Long-range correlation analysis of urban traffic data

International Nuclear Information System (INIS)

Peng, Sheng; Jun-Feng, Wang; Shu-Long, Zhao; Tie-Qiao, Tang

2010-01-01

This paper investigates urban traffic data by analysing the long-range correlation with detrended fluctuation analysis. Through a large number of real data collected by the travel time detection system in Beijing, the variation of flow in different time periods and intersections is studied. According to the long-range correlation in different time scales, it mainly discusses the effect of intersection location in road net, people activity customs and special traffic controls on urban traffic flow. As demonstrated by the obtained results, the urban traffic flow represents three-phase characters similar to highway traffic. Moreover, compared by the two groups of data obtained before and after the special traffic restrictions (vehicles with special numbered plates only run in a special workday) enforcement, it indicates that the rules not only reduce the flow but also avoid irregular fluctuation. (general)

Effects of urban sprawl and vehicle miles traveled on traffic fatalities.

Science.gov (United States)

Yeo, Jiho; Park, Sungjin; Jang, Kitae

2015-01-01

Previous research suggests that urban sprawl increases auto-dependency and that excessive auto use increases the risk of traffic fatalities. This indirect effect of urban sprawl on traffic fatalities is compared to non-vehicle miles traveled (VMT)-related direct effect of sprawl on fatalities. We conducted a path analysis to examine the causal linkages among urban sprawl, VMT, traffic fatalities, income, and fuel cost. The path diagram includes 2 major linkages: the direct relationship between urban sprawl and traffic fatalities and the indirect effect on fatalities through increased VMT in sprawling urban areas. To measure the relative strength of these causal linkages, path coefficients are estimated using data collected nationally from 147 urbanized areas in the United States. Through both direct and indirect paths, urban sprawl is associated with greater numbers of traffic fatalities, but the direct effect of sprawl on fatalities is more influential than the indirect effect. Enhancing traffic safety can be achieved by impeding urban sprawl and encouraging compact development. On the other hand, policy tools reducing VMT may be less effective than anticipated for traffic safety.

How and when urban vehicular traffic pollutes the environment

International Nuclear Information System (INIS)

Cera, L.; Di Mascio, P.

1993-01-01

This paper first compares monitored values of urban traffic air and noise pollution with Italian and European Communities pollution limits to assess the efficacy of current and proposed pollution regulations. The paper then focuses on the environmental impacts of the generation and discharge of waste waters during the construction and use of road surfaces. The related problems discussed include: soil erosion due to the increased exposure of bordering terrestrial ecosystems to damaging atmospheric pollutants; and the reception by roadside land areas of pollutants absorbed in rainfall runoff which has come into contact with road surfaces. Some suggestions are made on how to abate these particular types of traffic derived pollutants

Spectral Analysis of Traffic Functions in Urban Areas

Directory of Open Access Journals (Sweden)

Florin Nemtanu

2015-12-01

Full Text Available The paper is focused on the Fourier transform application in urban traffic analysis and the use of said transform in traffic decomposition. The traffic function is defined as traffic flow generated by different categories of traffic participants. A Fourier analysis was elaborated in terms of identifying the main traffic function components, called traffic sub-functions. This paper presents the results of the method being applied in a real case situation, that is, an intersection in the city of Bucharest where the effect of a bus line was analysed. The analysis was done using different time scales, while three different traffic functions were defined to demonstrate the theoretical effect of the proposed method of analysis. An extension of the method is proposed to be applied in urban areas, especially in the areas covered by predictive traffic control.

A Survey on Urban Traffic Management System Using Wireless Sensor Networks

Science.gov (United States)

Nellore, Kapileswar; Hancke, Gerhard P.

2016-01-01

Nowadays, the number of vehicles has increased exponentially, but the bedrock capacities of roads and transportation systems have not developed in an equivalent way to efficiently cope with the number of vehicles traveling on them. Due to this, road jamming and traffic correlated pollution have increased with the associated adverse societal and financial effect on different markets worldwide. A static control system may block emergency vehicles due to traffic jams. Wireless Sensor networks (WSNs) have gained increasing attention in traffic detection and avoiding road congestion. WSNs are very trendy due to their faster transfer of information, easy installation, less maintenance, compactness and for being less expensive compared to other network options. There has been significant research on Traffic Management Systems using WSNs to avoid congestion, ensure priority for emergency vehicles and cut the Average Waiting Time (AWT) of vehicles at intersections. In recent decades, researchers have started to monitor real-time traffic using WSNs, RFIDs, ZigBee, VANETs, Bluetooth devices, cameras and infrared signals. This paper presents a survey of current urban traffic management schemes for priority-based signalling, and reducing congestion and the AWT of vehicles. The main objective of this survey is to provide a taxonomy of different traffic management schemes used for avoiding congestion. Existing urban traffic management schemes for the avoidance of congestion and providing priority to emergency vehicles are considered and set the foundation for further research. PMID:26828489

Examining perimeter gating control of urban traffic networkswith locally adaptive traffic signals

NARCIS (Netherlands)

Keyvan Ekbatani, M.; Gao, X.; Gayah, V.V.; Knoop, V.L.

2015-01-01

Traditionally, urban traffic is controlled by traffic lights. Recent findings of the Macroscopic or Network Fundamental Diagram (MFD or NFD) have led to the development of novel traffic control strategies that can be applied at a networkwide level. One pertinent example is perimeter flow control

UTRaLab – Urban Traffic Research Laboratory

Directory of Open Access Journals (Sweden)

Karsten Kozempel

2017-08-01

Full Text Available The Urban Traffic Research Laboratory (UTRaLab is a research and test track for traffic detection methods and sensors. It is located at the Ernst-Ruska-Ufer, in the southeast of the city of Berlin (Germany. The UTRaLab covers 1 km of a highly-frequented urban road and is connected to a motorway. It is equipped with two gantries with distance of 850 m in between and has several outstations for data collection. The gantries contain many different traffic sensors like inductive loops, cameras, lasers or wireless sensors for traffic data acquisition. Additionally a weather station records environmental data. The UTRaLab’s main purposes are the data collection of traffic data on the one hand and testing newly developed sensors on the other hand.

Characterizing local traffic contributions to particulate air pollution in street canyons using mobile monitoring techniques

Science.gov (United States)

Zwack, Leonard M.; Paciorek, Christopher J.; Spengler, John D.; Levy, Jonathan I.

2011-05-01

Traffic within urban street canyons can contribute significantly to ambient concentrations of particulate air pollution. In these settings, it is challenging to separate within-canyon source contributions from urban and regional background concentrations given the highly variable and complex emissions and dispersion characteristics. In this study, we used continuous mobile monitoring of traffic-related particulate air pollutants to assess the contribution to concentrations, above background, of traffic in the street canyons of midtown Manhattan. Concentrations of both ultrafine particles (UFP) and fine particles (PM 2.5) were measured at street level using portable instruments. Statistical modeling techniques accounting for autocorrelation were used to investigate the presence of spatial heterogeneity of pollutant concentrations as well as to quantify the contribution of within-canyon traffic sources. Measurements were also made within Central Park, to examine the impact of offsets from major roadways in this urban environment. On average, an approximate 11% increase in concentrations of UFP and 8% increase in concentrations of PM 2.5 over urban background was estimated during high-traffic periods in street canyons as opposed to low traffic periods. Estimates were 8% and 5%, respectively, after accounting for temporal autocorrelation. Within Central Park, concentrations were 40% higher than background (5% after accounting for temporal autocorrelation) within the first 100 m from the nearest roadway for UFP, with a smaller but statistically significant increase for PM 2.5. Our findings demonstrate the viability of a mobile monitoring protocol coupled with spatiotemporal modeling techniques in characterizing local source contributions in a setting with street canyons.

Management of Traffic Congestion in Urban Areas

Directory of Open Access Journals (Sweden)

Vilibald Premzl

2012-10-01

Full Text Available The use of road vehicles is increasing, the benefits they affordhave been progressively diminished by external costs.Whereas traffic increases as we approach the centre, the roadand open space decreases. The greater specialisation allows thecity growth in size and in traffic attraction. In this way urbangrowth feeds itself !mer-urban transp011 facilities also becomemore extensive. Growth in size of the city generates greateramounts of traffic and can eventually give rise to agglomerationdiseconomies. Higher transport costs, offices and shops, attractedby the accessibility of central locations, gradually replaceresidential uses, people being forced to seek housing inthe suburbs. As the urban area expands and offices in the citycentre are built denser and highe1; traffic congestion increases.This may result in the fall in centra/land values, since accessibilitydiminishes with the saturation of transport network. Increasedpollution takes various forms as noise, smoke andovercrowded housing in the centre, urban decay in the transitionalzone as commercial development is anticipated.

Monitoring road traffic congestion using a macroscopic traffic model and a statistical monitoring scheme

KAUST Repository

Zeroual, Abdelhafid; Harrou, Fouzi; Sun, Ying; Messai, Nadhir

2017-01-01

Monitoring vehicle traffic flow plays a central role in enhancing traffic management, transportation safety and cost savings. In this paper, we propose an innovative approach for detection of traffic congestion. Specifically, we combine the flexibility and simplicity of a piecewise switched linear (PWSL) macroscopic traffic model and the greater capacity of the exponentially-weighted moving average (EWMA) monitoring chart. Macroscopic models, which have few, easily calibrated parameters, are employed to describe a free traffic flow at the macroscopic level. Then, we apply the EWMA monitoring chart to the uncorrelated residuals obtained from the constructed PWSL model to detect congested situations. In this strategy, wavelet-based multiscale filtering of data has been used before the application of the EWMA scheme to improve further the robustness of this method to measurement noise and reduce the false alarms due to modeling errors. The performance of the PWSL-EWMA approach is successfully tested on traffic data from the three lane highway portion of the Interstate 210 (I-210) highway of the west of California and the four lane highway portion of the State Route 60 (SR60) highway from the east of California, provided by the Caltrans Performance Measurement System (PeMS). Results show the ability of the PWSL-EWMA approach to monitor vehicle traffic, confirming the promising application of this statistical tool to the supervision of traffic flow congestion.

Monitoring road traffic congestion using a macroscopic traffic model and a statistical monitoring scheme

KAUST Repository

Zeroual, Abdelhafid

2017-08-19

Monitoring vehicle traffic flow plays a central role in enhancing traffic management, transportation safety and cost savings. In this paper, we propose an innovative approach for detection of traffic congestion. Specifically, we combine the flexibility and simplicity of a piecewise switched linear (PWSL) macroscopic traffic model and the greater capacity of the exponentially-weighted moving average (EWMA) monitoring chart. Macroscopic models, which have few, easily calibrated parameters, are employed to describe a free traffic flow at the macroscopic level. Then, we apply the EWMA monitoring chart to the uncorrelated residuals obtained from the constructed PWSL model to detect congested situations. In this strategy, wavelet-based multiscale filtering of data has been used before the application of the EWMA scheme to improve further the robustness of this method to measurement noise and reduce the false alarms due to modeling errors. The performance of the PWSL-EWMA approach is successfully tested on traffic data from the three lane highway portion of the Interstate 210 (I-210) highway of the west of California and the four lane highway portion of the State Route 60 (SR60) highway from the east of California, provided by the Caltrans Performance Measurement System (PeMS). Results show the ability of the PWSL-EWMA approach to monitor vehicle traffic, confirming the promising application of this statistical tool to the supervision of traffic flow congestion.

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.

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.

Application of GIS in Urban Traffic Noise Pollution

OpenAIRE

Manouchehr Omidvari; Ali Asghar Alesheikh

2010-01-01

Large urban areas are facing growing problems of noise pollutions. Geospatial Information Systems (GIS) can conveniently be adapted to gather, analyze and present noise information. GIS can also be extended to answer to user specific problems through deterministic and statistics models. The objectives of this research were to measure urban traffic noise levels, analyze temporal and spatial dynamics of urban traffic-induced noise pollution in the first districted of Tehran estimate the noise f...

Land use regression modeling of intra-urban residential variability in multiple traffic-related air pollutants

Directory of Open Access Journals (Sweden)

Baxter Lisa K

2008-05-01

Full Text Available Abstract Background There is a growing body of literature linking GIS-based measures of traffic density to asthma and other respiratory outcomes. However, no consensus exists on which traffic indicators best capture variability in different pollutants or within different settings. As part of a study on childhood asthma etiology, we examined variability in outdoor concentrations of multiple traffic-related air pollutants within urban communities, using a range of GIS-based predictors and land use regression techniques. Methods We measured fine particulate matter (PM2.5, nitrogen dioxide (NO2, and elemental carbon (EC outside 44 homes representing a range of traffic densities and neighborhoods across Boston, Massachusetts and nearby communities. Multiple three to four-day average samples were collected at each home during winters and summers from 2003 to 2005. Traffic indicators were derived using Massachusetts Highway Department data and direct traffic counts. Multivariate regression analyses were performed separately for each pollutant, using traffic indicators, land use, meteorology, site characteristics, and central site concentrations. Results PM2.5 was strongly associated with the central site monitor (R2 = 0.68. Additional variability was explained by total roadway length within 100 m of the home, smoking or grilling near the monitor, and block-group population density (R2 = 0.76. EC showed greater spatial variability, especially during winter months, and was predicted by roadway length within 200 m of the home. The influence of traffic was greater under low wind speed conditions, and concentrations were lower during summer (R2 = 0.52. NO2 showed significant spatial variability, predicted by population density and roadway length within 50 m of the home, modified by site characteristics (obstruction, and with higher concentrations during summer (R2 = 0.56. Conclusion Each pollutant examined displayed somewhat different spatial patterns

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)

Modeling the heterogeneous traffic correlations in urban road systems using traffic-enhanced community detection approach

Science.gov (United States)

Lu, Feng; Liu, Kang; Duan, Yingying; Cheng, Shifen; Du, Fei

2018-07-01

A better characterization of the traffic influence among urban roads is crucial for traffic control and traffic forecasting. The existence of spatial heterogeneity imposes great influence on modeling the extent and degree of road traffic correlation, which is usually neglected by the traditional distance based method. In this paper, we propose a traffic-enhanced community detection approach to spatially reveal the traffic correlation in city road networks. First, the road network is modeled as a traffic-enhanced dual graph with the closeness between two road segments determined not only by their topological connection, but also by the traffic correlation between them. Then a flow-based community detection algorithm called Infomap is utilized to identify the road segment clusters. Evaluated by Moran's I, Calinski-Harabaz Index and the traffic interpolation application, we find that compared to the distance based method and the community based method, our proposed traffic-enhanced community based method behaves better in capturing the extent of traffic relevance as both the topological structure of the road network and the traffic correlations among urban roads are considered. It can be used in more traffic-related applications, such as traffic forecasting, traffic control and guidance.

The Fusion Model of Intelligent Transportation Systems Based on the Urban Traffic Ontology

Science.gov (United States)

Yang, Wang-Dong; Wang, Tao

On these issues unified representation of urban transport information using urban transport ontology, it defines the statute and the algebraic operations of semantic fusion in ontology level in order to achieve the fusion of urban traffic information in the semantic completeness and consistency. Thus this paper takes advantage of the semantic completeness of the ontology to build urban traffic ontology model with which we resolve the problems as ontology mergence and equivalence verification in semantic fusion of traffic information integration. Information integration in urban transport can increase the function of semantic fusion, and reduce the amount of data integration of urban traffic information as well enhance the efficiency and integrity of traffic information query for the help, through the practical application of intelligent traffic information integration platform of Changde city, the paper has practically proved that the semantic fusion based on ontology increases the effect and efficiency of the urban traffic information integration, reduces the storage quantity, and improve query efficiency and information completeness.

Applicability of models to estimate traffic noise for urban roads.

Science.gov (United States)

Melo, Ricardo A; Pimentel, Roberto L; Lacerda, Diego M; Silva, Wekisley M

2015-01-01

Traffic noise is a highly relevant environmental impact in cities. Models to estimate traffic noise, in turn, can be useful tools to guide mitigation measures. In this paper, the applicability of models to estimate noise levels produced by a continuous flow of vehicles on urban roads is investigated. The aim is to identify which models are more appropriate to estimate traffic noise in urban areas since several models available were conceived to estimate noise from highway traffic. First, measurements of traffic noise, vehicle count and speed were carried out in five arterial urban roads of a brazilian city. Together with geometric measurements of width of lanes and distance from noise meter to lanes, these data were input in several models to estimate traffic noise. The predicted noise levels were then compared to the respective measured counterparts for each road investigated. In addition, a chart showing mean differences in noise between estimations and measurements is presented, to evaluate the overall performance of the models. Measured Leq values varied from 69 to 79 dB(A) for traffic flows varying from 1618 to 5220 vehicles/h. Mean noise level differences between estimations and measurements for all urban roads investigated ranged from -3.5 to 5.5 dB(A). According to the results, deficiencies of some models are discussed while other models are identified as applicable to noise estimations on urban roads in a condition of continuous flow. Key issues to apply such models to urban roads are highlighted.

Spatial correlation analysis of urban traffic state under a perspective of community detection

Science.gov (United States)

Yang, Yanfang; Cao, Jiandong; Qin, Yong; Jia, Limin; Dong, Honghui; Zhang, Aomuhan

2018-05-01

Understanding the spatial correlation of urban traffic state is essential for identifying the evolution patterns of urban traffic state. However, the distribution of traffic state always has characteristics of large spatial span and heterogeneity. This paper adapts the concept of community detection to the correlation network of urban traffic state and proposes a new perspective to identify the spatial correlation patterns of traffic state. In the proposed urban traffic network, the nodes represent road segments, and an edge between a pair of nodes is added depending on the result of significance test for the corresponding correlation of traffic state. Further, the process of community detection in the urban traffic network (named GWPA-K-means) is applied to analyze the spatial dependency of traffic state. The proposed method extends the traditional K-means algorithm in two steps: (i) redefines the initial cluster centers by two properties of nodes (the GWPA value and the minimum shortest path length); (ii) utilizes the weight signal propagation process to transfer the topological information of the urban traffic network into a node similarity matrix. Finally, numerical experiments are conducted on a simple network and a real urban road network in Beijing. The results show that GWPA-K-means algorithm is valid in spatial correlation analysis of traffic state. The network science and community structure analysis perform well in describing the spatial heterogeneity of traffic state on a large spatial scale.

Urban scale air quality modelling using detailed traffic emissions estimates

Science.gov (United States)

Borrego, C.; Amorim, J. H.; Tchepel, O.; Dias, D.; Rafael, S.; Sá, E.; Pimentel, C.; Fontes, T.; Fernandes, P.; Pereira, S. R.; Bandeira, J. M.; Coelho, M. C.

2016-04-01

The atmospheric dispersion of NOx and PM10 was simulated with a second generation Gaussian model over a medium-size south-European city. Microscopic traffic models calibrated with GPS data were used to derive typical driving cycles for each road link, while instantaneous emissions were estimated applying a combined Vehicle Specific Power/Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe (VSP/EMEP) methodology. Site-specific background concentrations were estimated using time series analysis and a low-pass filter applied to local observations. Air quality modelling results are compared against measurements at two locations for a 1 week period. 78% of the results are within a factor of two of the observations for 1-h average concentrations, increasing to 94% for daily averages. Correlation significantly improves when background is added, with an average of 0.89 for the 24 h record. The results highlight the potential of detailed traffic and instantaneous exhaust emissions estimates, together with filtered urban background, to provide accurate input data to Gaussian models applied at the urban scale.

Urban snow indicates pollution originating from road traffic.

Science.gov (United States)

Kuoppamäki, Kirsi; Setälä, Heikki; Rantalainen, Anna-Lea; Kotze, D Johan

2014-12-01

Traffic is a major source of pollutants in cities. In this well-replicated study we analysed a broad array of contaminants in snowpacks along roads of different traffic intensities. The majority of pollutants showed a similar pattern with respect to traffic intensity: pH and conductivity as well as concentrations of PAHs, total suspended solids, phosphorus and most heavy metals were higher next to high intensity roads compared to low intensity roads. These pollutant levels also decreased considerably up to 5 m distance from the roads. Furthermore, apart from nitrogen, these variables increased in concentration from control sites in urban forest patches to road bank sites next to roads of low, intermediate and high traffic intensities. The deposition pattern of various traffic-derived pollutants--whether gaseous or particle-bound--was the same. Such information can be useful for the purposes of managing pollutants in urban areas. Copyright © 2014 Elsevier Ltd. All rights reserved.

Integrated Quality Management System in Public Urban Traffic

Directory of Open Access Journals (Sweden)

Husein Pašagić

2005-09-01

Full Text Available Public urban traffic (PUT requirements are based on thespecific characteristics that dictate the requirements themselves.The problems faced by all the big cities regarding public urbantransport are very similar, and they range from unacceptabilityof the very organisational structure of the system facing the populationgrowth, limitations and congestions of the traffic routesloaded by an increasing number of automobiles, to the chroniclack of economic funds for the investments that would createthe necessary conditions for positive shifts. In PUT there aremany random parameters whose statistical laws are not easy todetermine and it is often the topic of research of various profilesof scientists. There is always the satisfaction, that is, the lack ofsatisfaction by the final user of the public urban transport andall the other involved groups. The result is that the potential usersof public urban transport give up and try to find other solutionsfor their transport needs, turning in principle to individualtraffic. Consequently, the number of passenger cars on the trafficroutes increases along with all the resulting negative effects.The complex systems of public urban transport facing the increasingrequirements to improve efficiency have to be subjectedto certain changes in order to achieve physical sustainability oftraffic at all, and to satisfy the environmental requirements thatoccur as counterbalance to the pollution of the urban area.With the aim of achieving optimal conditions for the qualityof service, and by introducing acceptable traffic solutionscombined with the integrated quality management systembased on the standards ISO 9001 and ISO 14000 high-qualityshifts are made possible. The integration of these standards resultsin the rational combining of the quality management systeminto a single efficient system, reflected in achieving high-quality traffic and transport service, improved informationflow, unique documentation, positive

Urbanization and traffic related exposures as risk factors for Schizophrenia

DEFF Research Database (Denmark)

Pedersen, Carsten Bøcker; Mortensen, Preben Bo

2006-01-01

to nearest major road had no significant effect. CONCLUSIONS: The cause(s) or exposure(s) responsible for the urban-rural differences in schizophrenia risk were closer related to the degree of urbanization than to the geographical distance to nearest major road. Traffic related exposures might thus be less......BACKGROUND: Urban birth or upbringing increase schizophrenia risk. Though unknown, the causes of these urban-rural differences have been hypothesized to include, e.g., infections, diet, toxic exposures, social class, or an artefact due to selective migration. METHODS: We investigated the hypothesis...... that traffic related exposures affect schizophrenia risk and that this potential effect is responsible for the urban-rural differences. The geographical distance from place of residence to nearest major road was used as a proxy variable for traffic related exposures. We used a large population-based sample...

Evaluation of diversion strategies in the context of advanced traffic management systems (ATMS) for an urban traffic corridor with heterogeneous traffic

Energy Technology Data Exchange (ETDEWEB)

Korlapati, D.R.

2007-07-01

Due to urbanization and accelerated growth in vehicular traffic, most big cities in India face problems related to traffic management resulting in severe congestion, pollution, and a high rate of accidents during peak hours. Lane blocking incidents on arterials or urban traffic corridors cause major disruption to traffic flow. Peak hour congestion with low average speeds and high accident rates are commonly associated with traffic in major cities in India. The situation is deteriorating further as creation of new facilities are almost impossible, with resource and space constraints. In such scenarios, application of advanced technologies seems to offer hope. One such application area is Advanced Traffic Management Systems (ATMS), a component of intelligent transportation system (ITS). Due to the unique traffic characteristics prevailing in India, the application of such systems needs to first be evaluated before implementation. This paper proposed a research methodology for the evaluation of diversion strategies in the context of ATMS for an urban corridor in India. The evaluation framework combined several relevant modules related to various aspects of traffic control, surveillance and advisory. As part of this study, a simulation model and a simulation optimization model were developed. The simulation model was microscopic in nature and captured the driver behaviour and traffic characteristics realistically by modeling the complex interactions among vehicles traversing a corridor. It was concluded that the results and observations were useful indicators to gauge the potential success of diversion plans. 10 refs., 1 tab., 2 figs.

