is presented, in which the new symmetric lane changing rules are introduced by considering driving behavioral difference and dynamic headway. After the numerical simulation, a broad scattering of simulated points is exhibited in the moderate density region on the flow-density plane. The synchronized flow phase accompanied with the wide moving jam phase is reproduced. The spatial-temporal profiles indicate that the vehicles move according to the R-STCA model can change lane more easily and more realistically. Then vehicles are convenient to get rid of the slow vehicles that turn into plugs ahead, and hence the capacity increases. Furthermore the phenomenon of the high speed car-following is discovered by using the R-STCA model, which has been already observed in the traffic measured data. All these results indicate that the presented model is reasonable and more realistic.

  14. Particle-based model for skiing traffic.

    Science.gov (United States)

    Holleczek, Thomas; Tröster, Gerhard

    2012-05-01

    We develop and investigate a particle-based model for ski slope traffic. Skiers are modeled as particles with a mass that are exposed to social and physical forces, which define the riding behavior of skiers during their descents on ski slopes. We also report position and speed data of 21 skiers recorded with GPS-equipped cell phones on two ski slopes. A comparison of these data with the trajectories resulting from computer simulations of our model shows a good correspondence. A study of the relationship among the density, speed, and flow of skiers reveals that congestion does not occur even with arrival rates of skiers exceeding the maximum ski lift capacity. In a sensitivity analysis, we identify the kinetic friction coefficient of skis on snow, the skier mass, the range of repelling social forces, and the arrival rate of skiers as the crucial parameters influencing the simulation results. Our model allows for the prediction of speed zones and skier densities on ski slopes, which is important in the prevention of skiing accidents.

  15. Particle-based model for skiing traffic

    Science.gov (United States)

    Holleczek, Thomas; Tröster, Gerhard

    2012-05-01

    We develop and investigate a particle-based model for ski slope traffic. Skiers are modeled as particles with a mass that are exposed to social and physical forces, which define the riding behavior of skiers during their descents on ski slopes. We also report position and speed data of 21 skiers recorded with GPS-equipped cell phones on two ski slopes. A comparison of these data with the trajectories resulting from computer simulations of our model shows a good correspondence. A study of the relationship among the density, speed, and flow of skiers reveals that congestion does not occur even with arrival rates of skiers exceeding the maximum ski lift capacity. In a sensitivity analysis, we identify the kinetic friction coefficient of skis on snow, the skier mass, the range of repelling social forces, and the arrival rate of skiers as the crucial parameters influencing the simulation results. Our model allows for the prediction of speed zones and skier densities on ski slopes, which is important in the prevention of skiing accidents.

  16. Optimum principle for a vehicular traffic network: minimum probability of congestion

    International Nuclear Information System (INIS)

    Kerner, Boris S

    2011-01-01

    We introduce an optimum principle for a vehicular traffic network with road bottlenecks. This network breakdown minimization (BM) principle states that the network optimum is reached when link flow rates are assigned in the network in such a way that the probability for spontaneous occurrence of traffic breakdown in at least one of the network bottlenecks during a given observation time reaches the minimum possible value. Based on numerical simulations with a stochastic three-phase traffic flow model, we show that in comparison to the well-known Wardrop's principles, the application of the BM principle permits considerably greater network inflow rates at which no traffic breakdown occurs and, therefore, free flow remains in the whole network. (fast track communication)

  17. An extended car-following model considering the acceleration derivative in some typical traffic environments

    Science.gov (United States)

    Zhou, Tong; Chen, Dong; Liu, Weining

    2018-03-01

    Based on the full velocity difference and acceleration car-following model, an extended car-following model is proposed by considering the vehicle’s acceleration derivative. The stability condition is given by applying the control theory. Considering some typical traffic environments, the results of theoretical analysis and numerical simulation show the extended model has a more actual acceleration of string vehicles than that of the previous models in starting process, stopping process and sudden brake. Meanwhile, the traffic jams more easily occur when the coefficient of vehicle’s acceleration derivative increases, which is presented by space-time evolution. The results confirm that the vehicle’s acceleration derivative plays an important role in the traffic jamming transition and the evolution of traffic congestion.

  18. Effect of optimal estimation of flux difference information on the lattice traffic flow model

    Science.gov (United States)

    Yang, Shu-hong; Li, Chun-gui; Tang, Xin-lai; Tian, Chuan

    2016-12-01

    In this paper, a new lattice model is proposed by considering the optimal estimation of flux difference information. The effect of this new consideration upon the stability of traffic flow is examined through linear stability analysis. Furthermore, a modified Korteweg-de Vries (mKdV) equation near the critical point is constructed and solved by means of nonlinear analysis method, and thus the propagation behavior of traffic jam can be described by the kink-antikink soliton solution of the mKdV equation. Numerical simulation is carried out under periodical condition with results in good agreement with theoretical analysis, therefore, it is verified that the new consideration can enhance the stability of traffic systems and suppress the emergence of traffic jams effectively.

  19. Throughput Analysis of Full Duplex Communication with Asymmetric Traffic in Small Cell Systems

    DEFF Research Database (Denmark)

    Mahmood, Nurul Huda; Berardinelli, Gilberto; Mogensen, Preben Elgaard

    2015-01-01

    Full duplex communication promises a 100% throughput gain by enabling simultaneous transmission and reception. However, such simultaneous communication leads to a corresponding increase in the network interference. In addition, full duplex communication can only be exploited when traffic...... is available in both uplink and downlink directions; while, cellular network traffic tend to be downlink heavy in practice. The potential throughput gains of full duplex communication over conventional half duplex transmission in a small cell network with asymmetric traffic conditions are investigated...... in this contribution using network analysis tools from stochastic geometry. The analytical findings are further confirmed through computer-based Monte-Carlo simulations. Asymmetric downlink/uplink traffic pattern and the increased network interference stemming from full duplex transmissions are found to limit its...