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

Understanding structure of urban traffic network based on spatial-temporal correlation analysis

Science.gov (United States)

Yang, Yanfang; Jia, Limin; Qin, Yong; Han, Shixiu; Dong, Honghui

2017-08-01

Understanding the structural characteristics of urban traffic network comprehensively can provide references for improving road utilization rate and alleviating traffic congestion. This paper focuses on the spatial-temporal correlations between different pairs of traffic series and proposes a complex network-based method of constructing the urban traffic network. In the network, the nodes represent road segments, and an edge between a pair of nodes is added depending on the result of significance test for the corresponding spatial-temporal correlation. Further, a modified PageRank algorithm, named the geographical weight-based PageRank algorithm (GWPA), is proposed to analyze the spatial distribution of important segments in the road network. Finally, experiments are conducted by using three kinds of traffic series collected from the urban road network in Beijing. Experimental results show that the urban traffic networks constructed by three traffic variables all indicate both small-world and scale-free characteristics. Compared with the results of PageRank algorithm, GWPA is proved to be valid in evaluating the importance of segments and identifying the important segments with small degree.

Research on Urban Road Traffic Congestion Charging Based on Sustainable Development

Science.gov (United States)

Ye, Sun

Traffic congestion is a major problem which bothers our urban traffic sustainable development at present. Congestion charging is an effective measure to alleviate urban traffic congestion. The paper first probes into several key issues such as the goal, the pricing, the scope, the method and the redistribution of congestion charging from theoretical angle. Then it introduces congestion charging practice in Singapore and London and draws conclusion and suggestion that traffic congestion charging should take scientific plan, support of public, public transportation development as the premise.

A Numerical Simulation of Traffic-Related Air Pollution Exposures in Urban Street Canyons

Science.gov (United States)

Liu, J.; Fu, X.; Tao, S.

2016-12-01

Urban street canyons are usually associated with intensive vehicle emissions. However, the high buildings successively along both sides of a street block the dispersion of traffic-generated air pollutants, which enhances human exposure and adversely affects human health. In this study, an urban scale traffic pollution dispersion model is developed with the consideration of street distribution, canyon geometry, background meteorology, traffic assignment, traffic emissions and air pollutant dispersion. Vehicle exhausts generated from traffic flows will first disperse inside a street canyon along the micro-scale wind field (generated by computational fluid dynamics (CFD) model) and then leave the street canyon and further disperse over the urban area. On the basis of this model, the effects of canyon geometry on the distribution of NOx and CO from traffic emissions were studied over the center of Beijing, China. We found that an increase of building height along the streets leads to higher pollution levels inside streets and lower pollution levels outside, resulting in higher domain-averaged concentrations over the area. In addition, street canyons with equal (or highly uneven) building heights on two sides of a street tend to lower the urban-scale air pollution concentrations at pedestrian level. Our results indicate that canyon geometry strongly influences human exposure to traffic pollutants in the populated urban area. Carefully planning street layout and canyon geometry in consideration of traffic demand as well as local weather pattern may significantly reduce the chances of unhealthy air being inhaled by urban residents.

The impacts of road traffic management on urban air quality

Energy Technology Data Exchange (ETDEWEB)

Oduyemi, K.O.K. [School of Construction and Environment, University of Abertay Dundee, Dundee (United Kingdom); Davidson, B. [Department of Environmental Health and Consumer Protection, Dundee City Council, Tayside House, Crichton Street, Dundee (United Kingdom)

1998-07-11

The effects of road traffic emissions on urban air quality are investigated, using long-term nitrogen dioxide (NO{sub 2}) data. The effectiveness of the several traffic management measures that have been made in Dundee city centre, UK, within the last 5 years in relation to urban air quality is discussed. The information assessed during this study indicates that the annual mean NO{sub 2} levels at all the study sites are, at present, below the current EC and WHO (long-term) air quality standards for NO{sub 2} concentration in the ambient air. Traffic restrictions appear to be effective in protecting urban air quality. The annual mean NO{sub 2} concentration at two of the study sites is currently close to 40 {mu}g/m{sup 3}, a value published in the Air Quality Regulations 1997 for the air quality objective to be achieved by the year 2005. Proactive traffic management mitigation measures are proposed for these sites and a methodology for the consideration of traffic management alternatives, based upon traffic flow modal split, is described. Some measures proposed are based upon a survey of vehicle occupancy rates, carried out at the busiest of the four study sites. The methodology and assessment procedures presented should be invaluable to assessors of traffic management and local air quality management in a small city, both at the planning and at the auditing stage

Assessing the representativeness of monitoring data from an urban intersection site in Central London, UK

Energy Technology Data Exchange (ETDEWEB)

Scaperdas, A.; Colvile, R.N. [Imperial College of Science, Technology and Medicine, London (United Kingdom). Centre for Environmental Technology

1999-02-01

The wind flow field around urban street-building configurations has an important influence on the microscale pollutant dispersion from road traffic, affecting overall dilution and creating localised spatial variations of pollutant concentration. As a result, the ``representatives`` of air quality measurements made at different urban monitoring sites can be strongly dependent on the interaction of the local wind flow field with the street-building geometry surrounding the monitor. The present study is an initial attempt to develop a method for appraising the significance of air quality measurements from urban monitoring sites, using a general application computational fluid dynamics (CFD) code to simulate small-scale flow and dispersion patterns around real urban building configurations. The main focus of the work was to evaluate routine CO monitoring data collected by Westminster City Council at an intersection of street canyons at Marylebone Road, Central London. Many monitors in the UK are purposely situated at urban canyon intersections, which are thought to be local ``hot spots`` of pollutant emissions, however very limited information exists in the literature on the flow and dispersion patterns associated with them. With the use of simple CFD simulations and the analysis of available monitoring data, it was possible to gain insights into the effect of wind direction on the small-scale dispersion patterns at the chosen intersection, and how that can influence the data captured by a monitor. It was found that a change in wind direction could result in an increase or decrease of monitored CO concentration of up to 80%, for a given level of traffic emissions and meteorological conditions. Understanding and de-coupling the local effect of wind direction from monitoring data using the methods presented in this work could prove a useful new tool for urban monitoring data interpretation. (author)

The impact of traffic-flow patterns on air quality in urban street canyons

International Nuclear Information System (INIS)

Thaker, Prashant; Gokhale, Sharad

2016-01-01

We investigated the effect of different urban traffic-flow patterns on pollutant dispersion in different winds in a real asymmetric street canyon. Free-flow traffic causes more turbulence in the canyon facilitating more dispersion and a reduction in pedestrian level concentration. The comparison of with and without a vehicle-induced-turbulence revealed that when winds were perpendicular, the free-flow traffic reduced the concentration by 73% on the windward side with a minor increase of 17% on the leeward side, whereas for parallel winds, it reduced the concentration by 51% and 29%. The congested-flow traffic increased the concentrations on the leeward side by 47% when winds were perpendicular posing a higher risk to health, whereas reduced it by 17–42% for parallel winds. The urban air quality and public health can, therefore, be improved by improving the traffic-flow patterns in street canyons as vehicle-induced turbulence has been shown to contribute significantly to dispersion. - Highlights: • CFD is used to study impact of traffic-flow patterns on urban air quality. • Facilitating free-flow patterns induce more turbulence in street canyons. • Traffic-generated turbulence alters pollutant levels in urban street canyons. - This study investigates the effect of vehicle-induced-turbulence generated during free-flow traffic pattern in reduction of air pollutant concentrations in urban street canyons.

Monitoring Street-Level Spatial-Temporal Variations of Carbon Monoxide in Urban Settings Using a Wireless Sensor Network (WSN) Framework

Science.gov (United States)

Wen, Tzai-Hung; Jiang, Joe-Air; Sun, Chih-Hong; Juang, Jehn-Yih; Lin, Tzu-Shiang

2013-01-01

Air pollution has become a severe environmental problem due to urbanization and heavy traffic. Monitoring street-level air quality is an important issue, but most official monitoring stations are installed to monitor large-scale air quality conditions, and their limited spatial resolution cannot reflect the detailed variations in air quality that may be induced by traffic jams. By deploying wireless sensors on crossroads and main roads, this study established a pilot framework for a wireless sensor network (WSN)-based real-time monitoring system to understand street-level spatial-temporal changes of carbon monoxide (CO) in urban settings. The system consists of two major components. The first component is the deployment of wireless sensors. We deployed 44 sensor nodes, 40 transmitter nodes and four gateway nodes in this study. Each sensor node includes a signal processing module, a CO sensor and a wireless communication module. In order to capture realistic human exposure to traffic pollutants, all sensors were deployed at a height of 1.5 m on lampposts and traffic signs. The study area covers a total length of 1.5 km of Keelung Road in Taipei City. The other component is a map-based monitoring platform for sensor data visualization and manipulation in time and space. Using intensive real-time street-level monitoring framework, we compared the spatial-temporal patterns of air pollution in different time periods. Our results capture four CO concentration peaks throughout the day at the location, which was located along an arterial and nearby traffic sign. The hourly average could reach 5.3 ppm from 5:00 pm to 7:00 pm due to the traffic congestion. The proposed WSN-based framework captures detailed ground information and potential risk of human exposure to traffic-related air pollution. It also provides street-level insights into real-time monitoring for further early warning of air pollution and urban environmental management. PMID:24287859

Monitoring Street-Level Spatial-Temporal Variations of Carbon Monoxide in Urban Settings Using a Wireless Sensor Network (WSN Framework

Directory of Open Access Journals (Sweden)

Tzai-Hung Wen

2013-11-01

Full Text Available Air pollution has become a severe environmental problem due to urbanization and heavy traffic. Monitoring street-level air quality is an important issue, but most official monitoring stations are installed to monitor large-scale air quality conditions, and their limited spatial resolution cannot reflect the detailed variations in air quality that may be induced by traffic jams. By deploying wireless sensors on crossroads and main roads, this study established a pilot framework for a wireless sensor network (WSN-based real-time monitoring system to understand street-level spatial-temporal changes of carbon monoxide (CO in urban settings. The system consists of two major components. The first component is the deployment of wireless sensors. We deployed 44 sensor nodes, 40 transmitter nodes and four gateway nodes in this study. Each sensor node includes a signal processing module, a CO sensor and a wireless communication module. In order to capture realistic human exposure to traffic pollutants, all sensors were deployed at a height of 1.5 m on lampposts and traffic signs. The study area covers a total length of 1.5 km of Keelung Road in Taipei City. The other component is a map-based monitoring platform for sensor data visualization and manipulation in time and space. Using intensive real-time street-level monitoring framework, we compared the spatial-temporal patterns of air pollution in different time periods. Our results capture four CO concentration peaks throughout the day at the location, which was located along an arterial and nearby traffic sign. The hourly average could reach 5.3 ppm from 5:00 pm to 7:00 pm due to the traffic congestion. The proposed WSN-based framework captures detailed ground information and potential risk of human exposure to traffic-related air pollution. It also provides street-level insights into real-time monitoring for further early warning of air pollution and urban environmental management.

Monitoring street-level spatial-temporal variations of carbon monoxide in urban settings using a wireless sensor network (WSN) framework.

Science.gov (United States)

Wen, Tzai-Hung; Jiang, Joe-Air; Sun, Chih-Hong; Juang, Jehn-Yih; Lin, Tzu-Shiang

2013-11-27

Air pollution has become a severe environmental problem due to urbanization and heavy traffic. Monitoring street-level air quality is an important issue, but most official monitoring stations are installed to monitor large-scale air quality conditions, and their limited spatial resolution cannot reflect the detailed variations in air quality that may be induced by traffic jams. By deploying wireless sensors on crossroads and main roads, this study established a pilot framework for a wireless sensor network (WSN)-based real-time monitoring system to understand street-level spatial-temporal changes of carbon monoxide (CO) in urban settings. The system consists of two major components. The first component is the deployment of wireless sensors. We deployed 44 sensor nodes, 40 transmitter nodes and four gateway nodes in this study. Each sensor node includes a signal processing module, a CO sensor and a wireless communication module. In order to capture realistic human exposure to traffic pollutants, all sensors were deployed at a height of 1.5 m on lampposts and traffic signs. The study area covers a total length of 1.5 km of Keelung Road in Taipei City. The other component is a map-based monitoring platform for sensor data visualization and manipulation in time and space. Using intensive real-time street-level monitoring framework, we compared the spatial-temporal patterns of air pollution in different time periods. Our results capture four CO concentration peaks throughout the day at the location, which was located along an arterial and nearby traffic sign. The hourly average could reach 5.3 ppm from 5:00 pm to 7:00 pm due to the traffic congestion. The proposed WSN-based framework captures detailed ground information and potential risk of human exposure to traffic-related air pollution. It also provides street-level insights into real-time monitoring for further early warning of air pollution and urban environmental management.

Road traffic impact on urban water quality: a step towards integrated traffic, air and stormwater modelling.

Science.gov (United States)

Fallah Shorshani, Masoud; Bonhomme, Céline; Petrucci, Guido; André, Michel; Seigneur, Christian

2014-04-01

Methods for simulating air pollution due to road traffic and the associated effects on stormwater runoff quality in an urban environment are examined with particular emphasis on the integration of the various simulation models into a consistent modelling chain. To that end, the models for traffic, pollutant emissions, atmospheric dispersion and deposition, and stormwater contamination are reviewed. The present study focuses on the implementation of a modelling chain for an actual urban case study, which is the contamination of water runoff by cadmium (Cd), lead (Pb), and zinc (Zn) in the Grigny urban catchment near Paris, France. First, traffic emissions are calculated with traffic inputs using the COPERT4 methodology. Next, the atmospheric dispersion of pollutants is simulated with the Polyphemus line source model and pollutant deposition fluxes in different subcatchment areas are calculated. Finally, the SWMM water quantity and quality model is used to estimate the concentrations of pollutants in stormwater runoff. The simulation results are compared to mass flow rates and concentrations of Cd, Pb and Zn measured at the catchment outlet. The contribution of local traffic to stormwater contamination is estimated to be significant for Pb and, to a lesser extent, for Zn and Cd; however, Pb is most likely overestimated due to outdated emissions factors. The results demonstrate the importance of treating distributed traffic emissions from major roadways explicitly since the impact of these sources on concentrations in the catchment outlet is underestimated when those traffic emissions are spatially averaged over the catchment area.

Good Practice Lessons from the Urban Traffic Project, Denmark

DEFF Research Database (Denmark)

Flyvbjerg, Bent

2002-01-01

In 1990, as the first government in the world, the Danish Cabinet approved a national action plan for sustainable transport. In 1992, as part of the implementation of this plan, the Urban Traffic Project was set up with the EPA. The policy situation was one of a state agency trying to motivate...... urban municipalities to work with T&E (transport and environment) integration, i.e. integration of concerns for safety, energy, air quality, noise etc. in urban traffic planning. 50 major urban municipalities participated in the project. The most important lessons to be learned from the project are: (1......) With a fairly modest investment (DKK 150 million in seed money) it has been possible on a voluntary basis to motivate the majority of urban municipalities to work with T&E integration. (2) The top motivating factor for municipalities to participate was a desire for organisational and professional learning. (3...

Bridging the gap between traffic generated health stressors in urban areas: Predicting xylene levels in EU cities

International Nuclear Information System (INIS)

Vlachokostas, Ch.; Michailidou, A.V.; Spyridi, D.; Moussiopoulos, N.

2013-01-01

Many citizens live, work, commute, or visit traffic intensive spaces and are exposed to high levels of chemical health stressors. However, urban conurbations worldwide present monitoring “shortage” – due to economical and/or practical constraints – for toxic stressors such as xylene isomers, which can pose human health risks. This “shortage” may be covered by the establishment of associations between rarely monitored substances such as xylenes and more frequently monitored (i.e. benzene) or usually monitored (i.e. CO). Regression analysis is used and strong statistical relationships are detected. The adopted models are applied to EU cities and comparison between measurements and predictions depicts their representativeness. The analysis provides transferability insights in an effort to bridge the gap between traffic-related stressors. Strong associations between substances of the air pollution mixture may be influential to interpret the complexity of the causal chain, especially if a synergetic exposure assessment in traffic intensive spaces is considered. -- Highlights: •EU cities present monitoring shortage for health stressors such as xylenes. •The multi-stressor multi-city stepwise regression modelling approach is presented. •Strong linear relationships between xylenes and toluene, benzene, CO are detected. •Modelling results are in good agreement with the respective available measurements. •Toluene seems the optimal marker to predict xylene trends in traffic environments. -- The multi-stressor, multi-city stepwise regression modelling approach develops reliable statistical associations which capture m,p-xylene and o-xylene trends in EU traffic intensive environments

National guidelines for traffic calming

CSIR Research Space (South Africa)

Schermers, G

1998-03-01

Full Text Available and provides a policy framework on traffic calming. It also describes the administrative and management procedures required to meet policy objectives in the implementation and monitoring of traffic calming in urban areas. Related legal requirements, liability...

Indirect Damage of Urban Flooding: Investigation of Flood-Induced Traffic Congestion Using Dynamic Modeling

Directory of Open Access Journals (Sweden)

Jingxuan Zhu

2018-05-01

Full Text Available In many countries, industrialization has led to rapid urbanization. Increased frequency of urban flooding is one consequence of the expansion of urban areas which can seriously affect the productivity and livelihoods of urban residents. Therefore, it is of vital importance to study the effects of rainfall and urban flooding on traffic congestion and driver behavior. In this study, a comprehensive method to analyze the influence of urban flooding on traffic congestion was developed. First, a flood simulation was conducted to predict the spatiotemporal distribution of flooding based on Storm Water Management Model (SWMM and TELAMAC-2D. Second, an agent-based model (ABM was used to simulate driver behavior during a period of urban flooding, and a car-following model was established. Finally, in order to study the mechanisms behind how urban flooding affects traffic congestion, the impact of flooding on urban traffic was investigated based on a case study of the urban area of Lishui, China, covering an area of 4.4 km2. It was found that for most events, two-hour rainfall has a certain impact on traffic congestion over a five-hour period, with the greatest impact during the hour following the cessation of the rain. Furthermore, the effects of rainfall with 10- and 20-year return periods were found to be similar and small, whereas the effects with a 50-year return period were obvious. Based on a combined analysis of hydrology and transportation, the proposed methods and conclusions could help to reduce traffic congestion during flood seasons, to facilitate early warning and risk management of urban flooding, and to assist users in making informed decisions regarding travel.

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.

A Novel Dual Traffic/Flash Flood Monitoring System Using Passive Infrared/Ultrasonic Sensors

KAUST Repository

Mousa, Mustafa

2015-10-19

Floods are the most common type of natural disaster, causing thousands of casualties every year. Among these events, urban flash floods are particularly deadly because of the short timescales on which they occur, and because of the high concentration of population in cities. Since most flash flood casualties are caused by a lack of information, it is critical to generate accurate and detailed warnings of flash floods. However, deploying an infrastructure that solely monitor flash floods makes little economic sense, since the average periodicity of catastrophic flash floods exceeds the lifetime of a typical sensor network. To address this issue, we propose a new sensing device that can simultaneously monitor urban flash floods and another phenomenon of interest (traffic congestion on the present case). This sensing device is based on the combination of an ultrasonic rangefinder with one or multiple remote temperature sensors. We show an implementation of this device, and illustrate its performance in both traffic flow and flash flood sensing. Field data shows that the sensor can detect vehicles with a 99% accuracy, in addition to estimating their speed and classifying them in function of their length. The same sensor can also monitor urban water levels with an accuracy of less than 2 cm. Two of the sensors have been deployed in a flood prone area, where they captured the only (minor) flash flood that occurred over the one-year test period, with no false detection, and an agreement in the estimated water level estimate (during the flash flood event) of about 2 cm.

A Novel Dual Traffic/Flash Flood Monitoring System Using Passive Infrared/Ultrasonic Sensors

KAUST Repository

Mousa, Mustafa; Odat, Enas M.; Claudel, Christian

2015-01-01

Floods are the most common type of natural disaster, causing thousands of casualties every year. Among these events, urban flash floods are particularly deadly because of the short timescales on which they occur, and because of the high concentration of population in cities. Since most flash flood casualties are caused by a lack of information, it is critical to generate accurate and detailed warnings of flash floods. However, deploying an infrastructure that solely monitor flash floods makes little economic sense, since the average periodicity of catastrophic flash floods exceeds the lifetime of a typical sensor network. To address this issue, we propose a new sensing device that can simultaneously monitor urban flash floods and another phenomenon of interest (traffic congestion on the present case). This sensing device is based on the combination of an ultrasonic rangefinder with one or multiple remote temperature sensors. We show an implementation of this device, and illustrate its performance in both traffic flow and flash flood sensing. Field data shows that the sensor can detect vehicles with a 99% accuracy, in addition to estimating their speed and classifying them in function of their length. The same sensor can also monitor urban water levels with an accuracy of less than 2 cm. Two of the sensors have been deployed in a flood prone area, where they captured the only (minor) flash flood that occurred over the one-year test period, with no false detection, and an agreement in the estimated water level estimate (during the flash flood event) of about 2 cm.

Multi-Agent Based Microscopic Simulation Modeling for Urban Traffic Flow

Directory of Open Access Journals (Sweden)

Xianyan Kuang

2014-10-01

Full Text Available Traffic simulation plays an important role in the evaluation of traffic decisions. The movement of vehicles essentially is the operating process of drivers, in order to reproduce the urban traffic flow from the micro-aspect on computer, this paper establishes an urban traffic flow microscopic simulation system (UTFSim based on multi-agent. The system is seen as an intelligent virtual environment system (IVES, and the four-layer structure of it is built. The road agent, vehicle agent and signal agent are modeled. The concept of driving trajectory which is divided into LDT (Lane Driving Trajectory and VDDT (Vehicle Dynamic Driving Trajectory is introduced. The “Link-Node” road network model is improved. The driving behaviors including free driving, following driving, lane changing, slowing down, vehicle stop, etc. are analyzed. The results of the signal control experiments utilizing the UTFSim developed in the platform of Visual Studio. NET indicates that it plays a good performance and can be used in the evaluation of traffic management and control.

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.  

Stereo-based Collision Avoidance System for Urban Traffic

Science.gov (United States)

Moriya, Takashi; Ishikawa, Naoto; Sasaki, Kazuyuki; Nakajima, Masato

2002-11-01

Numerous car accidents occur on urban road. However, researches done so far on driving assistance are subjecting highways whose environment is relatively simple and easy to handle, and new approach for urban settings is required. Our purpose is to extend its support to the following conditions in city traffic: the presence of obstacles such as pedestrians and telephone poles; the lane mark is not always drawn on a road; drivers may lack the sense of awareness of the lane mark. We propose a collision avoidance system, which can be applied to both highways and urban traffic environment. In our system, stereo cameras are set in front of a vehicle and the captured images are processed through a computer. We create a Projected Disparity Map (PDM) from stereo image pair, which is a disparity histogram taken along ordinate direction of obtained disparity image. When there is an obstacle in front, we can detect it by finding a peak appeared in the PDM. With a speed meter and a steering sensor, the stop distance and the radius of curvature of the self-vehicle are calculated, in order to set the observation-required area, which does not depend on lane marks, within a PDM. A danger level will be computed from the distance and the relative speed to the closest approaching object detected within the observation-required area. The method has been tested in urban traffic scenes and has shown to be effective for judging dangerous situation, and gives proper alarm to a driver.

Reducing local traffic emissions at urban intersection using ITS countermeasures

NARCIS (Netherlands)

Mahmod, M.; Arem, B. van; Pueboobpaphan, R.; Lange, R. de

2013-01-01

In many countries traffic emissions have significantly increased during the last two decades because of the increased number of vehicles. As such, traffic emissions have become the main source of air pollution in urban areas, where breaches of the EU limit values frequently occur. To reduce these

Urbanization and traffic related exposures as risk factors for Schizophrenia

DEFF Research Database (Denmark)

Pedersen, Carsten Bøcker; Mortensen, Preben Bo

2006-01-01

: The geographical distance from place of residence to nearest major road had a significant effect. The highest risk was found in children living 500-1000 metres from nearest major road (RR=1.30 (95% Confidence Interval: 1.17-1.44). However, when we accounted for the degree of urbanization, the geographical distance...... that traffic related exposures affect schizophrenia risk and that this potential effect is responsible for the urban-rural differences. The geographical distance from place of residence to nearest major road was used as a proxy variable for traffic related exposures. We used a large population-based sample......BACKGROUND: Urban birth or upbringing increase schizophrenia risk. Though unknown, the causes of these urban-rural differences have been hypothesized to include, e.g., infections, diet, toxic exposures, social class, or an artefact due to selective migration. METHODS: We investigated the hypothesis...

Cellular automata model for urban road traffic flow considering pedestrian crossing street

Science.gov (United States)

Zhao, Han-Tao; Yang, Shuo; Chen, Xiao-Xu

2016-11-01

In order to analyze the effect of pedestrians' crossing street on vehicle flows, we investigated traffic characteristics of vehicles and pedestrians. Based on that, rules of lane changing, acceleration, deceleration, randomization and update are modified. Then we established two urban two-lane cellular automata models of traffic flow, one of which is about sections with non-signalized crosswalk and the other is on uncontrolled sections with pedestrians crossing street at random. MATLAB is used for numerical simulation of the different traffic conditions; meanwhile space-time diagram and relational graphs of traffic flow parameters are generated and then comparatively analyzed. Simulation results indicate that when vehicle density is lower than around 25 vehs/(km lane), pedestrians have modest impact on traffic flow, whereas when vehicle density is higher than about 60 vehs/(km lane), traffic speed and volume will decrease significantly especially on sections with non-signal-controlled crosswalk. The results illustrate that the proposed models reconstruct the traffic flow's characteristic with the situation where there are pedestrians crossing and can provide some practical reference for urban traffic management.

A sensor network architecture for urban traffic state estimation with mixed eulerian/lagrangian sensing based on distributed computing

KAUST Repository

Canepa, Edward S.; Odat, Enas M.; Dehwah, Ahmad H.; Mousa, Mustafa; Jiang, Jiming; Claudel, Christian G.

2014-01-01

This article describes a new approach to urban traffic flow sensing using decentralized traffic state estimation. Traffic sensor data is generated both by fixed traffic flow sensor nodes and by probe vehicles equipped with a short range transceiver. The data generated by these sensors is sent to a local coordinator node, that poses the problem of estimating the local state of traffic as a mixed integer linear program (MILP). The resulting optimization program is then solved by the nodes in a distributed manner, using branch-and-bound methods. An optimal amount of noise is then added to the maps before dissemination to a central database. Unlike existing probe-based traffic monitoring systems, this system does not transmit user generated location tracks nor any user presence information to a centralized server, effectively preventing privacy attacks. A simulation of the system performance on computer-generated traffic data shows that the system can be implemented with currently available technology. © 2014 Springer International Publishing Switzerland.

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.

Impact of traffic volume and composition on the air quality and pedestrian exposure in urban street canyon

Science.gov (United States)

Rakowska, Agata; Wong, Ka Chun; Townsend, Thomas; Chan, Ka Lok; Westerdahl, Dane; Ng, Simon; Močnik, Griša; Drinovec, Luka; Ning, Zhi

2014-12-01

Vehicle emissions are identified as a major source of air pollution in metropolitan areas. Emission control programs in many cities have been implemented as part of larger scale transport policy interventions to control traffic pollutants and reduce public health risks. These interventions include provision of traffic-free and low emission zones and congestion charging. Various studies have investigated the impact of urban street configurations, such as street canyon in urban centers, on pollutants dispersion and roadside air quality. However, there are few investigations in the literature to study the impact of change of fleet composition and street canyon effects on the on-road pollutants concentrations and associated roadside pedestrian exposure to the pollutants. This study presents an experimental investigation on the traffic related gas and particle pollutants in and near major streets in one of the most developed business districts in Hong Kong, known as Central. Both street canyon and open roadway configurations were included in the study design. Mobile measurement techniques were deployed to monitor both on-road and roadside pollutants concentrations at different times of the day and on different days of a week. Multiple traffic counting points were also established to concurrently collect data on traffic volume and fleet composition on individual streets. Street canyon effects were evident with elevated on-road pollutants concentrations. Diesel vehicles were found to be associated with observed pollutant levels. Roadside black carbon concentrations were found to correlate with their on-road levels but with reduced concentrations. However, ultrafine particles showed very high concentrations in roadside environment with almost unity of roadside/on-road ratios possibly due to the accumulation of primary emissions and secondary PM formation. The results from the study provide useful information for the effective urban transport design and bus route

Discovering urban mobility patterns with PageRank based traffic modeling and prediction

Science.gov (United States)

Wang, Minjie; Yang, Su; Sun, Yi; Gao, Jun

2017-11-01

Urban transportation system can be viewed as complex network with time-varying traffic flows as links to connect adjacent regions as networked nodes. By computing urban traffic evolution on such temporal complex network with PageRank, it is found that for most regions, there exists a linear relation between the traffic congestion measure at present time and the PageRank value of the last time. Since the PageRank measure of a region does result from the mutual interactions of the whole network, it implies that the traffic state of a local region does not evolve independently but is affected by the evolution of the whole network. As a result, the PageRank values can act as signatures in predicting upcoming traffic congestions. We observe the aforementioned laws experimentally based on the trajectory data of 12000 taxies in Beijing city for one month.

MOE-Analysis for Oversaturated Flow with Interrupted Facility and Heterogeneous Traffic for Urban Roads

Directory of Open Access Journals (Sweden)

Hemant Kumar Sharma

2012-09-01

Full Text Available Speed-flow functions have been developed by several transportation experts to predict accurately the speed of urban road networks. HCM Speed-Flow Curve, BPR Curve, MTC Speed-Flow Curve, Akçelik Speed-Flow Curve are some extraordinary efforts to define the shape of speed-flow curves. However, the complexity of driver's behaviour, interactions among different type of vehicles, lateral clearance, co-relation of driver's psychology with vehicular characteristics and interdependence of various variables of traffic has led to continuous development and refinement of speed-flow curves. The problem gets more difficult in the case of urban roads with heterogeneous traffic, oversaturated flow and signalized network (which includes some unsignalized intersections as well. This paper presents analysis for various measures of effectiveness (MOE for urban roads with interrupted flow comprising heterogeneous traffic. Model has been developed for heterogeneous traffic under constraints of roadway geometry, vehicle characteristics, driving behaviour and traffic controls. The model developed in this paper predicts speed, delay, average queue and maximum queue estimates for urban roads and quantifies congestion for oversaturated conditions. The investigation details the oversaturated portion of flow in particular.

Urban street structure and traffic safety.

Science.gov (United States)

Mohan, Dinesh; Bangdiwala, Shrikant I; Villaveces, Andres

2017-09-01

This paper reports the influence of road type and junction density on road traffic fatality rates in U.S. cities. The Fatality Analysis Reporting System (FARS) files were used to obtain fatality rates for all cities for the years 2005-2010. A stratified random sample of 16 U.S. cities was taken, and cities with high and low road traffic fatality rates were compared on their road layout details (TIGER maps were used). Statistical analysis was done to determine the effect of junction density and road type on road traffic fatality rates. The analysis of road network and road traffic crash fatality rates in these randomly selected U.S. cities shows that, (a) higher number of junctions per road length was significantly associated with a lower motor- vehicle crash and pedestrian mortality rates, and, (b) increased number of kilometers of roads of any kind was associated with higher fatality rates, but an additional kilometer of main arterial road was associated with a significantly higher increase in total fatalities. When compared to non-arterial roads, the higher the ratio of highways and main arterial roads, there was an association with higher fatality rates. These results have important implications for road safety professionals. They suggest that once the road and street structure is put in place, that will influence whether a city has low or high traffic fatality rates. A city with higher proportion of wider roads and large city blocks will tend to have higher traffic fatality rates, and therefore in turn require much more efforts in police enforcement and other road safety measures. Urban planners need to know that smaller block size with relatively less wide roads will result in lower traffic fatality rates and this needs to be incorporated at the planning stage. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

Traffic improvement and transportation pollution control in Xiamen

Energy Technology Data Exchange (ETDEWEB)

Dongxing Yuan; Zilin, Wu

1996-12-31

in this paper, the urban traffic improvement and transportation control in Xiamen are highlighted. Xiamen is a port city and an economical special zone of China. As the economy grows, the transportation is developing dramatically and becoming the key for further economic development. The air quality is threatened by the rapid growth of the vehicles in the city. The most urgent task in improving urban traffic is to establish a sound traffic system. The municipal government takes great effort to improve the traffic condition, as well as to reduce green house gases and protect air environment. Some management and technical measures are carried out. Those management measures are mainly as follows: (1) systematic planning of the city arrangement and city functional division, and integrated planning of the urban roads system, (2) putting great emphasis on tail gas monitoring and management, and (3) establishing optimized utilization of motor vehicles. Those included in the main technical measures are (1) making the roads clear, (2) enlarging traffic capacity, and (3) developing the public transport. The most urgent task in improving urban traffic is to establish a sound traffic system. The city municipal government and Transportation Management Bureau plan to make a series of reforms to improve the urban traffic condition, such as building high quality road around the city, reducing the number of one way roads and replacing gasoline buses with electric buses. An optimized traffic system of Xiamen, taking public transport as the main means, is the key to meet the needs of both traffic improvement and urban transportation pollution control.

A regression-based method for mapping traffic-related air pollution. Application and testing in four contrasting urban environments

International Nuclear Information System (INIS)

Briggs, D.J.; De Hoogh, C.; Elliot, P.; Gulliver, J.; Wills, J.; Kingham, S.; Smallbone, K.

2000-01-01

Accurate, high-resolution maps of traffic-related air pollution are needed both as a basis for assessing exposures as part of epidemiological studies, and to inform urban air-quality policy and traffic management. This paper assesses the use of a GIS-based, regression mapping technique to model spatial patterns of traffic-related air pollution. The model - developed using data from 80 passive sampler sites in Huddersfield, as part of the SAVIAH (Small Area Variations in Air Quality and Health) project - uses data on traffic flows and land cover in the 300-m buffer zone around each site, and altitude of the site, as predictors of NO 2 concentrations. It was tested here by application in four urban areas in the UK: Huddersfield (for the year following that used for initial model development), Sheffield, Northampton, and part of London. In each case, a GIS was built in ArcInfo, integrating relevant data on road traffic, urban land use and topography. Monitoring of NO 2 was undertaken using replicate passive samplers (in London, data were obtained from surveys carried out as part of the London network). In Huddersfield, Sheffield and Northampton, the model was first calibrated by comparing modelled results with monitored NO 2 concentrations at 10 randomly selected sites; the calibrated model was then validated against data from a further 10-28 sites. In London, where data for only 11 sites were available, validation was not undertaken. Results showed that the model performed well in all cases. After local calibration, the model gave estimates of mean annual NO 2 concentrations within a factor of 1.5 of the actual mean (approx. 70-90%) of the time and within a factor of 2 between 70 and 100% of the time. r 2 values between modelled and observed concentrations are in the range of 0.58-0.76. These results are comparable to those achieved by more sophisticated dispersion models. The model also has several advantages over dispersion modelling. It is able, for example, to

Estimation of Bimodal Urban Link Travel Time Distribution and Its Applications in Traffic Analysis

Directory of Open Access Journals (Sweden)

Yuxiong Ji

2015-01-01

Full Text Available Vehicles travelling on urban streets are heavily influenced by traffic signal controls, pedestrian crossings, and conflicting traffic from cross streets, which would result in bimodal travel time distributions, with one mode corresponding to travels without delays and the other travels with delays. A hierarchical Bayesian bimodal travel time model is proposed to capture the interrupted nature of urban traffic flows. The travel time distributions obtained from the proposed model are then considered to analyze traffic operations and estimate travel time distribution in real time. The advantage of the proposed bimodal model is demonstrated using empirical data, and the results are encouraging.

Using mobile probes to inform and measure the effectiveness of traffic control strategies on urban networks.

Science.gov (United States)

2015-07-01

Urban traffic congestion is a problem that plagues many cities in the United States. Testing strategies to alleviate this : congestion is especially challenging due to the difficulty of modeling complex urban traffic networks. However, recent work ha...

An Efficient Traffic Congestion Monitoring System on Internet of Vehicles

Directory of Open Access Journals (Sweden)

Duc-Binh Nguyen

2018-01-01

Full Text Available Existing intelligent transport systems (ITS do not fully consider and resolve accuracy, instantaneity, and compatibility challenges while resolving traffic congestion in Internet of Vehicles (IoV environments. This paper proposes a traffic congestion monitoring system, which includes data collection, segmented structure establishment, traffic-flow modelling, local segment traffic congestion prediction, and origin-destination traffic congestion service for drivers. Macroscopic model-based traffic-flow factors were formalized on the basis of the analysis results. Fuzzy rules-based local segment traffic congestion prediction was performed to determine the traffic congestion state. To enhance prediction efficiency, this paper presents a verification process for minimizing false predictions which is based on the Rankine-Hugoniot condition and an origin-destination traffic congestion service is also provided. To verify the feasibility of the proposed system, a prototype was implemented. The experimental results demonstrate that the proposed scheme can effectively monitor traffic congestion in terms of accuracy and system response time.

Estimating Urban Traffic Patterns through Probabilistic Interconnectivity of Road Network Junctions.

Directory of Open Access Journals (Sweden)

Ed Manley

Full Text Available The emergence of large, fine-grained mobility datasets offers significant opportunities for the development and application of new methodologies for transportation analysis. In this paper, the link between routing behaviour and traffic patterns in urban areas is examined, introducing a method to derive estimates of traffic patterns from a large collection of fine-grained routing data. Using this dataset, the interconnectivity between road network junctions is extracted in the form of a Markov chain. This representation encodes the probability of the successive usage of adjacent road junctions, encoding routes as flows between decision points rather than flows along road segments. This network of functional interactions is then integrated within a modified Markov chain Monte Carlo (MCMC framework, adapted for the estimation of urban traffic patterns. As part of this approach, the data-derived links between major junctions influence the movement of directed random walks executed across the network to model origin-destination journeys. The simulation process yields estimates of traffic distribution across the road network. The paper presents an implementation of the modified MCMC approach for London, United Kingdom, building an MCMC model based on a dataset of nearly 700000 minicab routes. Validation of the approach clarifies how each element of the MCMC framework contributes to junction prediction performance, and finds promising results in relation to the estimation of junction choice and minicab traffic distribution. The paper concludes by summarising the potential for the development and extension of this approach to the wider urban modelling domain.

System And Method For Monitoring Traffic While Preserving Personal Privacy

KAUST Repository

Canepa, Edward

2015-08-06

A traffic monitoring system and method for mapping traffic speed and density while preserving privacy. The system can include fixed stations that make up a network and mobile probes that are associated with vehicles. The system and method do not gather, store, or transmit any unique or identifying information, and thereby preserves the privacy of members of traffic. The system and method provide real-time traffic density and speed mapping. The system and method can further be integrated with a complementary flood monitoring system and method.

An optimal general type-2 fuzzy controller for Urban Traffic Network

DEFF Research Database (Denmark)

Khooban, Mohammad Hassan; Vafamand, Navid; Liaghat, Alireza

2017-01-01

Urban traffic network model is illustrated by state-charts and object-diagram. However, they have limitations to show the behavioral perspective of the Traffic Information flow. Consequently, a state space model is used to calculate the half-value waiting time of vehicles. In this study......, a combination of the general type-2 fuzzy logic sets and the Modified Backtracking Search Algorithm (MBSA) techniques are used in order to control the traffic signal scheduling and phase succession so as to guarantee a smooth flow of traffic with the least wait times and average queue length. The parameters...

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.

The impact of traffic-flow patterns on air quality in urban street canyons.

Science.gov (United States)

Thaker, Prashant; Gokhale, Sharad

2016-01-01

We investigated the effect of different urban traffic-flow patterns on pollutant dispersion in different winds in a real asymmetric street canyon. Free-flow traffic causes more turbulence in the canyon facilitating more dispersion and a reduction in pedestrian level concentration. The comparison of with and without a vehicle-induced-turbulence revealed that when winds were perpendicular, the free-flow traffic reduced the concentration by 73% on the windward side with a minor increase of 17% on the leeward side, whereas for parallel winds, it reduced the concentration by 51% and 29%. The congested-flow traffic increased the concentrations on the leeward side by 47% when winds were perpendicular posing a higher risk to health, whereas reduced it by 17-42% for parallel winds. The urban air quality and public health can, therefore, be improved by improving the traffic-flow patterns in street canyons as vehicle-induced turbulence has been shown to contribute significantly to dispersion. Copyright © 2015 Elsevier Ltd. All rights reserved.

Grid Mapping for Spatial Pattern Analyses of Recurrent Urban Traffic Congestion Based on Taxi GPS Sensing Data

Directory of Open Access Journals (Sweden)

Yang Liu

2017-03-01

Full Text Available Traffic congestion is one of the most serious problems that impact urban transportation efficiency, especially in big cities. Identifying traffic congestion locations and occurring patterns is a prerequisite for urban transportation managers in order to take proper countermeasures for mitigating traffic congestion. In this study, the historical GPS sensing data of about 12,000 taxi floating cars in Beijing were used for pattern analyses of recurrent traffic congestion based on the grid mapping method. Through the use of ArcGIS software, 2D and 3D maps of the road network congestion were generated for traffic congestion pattern visualization. The study results showed that three types of traffic congestion patterns were identified, namely: point type, stemming from insufficient capacities at the nodes of the road network; line type, caused by high traffic demand or bottleneck issues in the road segments; and region type, resulting from multiple high-demand expressways merging and connecting to each other. The study illustrated that the proposed method would be effective for discovering traffic congestion locations and patterns and helpful for decision makers to take corresponding traffic engineering countermeasures in order to relieve the urban traffic congestion issues.

Evolution of traffic emissions in European urban areas: Milan case study

International Nuclear Information System (INIS)

Giugliano, M.; Cemin, A.; Cernuschi, S.

1992-01-01

The worldwide increasing role of mobile sources on the air quality of urban areas requires a careful evaluation of all the potential intervention policies for the reduction of traffic related emissions. The accurate description of the evolution of the source, following the renewal of the fleet with vehicles regulated by stricter emission standards, represents the basic premise for this evaluation. This paper outlines a proposed methodology for the evaluation of the trend of mobile source emissions, implemented on the calculation program EMISMOB, and reports the results obtained with its application to predict the evolution of traffic emissions in the urban area of Milan (Italy) until the year 2010

Using mobile probes to inform and measure the effectiveness of macroscopic traffic control strategies on urban networks.

Science.gov (United States)

2015-06-01

Urban traffic congestion is a problem that plagues many cities in the United States. Testing strategies to alleviate this : congestion is especially challenging due to the difficulty of modeling complex urban traffic networks. However, recent work ha...

Carbon emissions tax policy of urban road traffic and its application in Panjin, China

Science.gov (United States)

Yang, Longhai; Fang, Lin

2018-01-01

How to effectively solve traffic congestion and transportation pollution in urban development is a main research emphasis for transportation management agencies. A carbon emissions tax can affect travelers’ generalized costs and will lead to changes in passenger demand, mode choice and traffic flow equilibrium in road networks, which are of significance in green travel and low-carbon transportation management. This paper first established a mesoscopic model to calculate the carbon emissions tax and determined the value of this charge in China, which was based on road traffic flow, vehicle speed, and carbon emissions. Referring to existing research results to calibrate the value of time, this paper modified the traveler’s generalized cost function, including the carbon emissions tax, fuel surcharge and travel time cost, which can be used in the travel impedance model with the consideration of the carbon emissions tax. Then, a method for analyzing urban road network traffic flow distribution was put forward, and a joint traffic distribution model was established, which considered the relationship between private cars and taxis. Finally, this paper took the city of Panjin as an example to analyze the road traffic carbon emissions tax’s impact. The results illustrated that the carbon emissions tax has a positive effect on road network flow equilibrium and carbon emission reduction. This paper will have good reference value and practical significance for the calculation and implementation of urban traffic carbon emissions taxes in China. PMID:29738580

Carbon emissions tax policy of urban road traffic and its application in Panjin, China.

Science.gov (United States)

Yang, Longhai; Hu, Xiaowei; Fang, Lin

2018-01-01

How to effectively solve traffic congestion and transportation pollution in urban development is a main research emphasis for transportation management agencies. A carbon emissions tax can affect travelers' generalized costs and will lead to changes in passenger demand, mode choice and traffic flow equilibrium in road networks, which are of significance in green travel and low-carbon transportation management. This paper first established a mesoscopic model to calculate the carbon emissions tax and determined the value of this charge in China, which was based on road traffic flow, vehicle speed, and carbon emissions. Referring to existing research results to calibrate the value of time, this paper modified the traveler's generalized cost function, including the carbon emissions tax, fuel surcharge and travel time cost, which can be used in the travel impedance model with the consideration of the carbon emissions tax. Then, a method for analyzing urban road network traffic flow distribution was put forward, and a joint traffic distribution model was established, which considered the relationship between private cars and taxis. Finally, this paper took the city of Panjin as an example to analyze the road traffic carbon emissions tax's impact. The results illustrated that the carbon emissions tax has a positive effect on road network flow equilibrium and carbon emission reduction. This paper will have good reference value and practical significance for the calculation and implementation of urban traffic carbon emissions taxes in China.

A network centrality measure framework for analyzing urban traffic flow: A case study of Wuhan, China

Science.gov (United States)

Zhao, Shuangming; Zhao, Pengxiang; Cui, Yunfan

2017-07-01

In this paper, we propose an improved network centrality measure framework that takes into account both the topological characteristics and the geometric properties of a road network in order to analyze urban traffic flow in relation to different modes: intersection, road, and community, which correspond to point mode, line mode, and area mode respectively. Degree, betweenness, and PageRank centralities are selected as the analysis measures, and GPS-enabled taxi trajectory data is used to evaluate urban traffic flow. The results show that the mean value of the correlation coefficients between the modified degree, the betweenness, and the PageRank centralities and the traffic flow in all periods are higher than the mean value of the correlation coefficients between the conventional degree, the betweenness, the PageRank centralities and the traffic flow at different modes; this indicates that the modified measurements, for analyzing traffic flow, are superior to conventional centrality measurements. This study helps to shed light into the understanding of urban traffic flow in relation to different modes from the perspective of complex networks.

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

OpenAIRE

Chen, Dongxu; Yang, Zhongzhen

2017-01-01

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

Comparisons of Traffic-Related Ultrafine Particle Number Concentrations Measured in Two Urban Areas by Central, Residential, and Mobile Monitoring.