  20. Symmetry breaking in optimal timing of traffic signals on an idealized two-way street.

    Science.gov (United States)

    Panaggio, Mark J; Ottino-Löffler, Bertand J; Hu, Peiguang; Abrams, Daniel M

    2013-09-01

    Simple physical models based on fluid mechanics have long been used to understand the flow of vehicular traffic on freeways; analytically tractable models of flow on an urban grid, however, have not been as extensively explored. In an ideal world, traffic signals would be timed such that consecutive lights turned green just as vehicles arrived, eliminating the need to stop at each block. Unfortunately, this "green-wave" scenario is generally unworkable due to frustration imposed by competing demands of traffic moving in different directions. Until now this has typically been resolved by numerical simulation and optimization. Here, we develop a theory for the flow in an idealized system consisting of a long two-way road with periodic intersections. We show that optimal signal timing can be understood analytically and that there are counterintuitive asymmetric solutions to this signal coordination problem. We further explore how these theoretical solutions degrade as traffic conditions vary and automotive density increases.

  1. The Impact of Trajectory Prediction Uncertainty on Air Traffic Controller Performance and Acceptability

    Science.gov (United States)

    Mercer, Joey S.; Bienert, Nancy; Gomez, Ashley; Hunt, Sarah; Kraut, Joshua; Martin, Lynne; Morey, Susan; Green, Steven M.; Prevot, Thomas; Wu, Minghong G.

    2013-01-01

    A Human-In-The-Loop air traffic control simulation investigated the impact of uncertainties in trajectory predictions on NextGen Trajectory-Based Operations concepts, seeking to understand when the automation would become unacceptable to controllers or when performance targets could no longer be met. Retired air traffic controllers staffed two en route transition sectors, delivering arrival traffic to the northwest corner-post of Atlanta approach control under time-based metering operations. Using trajectory-based decision-support tools, the participants worked the traffic under varying levels of wind forecast error and aircraft performance model error, impacting the ground automations ability to make accurate predictions. Results suggest that the controllers were able to maintain high levels of performance, despite even the highest levels of trajectory prediction errors.

  2. Optimum principle for a vehicular traffic network: minimum probability of congestion

    Energy Technology Data Exchange (ETDEWEB)

    Kerner, Boris S, E-mail: boris.kerner@daimler.com [Daimler AG, GR/PTF, HPC: G021, 71059 Sindelfingen (Germany)

    2011-03-04

    We introduce an optimum principle for a vehicular traffic network with road bottlenecks. This network breakdown minimization (BM) principle states that the network optimum is reached when link flow rates are assigned in the network in such a way that the probability for spontaneous occurrence of traffic breakdown in at least one of the network bottlenecks during a given observation time reaches the minimum possible value. Based on numerical simulations with a stochastic three-phase traffic flow model, we show that in comparison to the well-known Wardrop's principles, the application of the BM principle permits considerably greater network inflow rates at which no traffic breakdown occurs and, therefore, free flow remains in the whole network. (fast track communication)

  3. 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.

  4. ARC Code TI: Multi-Fidelity Simulator (MFSim)

    Data.gov (United States)

    National Aeronautics and Space Administration — Multi-Fidelity Simulator, MFSim is a pluggable framework for creating an air traffic flow simulator at multiple levels of fidelity. The framework is designed to...

  5. A System for Traffic Violation Detection

    Directory of Open Access Journals (Sweden)

    Nourdine Aliane

    2014-11-01

    Full Text Available This paper describes the framework and components of an experimental platform for an advanced driver assistance system (ADAS aimed at providing drivers with a feedback about traffic violations they have committed during their driving. The system is able to detect some specific traffic violations, record data associated to these faults in a local data-base, and also allow visualization of the spatial and temporal information of these traffic violations in a geographical map using the standard Google Earth tool. The test-bed is mainly composed of two parts: a computer vision subsystem for traffic sign detection and recognition which operates during both day and nighttime, and an event data recorder (EDR for recording data related to some specific traffic violations. The paper covers firstly the description of the hardware architecture and then presents the policies used for handling traffic violations.

  6. Classification and Analysis of Computer Network Traffic

    DEFF Research Database (Denmark)

    Bujlow, Tomasz

    2014-01-01

    for traffic classification, which can be used for nearly real-time processing of big amounts of data using affordable CPU and memory resources. Other questions are related to methods for real-time estimation of the application Quality of Service (QoS) level based on the results obtained by the traffic...... to create realistic traffic profiles of the selected applications, which can server as the training data for MLAs. We assessed the usefulness of C5.0 Machine Learning Algorithm (MLA) in the classification of computer network traffic. We showed that the application-layer payload is not needed to train the C5......Traffic monitoring and analysis can be done for multiple different reasons: to investigate the usage of network resources, assess the performance of network applications, adjust Quality of Service (QoS) policies in the network, log the traffic to comply with the law, or create realistic models...

  7. A novel downlink scheduling strategy for traffic communication system based on TD-LTE technology.

    Science.gov (United States)

    Chen, Ting; Zhao, Xiangmo; Gao, Tao; Zhang, Licheng

    2016-01-01

    There are many existing classical scheduling algorithms which can obtain better system throughput and user equality, however, they are not designed for traffic transportation environment, which cannot consider whether the transmission performance of various information flows could meet comprehensive requirements of traffic safety and delay tolerance. This paper proposes a novel downlink scheduling strategy for traffic communication system based on TD-LTE technology, which can perform two classification mappings for various information flows in the eNodeB: firstly, associate every information flow packet with traffic safety importance weight according to its relevance to the traffic safety; secondly, associate every traffic information flow with service type importance weight according to its quality of service (QoS) requirements. Once the connection is established, at every scheduling moment, scheduler would decide the scheduling order of all buffers' head of line packets periodically according to the instant value of scheduling importance weight function, which calculated by the proposed algorithm. From different scenario simulations, it can be verified that the proposed algorithm can provide superior differentiated transmission service and reliable QoS guarantee to information flows with different traffic safety levels and service types, which is more suitable for traffic transportation environment compared with the existing popularity PF algorithm. With the limited wireless resource, information flow closed related to traffic safety will always obtain priority scheduling right timely, which can help the passengers' journey more safe. Moreover, the proposed algorithm cannot only obtain good flow throughput and user fairness which are almost equal to those of the PF algorithm without significant differences, but also provide better realtime transmission guarantee to realtime information flow.

  8. Robust and Agile System against Fault and Anomaly Traffic in Software Defined Networks

    Directory of Open Access Journals (Sweden)

    Mihui Kim

    2017-03-01

    Full Text Available The main advantage of software defined networking (SDN is that it allows intelligent control and management of networking though programmability in real time. It enables efficient utilization of network resources through traffic engineering, and offers potential attack defense methods when abnormalities arise. However, previous studies have only identified individual solutions for respective problems, instead of finding a more global solution in real time that is capable of addressing multiple situations in network status. To cover diverse network conditions, this paper presents a comprehensive reactive system for simultaneously monitoring failures, anomalies, and attacks for high availability and reliability. We design three main modules in the SDN controller for a robust and agile defense (RAD system against network anomalies: a traffic analyzer, a traffic engineer, and a rule manager. RAD provides reactive flow rule generation to control traffic while detecting network failures, anomalies, high traffic volume (elephant flows, and attacks. The traffic analyzer identifies elephant flows, traffic anomalies, and attacks based on attack signatures and network monitoring. The traffic engineer module measures network utilization and delay in order to determine the best path for multi-dimensional routing and load balancing under any circumstances. Finally, the rule manager generates and installs a flow rule for the selected best path to control traffic. We implement the proposed RAD system based on Floodlight, an open source project for the SDN controller. We evaluate our system using simulation with and without the aforementioned RAD modules. Experimental results show that our approach is both practical and feasible, and can successfully augment an existing SDN controller in terms of agility, robustness, and efficiency, even in the face of link failures, attacks, and elephant flows.

  9. Day-to-day evolution of the traffic network with Advanced Traveler Information System

    International Nuclear Information System (INIS)

    Han Linghui; Sun Huijun; Wu Jianjun; Zhu Chengjuan

    2011-01-01

    Highlights: → We develop a dynamical system with Advanced Travelers Information System (ATIS). → We use the dynamical system to study stability of the traffic network with ATIS. → It is found that some periodic attractors appear in some cases. → A road pricing is implemented to alleviate the instability of the traffic network with ATIS. - Abstract: Since the notion of user equilibrium (UE) was proposed by Wardrop , it has become a cornerstone for traffic assignment analysis. But, it is not sufficient to only ask whether equilibrium exists or not; it is equally important to ask whether and how the system can achieve equilibrium. Meanwhile, stability is an important performance in the sense that if equilibrium is unsustainable, both the equilibrium and the trajectory are sensitive to disturbances, even a small perturbation will result in the system evolution away from the equilibrium point. These incentive a growing interest in day-to-day dynamics. In this paper, we develop a dynamical system with Advanced Traveler Information System (ATIS) and study the stability of the network with ATIS. A simple network is used to simulate the model, and the results show that there exist periodic attractors in the traffic network in some cases (for example, the market penetration level of ATIS is 0.25 and traffic demand is 2 unit). It is found that the logit parameter of the dynamical model and the traffic demand can also affect the stability of the traffic network. More periodic attractors appear in the system when the traffic demand is large and the low logit parameter can delay the appearance of periodic attractors. By simulation, it can be concluded that if the range of the periodic attractors' domain of the simple network is known, the road pricing based on the range of the attraction domain is effective to alleviate the instability of the system.

  10. Real-Time Corrected Traffic Correlation Model for Traffic Flow Forecasting

    Directory of Open Access Journals (Sweden)

    Hua-pu Lu

    2015-01-01

    Full Text Available This paper focuses on the problems of short-term traffic flow forecasting. The main goal is to put forward traffic correlation model and real-time correction algorithm for traffic flow forecasting. Traffic correlation model is established based on the temporal-spatial-historical correlation characteristic of traffic big data. In order to simplify the traffic correlation model, this paper presents correction coefficients optimization algorithm. Considering multistate characteristic of traffic big data, a dynamic part is added to traffic correlation model. Real-time correction algorithm based on Fuzzy Neural Network is presented to overcome the nonlinear mapping problems. A case study based on a real-world road network in Beijing, China, is implemented to test the efficiency and applicability of the proposed modeling methods.

  11. Seat belt, DWI, and other traffic violations among recent immigrants in Florida and Tennessee : traffic tech.

    Science.gov (United States)

    2013-05-01

    The rapidly changing racial and ethnic composition of the : U.S. population is important to traffic safety specialists : because involvement in fatal traffic crashes varies across : racial and ethnic groups. Some research suggests that certain : mino...

  12. Traffic Management for Satellite-ATM Networks

    Science.gov (United States)

    Goyal, Rohit; Jain, Raj; Fahmy, Sonia; Vandalore, Bobby; Goyal, Mukul

    1998-01-01

    Various issues associated with "Traffic Management for Satellite-ATM Networks" are presented in viewgraph form. Specific topics include: 1) Traffic management issues for TCP/IP based data services over satellite-ATM networks; 2) Design issues for TCP/IP over ATM; 3) Optimization of the performance of TCP/IP over ATM for long delay networks; and 4) Evaluation of ATM service categories for TCP/IP traffic.

  13. The Technical Issues Of Traffic Analysis

    Directory of Open Access Journals (Sweden)

    Pavel Vladimirovich Yegorov

    2016-03-01

    Full Text Available The main problem in the analysis of Internet traffic associated with a large number of network applications, complex patterns of communication and a significant amounts of information. The definition of the category of traffic using the analysis of the number of port is irrelevant for P2P applications, streaming data and many other types of network applications. The article describes some of technical issues related to the analysis of Internet traffic.