Science.gov (United States)

Simon, Matthew C; Hudda, Neelakshi; Naumova, Elena N; Levy, Jonathan I; Brugge, Doug; Durant, John L

2017-11-01

Traffic-related ultrafine particles (UFP; monitoring strategies upon which the models are based have varied between studies. Our study compares particle number concentrations (PNC; a proxy for UFP) measured by three different monitoring approaches (central-site, short-term residential-site, and mobile on-road monitoring) in two study areas in metropolitan Boston (MA, USA). Our objectives were to quantify ambient PNC differences between the three monitoring platforms, compare the temporal patterns and the spatial heterogeneity of PNC between the monitoring platforms, and identify factors that affect correlations across the platforms. We collected >12,000 hours of measurements at the central sites, 1,000 hours of measurements at each of 20 residential sites in the two study areas, and >120 hours of mobile measurements over the course of ~1 year in each study area. Our results show differences between the monitoring strategies: mean one-minute PNC on-roads were higher (64,000 and 32,000 particles/cm 3 in Boston and Chelsea, respectively) compared to central-site measurements (23,000 and 19,000 particles/cm 3 ) and both were higher than at residences (14,000 and 15,000 particles/cm 3 ). Temporal correlations and spatial heterogeneity also differed between the platforms. Temporal correlations were generally highest between central and residential sites, and lowest between central-site and on-road measurements. We observed the greatest spatial heterogeneity across monitoring platforms during the morning rush hours (06:00-09:00) and the lowest during the overnight hours (18:00-06:00). Longer averaging times (days and hours vs. minutes) increased temporal correlations (Pearson correlations were 0.69 and 0.60 vs. 0.39 in Boston; 0.71 and 0.61 vs. 0.45 in Chelsea) and reduced spatial heterogeneity (coefficients of divergence were 0.24 and 0.29 vs. 0.33 in Boston; 0.20 and 0.27 vs. 0.31 in Chelsea). Our results suggest that combining stationary and mobile monitoring may lead

The statistical evaluation and comparison of ADMS-Urban model for the prediction of nitrogen dioxide with air quality monitoring network.

Science.gov (United States)

Dėdelė, Audrius; Miškinytė, Auksė

2015-09-01

In many countries, road traffic is one of the main sources of air pollution associated with adverse effects on human health and environment. Nitrogen dioxide (NO2) is considered to be a measure of traffic-related air pollution, with concentrations tending to be higher near highways, along busy roads, and in the city centers, and the exceedances are mainly observed at measurement stations located close to traffic. In order to assess the air quality in the city and the air pollution impact on public health, air quality models are used. However, firstly, before the model can be used for these purposes, it is important to evaluate the accuracy of the dispersion modelling as one of the most widely used method. The monitoring and dispersion modelling are two components of air quality monitoring system (AQMS), in which statistical comparison was made in this research. The evaluation of the Atmospheric Dispersion Modelling System (ADMS-Urban) was made by comparing monthly modelled NO2 concentrations with the data of continuous air quality monitoring stations in Kaunas city. The statistical measures of model performance were calculated for annual and monthly concentrations of NO2 for each monitoring station site. The spatial analysis was made using geographic information systems (GIS). The calculation of statistical parameters indicated a good ADMS-Urban model performance for the prediction of NO2. The results of this study showed that the agreement of modelled values and observations was better for traffic monitoring stations compared to the background and residential stations.

Evaluation of daily time spent in transportation and traffic-influenced microenvironments by urban Canadians.

Science.gov (United States)

Matz, Carlyn J; Stieb, David M; Egyed, Marika; Brion, Orly; Johnson, Markey

2018-01-01

Exposure to traffic and traffic-related air pollution is associated with a wide array of health effects. Time spent in a vehicle, in active transportation, along roadsides, and in close proximity to traffic can substantially contribute to daily exposure to air pollutants. For this study, we evaluated daily time spent in transportation and traffic-influenced microenvironments by urban Canadians using the Canadian Human Activity Pattern Survey (CHAPS) 2 results. Approximately 4-7% of daily time was spent in on- or near-road locations, mainly associated with being in a vehicle and smaller contributions from active transportation. Indoor microenvironments can be impacted by traffic emissions, especially when located near major roadways. Over 60% of the target population reported living within one block of a roadway with moderate to heavy traffic, which was variable with income level and city, and confirmed based on elevated NO 2 exposure estimated using land use regression. Furthermore, over 55% of the target population ≤ 18 years reported attending a school or daycare in close proximity to moderate to heavy traffic, and little variation was observed based on income or city. The results underline the importance of traffic emissions as a major source of exposure in Canadian urban centers, given the time spent in traffic-influenced microenvironments.

CLASSIFICATION OF TRAFFIC RELATED SHORT TEXTS TO ANALYSE ROAD PROBLEMS IN URBAN AREAS

Directory of Open Access Journals (Sweden)

A. M. M. Saldana-Perez

2017-09-01

Full Text Available The Volunteer Geographic Information (VGI can be used to understand the urban dynamics. In the classification of traffic related short texts to analyze road problems in urban areas, a VGI data analysis is done over a social media’s publications, in order to classify traffic events at big cities that modify the movement of vehicles and people through the roads, such as car accidents, traffic and closures. The classification of traffic events described in short texts is done by applying a supervised machine learning algorithm. In the approach users are considered as sensors which describe their surroundings and provide their geographic position at the social network. The posts are treated by a text mining process and classified into five groups. Finally, the classified events are grouped in a data corpus and geo-visualized in the study area, to detect the places with more vehicular problems.

Classification of Traffic Related Short Texts to Analyse Road Problems in Urban Areas

Science.gov (United States)

Saldana-Perez, A. M. M.; Moreno-Ibarra, M.; Tores-Ruiz, M.

2017-09-01

The Volunteer Geographic Information (VGI) can be used to understand the urban dynamics. In the classification of traffic related short texts to analyze road problems in urban areas, a VGI data analysis is done over a social media's publications, in order to classify traffic events at big cities that modify the movement of vehicles and people through the roads, such as car accidents, traffic and closures. The classification of traffic events described in short texts is done by applying a supervised machine learning algorithm. In the approach users are considered as sensors which describe their surroundings and provide their geographic position at the social network. The posts are treated by a text mining process and classified into five groups. Finally, the classified events are grouped in a data corpus and geo-visualized in the study area, to detect the places with more vehicular problems.

Attitudes of Community to Urban Traffic Noise in Morogoro, Tanzania

African Journals Online (AJOL)

Attitudes of Community to Urban Traffic Noise in Morogoro, Tanzania. ... which is the daytime governmentally prescribed noise limit for residential-commercial areas. ... The main impacts of exposure to noise were reported to be headache, ...

Sonification of network traffic flow for monitoring and situational awareness

Science.gov (United States)

2018-01-01

Maintaining situational awareness of what is happening within a computer network is challenging, not only because the behaviour happens within machines, but also because data traffic speeds and volumes are beyond human ability to process. Visualisation techniques are widely used to present information about network traffic dynamics. Although they provide operators with an overall view and specific information about particular traffic or attacks on the network, they often still fail to represent the events in an understandable way. Also, because they require visual attention they are not well suited to continuous monitoring scenarios in which network administrators must carry out other tasks. Here we present SoNSTAR (Sonification of Networks for SiTuational AwaReness), a real-time sonification system for monitoring computer networks to support network administrators’ situational awareness. SoNSTAR provides an auditory representation of all the TCP/IP traffic within a network based on the different traffic flows between between network hosts. A user study showed that SoNSTAR raises situational awareness levels by enabling operators to understand network behaviour and with the benefit of lower workload demands (as measured by the NASA TLX method) than visual techniques. SoNSTAR identifies network traffic features by inspecting the status flags of TCP/IP packet headers. Combinations of these features define particular traffic events which are mapped to recorded sounds to generate a soundscape that represents the real-time status of the network traffic environment. The sequence, timing, and loudness of the different sounds allow the network to be monitored and anomalous behaviour to be detected without the need to continuously watch a monitor screen. PMID:29672543

Sonification of network traffic flow for monitoring and situational awareness.

Science.gov (United States)

Debashi, Mohamed; Vickers, Paul

2018-01-01

Maintaining situational awareness of what is happening within a computer network is challenging, not only because the behaviour happens within machines, but also because data traffic speeds and volumes are beyond human ability to process. Visualisation techniques are widely used to present information about network traffic dynamics. Although they provide operators with an overall view and specific information about particular traffic or attacks on the network, they often still fail to represent the events in an understandable way. Also, because they require visual attention they are not well suited to continuous monitoring scenarios in which network administrators must carry out other tasks. Here we present SoNSTAR (Sonification of Networks for SiTuational AwaReness), a real-time sonification system for monitoring computer networks to support network administrators' situational awareness. SoNSTAR provides an auditory representation of all the TCP/IP traffic within a network based on the different traffic flows between between network hosts. A user study showed that SoNSTAR raises situational awareness levels by enabling operators to understand network behaviour and with the benefit of lower workload demands (as measured by the NASA TLX method) than visual techniques. SoNSTAR identifies network traffic features by inspecting the status flags of TCP/IP packet headers. Combinations of these features define particular traffic events which are mapped to recorded sounds to generate a soundscape that represents the real-time status of the network traffic environment. The sequence, timing, and loudness of the different sounds allow the network to be monitored and anomalous behaviour to be detected without the need to continuously watch a monitor screen.

How healthy is urban horticulture in high traffic areas? Trace metal concentrations in vegetable crops from plantings within inner city neighbourhoods in Berlin, Germany.

Science.gov (United States)

Säumel, Ina; Kotsyuk, Iryna; Hölscher, Marie; Lenkereit, Claudia; Weber, Frauke; Kowarik, Ingo

2012-06-01

Food production by urban dwellers is of growing importance in developing and developed countries. Urban horticulture is associated with health risks as crops in urban settings are generally exposed to higher levels of pollutants than those in rural areas. We determined the concentration of trace metals in the biomass of different horticultural crops grown in the inner city of Berlin, Germany, and analysed how the local setting shaped the concentration patterns. We revealed significant differences in trace metal concentrations depending on local traffic, crop species, planting style and building structures, but not on vegetable type. Higher overall traffic burden increased trace metal content in the biomass. The presence of buildings and large masses of vegetation as barriers between crops and roads reduced trace metal content in the biomass. Based on this we discuss consequences for urban horticulture, risk assessment, and planting and monitoring guidelines for cultivation and consumption of crops. Copyright © 2012 Elsevier Ltd. All rights reserved.

Comparisons of traffic-related ultrafine particle number concentrations measured in two urban areas by central, residential, and mobile monitoring

Science.gov (United States)

Simon, Matthew C.; Hudda, Neelakshi; Naumova, Elena N.; Levy, Jonathan I.; Brugge, Doug; Durant, John L.

2017-11-01

Traffic-related ultrafine particles (UFP; strategies upon which the models are based have varied between studies. Our study compares particle number concentrations (PNC; a proxy for UFP) measured by three different monitoring approaches (central-site, short-term residential-site, and mobile on-road monitoring) in two study areas in metropolitan Boston (MA, USA). Our objectives were to quantify ambient PNC differences between the three monitoring platforms, compare the temporal patterns and the spatial heterogeneity of PNC between the monitoring platforms, and identify factors that affect correlations across the platforms. We collected >12,000 h of measurements at the central sites, 1000 h of measurements at each of 20 residential sites in the two study areas, and >120 h of mobile measurements over the course of ∼1 year in each study area. Our results show differences between the monitoring strategies: mean 1 min PNC on-roads were higher (64,000 and 32,000 particles/cm3 in Boston and Chelsea, respectively) compared to central-site measurements (23,000 and 19,000 particles/cm3) and both were higher than at residences (14,000 and 15,000 particles/cm3). Temporal correlations and spatial heterogeneity also differed between the platforms. Temporal correlations were generally highest between central and residential sites, and lowest between central-site and on-road measurements. We observed the greatest spatial heterogeneity across monitoring platforms during the morning rush hours (06:00-09:00) and the lowest during the overnight hours (18:00-06:00). Longer averaging times (days and hours vs. minutes) increased temporal correlations (Pearson correlations were 0.69 and 0.60 vs. 0.39 in Boston; 0.71 and 0.61 vs. 0.45 in Chelsea) and reduced spatial heterogeneity (coefficients of divergence were 0.24 and 0.29 vs. 0.33 in Boston; 0.20 and 0.27 vs. 0.31 in Chelsea). Our results suggest that combining stationary and mobile monitoring may lead to improved characterization of

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

Directory of Open Access Journals (Sweden)

Dongxu Chen

2017-01-01

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

Expert workshop traffic-caused airborne particles in urban areas; Experten-Workshop 'Verkehrsbedingte Feinstaeube in der Stadt'

Energy Technology Data Exchange (ETDEWEB)

Lanzendorf, Martin; Birmili, Wolfram; Franke, Patrick

2006-07-15

The proceedings of the expert workshop on traffic-caused airborne particulates in urban regions include the following contributions: epidemiology of ultra-fine particulates, ultra-fine particulates and their impacts in human health, environmental particulates in the urban atmosphere: properties and future requirement of measuring methods; ultra-fine particulates from traffic emissions - problems of measuring site selection for the evaluation of human exposure, modeling of PMx emissions in the context of environmental compatibility assessments and mitigation planning, traffic-caused particulates - need for action and remedial actions from the sight of the Federal environment Agency, traffic-related measures for the reduction of urban particulate exposure and their impact on the planning of air pollution prevention, strategic environmental assessment as an instrument for the airborne particulate consideration within the traffic and regional planning.

Urban planning, traffic planning and traffic safety of pedestrians and cyclists : report presented to the 1979 Road Research Symposium on Safety of Pedestrians and Cyclists, OECD Headquarters, Paris, 14-16 May 1979. Session III: Physical Countermeasures; Subsession III.1: Urban planning and traffic planning.

NARCIS (Netherlands)

Wegman, F.C.M.

1979-01-01

The traffic safety of pedestrians and cyclists can be improved by means of urban planning and traffic planning, as one of the possibilities. This paper discusses the framework of these measures and activities and also the effects on the field of traffic planning. Chapter I show that it is not

A self-sensing carbon nanotube/cement composite for traffic monitoring

International Nuclear Information System (INIS)

Han Baoguo; Yu Xun; Kwon, Eil

2009-01-01

In this paper, a self-sensing carbon nanotube (CNT)/cement composite is investigated for traffic monitoring. The cement composite is filled with multi-walled carbon nanotubes whose piezoresistive properties enable the detection of mechanical stresses induced by traffic flow. The sensing capability of the self-sensing CNT/cement composite is explored in laboratory tests and road tests. Experimental results show that the fabricated self-sensing CNT/cement composite presents sensitive and stable responses to repeated compressive loadings and impulsive loadings, and has remarkable responses to vehicular loadings. These findings indicate that the self-sensing CNT/cement composite has great potential for traffic monitoring use, such as in traffic flow detection, weigh-in-motion measurement and vehicle speed detection.

Calculating the Contribution Rate of Intelligent Transportation System in Improving Urban Traffic Smooth Based on Advanced DID Model

Directory of Open Access Journals (Sweden)

Ming-wei Li

2015-01-01

Full Text Available Recent years have witnessed the rapid development of intelligent transportation system around the world, which helps to relieve urban traffic congestion problems. For instance, many mega-cities in China have devoted a large amount of money and resources to the development of intelligent transportation system. This poses an intriguing and important issue: how to measure and quantify the contribution of intelligent transportation system to the urban city, which is still a puzzle. This paper proposes a matching difference-in-difference model to calculate the contribution rate of intelligent transportation system on traffic smoothness. Within the model, the main effect indicators of traffic smoothness are first identified, and then the evaluation index system is built, and finally the ideas of the matching pool are introduced. The proposed model is illustrated in Guangzhou, China (capital city of Guangdong province. The results show that introduction of ITS contributes 9.25% to the improvement of traffic smooth in Guangzhou. Also, the research explains the working mechanism of how ITS improves urban traffic smooth. Eventually, some strategy recommendations are put forward to improve urban traffic smooth.

How healthy is urban horticulture in high traffic areas? Trace metal concentrations in vegetable crops from plantings within inner city neighbourhoods in Berlin, Germany

International Nuclear Information System (INIS)

Säumel, Ina; Kotsyuk, Iryna; Hölscher, Marie; Lenkereit, Claudia; Weber, Frauke; Kowarik, Ingo

2012-01-01

Food production by urban dwellers is of growing importance in developing and developed countries. Urban horticulture is associated with health risks as crops in urban settings are generally exposed to higher levels of pollutants than those in rural areas. We determined the concentration of trace metals in the biomass of different horticultural crops grown in the inner city of Berlin, Germany, and analysed how the local setting shaped the concentration patterns. We revealed significant differences in trace metal concentrations depending on local traffic, crop species, planting style and building structures, but not on vegetable type. Higher overall traffic burden increased trace metal content in the biomass. The presence of buildings and large masses of vegetation as barriers between crops and roads reduced trace metal content in the biomass. Based on this we discuss consequences for urban horticulture, risk assessment, and planting and monitoring guidelines for cultivation and consumption of crops. - Highlights: ► Traffic-related pollutant deposition as important pathway for crop contamination. ► Heavy metal content often over EU standards for lead concentration in food crops. ► ‘Grow your own’ food in inner cities not always ‘healthier’ than supermarket products. ► No support for generalisations of crops as ‘risky high’ or ‘safe low’ accumulators. - Higher overall traffic burden increased, while the presence of buildings and large masses of vegetation as barriers between crops and roads reduced heavy metal content in crop biomass.

HOW TRAVEL DEMAND AFFECTS DETECTION OF NON-RECURRENT TRAFFIC CONGESTION ON URBAN ROAD NETWORKS

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B. Anbaroglu

2016-06-01

Full Text Available Occurrence of non-recurrent traffic congestion hinders the economic activity of a city, as travellers could miss appointments or be late for work or important meetings. Similarly, for shippers, unexpected delays may disrupt just-in-time delivery and manufacturing processes, which could lose them payment. Consequently, research on non-recurrent congestion detection on urban road networks has recently gained attention. By analysing large amounts of traffic data collected on a daily basis, traffic operation centres can improve their methods to detect non-recurrent congestion rapidly and then revise their existing plans to mitigate its effects. Space-time clusters of high link journey time estimates correspond to non-recurrent congestion events. Existing research, however, has not considered the effect of travel demand on the effectiveness of non-recurrent congestion detection methods. Therefore, this paper investigates how travel demand affects detection of non-recurrent traffic congestion detection on urban road networks. Travel demand has been classified into three categories as low, normal and high. The experiments are carried out on London’s urban road network, and the results demonstrate the necessity to adjust the relative importance of the component evaluation criteria depending on the travel demand level.

The improved degree of urban road traffic network: A case study of Xiamen, China

Science.gov (United States)

Wang, Shiguang; Zheng, Lili; Yu, Dexin

2017-03-01

The complex network theory is applied to the study of urban road traffic network topology, and we constructed a new measure to characterize an urban road network. It is inspiring to quantify the interaction more appropriately between nodes in complex networks, especially in the field of traffic. The measure takes into account properties of lanes (e.g. number of lanes, width, traffic direction). As much, it is a more comprehensive measure in comparison to previous network measures. It can be used to grasp the features of urban street network more clearly. We applied this measure to the road network in Xiamen, China. Based on a standard method from statistical physics, we examined in more detail the distribution of this new measure and found that (1) due to the limitation of space geographic attributes, traditional research conclusions acquired by using the original definition of degree to study the primal approach modeled urban street network are not very persuasive; (2) both of the direction of the network connection and the degree's odd or even classifications need to be analyzed specifically; (3) the improved degree distribution presents obvious hierarchy, and hierarchical values conform to the power-law distribution, and correlation of our new measure shows some significant segmentation of the urban road network.

Binational school-based monitoring of traffic-related air pollutants in El Paso, Texas (USA) and Ciudad Juarez, Chihuahua (Mexico)

International Nuclear Information System (INIS)

Raysoni, Amit U.; Sarnat, Jeremy A.; Sarnat, Stefanie Ebelt; Garcia, Jose Humberto; Holguin, Fernando; Flores Luevano, Silvia; Li, Wen-Whai

2011-01-01

Paired indoor and outdoor concentrations of fine and coarse particulate matter (PM), PM2.5 reflectance [black carbon(BC)], and nitrogen dioxide (NO 2 ) were determined for sixteen weeks in 2008 at four elementary schools (two in high and two in low traffic density zones) in a U.S.-Mexico border community to aid a binational health effects study. Strong spatial heterogeneity was observed for all outdoor pollutant concentrations. Concentrations of all pollutants, except coarse PM, were higher in high traffic zones than in the respective low traffic zones. Black carbon and NO 2 appear to be better traffic indicators than fine PM. Indoor air pollution was found to be well associated with outdoor air pollution, although differences existed due to uncontrollable factors involving student activities and building/ventilation configurations. Results of this study indicate substantial spatial variability of pollutants in the region, suggesting that children's exposures to these pollutants vary based on the location of their school. - Highlights: → First binational investigation characterizing traffic air pollutants at four schools in El Paso, USA and Cd. Juarez, Mexico. → Paired in-outdoor sampling of PM 2.5 , PM 10-2.5 , reflectance [black carbon(BC)], and NO 2 for 16 weeks in 2008 at each school. → Two schools (one in each city) were located in high traffic density areas and the other two in areas of low traffic density. → Usage of spatially resolved environmental indictors of traffic pollutants in a range of exposure settings. → Substantial intra-urban spatial variability in pollutant concentrations observed between and within the two cities. - Spatial variability in traffic-mediated pollutant concentrations can exist at the intra-urban level and ambient monitoring sites may not accurately represent these concentration gradients.

Impacts of Roadway Emissions on Urban Fine Particle Exposures: the Nairobi Area Traffic Contribution to Air Pollution (NATCAP) Study

Science.gov (United States)

Gatari, Michael; Ngo, Nicole; Ndiba, Peter; Kinney, Patrick

2010-05-01

Air quality is a serious and worsening problem in the rapidly growing cities of sub-Saharan Africa (SSA), due to rapid urbanization, growing vehicle fleets, changing life styles, limited road infrastructure and land use planning, and high per-vehicle emissions. However, the absence of ambient monitoring data, and particularly urban roadside concentrations of particulate matter in SSA cities, severely limits our ability to assess the real extent of air quality problems. Emitted fine particles by on-road vehicles may be particularly important in SSA cities because large concentrations of poorly maintained vehicles operate in close proximity to commercial and other activities of low-income urban residents. This scenario provokes major air quality concerns and its investigation should be of priority interest to policy makers, city planners and managers, and the affected population. As part of collaboration between Columbia University and the University of Nairobi, a PM2.5 air monitoring study was carried out over two weeks in July 2009. The objectives of the study were 1) to assess average daytime PM2.5 concentrations on a range of Nairobi streets that represent important hot-spots in terms of the joint distribution of traffic, commercial, and resident pedestrian activities, 2) to relate those concentrations to motor vehicle counts, 3) to compare urban street concentrations to urban and rural background levels, and 4) to assess vertical and horizontal dispersion of PM2.5 near roadways. Portable, battery-operated PM2.5 samplers were carried by field teams at each of the five sites (three urban, one commuter highway, and one rural site), each of which operated from 7 AM to 7 PM during 10 weekdays in July 2009. Urban background monitoring took place on a rooftop at the University of Nairobi. Preliminary findings suggest highly elevated PM2.5 concentrations at the urban sites where the greatest pedestrian traffic was observed. These findings underscore the need for air

Spatial and temporal differences in traffic-related air pollution in three urban neighborhoods near an interstate highway

Science.gov (United States)

Patton, Allison P.; Perkins, Jessica; Zamore, Wig; Levy, Jonathan I.; Brugge, Doug; Durant, John L.