  14. Trafficability Analysis at Traffic Crossing and Parameters Optimization Based on Particle Swarm Optimization Method

    Directory of Open Access Journals (Sweden)

    Bin He

    2014-01-01

    Full Text Available In city traffic, it is important to improve transportation efficiency and the spacing of platoon should be shortened when crossing the street. The best method to deal with this problem is automatic control of vehicles. In this paper, a mathematical model is established for the platoon’s longitudinal movement. A systematic analysis of longitudinal control law is presented for the platoon of vehicles. However, the parameter calibration for the platoon model is relatively difficult because the platoon model is complex and the parameters are coupled with each other. In this paper, the particle swarm optimization method is introduced to effectively optimize the parameters of platoon. The proposed method effectively finds the optimal parameters based on simulations and makes the spacing of platoon shorter.

  15. The negative effects of homogeneous traffic on merging sections

    NARCIS (Netherlands)

    Elbers, Bart; van Berkum, Eric C.

    2003-01-01

    Homogeneous traffic flows are believed to be better in absorbing disturbances, raise capacity and stimulate traffic safety. Measures to make traffic more homogeneous are therefore often taken to increase capacity. This paper shows that the ability of a traffic flow to deal with traffic coming from

  16. Traffic light control by multiagent reinforcement learning systems

    NARCIS (Netherlands)

    Bakker, B.; Whiteson, S.; Kester, L.; Groen, F.C.A.; Babuška, R.; Groen, F.C.A.

    2010-01-01

    Traffic light control is one of the main means of controlling road traffic. Improving traffic control is important because it can lead to higher traffic throughput and reduced traffic congestion. This chapter describes multiagent reinforcement learning techniques for automatic optimization of

  17. Traffic Light Control by Multiagent Reinforcement Learning Systems

    NARCIS (Netherlands)

    Bakker, B.; Whiteson, S.; Kester, L.J.H.M.; Groen, F.C.A.

    2010-01-01

    Traffic light control is one of the main means of controlling road traffic. Improving traffic control is important because it can lead to higher traffic throughput and reduced traffic congestion. This chapter describes multiagent reinforcement learning techniques for automatic optimization of

  18. On traffic modelling in GPRS networks

    DEFF Research Database (Denmark)

    Madsen, Tatiana Kozlova; Schwefel, Hans-Peter; Prasad, Ramjee

    2005-01-01

    Optimal design and dimensioning of wireless data networks, such as GPRS, requires the knowledge of traffic characteristics of different data services. This paper presents an in-detail analysis of an IP-level traffic measurements taken in an operational GPRS network. The data measurements reported...... here are done at the Gi interface. The aim of this paper is to reveal some key statistics of GPRS data applications and to validate if the existing traffic models can adequately describe traffic volume and inter-arrival time distribution for different services. Additionally, we present a method of user...

  19. Air traffic management evaluation tool

    Science.gov (United States)

    Sridhar, Banavar (Inventor); Sheth, Kapil S. (Inventor); Chatterji, Gano Broto (Inventor); Bilimoria, Karl D. (Inventor); Grabbe, Shon (Inventor); Schipper, John F. (Inventor)

    2012-01-01

    Methods for evaluating and implementing air traffic management tools and approaches for managing and avoiding an air traffic incident before the incident occurs. A first system receives parameters for flight plan configurations (e.g., initial fuel carried, flight route, flight route segments followed, flight altitude for a given flight route segment, aircraft velocity for each flight route segment, flight route ascent rate, flight route descent route, flight departure site, flight departure time, flight arrival time, flight destination site and/or alternate flight destination site), flight plan schedule, expected weather along each flight route segment, aircraft specifics, airspace (altitude) bounds for each flight route segment, navigational aids available. The invention provides flight plan routing and direct routing or wind optimal routing, using great circle navigation and spherical Earth geometry. The invention provides for aircraft dynamics effects, such as wind effects at each altitude, altitude changes, airspeed changes and aircraft turns to provide predictions of aircraft trajectory (and, optionally, aircraft fuel use). A second system provides several aviation applications using the first system. Several classes of potential incidents are analyzed and averted, by appropriate change en route of one or more parameters in the flight plan configuration, as provided by a conflict detection and resolution module and/or traffic flow management modules. These applications include conflict detection and resolution, miles-in trail or minutes-in-trail aircraft separation, flight arrival management, flight re-routing, weather prediction and analysis and interpolation of weather variables based upon sparse measurements. The invention combines these features to provide an aircraft monitoring system and an aircraft user system that interact and negotiate changes with each other.

  20. Research on three-phase traffic flow modeling based on interaction range

    Science.gov (United States)

    Zeng, Jun-Wei; Yang, Xu-Gang; Qian, Yong-Sheng; Wei, Xu-Ting

    2017-12-01

    On the basis of the multiple velocity difference effect (MVDE) model and under short-range interaction, a new three-phase traffic flow model (S-MVDE) is proposed through careful consideration of the influence of the relationship between the speeds of the two adjacent cars on the running state of the rear car. The random slowing rule in the MVDE model is modified in order to emphasize the influence of vehicle interaction between two vehicles on the probability of vehicles’ deceleration. A single-lane model which without bottleneck structure under periodic boundary conditions is simulated, and it is proved that the traffic flow simulated by S-MVDE model will generate the synchronous flow of three-phase traffic theory. Under the open boundary, the model is expanded by adding an on-ramp, the congestion pattern caused by the bottleneck is simulated at different main road flow rates and on-ramp flow rates, which is compared with the traffic congestion pattern observed by Kerner et al. and it is found that the results are consistent with the congestion characteristics in the three-phase traffic flow theory.

  1. Phase Transitions and the Korteweg-De Vries Equation in the Density Difference Lattice Hydrodynamic Model of Traffic Flow

    Science.gov (United States)

    Tian, Jun-Fang; Yuan, Zhen-Zhou; Jia, Bin; Fan, Hong-Qiang

    2013-03-01

    We investigate the phase transitions and the Korteweg-de Vries (KdV) equation in the density difference lattice hydrodynamic (DDLM) model, which shows a close connection with the gas-kinetic-based model and the microscopic car following model. The KdV equation near the neutral stability line is derived and the corresponding soliton solution describing the density waves is obtained. Numerical simulations are conducted in two aspects. On the one hand, under periodic conditions perturbations are applied to demonstrate the nonlinear analysis result. On the other hand, the open boundary condition with random fluctuations is designed to explore the empirical congested traffic patterns. The phase transitions among the free traffic (FT), widening synchronized flow pattern (WSP), moving localized cluster (MLC), oscillatory congested traffic (OCT) and homogeneous congested traffic (HCT) occur by varying the amplitude of the fluctuations. To our knowledge, it is the first research showing that the lattice hydrodynamic model could reproduce so many congested traffic patterns.

  2. Traffic Information Unit, Traffic Information System, Vehicle Management System, Vehicle, and Method of Controlling a Vehicle

    NARCIS (Netherlands)

    Papp, Z.; Doodeman, G.J.N.; Nelisse, M.W.; Sijs, J.; Theeuwes, J.A.C.; Driessen, B.J.F.

    2010-01-01

    A traffic information unit (MD1, MD2, MD3) according to the invention comprises a facility (MI) for tracking vehicle state information of individual vehicles present at a traffic infrastructure and a facility (T) for transmitting said vehicle state information to a vehicle (70B, 70E). A traffic

  3. Forecasting Multivariate Road Traffic Flows Using Bayesian Dynamic Graphical Models, Splines and Other Traffic Variables

    NARCIS (Netherlands)

    Anacleto, Osvaldo; Queen, Catriona; Albers, Casper J.

    Traffic flow data are routinely collected for many networks worldwide. These invariably large data sets can be used as part of a traffic management system, for which good traffic flow forecasting models are crucial. The linear multiregression dynamic model (LMDM) has been shown to be promising for

  4. Travelers ability to observe changes in traffic intensities and traffic light settings

    NARCIS (Netherlands)

    Vreeswijk, Jacob Dirk; Do, Michael; Middag, Wilco; Martens, Marieke Hendrikje; van Berkum, Eric C.; van Arem, Bart; ITSC,

    2011-01-01

    Travel choice behavior is an important determinant in traffic and subject to human imperfection and bounded rationality. In decision-making processes travelers seldom act perfectly rational. Traffic models and traffic network management measure could become more realistic and effective, if

  5. Remark on the Causes of Traffic Accidents and Traffic Awareness: Examples of Usak Province

    Directory of Open Access Journals (Sweden)

    Ercan ÖZEN

    2014-01-01

    Full Text Available Traffic accidents cause important losses on the social and economics structure of countries. While economic losses are able to be compensated in a short time, it isn’t possible to compensate social and communal losses. This study tackles with not the economic aspect of traffic accidents but the social dimension, evaluates the causes of the traffic accidents with respect to views of individuals on traffic and aims to measure the levels of awareness of individuals about traffic. To achieve these goals, a group of 506 people were surveyed in Uşak province and the acquired data were analyzed via one-way ANOVA test in SPSS 16 program. According to the analysis results, drivers and pedestrians are considered to have significant flaws in traffic accidents. But alongside this thought, the idea that traffic accidents are caused by the road having technical and physical problems has come to the fore. This results present a valid motive for the established approach “Vision Zero” , being practised in Sweden, to be adopted in Turkey. When the level of awareness about traffic is examined, it is seen that individuals generally have got inadequate information related traffic rules and traffic authorities. Besides, the fact that individuals are inadequate in terms of courtesy and respect in traffic and that more serious efforts on traffic education is needed to be spent come out as the important findings of this study. The findings of this study can be thought as a directive tool to the policy makers.

  6. Scaling in Computer Network Traffic

    Science.gov (United States)

    2005-01-07

    behaviour, measurement .... 29 The Self-Similar Traffic Model Fractional Gaussian Noise (fGn) and Fractional Brownian Motion (fBm) The unique...AVAILABILITY STATEMENT Approved for public release, distribution unlimited 13. SUPPLEMENTARY NOTES See also ADM001750, Wavelets and Multifractal Analysis... Multifractality Wavelet qth order moments: IE|dX(j, k)|q ∼ C 2αqj, j → 0. Estimating the LHS from data using Sq(j) = 1 nj ∑ k |dX(j, k)|q, and measure the slopes

  7. Nitrogen deposition and traffic. State-of-the-art

    International Nuclear Information System (INIS)

    Teeuwisse, S.

    2010-01-01

    Nitrogen deposition is caused, among other things, by road traffic. This article addresses the relation between traffic and nitrogen deposition and the manner in which the contribution of traffic to nitrogen deposition can be quantified. [nl

  8. Symbols and warrants for major traffic generator guide signing.

    Science.gov (United States)

    2009-09-01

    The Texas Manual on Uniform Traffic Control Devices (TMUTCD) provides the definition of regular traffic generators based on four population types but not for major traffic generators (MTGs). MTG signs have been considered to supplement the overall si...

  9. Traffic flow characteristic and capacity in intelligent work zones.

    Science.gov (United States)

    2009-10-15

    Intellgent transportation system (ITS) technologies are utilized to manage traffic flow and safety in : highway work zones. Traffic management plans for work zones require queuing analyses to determine : the anticipated traffic backups, but the predi...

  10. NASA UAS Traffic Management National Campaign Operations across Six UAS Test Sites

    Science.gov (United States)

    Rios, Joseph; Mulfinger, Daniel; Homola, Jeff; Venkatesan, Priya

    2016-01-01

    NASA's Unmanned Aircraft Systems Traffic Management research aims to develop policies, procedures, requirements, and other artifacts to inform the implementation of a future system that enables small drones to access the low altitude airspace. In this endeavor, NASA conducted a geographically diverse flight test in conjunction with the FAA's six unmanned aircraft systems Test Sites. A control center at NASA Ames Research Center autonomously managed the airspace for all participants in eight states as they flew operations (both real and simulated). The system allowed for common situational awareness across all stakeholders, kept traffic procedurally separated, offered messages to inform the participants of activity relevant to their operations. Over the 3- hour test, 102 flight operations connected to the central research platform with 17 different vehicle types and 8 distinct software client implementations while seamlessly interacting with simulated traffic.