2014-01-01

Relatively few studies have characterized differences in intra- and inter-neighborhood traffic-related air pollutant (TRAP) concentrations and distance-decay gradients in along an urban highway for the purposes of exposure assessment. The goal of this work was to determine the extent to which intra- and inter-neighborhood differences in TRAP concentrations can be explained by traffic and meteorology in three pairs of neighborhoods along Interstate 93 (I-93) in the metropolitan Boston area (USA). We measured distance-decay gradients of seven TRAPs (PNC, pPAH, NO, NOX, BC, CO, PM2.5) in near-highway (1 km) in Somerville, Dorchester/South Boston, Chinatown and Malden to determine whether (1) spatial patterns in concentrations and inter-pollutant correlations differ between neighborhoods, and (2) variation within and between neighborhoods can be explained by traffic and meteorology. The neighborhoods ranged in area from 0.5 to 2.3 km2. Mobile monitoring was performed over the course of one year in each pair of neighborhoods (one pair of neighborhoods per year in three successive years; 35-47 days of monitoring in each neighborhood). Pollutant levels generally increased with highway proximity, consistent with I-93 being a major source of TRAP; however, the slope and extent of the distance-decay gradients varied by neighborhood as well as by pollutant, season and time of day. Correlations among pollutants differed between neighborhoods (e.g., ρ = 0.35-0.80 between PNC and NOX and ρ = 0.11-0.60 between PNC and BC) and were generally lower in Dorchester/South Boston than in the other neighborhoods. We found that the generalizability of near-road gradients and near-highway/urban background contrasts was limited for near-highway neighborhoods in a metropolitan area with substantial local street traffic. Our findings illustrate the importance of measuring gradients of multiple pollutants under different ambient conditions in individual near-highway neighborhoods for health

Traffic Command Gesture Recognition for Virtual Urban Scenes Based on a Spatiotemporal Convolution Neural Network

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Chunyong Ma

2018-01-01

Full Text Available Intelligent recognition of traffic police command gestures increases authenticity and interactivity in virtual urban scenes. To actualize real-time traffic gesture recognition, a novel spatiotemporal convolution neural network (ST-CNN model is presented. We utilized Kinect 2.0 to construct a traffic police command gesture skeleton (TPCGS dataset collected from 10 volunteers. Subsequently, convolution operations on the locational change of each skeletal point were performed to extract temporal features, analyze the relative positions of skeletal points, and extract spatial features. After temporal and spatial features based on the three-dimensional positional information of traffic police skeleton points were extracted, the ST-CNN model classified positional information into eight types of Chinese traffic police gestures. The test accuracy of the ST-CNN model was 96.67%. In addition, a virtual urban traffic scene in which real-time command tests were carried out was set up, and a real-time test accuracy rate of 93.0% was achieved. The proposed ST-CNN model ensured a high level of accuracy and robustness. The ST-CNN model recognized traffic command gestures, and such recognition was found to control vehicles in virtual traffic environments, which enriches the interactive mode of the virtual city scene. Traffic command gesture recognition contributes to smart city construction.

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

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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.

Detecting Traffic Anomalies in Urban Areas Using Taxi GPS Data

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Weiming Kuang

2015-01-01

Full Text Available Large-scale GPS data contain hidden information and provide us with the opportunity to discover knowledge that may be useful for transportation systems using advanced data mining techniques. In major metropolitan cities, many taxicabs are equipped with GPS devices. Because taxies operate continuously for nearly 24 hours per day, they can be used as reliable sensors for the perceived traffic state. In this paper, the entire city was divided into subregions by roads, and taxi GPS data were transformed into traffic flow data to build a traffic flow matrix. In addition, a highly efficient anomaly detection method was proposed based on wavelet transform and PCA (principal component analysis for detecting anomalous traffic events in urban regions. The traffic anomaly is considered to occur in a subregion when the values of the corresponding indicators deviate significantly from the expected values. This method was evaluated using a GPS dataset that was generated by more than 15,000 taxies over a period of half a year in Harbin, China. The results show that this detection method is effective and efficient.

Urban Traffic Signal System Control Structural Optimization Based on Network Analysis

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Li Wang

2013-01-01

Full Text Available Advanced urban traffic signal control systems such as SCOOT and SCATS normally coordinate traffic network using multilevel hierarchical control mechanism. In this mechanism, several key intersections will be selected from traffic signal network and the network will be divided into different control subareas. Traditionally, key intersection selection and control subareas division are executed according to dynamic traffic counts and link length between intersections, which largely rely on traffic engineers’ experience. However, it omits important inherent characteristics of traffic network topology. In this paper, we will apply network analysis approach into these two aspects for traffic system control structure optimization. Firstly, the modified C-means clustering algorithm will be proposed to assess the importance of intersections in traffic network and furthermore determine the key intersections based on three indexes instead of merely on traffic counts in traditional methods. Secondly, the improved network community discovery method will be used to give more reasonable evidence in traffic control subarea division. Finally, to test the effectiveness of network analysis approach, a hardware-in-loop simulation environment composed of regional traffic control system, microsimulation software and signal controller hardware, will be built. Both traditional method and proposed approach will be implemented on simulation test bed to evaluate traffic operation performance indexes, for example, travel time, stop times, delay and average vehicle speed. Simulation results show that the proposed network analysis approach can improve the traffic control system operation performance effectively.

Minimal-Intrusion Traffic Monitoring And Analysis In Mission-Critical Communication Networks

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Alberto Domingo Ajenjo

2003-10-01

Full Text Available A good knowledge of expected and actual traffic patterns is an essential tool for network planning, design and operation in deployed, mission-critical applications. This paper describes those needs, and explains the Traffic Monitoring and Analysis Platform (TMAP concept, as developed in support of NATO deployed military headquarters Communications and Information Systems. It shows how a TMAP was deployed to a real NATO exercise, to prove the concept and baseline the traffic needs per application, per user community and per time of day. Then, it analyses the obtained results and derives conclusions on how to integrate traffic monitoring and analysis platforms in future deployments.

Establishing an air pollution monitoring network for intra-urban population exposure assessment : a location-allocation approach

Energy Technology Data Exchange (ETDEWEB)

Kanaroglou, P.S. [McMaster Univ., Hamilton, ON (Canada). School of Geography and Geology; Jerrett, M.; Beckerman, B.; Arain, M.A. [McMaster Univ., Hamilton, ON (Canada). School of Geography and Geology]|[McMaster Univ., Hamilton, ON (Canada). McMaster Inst. of Environment and Health; Morrison, J. [Carleton Univ., Ottawa, ON (Canada). School of Computer Science; Gilbert, N.L. [Health Canada, Ottawa, ON (Canada). Air Health Effects Div; Brook, J.R. [Meteorological Service of Canada, Toronto, ON (Canada)

2004-10-01

A study was conducted to assess the relation between traffic-generated air pollution and health reactions ranging from childhood asthma to mortality from lung cancer. In particular, it developed a formal method of optimally locating a dense network of air pollution monitoring stations in order to derive an exposure assessment model based on the data obtained from the monitoring stations and related land use, population and biophysical information. The method for determining the locations of 100 nitrogen dioxide monitors in Toronto, Ontario focused on land use, transportation infrastructure and the distribution of at-risk populations. The exposure assessment produced reasonable estimates at the intra-urban scale. This method for locating air pollution monitors effectively maximizes sampling coverage in relation to important socio-demographic characteristics and likely pollution variability. The location-allocation approach integrates many variables into the demand surface to reconfigure a monitoring network and is especially useful for measuring traffic pollutants with fine-scale spatial variability. The method also shows great promise for improving the assessment of exposure to ambient air pollution in epidemiologic studies. 19 refs., 3 tabs., 4 figs.

Adaptation Computing Parameters of Pan-Tilt-Zoom Cameras for Traffic Monitoring

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Ya Lin WU

2014-01-01

Full Text Available The Closed- CIRCUIT television (CCTV cameras have been widely used in recent years for traffic monitoring and surveillance applications. We can use CCTV cameras to extract automatically real-time traffic parameters according to the image processing and tracking technologies. Especially, the pan-tilt-zoom (PTZ cameras can provide flexible view selection as well as a wider observation range, and this makes the traffic parameters can be accurately calculated. Therefore, that the parameters of PTZ cameras are calibrated plays an important role in vision-based traffic applications. However, in the specific traffic environment, which is that the license plate number of the illegal parking is located, the parameters of PTZ cameras have to be updated according to the position and distance of illegal parking. In proposed traffic monitoring systems, we use the ordinary webcam and PTZ camera. We get vanishing-point of traffic lane lines in the pixel-based coordinate system by fixed webcam. The parameters of PTZ camera can be initialized by distance of the traffic monitoring and specific objectives and vanishing-point. And then we can use the coordinate position of the illegally parked car to update the parameters of PTZ camera and then get the real word coordinate position of the illegally parked car and use it to compute the distance. The result shows the error of the tested distance and real distance is only 0.2064 meter.

Minnesota urban partnership agreement national evaluation : traffic system data test plan.

Science.gov (United States)

2009-11-17

This report presents the traffic system data test plan for the Minnesota Urban Partnership Agreement (UPA) under the United States Department of Transportation (U.S. DOT) UPA Program. The Minnesota UPA projects focus on reducing congestion by employi...

Monitoring Traffic Information with a Developed Acceleration Sensing Node

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Zhoujing Ye

2017-12-01

Full Text Available In this paper, an acceleration sensing node for pavement vibration was developed to monitor traffic information, including vehicle speed, vehicle types, and traffic flow, where a hardware design with low energy consumption and node encapsulation could be accomplished. The service performance of the sensing node was evaluated, by methods including waterproof test, compression test, sensing performance analysis, and comparison test. The results demonstrate that the sensing node is low in energy consumption, high in strength, IPX8 waterproof, and high in sensitivity and resolution. These characteristics can be applied to practical road environments. Two sensing nodes were spaced apart in the direction of travelling. In the experiment, three types of vehicles passed by the monitoring points at several different speeds and values of d (the distance between the sensor and the nearest tire center line. Based on cross-correlation with kernel pre-smoothing, a calculation method was applied to process the raw data. New algorithms for traffic flow, speed, and axle length were proposed. Finally, the effects of vehicle speed, vehicle weight, and d value on acceleration amplitude were statistically evaluated. It was found that the acceleration sensing node can be used for traffic flow, vehicle speed, and other types of monitoring.

Monitoring Traffic Information with a Developed Acceleration Sensing Node.

Science.gov (United States)

Ye, Zhoujing; Wang, Linbing; Xu, Wen; Gao, Zhifei; Yan, Guannan

2017-12-05

In this paper, an acceleration sensing node for pavement vibration was developed to monitor traffic information, including vehicle speed, vehicle types, and traffic flow, where a hardware design with low energy consumption and node encapsulation could be accomplished. The service performance of the sensing node was evaluated, by methods including waterproof test, compression test, sensing performance analysis, and comparison test. The results demonstrate that the sensing node is low in energy consumption, high in strength, IPX8 waterproof, and high in sensitivity and resolution. These characteristics can be applied to practical road environments. Two sensing nodes were spaced apart in the direction of travelling. In the experiment, three types of vehicles passed by the monitoring points at several different speeds and values of d (the distance between the sensor and the nearest tire center line). Based on cross-correlation with kernel pre-smoothing, a calculation method was applied to process the raw data. New algorithms for traffic flow, speed, and axle length were proposed. Finally, the effects of vehicle speed, vehicle weight, and d value on acceleration amplitude were statistically evaluated. It was found that the acceleration sensing node can be used for traffic flow, vehicle speed, and other types of monitoring.

A sustainable safe traffic and transport system : déjà-vu in urban planning ? Contribution to the conference `Traffic safety on two continents', Lisbon, Portugal, September 22-24, 1997.

NARCIS (Netherlands)

Dijkstra, A.

1997-01-01

This paper deals with the question of how to reconcile urban development with traffic structure, traffic flows and transport modes. A distinction is drawn between the so-called `pan-urban' projects and those within individual residential areas. A sketch of developments and trends is given, designed

Spatial and temporal variations in traffic-related particulate matter at New York City high schools

Science.gov (United States)

Patel, Molini M.; Chillrud, Steven N.; Correa, Juan C.; Feinberg, Marian; Hazi, Yair; Deepti, K. C.; Prakash, Swati; Ross, James M.; Levy, Diane; Kinney, Patrick L.

Relatively little is known about exposures to traffic-related particulate matter at schools located in dense urban areas. The purpose of this study was to examine the influences of diesel traffic proximity and intensity on ambient concentrations of fine particulate matter (PM 2.5) and black carbon (BC), an indicator of diesel exhaust particles, at New York City (NYC) high schools. Outdoor PM 2.5 and BC were monitored continuously for 4-6 weeks at each of 3 NYC schools and 1 suburban school located 40 km upwind of the city. Traffic count data were obtained using an automated traffic counter or video camera. BC concentrations were 2-3 fold higher at urban schools compared with the suburban school, and among the 3 urban schools, BC concentrations were higher at schools located adjacent to highways. PM 2.5 concentrations were significantly higher at urban schools than at the suburban school, but concentrations did not vary significantly among urban schools. Both hourly average counts of trucks and buses and meteorological factors such as wind direction, wind speed, and humidity were significantly associated with hourly average ambient BC and PM 2.5 concentrations in multivariate regression models. An increase of 443 trucks/buses per hour was associated with a 0.62 μg/m 3 increase in hourly average BC at an NYC school located adjacent to a major interstate highway. Car traffic counts were not associated with BC. The results suggest that local diesel vehicle traffic may be important sources of airborne fine particles in dense urban areas and consequently may contribute to local variations in PM 2.5 concentrations. In urban areas with higher levels of diesel traffic, local, neighborhood-scale monitoring of pollutants such as BC, which compared to PM 2.5, is a more specific indicator of diesel exhaust particles, may more accurately represent population exposures.

An Information-Theoretic Approach for Indirect Train Traffic Monitoring Using Building Vibration

OpenAIRE

Xu, Susu; Zhang, Lin; Zhang, Pei; Noh, Hae Young

2017-01-01

This paper introduces an indirect train traffic monitoring method to detect and infer real-time train events based on the vibration response of a nearby building. Monitoring and characterizing traffic events are important for cities to improve the efficiency of transportation systems (e.g., train passing, heavy trucks, and traffic). Most prior work falls into two categories: (1) methods that require intensive labor to manually record events or (2) systems that require deployment of dedicated ...

Prevalence and regional correlates of road traffic injury among Chinese urban residents: A 21-city population-based study.

Science.gov (United States)

Rockett, Ian R H; Jiang, Shuhan; Yang, Qian; Yang, Tingzhong; Yang, Xiaozhao Y; Peng, Sihui; Yu, Lingwei

2017-08-18

This study estimated the prevalence of road traffic injury among Chinese urban residents and examined individual and regional-level correlates. A cross-sectional multistage process was used to sample residents from 21 selected cities in China. Survey respondents reported their history of road traffic injury in the past 12 months through a community survey. Multilevel, multivariable logistic regression analysis was used to identify injury correlates. Based on a retrospective 12-month reporting window, road traffic injury prevalence among urban residents was 13.2%. Prevalence of road traffic injury, by type, was 8.7, 8.7, 8.5, and 7.7% in the automobile, bicycle, motorcycle, and pedestrian categories, respectively. Multilevel analysis showed that prevalence of road traffic injury was positively associated with minority status, income, and mental health disorder score at the individual level. Regionally, road traffic injury was associated with geographic location of residence and prevalence of mental health disorders. Both individual and regional-level variables were associated with road traffic injury among Chinese urban residents, a finding whose implications transcend wholesale imported generic solutions. This descriptive research demonstrates an urgent need for longitudinal studies across China on risk and protective factors, in order to inform injury etiology, surveillance, prevention, treatment, and evaluation.

Traffic data for local emissions monitoring at a signalized intersection

NARCIS (Netherlands)

Bigazzi, A.; Lint, J.W.C. van; Klunder, G.; Stelwagen, U.; Ligterink, N.E.

2010-01-01

In order to assist planning efforts for air pollution-responsive dynamic traffic management (DTM) systems, this research assesses the accuracy of local emissions monitoring based on traffic data and models. The study quantifies the benefits of increased data resolution for short-term emissions

Passive performance monitoring and traffic characteristics on the SLAC internet border

International Nuclear Information System (INIS)

Logg, C.; Cottrell, L.

2001-01-01

Understanding how the Internet is used by HEP is critical to optimizing the performance of the inter-lab computing environment. Typically use requirements have been defined by discussions between collaborators. However, later analysis of the actual traffic has show this is often misunderstood and actual use is significantly different to that predicted. Passive monitoring of the real traffic provides insight into the true communications requirements and the performance of a large number of inter-communicating nodes. It may be useful in identifying performance problems that are due to factors other than Internet congestion, especially when compared to other methods such as active monitoring where traffic is generated specifically to measure its performance. Controlled active monitoring between dedicated servers often gives an indication of what can be achieved on a network. Passive monitoring of the real traffic gives a picture of the true performance. The authors will discuss the method and results of collecting and analyzing flows of data obtained from the SLAC Internet border. The insights this has brought to understanding the network will be reviewed and the benefit it can bring to engineering networks will be discussed

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

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Ziyuan Pu

2017-01-01

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

Urban compaction vs city sprawl: impact of road traffic on air quality in the greater Paris

Science.gov (United States)

Etuman Arthur, Elessa; Isabelle, Coll; Vincent, Viguie; Nicolas, Coulombel; Julie, Prud'homme

2017-04-01

Urban pollution remains a major sanitary and economic concern. In France, particulate pollution is known to cause 48,000 premature deaths every year (Santé Publique France, 2016), while the economic cost of air pollution reaches almost 25 billion euros per year (CGDD, 2012). In the Greater Paris, despite strengthened emission standards, restricted traffic areas, car-sharing and incentives for electric vehicle use, road transport plays a substantial role in the exposure of inhabitants to high levels of pollutants. In this context, urban planning could possibly constitute an innovative strategy to reduce emissions from road traffic, through its actions on transport demand, travel distances, modal shift (public transportation, cycling, walking...) or even proximity to emitters. We have developed a multi-scalar modeling of urban pollution by coupling an urban economic growth model NEDUM (CIRED), a model for urban mobility (LISA), a traffic emission model (LISA) and the CHIMERE Chemistry-Transport model (CTM) for air quality simulation (LISA). The innovative aspect of this modeling system is to integrate into a classic CTM the mechanisms underlying the dynamics of an urban system. This way, we establish a quantitative and comprehensive link between a given urban scenario, the associated public and individual transport matrix, and local air quality. We then make it possible to highlight the levers of energy consumption reductions inside compact or sprawled cities. We have been working on the Ile de France region (centered on the Paris agglomeration) which relies on a broad urban structure of megacity, a high density of housing and an expanding urban peripheral zone, clearly raising the issue of transport demand, mobility and traffic congestion. Two scenarios, considering opposite urban development policies from the 1960s to 2010, have been simulated over the whole modelling chain. The first one promotes a dense and compact city while the second favors city spread

INFRASTRUCTURE FACILITIES FOR MONITORING AND INTELLECTUAL ROAD TRAFFIC MANAGEMENT

Directory of Open Access Journals (Sweden)

G. Belov

2014-10-01

Full Text Available Review of automatic management of road traffic technologies in major cities of Ukraine is carried out in the given article. Priority directions of studies are determined for producing modern and perspective technologies in the given area. The facilities for monitoring and intelligence management of the road traffic on the basis of the programmed logical controller, using the device of fuzzy logic are considered.

An indicator for emissions from traffic; Een indicator voor verkeersemissies

Energy Technology Data Exchange (ETDEWEB)

Molenaar, R.; De Gier, C. [DCMR Milieudienst Rijnmond, Rotterdam (Netherlands)

2011-08-15

Traffic is an important source of air pollution in urban areas. Of all the substances we measure in the air, soot seems to be the best parameter for monitoring traffic emissions. [Dutch] Verkeer is de belangrijkste bron van luchtverontreiniging in stedelijke gebieden. Van alle stoffen die we in de lucht meten, blijkt roet de beste parameter om verkeersemissies te monitoren.

Decentralized State-Observer-Based Traffic Density Estimation of Large-Scale Urban Freeway Network by Dynamic Model

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Yuqi Guo

2017-08-01

Full Text Available In order to estimate traffic densities in a large-scale urban freeway network in an accurate and timely fashion when traffic sensors do not cover the freeway network completely and thus only local measurement data can be utilized, this paper proposes a decentralized state observer approach based on a macroscopic traffic flow model. Firstly, by using the well-known cell transmission model (CTM, the urban freeway network is modeled in the way of distributed systems. Secondly, based on the model, a decentralized observer is designed. With the help of the Lyapunov function and S-procedure theory, the observer gains are computed by using linear matrix inequality (LMI technique. So, the traffic densities of the whole road network can be estimated by the designed observer. Finally, this method is applied to the outer ring of the Beijing’s second ring road and experimental results demonstrate the effectiveness and applicability of the proposed approach.

Effects of the amount of feedback information on urban traffic with advanced traveler information system

Science.gov (United States)

Chen, Jie; Li, Ming; Jiang, Rui; Hu, Mao-Bin

2017-09-01

In a real traffic system, information feedback has already been proven to be a good way to alleviate traffic jams. However, due to the massive traffic information of real system, the procedure is often difficult in practice. In this paper, we study the effects of the amount of feedback information based on a cellular automaton model of urban traffic. What we found most interesting is that when providing the traffic information of a part of a road to travelers, the performance of the system will be better than that providing the road's full traffic information. From this basis, we can provide more effective routing strategy with less information. We demonstrate that only providing the traffic information of about first half road from upstream to downstream can maximize the traffic capacity of the system. We also give an explanation for these phenomena by studying the distribution pattern of vehicles and the detailed turning environment at the intersections. The effects of the traffic light period are also provided.

Assessing the air quality impact of nitrogen oxides and benzene from road traffic and domestic heating and the associated cancer risk in an urban area of Verona (Italy)

Science.gov (United States)

Schiavon, Marco; Redivo, Martina; Antonacci, Gianluca; Rada, Elena Cristina; Ragazzi, Marco; Zardi, Dino; Giovannini, Lorenzo

2015-11-01

Simulations of emission and dispersion of nitrogen oxides (NOx) are performed in an urban area of Verona (Italy), characterized by street canyons and typical sources of urban pollutants. Two dominant source categories are considered: road traffic and, as an element of novelty, domestic heaters. Also, to assess the impact of urban air pollution on human health and, in particular, the cancer risk, simulations of emission and dispersion of benzene are carried out. Emissions from road traffic are estimated by the COPERT 4 algorithm, whilst NOx emission factors from domestic heaters are retrieved by means of criteria provided in the technical literature. Then maps of the annual mean concentrations of NOx and benzene are calculated using the AUSTAL2000 dispersion model, considering both scenarios representing the current situation, and scenarios simulating the introduction of environmental strategies for air pollution mitigation. The simulations highlight potentially critical situations of human exposure that may not be detected by the conventional network of air quality monitoring stations. The proposed methodology provides a support for air quality policies, such as planning targeted measurement campaigns, re-locating monitoring stations and adopting measures in favour of better air quality in urban planning. In particular, the estimation of the induced cancer risk is an important starting point to conduct zoning analyses and to detect the areas where population is more directly exposed to potential risks for health.

Evaluation of noise pollution in urban traffic hubs—Noise maps and measurements

International Nuclear Information System (INIS)

Fiedler, Paulo Eduardo Kirrian; Zannin, Paulo Henrique Trombetta

2015-01-01

A study was made of some of the main traffic hubs in a Latin American metropolis, in order to determine the presence or absence of noise by means of noise measurements and acoustic mapping. To characterize noise in the evaluated road stretches, 232 measurements were taken at different points. The Predictor software package was used for the noise mapping calculations. Noise sensitive areas, e.g., hospitals, were identified in the evaluated road stretches. Noise maps were calculated for two hospitals, showing the current levels of noise that reach their facades. Hypothetical scenarios were simulated by making changes in the composition of traffic and total number of vehicles, and an assessment was made of the potential influence of these modifications in reducing the noise levels reaching the facades of the buildings in question. The simulations indicated that a 50% reduction in total traffic flow, or a 50% reduction in heavy vehicle traffic flow, would reduce the noise levels by about 3 dB(A). - Highlights: • Evaluation of noise pollution in urban traffic hubs • Street systems • Environmental noise impacts • Noise mapping

Evaluation of noise pollution in urban traffic hubs—Noise maps and measurements

Energy Technology Data Exchange (ETDEWEB)

Fiedler, Paulo Eduardo Kirrian; Zannin, Paulo Henrique Trombetta, E-mail: paulo.zannin@pesquisador.cnpq.br

2015-02-15

A study was made of some of the main traffic hubs in a Latin American metropolis, in order to determine the presence or absence of noise by means of noise measurements and acoustic mapping. To characterize noise in the evaluated road stretches, 232 measurements were taken at different points. The Predictor software package was used for the noise mapping calculations. Noise sensitive areas, e.g., hospitals, were identified in the evaluated road stretches. Noise maps were calculated for two hospitals, showing the current levels of noise that reach their facades. Hypothetical scenarios were simulated by making changes in the composition of traffic and total number of vehicles, and an assessment was made of the potential influence of these modifications in reducing the noise levels reaching the facades of the buildings in question. The simulations indicated that a 50% reduction in total traffic flow, or a 50% reduction in heavy vehicle traffic flow, would reduce the noise levels by about 3 dB(A). - Highlights: • Evaluation of noise pollution in urban traffic hubs • Street systems • Environmental noise impacts • Noise mapping.

A new smart traffic monitoring method using embedded cement-based piezoelectric sensors

International Nuclear Information System (INIS)

Zhang, Jinrui; Lu, Youyuan; Lu, Zeyu; Liu, Chao; Sun, Guoxing; Li, Zongjin

2015-01-01

Cement-based piezoelectric composites are employed as the sensing elements of a new smart traffic monitoring system. The piezoelectricity of the cement-based piezoelectric sensors enables powerful and accurate real-time detection of the pressure induced by the traffic flow. To describe the mechanical-electrical conversion mechanism between traffic flow and the electrical output of the embedded piezoelectric sensors, a mathematical model is established based on Duhamel’s integral, the constitutive law and the charge-leakage characteristics of the piezoelectric composite. Laboratory tests show that the voltage magnitude of the sensor is linearly proportional to the applied pressure, which ensures the reliability of the cement-based piezoelectric sensors for traffic monitoring. A series of on-site road tests by a 10 tonne truck and a 6.8 tonne van show that vehicle weight-in-motion can be predicted based on the mechanical-electrical model by taking into account the vehicle speed and the charge-leakage property of the piezoelectric sensor. In the speed range from 20 km h −1 to 70 km h −1 , the error of the repeated weigh-in-motion measurements of the 6.8 tonne van is less than 1 tonne. The results indicate that the embedded cement-based piezoelectric sensors and associated measurement setup have good capability of smart traffic monitoring, such as traffic flow detection, vehicle speed detection and weigh-in-motion measurement. (paper)

Noise, air pollutants and traffic: continuous measurement and correlation at a high-traffic location in New York City.

Science.gov (United States)

Ross, Zev; Kheirbek, Iyad; Clougherty, Jane E; Ito, Kazuhiko; Matte, Thomas; Markowitz, Steven; Eisl, Holger

2011-11-01

Epidemiological studies have linked both noise and air pollution to common adverse health outcomes such as increased blood pressure and myocardial infarction. In urban settings, noise and air pollution share important sources, notably traffic, and several recent studies have shown spatial correlations between noise and air pollution. The temporal association between these exposures, however, has yet to be thoroughly investigated despite the importance of time series studies in air pollution epidemiology and the potential that correlations between these exposures could at least partly confound statistical associations identified in these studies. An aethelometer, for continuous elemental carbon measurement, was co-located with a continuous noise monitor near a major urban highway in New York City for six days in August 2009. Hourly elemental carbon measurements and hourly data on overall noise levels and low, medium and high frequency noise levels were collected. Hourly average concentrations of fine particles and nitrogen oxides, wind speed and direction and car, truck and bus traffic were obtained from nearby regulatory monitors. Overall temporal patterns, as well as day-night and weekday-weekend patterns, were characterized and compared for all variables. Noise levels were correlated with car, truck, and bus traffic and with air pollutants. We observed strong day-night and weekday-weekend variation in noise and air pollutants and correlations between pollutants varied by noise frequency. Medium and high frequency noise were generally more strongly correlated with traffic and traffic-related pollutants than low frequency noise and the correlation with medium and high frequency noise was generally stronger at night. Correlations with nighttime high frequency noise were particularly high for car traffic (Spearman rho=0.84), nitric oxide (0.73) and nitrogen dioxide (0.83). Wind speed and direction mediated relationships between pollutants and noise. Noise levels are

Indoor-outdoor concentrations of RSPM in classroom of a naturally ventilated school building near an urban traffic roadway

Science.gov (United States)

Goyal, Radha; Khare, Mukesh

2009-12-01

A study on indoor-outdoor RSPM (PM 10, PM 2.5 and PM 1.0) mass concentration monitoring has been carried out at a classroom of a naturally ventilated school building located near an urban roadway in Delhi City. The monitoring has been planned for a year starting from August 2006 till August 2007, including weekdays (Monday, Wednesday and Friday) and weekends (Saturday and Sunday) from 8:0 a.m. to 2:0 p.m., in order to take into account hourly, daily, weekly, monthly and seasonal variations in pollutant concentrations. Meteorological parameters, including temperature, rH, pressure, wind speed and direction, and traffic parameters, including its type and volume has been monitored simultaneously to relate the concentrations of indoor-outdoor RSPM with them. Ventilation rate has also been estimated to find out its relation with indoor particulate concentrations. The results of the study indicates that RSPM concentrations in classroom exceeds the permissible limits during all monitoring hours of weekdays and weekends in all seasons that may cause potential health hazards to occupants, when exposed. I/O for all sizes of particulates are greater than 1, which implies that building envelop does not provide protection from outdoor pollutants. Further, a significant influence of meteorological parameters, ventilation rate and of traffic has been observed on I/O. Higher I/O for PM 10 is indicating the presence of its indoor sources in classroom and their indoor concentrations are strongly influenced by activities of occupants during weekdays.

Correlation between the nitrogen concentration of two epiphytic lichens and the traffic density in an urban area

International Nuclear Information System (INIS)

Gombert, S.; Asta, J.; Seaward, M.R.D.

2003-01-01

Nitrogen concentrations of the lichen Physcia adscendens are related to traffic exposure. - A field experiment was carried out in the urban environment of the Grenoble area using two epiphytic lichens: the nitrophytic Physcia adscendens and the acidiphytic Hypogymnia physodes. Two complementary studies characterized this experiment. Firstly, a sampling of the two lichens in 48 sites randomly located throughout the Grenoble area indicated that roads (size and proximity to sampling sites) influenced the nitrogen concentrations of P. adscendens, but not those of H. physodes. Secondly, to study more accurately the influence of roads, a traffic index was calculated and applied along two transects located perpendicularly to urban motorways. Significant positive correlations were found between this traffic index and the total nitrogen concentration of P. adscendens

Road Traffic Accidents In Uyo Urban, Akwa Ibom State: The Scourge ...

African Journals Online (AJOL)

The aim was to determnie the scope of Road Traffic accidents in Uyo Urban, the hub of Akwa Ibom State commercial life, the role of motor cycles in the mishaps, the nature of trauma sustained; the bones commonly involved and the possible causes of the accidents: The data obtained, showed that motor cycles are involved ...

A PHOTOGRAMMETRIC APPRAOCH FOR AUTOMATIC TRAFFIC ASSESSMENT USING CONVENTIONAL CCTV CAMERA

Directory of Open Access Journals (Sweden)

N. Zarrinpanjeh

2015-12-01

Full Text Available One of the most practical tools for urban traffic monitoring is CCTV imaging which is widely used for traffic map generation and updating through human surveillance. But due to the expansion of urban road network and the use of huge number of CCTV cameras, visual inspection and updating of traffic sometimes seems to be ineffective and time consuming and therefore not providing real-time robust update. In this paper a method for vehicle detection accounting and speed estimation is proposed to give a more automated solution for traffic assessment. Through removing violating objects and detection of vehicles via morphological filtering and also classification of moving objects at the scene vehicles are counted and traffic speed is estimated. The proposed method is developed and tested using two datasets and evaluation values are computed. The results show that the successfulness of the algorithm decreases by about 12 % due to decrease in illumination quality of imagery.

Bicyclists' Uptake of Traffic-Related Air Pollution: Effects of the Urban Transportation System

Science.gov (United States)

2014-10-27

While bicyclists and other active travelers obtain health benefits from increased physical activity, they also risk uptake of traffic-related air pollution. But pollution uptake by urban bicyclists is not well understood due to a lack of direct measu...

Real-time Monitoring and Simulating of Urban Flood, a Case Study in Guangzhou

Science.gov (United States)

Huang, H.; Wang, X.; Zhang, S.; Liu, Y.

2014-12-01

In recent years urban flood frequently occurred and seriously impacted city's normal operation, particular on transportation. The increase of urban flood could be attributed to many factors, such as the increase of impervious land surface and extreme precipitation, the decrease of surface storage capacity, poor maintenance of drainage utilities, and so on. In order to provide accurate and leading prediction on urban flooding, this study acquires precise urban topographic data via air-borne Lidar system, collects detailed underground drainage pipes, and installs in-situ monitoring networks on precipitation, water level, video record and traffic speed in the downtown area of Panyu District, Guangzhou, China. Based on the above data acquired, a urban flood model with EPA SWMM5 is established to simulate the flooding and inundation processes in the study area of 20 km2. The model is driven by the real-time precipitation data and calibrated by the water level data, which are converted to flooding volume with precise topographic data. After calibration, the model could be employed to conduct sensitivity analysis for investigating primary factors of urban flooding, and to simulate the flooding processes in different scenarios, which are beneficial to assessment of flooding risk and drainage capacity. This model is expected to provide real-time forecasting in emergency management.

Application of magnetic, geochemical and micro-morphological methods in environmental studies of urban pollution generated by road traffic

Energy Technology Data Exchange (ETDEWEB)

Bucko, M.

2012-11-01

Road traffic is at present one of the major sources of environmental pollution in urban areas. Magnetic particles, heavy metals and other compounds generated by traffic can greatly affect ambient air quality and have direct implications for human health. The general aim of this research was to identify and characterize magnetic vehicle-derived particulates using magnetic, geochemical and micro-morphological methods. A combination of three different methods was used to discriminate sources of particular anthropogenic particles. Special emphasis was placed on the application of various collectors (roadside soil, snow, lichens and moss bags) to monitor spatial and temporal distribution of traffic pollution on roadsides. The spatial distribution of magnetic parameters of road dust accumulated in roadside soil, snow, lichens and moss bags indicates that the highest concentration of magnetic particles is in the sampling points situated closest to the road edge. The concentration of magnetic particles decreases with increasing distance from the road indicating vehicle traffic as a major source of emission. Significant differences in horizontal distribution of magnetic susceptibility were observed between soil and snow. Magnetic particles derived from road traffic deposit on soil within a few meters from the road, but on snow up to 60 m from the road. The values of magnetic susceptibility of road dust deposited near busy urban motorway are significantly higher than in the case of low traffic road. These differences are attributed to traffic volume, which is 30 times higher on motorway than on local road. Moss bags placed at the edge of urban parks situated near major roads show higher values of magnetic susceptibility than moss bags from parks located near minor routes. Enhanced concentrations of heavy metals (e.g. Fe, Mn, Zn, Cu, Cr, Ni and Co) were observed in the studied samples. This may be associated with specific sources of vehicle emissions (e.g. exhaust and non

Using mobile monitoring to visualise diurnal variation of traffic pollutants across two near-highway neighbourhoods

Science.gov (United States)

Pattinson, Woodrow; Longley, Ian; Kingham, Simon

2014-09-01

It is widely accepted that concentrations of primary traffic pollutants can vary substantially across relatively small urban areas. Fixed-site monitors have been shown to be largely inadequate for representing concentrations at nearby locations, resulting in the increasing use of spatial modelling or mobile sampling methods to achieve spatial saturation. In this study, we employ the use of a simple bicycle to sample concentrations of ultrafine particles (UFPs), carbon monoxide (CO) and particulate matter (PM10) at two small areas (arterials and quieter streets, at periods of contrasting meteorological and traffic conditions. A total of 20 sampling runs in each area (five at each of the four timings) were conducted. Meteorological data were logged continuously at background sites within each study area. Results show that the influence of highway traffic (UFPs, CO) was strongest during the mornings and late evenings when wind speeds were low, while for the midday and afternoon timings, concentrations were highest at the arterial and shopping zones. Concentrations of PM10 appeared to be strongest in the residential areas during mornings and late evenings, suggesting an influence of wood burning for home heating. For all timings combined, for all three pollutants, it appears the arterial roads featuring shops and numerous intersections with traffic lights, had a stronger influence on concentrations than the busier but more free-flowing highways. This study provides not only an insight into microspatial hotspot variation across suburbs, but also how this variation shifts diurnally.

Traffic-related air pollution and allergic disease: an update in the context of global urbanization.

Science.gov (United States)

Carlsten, Christopher; Rider, Christopher F

2017-04-01

The review aims to give an update on the literature around traffic-related air pollution (TRAP) and allergic disease in the context of global urbanization, as the most populous countries in the world face severe TRAP exposure challenges. As research continues to show that gene-environment interactions and epigenetics contribute to the TRAP-allergy link, evidence around the links to climate change grows. Greenspace may provide a buffer to adverse effects of traffic on health, overall, but pose risks in terms of allergic disease. The link between traffic-related pollution and allergy continues to strengthen, in terms of supportive observational findings and mechanistic studies. Levels of TRAP across the world, particularly in Asia, continue to dramatically exceed acceptable levels, suggesting that the related adverse health consequences will accelerate. This could be counterbalanced by primary emission control and urban planning. Attention to combined effects of TRAP and allergen exposure is critical to avoiding misleading inferences drawn though examination only of isolated factors.

Incorporating real-time traffic and weather data to explore road accident likelihood and severity in urban arterials.

Science.gov (United States)

Theofilatos, Athanasios

2017-06-01

The effective treatment of road accidents and thus the enhancement of road safety is a major concern to societies due to the losses in human lives and the economic and social costs. The investigation of road accident likelihood and severity by utilizing real-time traffic and weather data has recently received significant attention by researchers. However, collected data mainly stem from freeways and expressways. Consequently, the aim of the present paper is to add to the current knowledge by investigating accident likelihood and severity by exploiting real-time traffic and weather data collected from urban arterials in Athens, Greece. Random Forests (RF) are firstly applied for preliminary analysis purposes. More specifically, it is aimed to rank candidate variables according to their relevant importance and provide a first insight on the potential significant variables. Then, Bayesian logistic regression as well finite mixture and mixed effects logit models are applied to further explore factors associated with accident likelihood and severity respectively. Regarding accident likelihood, the Bayesian logistic regression showed that variations in traffic significantly influence accident occurrence. On the other hand, accident severity analysis revealed a generally mixed influence of traffic variations on accident severity, although international literature states that traffic variations increase severity. Lastly, weather parameters did not find to have a direct influence on accident likelihood or severity. The study added to the current knowledge by incorporating real-time traffic and weather data from urban arterials to investigate accident occurrence and accident severity mechanisms. The identification of risk factors can lead to the development of effective traffic management strategies to reduce accident occurrence and severity of injuries in urban arterials. Copyright © 2017 Elsevier Ltd and National Safety Council. All rights reserved.

Safety concepts for the design of transport and traffic facilities for pedestrians, cyclists, children and disabled in urban areas. Contribution to the 5th National Congress on Traffic Safety, Barcelona, Spain, November 24-26, 1982.

NARCIS (Netherlands)

Asmussen, E.

1982-01-01

The "vulnerable" road users, pedestrians, cyclists, children and disabled in urban -areas mainly are victims of motorised traffic. The intensity and speed of this motorized traffic are the main agents for the unsafety of the "vulnerable" road users. Safety concepts for urban areas should be directed

Wireless Magnetic Sensor Network for Road Traffic Monitoring and Vehicle Classification

Directory of Open Access Journals (Sweden)

Velisavljevic Vladan

2016-12-01

Full Text Available Efficiency of transportation of people and goods is playing a vital role in economic growth. A key component for enabling effective planning of transportation networks is the deployment and operation of autonomous monitoring and traffic analysis tools. For that reason, such systems have been developed to register and classify road traffic usage. In this paper, we propose a novel system for road traffic monitoring and classification based on highly energy efficient wireless magnetic sensor networks. We develop novel algorithms for vehicle speed and length estimation and vehicle classification that use multiple magnetic sensors. We also demonstrate that, using such a low-cost system with simplified installation and maintenance compared to current solutions, it is possible to achieve highly accurate estimation and a high rate of positive vehicle classification.

Urban Road Traffic Simulation Techniques

Directory of Open Access Journals (Sweden)

Ana Maria Nicoleta Mocofan

2011-09-01

Full Text Available For achieving a reliable traffic control system it is necessary to first establish a network parameter evaluation system and also a simulation system for the traffic lights plan. In 40 years of history, the computer aided traffic simulation has developed from a small research group to a large scale technology for traffic systems planning and development. In the following thesis, a presentation of the main modeling and simulation road traffic applications will be provided, along with their utility, as well as the practical application of one of the models in a case study.

The Traffic Adaptive Data Dissemination (TrAD Protocol for both Urban and Highway Scenarios

Directory of Open Access Journals (Sweden)

Bin Tian

2016-06-01

Full Text Available The worldwide economic cost of road crashes and injuries is estimated to be US$518 billion per year and the annual congestion cost in France is estimated to be €5.9 billion. Vehicular Ad hoc Networks (VANETs are one solution to improve transport features such as traffic safety, traffic jam and infotainment on wheels, where a great number of event-driven messages need to be disseminated in a timely way in a region of interest. In comparison with traditional wireless networks, VANETs have to consider the highly dynamic network topology and lossy links due to node mobility. Inter-Vehicle Communication (IVC protocols are the keystone of VANETs. According to our survey, most of the proposed IVC protocols focus on either highway or urban scenarios, but not on both. Furthermore, too few protocols, considering both scenarios, can achieve high performance. In this paper, an infrastructure-less Traffic Adaptive data Dissemination (TrAD protocol which takes into account road traffic and network traffic status for both highway and urban scenarios will be presented. TrAD has double broadcast suppression techniques and is designed to adapt efficiently to the irregular road topology. The performance of the TrAD protocol was evaluated quantitatively by means of realistic simulations taking into account different real road maps, traffic routes and vehicular densities. The obtained simulation results show that TrAD is more efficient in terms of packet delivery ratio, number of transmissions and delay in comparison with the performance of three well-known reference protocols. Moreover, TrAD can also tolerate a reasonable degree of GPS drift and still achieve efficient data dissemination.

The Traffic Adaptive Data Dissemination (TrAD) Protocol for both Urban and Highway Scenarios.

Science.gov (United States)

Tian, Bin; Hou, Kun Mean; Zhou, Haiying

2016-06-21

The worldwide economic cost of road crashes and injuries is estimated to be US$518 billion per year and the annual congestion cost in France is estimated to be €5.9 billion. Vehicular Ad hoc Networks (VANETs) are one solution to improve transport features such as traffic safety, traffic jam and infotainment on wheels, where a great number of event-driven messages need to be disseminated in a timely way in a region of interest. In comparison with traditional wireless networks, VANETs have to consider the highly dynamic network topology and lossy links due to node mobility. Inter-Vehicle Communication (IVC) protocols are the keystone of VANETs. According to our survey, most of the proposed IVC protocols focus on either highway or urban scenarios, but not on both. Furthermore, too few protocols, considering both scenarios, can achieve high performance. In this paper, an infrastructure-less Traffic Adaptive data Dissemination (TrAD) protocol which takes into account road traffic and network traffic status for both highway and urban scenarios will be presented. TrAD has double broadcast suppression techniques and is designed to adapt efficiently to the irregular road topology. The performance of the TrAD protocol was evaluated quantitatively by means of realistic simulations taking into account different real road maps, traffic routes and vehicular densities. The obtained simulation results show that TrAD is more efficient in terms of packet delivery ratio, number of transmissions and delay in comparison with the performance of three well-known reference protocols. Moreover, TrAD can also tolerate a reasonable degree of GPS drift and still achieve efficient data dissemination.

Spoofing cyber attack detection in probe-based traffic monitoring systems using mixed integer linear programming

KAUST Repository

Canepa, Edward S.; Claudel, Christian G.

2013-01-01

in traffic flow monitoring systems by using the underlying traffic flow model. The state of traffic is modeled by the Lighthill-Whitham- Richards traffic flow model, which is a first order scalar conservation law with concave flux function. Given a set

Effects of canyon geometry on the distribution of traffic-related air pollution in a large urban area: Implications of a multi-canyon air pollution dispersion model

Science.gov (United States)

Fu, Xiangwen; Liu, Junfeng; Ban-Weiss, George A.; Zhang, Jiachen; Huang, Xin; Ouyang, Bin; Popoola, Olalekan; Tao, Shu

2017-09-01

Street canyons are ubiquitous in urban areas. Traffic-related air pollutants in street canyons can adversely affect human health. In this study, an urban-scale traffic pollution dispersion model is developed considering street distribution, canyon geometry, background meteorology, traffic assignment, traffic emissions and air pollutant dispersion. In the model, vehicle exhausts generated from traffic flows first disperse inside street canyons along the micro-scale wind field generated by computational fluid dynamics (CFD) model. Then, pollutants leave the street canyon and further disperse over the urban area. On the basis of this model, the effects of canyon geometry on the distribution of NOx and CO from traffic emissions were studied over the center of Beijing. We found that an increase in building height leads to heavier pollution inside canyons and lower pollution outside canyons at pedestrian level, resulting in higher domain-averaged concentrations over the area. In addition, canyons with highly even or highly uneven building heights on each side of the street tend to lower the urban-scale air pollution concentrations at pedestrian level. Further, increasing street widths tends to lead to lower pollutant concentrations by reducing emissions and enhancing ventilation simultaneously. Our results indicate that canyon geometry strongly influences human exposure to traffic pollutants in the populated urban area. Carefully planning street layout and canyon geometry while considering traffic demand as well as local weather patterns may significantly reduce inhalation of unhealthy air by urban residents.

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.

An Information-Theoretic Approach for Indirect Train Traffic Monitoring Using Building Vibration

Directory of Open Access Journals (Sweden)

Susu Xu

2017-05-01

Full Text Available This paper introduces an indirect train traffic monitoring method to detect and infer real-time train events based on the vibration response of a nearby building. Monitoring and characterizing traffic events are important for cities to improve the efficiency of transportation systems (e.g., train passing, heavy trucks, and traffic. Most prior work falls into two categories: (1 methods that require intensive labor to manually record events or (2 systems that require deployment of dedicated sensors. These approaches are difficult and costly to execute and maintain. In addition, most prior work uses dedicated sensors designed for a single purpose, resulting in deployment of multiple sensor systems. This further increases costs. Meanwhile, with the increasing demands of structural health monitoring, many vibration sensors are being deployed in commercial buildings. Traffic events create ground vibration that propagates to nearby building structures inducing noisy vibration responses. We present an information-theoretic method for train event monitoring using commonly existing vibration sensors deployed for building health monitoring. The key idea is to represent the wave propagation in a building induced by train traffic as information conveyed in noisy measurement signals. Our technique first uses wavelet analysis to detect train events. Then, by analyzing information exchange patterns of building vibration signals, we infer the category of the events (i.e., southbound or northbound train. Our algorithm is evaluated with an 11-story building where trains pass by frequently. The results show that the method can robustly achieve a train event detection accuracy of up to a 93% true positive rate and an 80% true negative rate. For direction categorization, compared with the traditional signal processing method, our information-theoretic approach reduces categorization error from 32.1 to 12.1%, which is a 2.5× improvement.