  11. 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.

  12. Capacity of Freeway Merge Areas with Different On-Ramp Traffic Flow

    Directory of Open Access Journals (Sweden)

    Jinxing Shen

    2015-06-01

    Full Text Available This paper is aimed at investigating the influence of different types of traffic flows on the capacity of freeway merge areas. Based on the classical gap-acceptance model, two calculating models were established specifically considering randomly arriving vehicles and individual difference in driving behaviours. Monte-Carlo simulation was implemented to reproduce the maximum traffic volume on the designed freeway merge area under different situations. The results demonstrated that the proposed calculating models have better performance than the conventional gap-acceptance theory on accurately predicting the capacity of freeway merge areas. The findings of research could be helpful to improve the microscopic traffic flow simulation model from a more practical perspective and support the designing of freeway merge areas as well.

  13. An analysis of the traffic safety phenomenon.

    NARCIS (Netherlands)

    Asmussen, E. & Kranenburg, A.

    1982-01-01

    The lack of traffic safety is a combination of the critical coincidence of circumstances in the traffic of incidents (near-accidents) and accidents with unwanted (permanent) consequences, such as fatalities, injured and disabled persons and material damage. This definition covers the whole of the

  14. Formation and Propagation of Local Traffic Jam

    Directory of Open Access Journals (Sweden)

    Hong-sheng Qi

    2013-01-01

    Full Text Available Large scale traffic congestion often stems from local traffic jam in single road or intersection. In this paper, macroscopic method was used to explore the formation and propagation of local traffic jam. It is found that (1 the propagation of traffic jam can be seen as the propagation of traffic signal parameters, that is, virtual split and virtual green time; (2 for a road with endogenous flow, entrance location influences the jam propagation. With the same demand (upstream links flow and entrance flow, the upstream got more influence; (3 when a one-lane road is thoroughly congested, virtual signal parameters everywhere are the same as that at stop line; for a basic road, the virtual signals work in a cooperative manner; (4 phase sequence is one important parameter that influences traffic performances during peak hour where spill back of channelization takes place. The same phase plan for left-turn flow and through flow would be preferred; (5 signal coordination plays an important role in traffic jam propagation and hence effective network signal parameters should be designed to prevent jam from propagation to the whole network. These findings would serve as a basis for future network traffic congestion control.

  15. Distraction-related road traffic collisions

    African Journals Online (AJOL)

    Abstract. Objectives: We aimed to prospectively study distraction-related road traffic collision injuries, their contributory factors, severity, and outcome. Methods: Data were prospectively collected on all hospitalized road traffic collision trauma patients in Al-Ain City who were drivers at the collision time over one and half years ...

  16. Symbols for cockpit displays of traffic information

    Science.gov (United States)

    2009-10-25

    A web-based study assessed pilots ability to learn and remember traffic symbols that may be shown on a Cockpit Display of Traffic Information (CDTI). These displays convey data obtained from Automatic Dependent Surveillance-Broadcast (ADS B) and rela...

  17. GPS queues with heterogeneous traffic classes

    NARCIS (Netherlands)

    Borst, Sem; Mandjes, M.R.H.; van Uitert, Miranda

    2002-01-01

    We consider a queue fed by a mixture of light-tailed and heavy-tailed traffic. The two traffic classes are served in accordance with the generalized processor sharing (GPS) discipline. GPS-based scheduling algorithms, such as weighted fair queueing (WFQ), have emerged as an important mechanism for

  18. 36 CFR 1004.13 - Obstructing traffic.

    Science.gov (United States)

    2010-07-01

    ... road, except as authorized by the Executive Director, or in the event of an accident or other condition... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Obstructing traffic. 1004.13 Section 1004.13 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.13...

  19. 36 CFR 4.13 - Obstructing traffic.

    Science.gov (United States)

    2010-07-01

    ... VEHICLES AND TRAFFIC SAFETY § 4.13 Obstructing traffic. The following are prohibited: (a) Stopping or parking a vehicle upon a park road, except as authorized by the superintendent, or in the event of an accident or other condition beyond the control of the operator. (b) Operating a vehicle so slowly as to...

  20. Environmental protection and traffic regulation in Slovenia

    Directory of Open Access Journals (Sweden)

    Aljaš Plevnik

    1998-01-01

    Full Text Available The article summarises the proposed chapter on traffic in the National programme for environmental protection. The main theme focuses on the suggested goals and measures to reach sustainable development in Slovenia. The goals and measures are derived from the current situation and traffic development trends and their influence on the environment, from international guidelines and the current Slovene policies.

  1. Floating car data for traffic monitoring

    DEFF Research Database (Denmark)

    Torp, Kristian; Lahrmann, Harry Spaabæk

    2005-01-01

    This paper describes a complete prototype system that uses Floating Car Data (FCD) for both automatic and manual detection of queues in traffic. The system is developed under EU’s Tempo program. The systems consists of small hardware units placed in mobile traffic report units (we use taxis...

  2. Visual Analysis in Traffic & Re-identification

    DEFF Research Database (Denmark)

    Møgelmose, Andreas

    Automated analysis of traffic situations - be it cars, signs, or pedestrians - is becoming increasingly relevant and feasible with the advent of powerful sensors, computers, and algorithms. This PhD thesis tackles three themes within this realm: Traffic sign detection, pedestrian detection...

  3. Gaussian queues in light and heavy traffic

    NARCIS (Netherlands)

    Dębicki, K.; Kosiński, K.M.; Mandjes, M.

    2012-01-01

    In this paper we investigate Gaussian queues in the light-traffic and in the heavy-traffic regime. Let $Q^{(c)}_{X}\\equiv\\{Q^{(c)}_{X}(t):t\\ge0\\}$ denote a stationary buffer content process for a fluid queue fed by the centered Gaussian process X≡{X(t):t∈ℝ} with stationary increments, X(0)=0,

  4. 7110.65H Air Traffic Control

    Science.gov (United States)

    1993-09-16

    these functions, it is rec. 2-75a2 Example.- ommended combining them on local control. The ATIS may be "Attention all aircraft. False air traffic...all aircraft. False air traffic control instructions used to specify the desired frequency. have been received in the area of Long Beach Airport

  5. Proportional green time scheduling for traffic lights

    NARCIS (Netherlands)

    P. Kovacs; Le, T. (Tung); R. Núñez Queija (Rudesindo); Vu, H. (Hai); N. Walton

    2016-01-01

    textabstractWe consider the decentralized scheduling of a large number of urban traffic lights. We investigate factors determining system performance, in particular, the length of the traffic light cycle and the proportion of green time allocated to each junction. We study the effect of the length

  6. Stochastic models for road traffic control

    NARCIS (Netherlands)

    Kovács, P.

    2016-01-01

    In this dissertation we make use of the theories of stochastic processes and operations research to develop models and methods to be applied for the analysis and control of road traffic networks. Within this field three subjects are considered: individual routing, urban traffic light networks and

  7. Traffic calming schemes : opportunities and implementation strategies.

    NARCIS (Netherlands)

    Schagen, I.N.L.G. van (ed.)

    2003-01-01

    Commissioned by the Swedish National Road Authority, this report aims to provide a concise overview of knowledge of and experiences with traffic calming schemes in urban areas, both on a technical level and on a policy level. Traffic calming refers to a combination of network planning and

  8. resource allocation methodology for internet heterogeneous traffic

    African Journals Online (AJOL)

    Dr Obe

    buffer capacity in switches - that are required for heterogeneous internet traffic which guarantees a given QoS, even under high network loading conditions. This paper, therefore, presents a method for determining the optimum internet resources required for heterogeneous (data and voice only) traffic services to guarantee ...

  9. Evaluating Performances of Traffic Noise Models | Oyedepo ...

    African Journals Online (AJOL)

    Traffic noise in decibel dB(A) were measured at six locations using 407780A Integrating Sound Level Meter, while spot speed and traffic volume were collected with cine-camera. The predicted sound exposure level (SEL) was evaluated using Burgess, British and FWHA model. The average noise level obtained are 77.64 ...

  10. Consistency analysis of network traffic repositories

    NARCIS (Netherlands)

    Lastdrager, Elmer; Lastdrager, E.E.H.; Pras, Aiko

    Traffic repositories with TCP/IP header information are very important for network analysis. Researchers often assume that such repositories reliably represent all traffic that has been flowing over the network; little thoughts are made regarding the consistency of these repositories. Still, for

  11. Survivable Impairment-Aware Traffic Grooming

    NARCIS (Netherlands)

    Beshir, A.; Nuijts, R.; Malhotra, R.; Kuipers, F.

    2011-01-01

    Traffic grooming allows efficient utilization of network capacity by aggregating several independent traffic streams into a wavelength. In addition, survivability and impairment-awareness (i.e., taking into account the effect of physical impairments) are two important issues that have gained a lot

  12. Calculating Traffic based on Road Sensor Data

    NARCIS (Netherlands)

    Bisseling, Rob; Gao, Fengnan; Hafkenscheid, Patrick; Idema, Reijer; Jetka, Tomasz; Guerra Ones, Valia; Rata, Debanshu; Sikora, Monika

    2014-01-01

    Road sensors gather a lot of statistical data about traffic. In this paper, we discuss how a measure for the amount of traffic on the roads can be derived from this data, such that the measure is independent of the number and placement of sensors, and the calculations can be performed quickly for

  13. Epidemiology o.f· Traffic Accidents

    African Journals Online (AJOL)

    Accidents. An analysis of some 2 100 fatal traffic accidents gave the following results: males-79%; females-21%; a ratio of 4: 1. The high proportion of males to females killed in traffic accidents may be due to the fact that (a) more males commute daily in private and commercial vehicles;. (b) more females commute daily in ...

  14. Accurate Numerical Simulation and Analysis of Multi-Dimensional Shock and Detonation Waves

    Science.gov (United States)

    2010-03-16

    Two of such phenomena, a circular hydraulic jump [9] and a traffic jam [7], have been investigated in detail. It was shown that both in traffic jam and...find a simple analytical solution to another textbook problem in gasdynamics/partial differential equations, namely the traffic jam [7] described...analogy: from traffic jams to black holes, MIT Applied Math- ematics Colloquium, 2009. 5. A.R. Kasimov, Theory and simulation of shock dynamics

  15. Learning styles: The learning methods of air traffic control students

    Science.gov (United States)

    Jackson, Dontae L.

    In the world of aviation, air traffic controllers are an integral part in the overall level of safety that is provided. With a number of controllers reaching retirement age, the Air Traffic Collegiate Training Initiative (AT-CTI) was created to provide a stronger candidate pool. However, AT-CTI Instructors have found that a number of AT-CTI students are unable to memorize types of aircraft effectively. This study focused on the basic learning styles (auditory, visual, and kinesthetic) of students and created a teaching method to try to increase memorization in AT-CTI students. The participants were asked to take a questionnaire to determine their learning style. Upon knowing their learning styles, participants attended two classroom sessions. The participants were given a presentation in the first class, and divided into a control and experimental group for the second class. The control group was given the same presentation from the first classroom session while the experimental group had a group discussion and utilized Middle Tennessee State University's Air Traffic Control simulator to learn the aircraft types. Participants took a quiz and filled out a survey, which tested the new teaching method. An appropriate statistical analysis was applied to determine if there was a significant difference between the control and experimental groups. The results showed that even though the participants felt that the method increased their learning, there was no significant difference between the two groups.