STUDY ON SUPPORTING FOR DRAWING UP THE BCP FOR URBAN EXPRESSWAY NETWORK USING BY TRAFFIC SIMULATION SYSTEM

Science.gov (United States)

Yamawaki, Masashi; Shiraki, Wataru; Inomo, Hitoshi; Yasuda, Keiichi

The urban expressway network is an important infrastructure to execute a disaster restoration. Therefore, it is necessary to draw up the BCP (Business Continuity Plan) to enable securing of road user's safety and restoration of facilities, etc. It is important that each urban expressway manager execute decision and improvement of effective BCP countermeasures when disaster occurs by assuming various disaster situations. Then, in this study, we develop the traffic simulation system that can reproduce various disaster situations and traffic actions, and examine some methods supporting for drawing up the BCP for an urban expressway network. For disaster outside assumption such as tsunami generated by a huge earthquake, we examine some approaches securing safety of users and cars on the Hanshin Expressway Network as well as on general roads. And, we aim to propose a tsunami countermeasure not considered in the current urban expressway BCP.

Intelligent vehicle based traffic monitoring – exploring application in South Africa

CSIR Research Space (South Africa)

Labuschagne, FJJ

2010-08-01

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

Heterogeneous Deployment to Meet Traffic Demand in a Realistic LTE Urban Scenario

DEFF Research Database (Denmark)

Coletti, Claudio; Hu, Liang; Nguyen, Huan Cong

2012-01-01

growth of mo-bile broadband traffic. Emphasis is put on how to optimally as-sign the spectrum for the different networks layers in an evolved HetNet including outdoor and indoor small cells. The study is conducted for a “Hot-Zone” scenario, i.e. a high-traffic area within a realistic dense urban...... performance with a minimum user data rate of 1 Mbps is achieved when deploying small cells on dedicated channels rather than co-channel deployment. Fur-thermore, the joint pico and femto deployment turns out to be the right trade-off between increased base station density and en-hanced network capacity....

Analysis of the Contribution of the Road Traffic Industry to the PM2.5 Emission for Different Land-Use Types

Directory of Open Access Journals (Sweden)

Peng Xu

2014-01-01

Full Text Available Road dust and vehicle exhaust are the main sources of air pollution in cities, especially in recent years with the quantity of vehicles and transportation construction continuously soaring; the hazy weather has been a dominant urban pollution form which is widely concerned by the Chinese society. By establishing a relationship model between traffic and land use, then applying analytic hierarchy process on the data from air quality monitoring station, this paper concludes the influence of different traffic behavior on air pollution which provides support to abate urban air pollution caused by traffic reasons through taking measures to control traffic.

Flood and Traffic Wireless Monitoring System for Smart Cities

KAUST Repository

Mousa, Mustafa

2016-01-01

The convergence of computation, communication and sensing has led to the emergence of Wireless Sensor Networks (WSNs), which allow distributed monitoring of physical phenomena over extended areas. In this thesis, we focus on a dual flood and traffic

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.

Method for predicting future developments of traffic noise in urban areas in Europe

NARCIS (Netherlands)

Salomons, E.; Hout, D. van den; Janssen, S.; Kugler, U.; MacA, V.

2010-01-01

Traffic noise in urban areas in Europe is a major environmental stressor. In this study we present a method for predicting how environmental noise can be expected to develop in the future. In the project HEIMTSA scenarios were developed for all relevant environmental stressors to health, for all

A pressure-sensitive carbon black cement composite for traffic monitoring

KAUST Repository

Monteiro, A.O.

2017-08-17

Recent advances in nanotechnology have guided the development of a new generation of multifunctional construction materials. An example of this are cement-based composites, some of which can be used not just to pave roads but also to monitor them. A cement composite, integrating a carbon black (CB) filler, was used as a piezoresistive sensor to identify different cyclic compressive loadings, at temperatures ranging from 15°C to 45°C. The mechanical essays were performed under realistic conditions using 600cm3 specimens and uniaxial loads typical of automobile traffic. A linear and reversible pressure-sensing performance was found with gauge factors ranging from 40 to 60. Overall, these results show that CB/cement composites can act as stress-sensitive materials for traffic monitoring.

On-line monitoring of benzene air concentrations while driving in traffic by means of isotopic dilution gas chromatography/mass spectrometry.

Science.gov (United States)

Davoli, E; Cappellini, L; Moggi, M; Ferrari, S; Fanelli, R

1996-01-01

There is no shortage of information about the average benzene concentrations in urban air, but there is very little about microenvironmental exposure, such as in-vehicle concentrations while driving in various traffic conditions, while refuelling, or while in a parking garage. The main reason for this lack of data is that no analytical instrumentation has been available to measure on-line trace amounts of benzene in such situations. We have recently proposed a highly accurate, high-speed cryofocusing gas chromatography/mass spectrometry (GC/MS) system for monitoring benzene concentrations in air. Accuracy of the analytical data is achieved by enrichment of the air sample before trapping, with a stable isotope permeation tube system. The same principles have been applied to a new instrument, specifically designed for operation on an electric vehicle (Ducato Elettra, Fiat). The zero emission vehicle and the fully transportable, battery-operated GC/MS system provide a unique possibility of monitoring benzene exposure in real everyday situations such as while driving, refuelling, or repairing a car. All power consumptions have been reduced so as to achieve a battery-operated GC/MS system. Liquid nitrogen cryofocusing has been replaced by a packed, inductively heated, graphitized charcoal microtrap. The instrument has been mounted on shock absorbers and installed in the van. The whole system has been tested in both fixed and mobile conditions. The maximum monitoring period without external power supply is 6 h. The full analytical cycle is 4 min, allowing close to real-time monitoring, and the minimum detectable level is 1 microgram/m3 for benzene. In-vehicle monitoring showed that, when recirculation was off and ventilation on, i.e., air from outside the vehicle was blown inside, concentrations varied widely in different driving conditions: moving from a parking lot into normal traffic on an urban traffic condition roadway yielded an increase in benzene concentration

Distinguishing between Rural and Urban Road Segment Traffic Safety Based on Zero-Inflated Negative Binomial Regression Models

Directory of Open Access Journals (Sweden)

Xuedong Yan

2012-01-01

Full Text Available In this study, the traffic crash rate, total crash frequency, and injury and fatal crash frequency were taken into consideration for distinguishing between rural and urban road segment safety. The GIS-based crash data during four and half years in Pikes Peak Area, US were applied for the analyses. The comparative statistical results show that the crash rates in rural segments are consistently lower than urban segments. Further, the regression results based on Zero-Inflated Negative Binomial (ZINB regression models indicate that the urban areas have a higher crash risk in terms of both total crash frequency and injury and fatal crash frequency, compared to rural areas. Additionally, it is found that crash frequencies increase as traffic volume and segment length increase, though the higher traffic volume lower the likelihood of severe crash occurrence; compared to 2-lane roads, the 4-lane roads have lower crash frequencies but have a higher probability of severe crash occurrence; and better road facilities with higher free flow speed can benefit from high standard design feature thus resulting in a lower total crash frequency, but they cannot mitigate the severe crash risk.

Research on Influence and Prediction Model of Urban Traffic Link Tunnel curvature on Fire Temperature Based on Pyrosim--SPSS Multiple Regression Analysis

Science.gov (United States)

Li, Xiao Ju; Yao, Kun; Dai, Jun Yu; Song, Yun Long

2018-05-01

The underground space, also known as the “fourth dimension” of the city, reflects the efficient use of urban development intensive. Urban traffic link tunnel is a typical underground limited-length space. Due to the geographical location, the special structure of space and the curvature of the tunnel, high-temperature smoke can easily form the phenomenon of “smoke turning” and the fire risk is extremely high. This paper takes an urban traffic link tunnel as an example to focus on the relationship between curvature and the temperature near the fire source, and use the pyrosim built different curvature fire model to analyze the influence of curvature on the temperature of the fire, then using SPSS Multivariate regression analysis simulate curvature of the tunnel and fire temperature data. Finally, a prediction model of urban traffic link tunnel curvature on fire temperature was proposed. The regression model analysis and test show that the curvature is negatively correlated with the tunnel temperature. This model is feasible and can provide a theoretical reference for the urban traffic link tunnel fire protection design and the preparation of the evacuation plan. And also, it provides some reference for other related curved tunnel curvature design and smoke control measures.

A GIS Approach to Evaluate Infrastructure Variables Influencing the Occurrence of Traffic Accidents in Urban Roads

Directory of Open Access Journals (Sweden)

Murat Selim Çepni

2017-03-01

Full Text Available Several studies worldwide have been developed that seek to explain the occurrence of traffic accidents from different perspectives. The analyses have addressed legal perspectives, technical attributes of vehicles and infrastructure as well as the psychological, behavioral and socio-economic components of the road system users. Recently, some analysis techniques based on the use of Geographic Information Systems (GIS have been used, which allow the generation of spatial distribution maps, models and risk estimates from a spatial perspective. Sometimes analyses of traffic accidents are performed using quantitative statistical techniques, which place significant importance on the evolution of accidents. Studies such as those in references have shown that conventional statistical models are sometimes inadequate to model the frequency of traffic accidents, as they may provide erroneous inferences. GIS approach has been used to explore different spatial and temporal visualization technologies to reveal accident patterns and significant factors relating to vehicle crashes, or as a management system for accident analysis and the determination of hot spots. This paper examines the relationship between urban road accidents and variables related to road infrastructure, environment and traffic volumes. Some accident-prone sections in the city of Kocaeli are specifically identified by GIS tools. Urban road accidents in Kocaeli are a serious problem and it is believed that accidents can be related to infrastructure characteristics. The study aimed to establish the relationship between urban road accidents and the road infrastructure variables and revealed some possible accident prone locations for the period of 2013 and 2015 in Kocaeli city

Effect of traffic restriction on atmospheric particle concentrations and their size distributions in urban Lanzhou, Northwestern China.

Science.gov (United States)

Zhao, Suping; Yu, Ye; Liu, Na; He, Jianjun; Chen, Jinbei

2014-02-01

During the 2012 Lanzhou International Marathon, the local government made a significant effort to improve traffic conditions and air quality by implementing traffic restriction measures. To evaluate the direct effect of these measures on urban air quality, especially particle concentrations and their size distributions, atmospheric particle size distributions (0.5-20 microm) obtained using an aerodynamic particle sizer (model 3321, TSI, USA) in June 2012 were analyzed. It was found that the particle number, surface area and volume concentrations for size range 0.5-10 microm were (15.0 +/- 2.1) cm(-3), (11.8 +/- 2.6) microm2/cm3 and (1.9 +/- 0.6) microm2/cm3, respectively, on the traffic-restricted day (Sunday), which is 63.2%, 53.0% and 47.2% lower than those on a normal Sunday. For number and surface area concentrations, the most affected size range was 0.5-0.7 and 0.5-0.8 microm, respectively, while for volume concentration, the most affected size ranges were 0.5-0.8, 1.7-2.0 and 5.0-5.4 microm. Number and volume concentrations of particles in size range 0.5-1.0 microm correlated well with the number of non-CNG (Compressed Natural Gas) powered vehicles, while their correlation with the number of CNG-powered vehicles was very low, suggesting that reasonable urban traffic controls along with vehicle technology improvements could play an important role in improving urban air quality.

Hybrid and electric low-noise cars cause an increase in traffic accidents involving vulnerable road users in urban areas.

Science.gov (United States)

Brand, Stephan; Petri, Maximilian; Haas, Philipp; Krettek, Christian; Haasper, Carl

2013-01-01

Due to resource scarcity, the number of low-noise and electric cars is expected to increase rapidly. The frequent use of these cars will lead to a significant reduction of traffic related noise and pollution. On the other hand, due to the adaption and conditioning of vulnerable road users the number of traffic accidents involving pedestrians and bicyclists is postulated to increase as well. Children, older people with reduced eyesight and the blind are especially reliant on a combination of acoustic and visual warning signals with approaching or accelerating vehicles. This is even more evident in urban areas where the engine sound is the dominating sound up to 30 kph (kilometres per hour). Above this, tyre-road interaction is the main cause of traffic noise. With the missing typical engine sound a new sound design is necessary to prevent traffic accidents in urban areas. Drivers should not be able to switch the sound generator off.

[Research on spatial differentiation of urban stormwater runoff quality by source area monitoring].

Science.gov (United States)

Li, Li-Qing; Zhu, Ren-Xiao; Guo, Shu-Gang; Yin, Cheng-Qing

2010-12-01

Runoff samples were collected from 14 source areas in Hanyang district during four rain events in an attempt to investigate the spatial differentiation and influencing factors of urban stormwater runoff quality. The outcomes are expected to offer practical guidance in sources control of urban runoff pollution. The results revealed that particle-bound proportion of chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) in stormwater runoff were 58% +/- 17%, 65% +/- 13% and 92% +/- 6%, respectively. The fractions of ammonia, nitrate and dissolved organic nitrogen were homogeneous in dissolved nitrogen composition. Urban surface function, traffic volume, land use, population density, and street sweeping practice are the main factors determining spatial differentiation of urban surface runoff quality. The highest magnitude of urban stormwater runoff pollution was expected in the old urban residential area, followed by general residential with restaurants, commercial and transport area, new developments and green land. In addition, the magnitude of road stormwater runoff pollution is positively correlated to traffic volume, in the following order: the first trunk road > the second trunk road > minor road. Street sweeping and critical source areas controls should be implemented to mitigate the adverse effects of urban stormwater runoff on receive waters.

Monitoring individual traffic flows within the ATLAS TDAQ network

CERN Document Server

Sjoen, R; Ciobotaru, M; Batraneanu, S M; Leahu, L; Martin, B; Al-Shabibi, A

2010-01-01

The ATLAS data acquisition system consists of four different networks interconnecting up to 2000 processors using up to 200 edge switches and five multi-blade chassis devices. The architecture of the system has been described in [1] and its operational model in [2]. Classical, SNMP-based, network monitoring provides statistics on aggregate traffic, but for performance monitoring and troubleshooting purposes there was an imperative need to identify and quantify single traffic flows. sFlow [3] is an industry standard based on statistical sampling which attempts to provide a solution to this. Due to the size of the ATLAS network, the collection and analysis of the sFlow data from all devices generates a data handling problem of its own. This paper describes how this problem is addressed by making it possible to collect and store data either centrally or distributed according to need. The methods used to present the results in a relevant fashion for system analysts are discussed and we explore the possibilities a...

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

Investigation of the impact of low cost traffic engineering measures on road safety in urban areas.

Science.gov (United States)

Yannis, George; Kondyli, Alexandra; Georgopoulou, Xenia

2014-01-01

This paper investigates the impact of low cost traffic engineering measures (LCTEMs) on the improvement of road safety in urban areas. A number of such measures were considered, such as speed humps, woonerfs, raised intersections and other traffic calming measures, which have been implemented on one-way, one-lane roads in the Municipality of Neo Psychiko in the Greater Athens Area. Data were analysed using the before-and-after safety analysis methodology with large control group. The selected control group comprised of two Municipalities in the Athens Greater Area, which present similar road network and land use characteristics with the area considered. The application of the methodology showed that the total number of crashes presented a statistically significant reduction, which can be possibly attributed to the introduction of LCTEMs. This reduction concerns passenger cars and single-vehicle crashes and is possibly due to the behavioural improvement of drivers of 25 years old or more. The results of this research are very useful for the identification of the appropriate low cost traffic engineering countermeasures for road safety problems in urban areas.

Quantifying the resilience of an urban traffic-electric power coupled system

International Nuclear Information System (INIS)

Fotouhi, Hossein; Moryadee, Seksun; Miller-Hooks, Elise

2017-01-01

Transportation system resilience has been the subject of several recent studies. To assess the resilience of a transportation network, however, it is essential to model its interactions with and reliance on other lifelines. Prior works might consider these interactions implicitly, perhaps in the form of hazard impact scenarios wherein services from a second lifeline (e.g. power) are precluded due to a hazard event. In this paper, a bi-level, mixed-integer, stochastic program is presented for quantifying the resilience of a coupled traffic-power network under a host of potential natural or anthropogenic hazard-impact scenarios. A two-layer network representation is employed that includes details of both systems. Interdependencies between the urban traffic and electric power distribution systems are captured through linking variables and logical constraints. The modeling approach was applied on a case study developed on a portion of the signalized traffic-power distribution system in southern Minneapolis. The results of the case study show the importance of explicitly considering interdependencies between critical infrastructures in transportation resilience estimation. The results also provide insights on lifeline performance from an alternate power perspective. - Highlights: • Model interdependent infrastructure systems. • Provide method for quantifying resilience of coupled traffic and power networks. • Propose bi-level, mixed-integer, stochastic program. • Take a multi-hazard, stochastic futures approach.

Scalable data-driven short-term traffic prediction

NARCIS (Netherlands)

Friso, K.; Wismans, L. J.J.; Tijink, M. B.

2017-01-01

Short-term traffic prediction has a lot of potential for traffic management. However, most research has traditionally focused on either traffic models-which do not scale very well to large networks, computationally-or on data-driven methods for freeways, leaving out urban arterials completely. Urban

Monitoring travel times in an urban network using video, GPS and Bluetooth

NARCIS (Netherlands)

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

2011-01-01

The travel time is an important measure for the quality of traffic. This paper discusses a few methods to measure or estimate the travel time in urban road networks. First of all, it is important to know that urban travel times display a large variation, so that the measurement of a single (average)

Eddy covariance measurements and parameterisation of traffic related particle emissions in an urban environment

Directory of Open Access Journals (Sweden)

E. M. Mårtensson

2006-01-01

Full Text Available Urban aerosol sources are important due to the health effects of particles and their potential impact on climate. Our aim has been to quantify and parameterise the urban aerosol source number flux F (particles m−2 s−1, in order to help improve how this source is represented in air quality and climate models. We applied an aerosol eddy covariance flux system 118.0 m above the city of Stockholm. This allowed us to measure the aerosol number flux for particles with diameters >11 nm. Upward source fluxes dominated completely over deposition fluxes in the collected dataset. Therefore, the measured fluxes were regarded as a good approximation of the aerosol surface sources. Upward fluxes were parameterised using a traffic activity (TA database, which is based on traffic intensity measurements. The footprint (area on the surface from which sources and sinks affect flux measurements, located at one point in space of the eddy system covered road and building construction areas, forests and residential areas, as well as roads with high traffic density and smaller streets. We found pronounced diurnal cycles in the particle flux data, which were well correlated with the diurnal cycles in traffic activities, strongly supporting the conclusion that the major part of the aerosol fluxes was due to traffic emissions. The emission factor for the fleet mix in the measurement area EFfm=1.4±0.1×1014 veh−1 km−1 was deduced. This agrees fairly well with other studies, although this study has an advantage of representing the actual effective emission from a mixed vehicle fleet. Emission from other sources, not traffic related, account for a F0=15±18×106 m−2 s−1. The urban aerosol source flux can then be written as F=EFfmTA+F0. In a second attempt to find a parameterisation, the friction velocity U* normalised with the average friction velocity has been included, F=EF . This parameterisation results in a somewhat reduced emission factor, 1.3×1014 veh�

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.

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.

Source apportionment of organic pollutants of a highway-traffic-influenced urban area in Bayreuth (Germany) using biomarker and stable carbon isotope signatures.

Science.gov (United States)

Glaser, Bruno; Dreyer, Annekatrin; Bock, Michael; Fiedler, Stefan; Mehring, Marion; Heitmann, Tobias

2005-06-01

Traffic- and urban-influenced areas are prone to enhanced pollution with products of incomplete combustion of fossil fuels and biomass such as black carbon or polycyclic aromatic hydrocarbons (PAHs). Black carbon is composed of aromatic and graphitic structures and may act as a carrier for pollutants such as PAHs and heavy metals. However, little is known about possible contributions of traffic-derived black carbon to the black carbon inventory in soils. Similar uncertainties exist regarding the contribution of different pollutant sources to total PAH and black carbon contents. Therefore, the objective of this study was to quantify the importance of traffic pollution to black carbon and PAH inventories in soils. PAH contamination of soils adjacent to a major German highway in the urban area of Bayreuth with about 50,000 vehicles per day was in the same order of magnitude compared to highway-close soils reported in other studies. Using molecular (black carbon and PAHs) and compound-specific stable carbon isotope evidence (PAHs) it was demonstrated that this contamination originated not only from automobile exhausts, here primarily diesel, but also from tire abrasion and tailpipe soot which significantly contributed to the traffic-caused black carbon and PAH contamination. Low molecular weight PAHs were more widely transported than their heavy molecular counterparts (local distillation), whereas highway-traffic-caused black carbon contamination was distributed to at least 30 m from the highway. On the other hand, urban fire exhausts were distributed more homogeneously among the urban area.

Simulation of traffic control signal systems

Science.gov (United States)

Connolly, P. J.; Concannon, P. A.; Ricci, R. C.

1974-01-01

In recent years there has been considerable interest in the development and testing of control strategies for networks of urban traffic signal systems by simulation. Simulation is an inexpensive and timely method for evaluating the effect of these traffic control strategies since traffic phenomena are too complex to be defined by analytical models and since a controlled experiment may be hazardous, expensive, and slow in producing meaningful results. This paper describes the application of an urban traffic corridor program, to evaluate the effectiveness of different traffic control strategies for the Massachusetts Avenue TOPICS Project.

Characterization of traffic-related PM concentration distribution and fluctuation patterns in near-highway urban residential street canyons.

Science.gov (United States)

Hahn, Intaek; Brixey, Laurie A; Wiener, Russell W; Henkle, Stacy W; Baldauf, Richard

2009-12-01

Analyses of outdoor traffic-related particulate matter (PM) concentration distribution and fluctuation patterns in urban street canyons within a microscale distance of less than 500 m from a highway source are presented as part of the results from the Brooklyn Traffic Real-Time Ambient Pollutant Penetration and Environmental Dispersion (B-TRAPPED) study. Various patterns of spatial and temporal changes in the street canyon PM concentrations were investigated using time-series data of real-time PM concentrations measured during multiple monitoring periods. Concurrent time-series data of local street canyon wind conditions and wind data from the John F. Kennedy (JFK) International Airport National Weather Service (NWS) were used to characterize the effects of various wind conditions on the behavior of street canyon PM concentrations.Our results suggest that wind direction may strongly influence time-averaged mean PM concentration distribution patterns in near-highway urban street canyons. The rooftop-level wind speeds were found to be strongly correlated with the PM concentration fluctuation intensities in the middle sections of the street blocks. The ambient turbulence generated by shifting local wind directions (angles) showed a good correlation with the PM concentration fluctuation intensities along the entire distance of the first and second street blocks only when the wind angle standard deviations were larger than 30 degrees. Within-canyon turbulent shearing, caused by fluctuating local street canyon wind speeds, showed no correlation with PM concentration fluctuation intensities. The time-averaged mean PM concentration distribution along the longitudinal distances of the street blocks when wind direction was mostly constantly parallel to the street was found to be similar to the distribution pattern for the entire monitoring period when wind direction fluctuated wildly. Finally, we showed that two different PM concentration metrics-time-averaged mean

Diurnal and seasonal variations of NO, NO2 and PM2.5 mass as a function of traffic volumes alongside an urban arterial

Science.gov (United States)

Kendrick, Christine M.; Koonce, Peter; George, Linda A.