  16. Prediction of Traffic Complexity and Controller Workload in Mixed Equipage NextGen Environments

    Science.gov (United States)

    Lee, Paul U.; Prevot, Thomas

    2012-01-01

    Controller workload is a key factor in limiting en route air traffic capacity. Past efforts to quantify and predict workload have resulted in identifying objective metrics that correlate well with subjective workload ratings during current air traffic control operations. Although these metrics provide a reasonable statistical fit to existing data, they do not provide a good mechanism for estimating controller workload for future air traffic concepts and environments that make different assumptions about automation, enabling technologies, and controller tasks. One such future environment is characterized by en route airspace with a mixture of aircraft equipped with and without Data Communications (Data Comm). In this environment, aircraft with Data Comm will impact controller workload less than aircraft requiring voice communication, altering the close correlation between aircraft count and controller workload that exists in current air traffic operations. This paper outlines a new trajectory-based complexity (TBX) calculation that was presented to controllers during a human-in-the-loop simulation. The results showed that TBX accurately estimated the workload in a mixed Data Comm equipage environment and the resulting complexity values were understood and readily interpreted by the controllers. The complexity was represented as a "modified aircraft account" that weighted different complexity factors and summed them in such a way that the controllers could effectively treat them as aircraft count. The factors were also relatively easy to tune without an extensive data set. The results showed that the TBX approach is well suited for presenting traffic complexity in future air traffic environments.

  17. Managing Traffic Flows for Cleaner Cities: The Role of Green Navigation Systems

    Directory of Open Access Journals (Sweden)

    Fiamma Perez-Prada

    2017-06-01

    Full Text Available Cities worldwide suffer from serious air pollution problems and are main contributors to climate change. Green Navigation systems have a great potential to reduce fuel consumption and exhaust emissions from traffic. This research evaluates the impacts of different percentages of green drivers on traffic, CO2, and NOx over the entire Madrid Region. A macroscopic traffic model was combined with an enhanced macroscopic emissions model and a GIS (Geographic Information Systems to simulate emissions on the basis of average vehicle speeds and traffic intensity at the link level. NOx emissions are evaluated, taking into account not only the exhaust emissions produced by transport activity, but also the amount of the population exposed to these air pollutants. Results show up to 10.4% CO2 and 13.8% NOx reductions in congested traffic conditions for a 90% penetration of green drivers; however, the population’s exposure to NOx increases up to 20.2%. Moreover, while traffic volumes decrease by 13.5% for the entire region, they increase by up to 16.4% downtown. Travel times also increase by 28.7%. Since green drivers tend to choose shorter routes through downtown areas, eco-routing systems are an effective tool for fighting climate change, but are ineffective to reduce air pollution in dense urban areas.

  18. Stability analysis of feedforward anticipation optimal flux difference in traffic lattice hydrodynamic theory

    Science.gov (United States)

    Sun, Di-Hua; Zhang, Geng; Zhao, Min; Cheng, Sen-Lin; Cao, Jian-Dong

    2018-03-01

    Recently, the influence of driver's individual behaviors on traffic stability is research hotspot with the fasting developing transportation cyber-physical systems. In this paper, a new traffic lattice hydrodynamic model is proposed with consideration of driver's feedforward anticipation optimal flux difference. The neutral stability condition of the new model is obtained through linear stability analysis theory. The results show that the stable region will be enlarged on the phase diagram when the feedforward anticipation optimal flux difference effect is taken into account. In order to depict traffic jamming transition properties theoretically, the mKdV equation near the critical point is derived via nonlinear reductive perturbation method. The propagation behavior of traffic density waves can be described by the kink-antikink solution of the mKdV equation. Numerical simulations are conducted to verify the analytical results and all the results confirms that traffic stability can be enhanced significantly by considering the feedforward anticipation optimal flux difference in traffic lattice hydrodynamic theory.

  19. ATLAS: a traffic load aware sensor MAC design for collaborative body area sensor networks.

    Science.gov (United States)

    Rahman, Md Obaidur; Hong, Choong Seon; Lee, Sungwon; Bang, Young-Cheol

    2011-01-01

    In collaborative body sensor networks, namely wireless body area networks (WBANs), each of the physical sensor applications is used to collaboratively monitor the health status of the human body. The applications of WBANs comprise diverse and dynamic traffic loads such as very low-rate periodic monitoring (i.e., observation) data and high-rate traffic including event-triggered bursts. Therefore, in designing a medium access control (MAC) protocol for WBANs, energy conservation should be the primary concern during low-traffic periods, whereas a balance between satisfying high-throughput demand and efficient energy usage is necessary during high-traffic times. In this paper, we design a traffic load-aware innovative MAC solution for WBANs, called ATLAS. The design exploits the superframe structure of the IEEE 802.15.4 standard, and it adaptively uses the contention access period (CAP), contention free period (CFP) and inactive period (IP) of the superframe based on estimated traffic load, by applying a dynamic "wh" (whenever which is required) approach. Unlike earlier work, the proposed MAC design includes load estimation for network load-status awareness and a multi-hop communication pattern in order to prevent energy loss associated with long range transmission. Finally, ATLAS is evaluated through extensive simulations in ns-2 and the results demonstrate the effectiveness of the protocol.

  20. Modeling Network Traffic in Wavelet Domain

    Directory of Open Access Journals (Sweden)

    Sheng Ma

    2004-12-01

    Full Text Available This work discovers that although network traffic has the complicated short- and long-range temporal dependence, the corresponding wavelet coefficients are no longer long-range dependent. Therefore, a "short-range" dependent process can be used to model network traffic in the wavelet domain. Both independent and Markov models are investigated. Theoretical analysis shows that the independent wavelet model is sufficiently accurate in terms of the buffer overflow probability for Fractional Gaussian Noise traffic. Any model, which captures additional correlations in the wavelet domain, only improves the performance marginally. The independent wavelet model is then used as a unified approach to model network traffic including VBR MPEG video and Ethernet data. The computational complexity is O(N for developing such wavelet models and generating synthesized traffic of length N, which is among the lowest attained.