2015-12-01

Urban arterial corridors are landscapes that give rise to short and long-term exposures to transportation-related pollution. With high traffic volumes and a wide mix of road users, urban arterial environments are important targets for improved exposure assessment to traffic-related pollution. A common method to estimate exposure is to use traffic volumes as a proxy. The study presented here analyzes a unique yearlong dataset of simultaneous roadside air quality and traffic observations for a U.S. arterial to assess the reliability of using traffic volumes as a proxy for traffic-related exposure. Results show how the relationships of traffic volumes with NO and NO2 vary not only by time of day and season but also by time aggregation. At short-term aggregations (15 min) nitrogen oxides were found to have a significant linear relationship with traffic volumes during morning hours for all seasons although variability was still high (r2 = 0.1-0.45 NO, r2 = 0.14-0.27 NO2), and little to no relationship during evening periods (r2 road users, these results show when traffic volumes alone can be a reliable proxy for exposure and when this approach is not warranted.

Dispersion of traffic exhausts in urban street canyons with tree plantings : experimental and numerical investigations

NARCIS (Netherlands)

Gromke, C.B.; Denev, J.; Ruck, B.

2007-01-01

Wind tunnel experiments and numerical computations have been performed in order to investigate the influence of avenuelike tree plantings on the dispersion of traffic exhaust in an urban street canyon. Reduced natural ventilation and enhanced pollutant concentrations have been found in the presence

Description of Anomalous Noise Events for Reliable Dynamic Traffic Noise Mapping in Real-Life Urban and Suburban Soundscapes

Directory of Open Access Journals (Sweden)

Francesc Alías

2017-02-01

Full Text Available Traffic noise is one of the main pollutants in urban and suburban areas. European authorities have driven several initiatives to study, prevent and reduce the effects of exposure of population to traffic. Recent technological advances have allowed the dynamic computation of noise levels by means of Wireless Acoustic Sensor Networks (WASN such as that developed within the European LIFE DYNAMAP project. Those WASN should be capable of detecting and discarding non-desired sound sources from road traffic noise, denoted as anomalous noise events (ANE, in order to generate reliable noise level maps. Due to the local, occasional and diverse nature of ANE, some works have opted to artificially build ANE databases at the cost of misrepresentation. This work presents the production and analysis of a real-life environmental audio database in two urban and suburban areas specifically conceived for anomalous noise events’ collection. A total of 9 h 8 min of labelled audio data is obtained differentiating among road traffic noise, background city noise and ANE. After delimiting their boundaries manually, the acoustic salience of the ANE samples is automatically computed as a contextual signal-to-noise ratio (SNR. The analysis of the real-life environmental database shows high diversity of ANEs in terms of occurrences, durations and SNRs, as well as confirming both the expected differences between the urban and suburban soundscapes in terms of occurrences and SNRs, and the rare nature of ANE.

Detecting Anomaly in Traffic Flow from Road Similarity Analysis

KAUST Repository

Liu, Xinran

2016-06-02

Taxies equipped with GPS devices are considered as 24-hour moving sensors widely distributed in urban road networks. Plenty of accurate and realtime trajectories of taxi are recorded by GPS devices and are commonly studied for understanding traffic dynamics. This paper focuses on anomaly detection in traffic volume, especially the non-recurrent traffic anomaly caused by unexpected or transient incidents, such as traffic accidents, celebrations and disasters. It is important to detect such sharp changes of traffic status for sensing abnormal events and planning their impact on the smooth volume of traffic. Unlike existing anomaly detection approaches that mainly monitor the derivation of current traffic status from history in the past, the proposed method in this paper evaluates the abnormal score of traffic on one road by comparing its current traffic volume with not only its historical data but also its neighbors. We define the neighbors as the roads that are close in sense of both geo-location and traffic patterns, which are extracted by matrix factorization. The evaluation results on trajectories data of 12,286 taxies over four weeks in Beijing show that our approach outperforms other baseline methods with higher precision and recall.

A Dynamic Traffic Signal Timing Model and its Algorithm for Junction of Urban Road

DEFF Research Database (Denmark)

Cai, Yanguang; Cai, Hao

2012-01-01

As an important part of Intelligent Transportation System, the scientific traffic signal timing of junction can improve the efficiency of urban transport. This paper presents a novel dynamic traffic signal timing model. According to the characteristics of the model, hybrid chaotic quantum...... evolutionary algorithm is employed to solve it. The proposed model has simple structure, and only requires traffic inflow speed and outflow speed are bounded functions with at most finite number of discontinuity points. The condition is very loose and better meets the requirements of the practical real......-time and dynamic signal control of junction. To obtain the optimal solution of the model by hybrid chaotic quantum evolutionary algorithm, the model is converted to an easily solvable form. To simplify calculation, we give the expression of the partial derivative and change rate of the objective function...

The indicative effects of inefficient urban traffic flow on fuel cost and exhaust air pollutant emissions

CSIR Research Space (South Africa)

Moselakgomo, M

2015-07-01

Full Text Available Poor urban traffic management such as poor intersection controls, congestions, illegal roadway blockages and construction works causes “stop-go” driving conditions with excessive idling resulting in wasted fuel and increased air pollutant emissions...

Pulmonary nodules in workers exposed to urban stressor

Energy Technology Data Exchange (ETDEWEB)

Sancini, A. [University of Rome ' Sapienza' , Department of Occupational Medicine, Viale Regina Elena 336, 00161 Rome (Italy); Fioravanti, M. [University of Rome ' Sapienza' , Department of Psychiatric Science and Psychological Medicine, Piazzale Aldo Moro 5, 00185 Rome (Italy); Ciarrocca, M.; Palermo, P.; Fiaschetti, M.; Schifano, M.P. [University of Rome ' Sapienza' , Department of Occupational Medicine, Viale Regina Elena 336, 00161 Rome (Italy); Tomei, G. [University of Rome ' Sapienza' , Department of Psychiatric Science and Psychological Medicine, Piazzale Aldo Moro 5, 00185 Rome (Italy); Tomei, F., E-mail: francesco.tomei@uniroma1.it [University of Rome ' Sapienza' , Department of Occupational Medicine, Viale Regina Elena 336, 00161 Rome (Italy)

2010-07-15

By multilayer spiral low-dose computed tomography (LD-CT) of the chest this study assesses the early detection of lung lesions on a sample of 100 traffic policemen of a big Italian city professionally exposed to urban pollutants and 100 controls non-occupationally exposed to urban pollutants matched by sex, age, length of service and cigarette smoking habit. Exposure to urban pollutants in traffic policemen was characterized using the annual average concentrations of PM{sub 10}, NO{sub 2} and benzene in the period 1998-2008 measured by fixed monitoring stations located in different areas of the city. A significant and increasing number of suspicious lung nodules with diameters between 5 and 10 mm was observed: in traffic policemen (including smokers and non-smokers) vs. controls (including smokers and non-smokers); in total smokers (including traffic policemen and controls) vs. total non-smokers (traffic policemen and controls); in smoker traffic policemen vs. smoker controls and vs. non-smoker traffic policemen; in non-smoker traffic policemen vs. non-smoker controls. The RR of finding cases with at least one lung nodule with diameters between 5 and 10 mm in traffic policemen (including smokers and non-smokers) compared to controls (including smokers and non-smokers) is 1.94 (CI 1.13-3.31); in total smokers vs. non-smokers the RR is 1.96 (CI 1.20-3.19). The comparison between the interaction exposure and smoking shows an increase in smoker traffic policemen than in smoker controls (RR=2.14; CI 1.02-4.52). The RR for smoker traffic policemen was higher than in non-smoker traffic policemen (RR=2.09; CI 1.19-3.66). The results of our study show that: (1) while smoker workers have a higher risk for developing solid suspicious lung nodules, the simple routinely exposure to urban pollutants is unable to produce the same kind of increased risk; (2) the interaction of smoking and exposure to urban pollutants greatly increases the risk for the development of solid

Pulmonary nodules in workers exposed to urban stressor

International Nuclear Information System (INIS)

Sancini, A.; Fioravanti, M.; Ciarrocca, M.; Palermo, P.; Fiaschetti, M.; Schifano, M.P.; Tomei, G.; Tomei, F.

2010-01-01

By multilayer spiral low-dose computed tomography (LD-CT) of the chest this study assesses the early detection of lung lesions on a sample of 100 traffic policemen of a big Italian city professionally exposed to urban pollutants and 100 controls non-occupationally exposed to urban pollutants matched by sex, age, length of service and cigarette smoking habit. Exposure to urban pollutants in traffic policemen was characterized using the annual average concentrations of PM 10 , NO 2 and benzene in the period 1998-2008 measured by fixed monitoring stations located in different areas of the city. A significant and increasing number of suspicious lung nodules with diameters between 5 and 10 mm was observed: in traffic policemen (including smokers and non-smokers) vs. controls (including smokers and non-smokers); in total smokers (including traffic policemen and controls) vs. total non-smokers (traffic policemen and controls); in smoker traffic policemen vs. smoker controls and vs. non-smoker traffic policemen; in non-smoker traffic policemen vs. non-smoker controls. The RR of finding cases with at least one lung nodule with diameters between 5 and 10 mm in traffic policemen (including smokers and non-smokers) compared to controls (including smokers and non-smokers) is 1.94 (CI 1.13-3.31); in total smokers vs. non-smokers the RR is 1.96 (CI 1.20-3.19). The comparison between the interaction exposure and smoking shows an increase in smoker traffic policemen than in smoker controls (RR=2.14; CI 1.02-4.52). The RR for smoker traffic policemen was higher than in non-smoker traffic policemen (RR=2.09; CI 1.19-3.66). The results of our study show that: (1) while smoker workers have a higher risk for developing solid suspicious lung nodules, the simple routinely exposure to urban pollutants is unable to produce the same kind of increased risk; (2) the interaction of smoking and exposure to urban pollutants greatly increases the risk for the development of solid suspicious lung

Variability of road traffic noise recorded by stationary monitoring stations

Science.gov (United States)

Bąkowski, Andrzej; Radziszewski, Leszek

2017-11-01

The paper presents the analysis results of equivalent sound level recorded by two road traffic noise monitoring stations. The stations were located in Kielce (an example of a medium-size town in Poland) at the roads out of the town in the direction of Kraków and Warszawa. The measurements were carried out through stationary stations monitoring the noise and traffic of motor vehicles. The RMS values based on A-weighted sound level were recorded every 1 s in the buffer and the results were registered every 1 min over the period of investigations. The registered data were the basis for calculating the equivalent sound level for three time intervals: from 6:00 to 18:00, from 18:00 to 22:00 and from 22:00 to 6:00. Analysis included the values of the equivalent sound level recorded for different days of the week split into 24h periods, nights, days and evenings. The data analysed included recordings from 2013. The coefficient of variation and positional variation were proposed for performing comparative analysis of the obtained data scattering. The investigations indicated that the recorded data varied depending on the traffic routes. The differences concerned the values of coefficients of variation of the equivalent sound levels.

CubeSat constellation design for air traffic monitoring

Science.gov (United States)

Nag, Sreeja; Rios, Joseph L.; Gerhardt, David; Pham, Camvu

2016-11-01

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. 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. It thereby 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 were obtained from NASA's Future ATM Concepts Evaluation Tool, for the Alaskan airspace over one day. The results presented were driven by MATLAB and the satellites propagated and coverage calculated using AGI's Satellite Tool. While Ad-hoc and precession spread constellations have been quantitatively evaluated, Walker constellations show the best performance in simulation. Sixteen satellites in two perpendicular orbital planes are shown to provide more than 99% coverage over representative Alaskan airspace and the maximum time gap where any airplane in Alaska is not covered is six minutes, therefore meeting the standard set by the International Civil Aviation Organization to monitor every airplane at least once every fifteen minutes. In spite of the risk of signal collision when multiple packets arrive at the satellite receiver, the proposed constellation shows 99% cumulative probability of reception within four minutes when the airplanes are transmitting every minute, and at 100% reception probability if transmitting every second. Data downlink can be performed using any of the three ground stations of NASA Earth Network in Alaska.

Lidar system for air-pollution monitoring over urban areas

Science.gov (United States)

Moskalenko, Irina V.; Shcheglov, Djolinard A.; Molodtsov, Nikolai A.

1997-05-01

The atmospheric environmental situation over the urban area of a large city is determined by a complex combination of anthropogenic pollution and meteorological factors. The efficient way to provide three-dimensional mapping of gaseous pollutants over wide areas is utilization of lidar systems employing tunable narrowband transmitters. The paper presented describes activity of RRC 'Kurchatov Institute' in the field of lidar atmospheric monitoring. The project 'mobile remote sensing system based on tunable laser transmitter for environmental monitoring' is developed under financial support of International Scientific and Technology Center (Moscow). The objective of the project is design, construction and field testing of a DIAL-technique system. The lidar transmitter consists of an excimer laser pumping dye laser, BBO crystal frequency doubler, and scanning flat mirror. Sulfur dioxide and atomic mercury have been selected as pollutants for field tests of the lidar system under development. A recent large increase in Moscow traffic stimulated taking into consideration also the remote sensing of lower troposphere ozone because of the photochemical smog problem. The status of the project is briefly discussed. The current activity includes also collecting of environmental data relevant to lidar remote sensing. Main attention is paid to pollutant concentration levels over Moscow city and Moscow district areas.

Urban traffic information system prototype: Use for Rome downtown area traffic control; 200 S.I.T.U. prototipo del sistema informativo per il traffico urbano: La sua applicazione allo studio della regolamentazione dell`accesso ai centri storici

Energy Technology Data Exchange (ETDEWEB)

Lombardi, L; Mattucci, A; Frondaroli, A

1993-12-31

This paper describes the characteristics, in terms of type of information and systems approaches utilized, of a prototype urban traffic simulator developed by ENEA (the Italian Agency for New Technology, Energy and the Environment). With reference to the development of the functional and architectural elements of this simulator, a preliminary review is made of problematics relevant to transportation system design, urban planning, and traffic control. The data base incorporated by the simulator is described and a comparison is made of different traffic modelling codes and man-machine interface methods. The paper concludes with an assessment of the results obtained with the first experimental application of the simulator in the control of the flow of traffic in Rome`s heavily congested downtown area.

Prediction of traffic-related nitrogen oxides concentrations using Structural Time-Series models

Science.gov (United States)

Lawson, Anneka Ruth; Ghosh, Bidisha; Broderick, Brian

2011-09-01

Ambient air quality monitoring, modeling and compliance to the standards set by European Union (EU) directives and World Health Organization (WHO) guidelines are required to ensure the protection of human and environmental health. Congested urban areas are most susceptible to traffic-related air pollution which is the most problematic source of air pollution in Ireland. Long-term continuous real-time monitoring of ambient air quality at such urban centers is essential but often not realistic due to financial and operational constraints. Hence, the development of a resource-conservative ambient air quality monitoring technique is essential to ensure compliance with the threshold values set by the standards. As an intelligent and advanced statistical methodology, a Structural Time Series (STS) based approach has been introduced in this paper to develop a parsimonious and computationally simple air quality model. In STS methodology, the different components of a time-series dataset such as the trend, seasonal, cyclical and calendar variations can be modeled separately. To test the effectiveness of the proposed modeling strategy, average hourly concentrations of nitrogen dioxide and nitrogen oxides from a congested urban arterial in Dublin city center were modeled using STS methodology. The prediction error estimates from the developed air quality model indicate that the STS model can be a useful tool in predicting nitrogen dioxide and nitrogen oxides concentrations in urban areas and will be particularly useful in situations where the information on external variables such as meteorology or traffic volume is not available.

Traffic-days at Aalborg University 1996. Conference report 1

International Nuclear Information System (INIS)

Lahrmann, H.; Hald Pedersen, L.

1996-01-01

Volume 1 (of two volumes) of the report on the conference 'Traffic days '96' held at Aalborg University (Denmark) on August 19-20, 1996, contains the papers presented at the conference under the general headings of the role of the car in the transport system of the future, traffic models, urban planning and traffic, traffic control, traffic and the urban environment, traffic and emissions, freight transport and railways. (EG)

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.

Implementation of a FPGA-Based Feature Detection and Networking System for Real-time Traffic Monitoring

OpenAIRE

Chen, Jieshi; Schafer, Benjamin Carrion; Ho, Ivan Wang-Hei

2016-01-01

With the growing demand of real-time traffic monitoring nowadays, software-based image processing can hardly meet the real-time data processing requirement due to the serial data processing nature. In this paper, the implementation of a hardware-based feature detection and networking system prototype for real-time traffic monitoring as well as data transmission is presented. The hardware architecture of the proposed system is mainly composed of three parts: data collection, feature detection,...

SENTINEL-1/2 DATA FOR SHIP TRAFFIC MONITORING ON THE DANUBE RIVER

Directory of Open Access Journals (Sweden)

I. Dana Negula

2016-06-01

Full Text Available After a long period of drought, the water level of the Danube River has significantly dropped especially on the Romanian sector, in July-August 2015. Danube reached the lowest water level recorded in the last 12 years, causing the blockage of the ships in the sector located close to Zimnicea Harbour. The rising sand banks in the navigable channel congested the commercial traffic for a few days with more than 100 ships involved. The monitoring of the decreasing water level and the traffic jam was performed based on Sentinel-1 and Sentinel-2 free data provided by the European Space Agency and the European Commission within the Copernicus Programme. Specific processing methods (calibration, speckle filtering, geocoding, change detection, image classification, principal component analysis, etc. were applied in order to generate useful products that the responsible authorities could benefit from. The Sentinel data yielded good results for water mask extraction and ships detection. The analysis continued after the closure of the crisis situation when the water reached the nominal level again. The results indicate that Sentinel data can be successfully used for ship traffic monitoring, building the foundation of future endeavours for a durable monitoring of the Danube River.

Pedestrian Friendly Traffic Signal Control.

Science.gov (United States)

2016-01-01

This project continues research aimed at real-time detection and use of pedestrian : traffic flow information to enhance adaptive traffic signal control in urban areas : where pedestrian traffic is substantial and must be given appropriate attention ...

Gis-Based Route Finding Using ANT Colony Optimization and Urban Traffic Data from Different Sources

Science.gov (United States)

Davoodi, M.; Mesgari, M. S.

2015-12-01

Nowadays traffic data is obtained from multiple sources including GPS, Video Vehicle Detectors (VVD), Automatic Number Plate Recognition (ANPR), Floating Car Data (FCD), VANETs, etc. All such data can be used for route finding. This paper proposes a model for finding the optimum route based on the integration of traffic data from different sources. Ant Colony Optimization is applied in this paper because the concept of this method (movement of ants in a network) is similar to urban road network and movements of cars. The results indicate that this model is capable of incorporating data from different sources, which may even be inconsistent.

A GPS-based Real-time Road Traffic Monitoring System

Science.gov (United States)

Tanti, Kamal Kumar

In recent years, monitoring systems are astonishingly inclined towards ever more automatic; reliably interconnected, distributed and autonomous operation. Specifically, the measurement, logging, data processing and interpretation activities may be carried out by separate units at different locations in near real-time. The recent evolution of mobile communication devices and communication technologies has fostered a growing interest in the GIS & GPS-based location-aware systems and services. This paper describes a real-time road traffic monitoring system based on integrated mobile field devices (GPS/GSM/IOs) working in tandem with advanced GIS-based application software providing on-the-fly authentications for real-time monitoring and security enhancement. The described system is developed as a fully automated, continuous, real-time monitoring system that employs GPS sensors and Ethernet and/or serial port communication techniques are used to transfer data between GPS receivers at target points and a central processing computer. The data can be processed locally or remotely based on the requirements of client’s satisfaction. Due to the modular architecture of the system, other sensor types may be supported with minimal effort. Data on the distributed network & measurements are transmitted via cellular SIM cards to a Control Unit, which provides for post-processing and network management. The Control Unit may be remotely accessed via an Internet connection. The new system will not only provide more consistent data about the road traffic conditions but also will provide methods for integrating with other Intelligent Transportation Systems (ITS). For communication between the mobile device and central monitoring service GSM technology is used. The resulting system is characterized by autonomy, reliability and a high degree of automation.

An Experimental Study of the Noise Due to Traffic in a Congested Urban Area

Science.gov (United States)

Sangeetha, M.; Sankar, P.

2016-03-01

Noise pollution in an urban environment is an issue of serious concern in the major cities of India. There are various factors that contribute to the increase of noise levels in urban areas. The intensity of traffic is one of the factors which contributes to a drastic increase in environmental noise. The management of noise pollution has to be considered in the decision making process. In this paper, an attempt is made to study the existing noise level due to the traffic in Velachery which is declared as a sensitive area by the Ministry of Environment and Forestry (MoEF). The noise level data is collected using the MS6710 digital sound meter. The Custic simulation software version 3.2 is used for finding the propagation of noise. The spatial patterns of measurement were also calculated, in the sub-urban area of Velachery, Chennai, Tamilnadu, India. A means of transmitting this data to vehicles moving in the area, through a wireless medium is simulated using NCTUns 6.0 (network simulator), to enable drivers to understand the environmental conditions. A hardware was also designed which can be used to transmit and receive the noise data using the Zigbee module. A noise transmitting station is placed at a junction, so that it can transmit this noise data to the receivers which are fitted inside the vehicles.

New considerations for PM, Black Carbon and particle number concentration for air quality monitoring across different European cities

Directory of Open Access Journals (Sweden)

C. Reche

2011-07-01

Full Text Available In many large cities of Europe standard air quality limit values of particulate matter (PM are exceeded. Emissions from road traffic and biomass burning are frequently reported to be the major causes. As a consequence of these exceedances a large number of air quality plans, most of them focusing on traffic emissions reductions, have been implemented in the last decade. In spite of this implementation, a number of cities did not record a decrease of PM levels. Thus, is the efficiency of air quality plans overestimated? Do the road traffic emissions contribute less than expected to ambient air PM levels in urban areas? Or do we need a more specific metric to evaluate the impact of the above emissions on the levels of urban aerosols?

This study shows the results of the interpretation of the 2009 variability of levels of PM, Black Carbon (BC, aerosol number concentration (N and a number of gaseous pollutants in seven selected urban areas covering road traffic, urban background, urban-industrial, and urban-shipping environments from southern, central and northern Europe.

The results showed that variations of PM and N levels do not always reflect the variation of the impact of road traffic emissions on urban aerosols. However, BC levels vary proportionally with those of traffic related gaseous pollutants, such as CO, NO₂ and NO. Due to this high correlation, one may suppose that monitoring the levels of these gaseous pollutants would be enough to extrapolate exposure to traffic-derived BC levels. However, the BC/CO, BC/NO₂ and BC/NO ratios vary widely among the cities studied, as a function of distance to traffic emissions, vehicle fleet composition and the influence of other emission sources such as biomass burning. Thus, levels of BC should be measured at air quality monitoring sites.

During morning traffic rush hours, a narrow variation in the N/BC ratio was evidenced, but a wide variation of

Shadow-Based Vehicle Detection in Urban Traffic

Directory of Open Access Journals (Sweden)

Manuel Ibarra-Arenado

2017-04-01

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

DEVELOPMENT OF METHODOLOGY FOR TRAFFIC ACCIDENT FORECASTING AT VARIOUS TYPICAL URBAN AREAS

OpenAIRE

D. V. Kapsky

2012-01-01

The paper provides investigation results pertaining to development of methodology for forecasting traffic accidents using a “conflict zone” method that considers potential danger for two typical urban areas, namely: signaled crossings and bumps that are made in the areas of zebra crossings and it also considers various types and kinds of conflicts. The investigations have made it possible to obtain various indices of threshold sensitivity in respect of  potential risks  and in relation to tra...

Impacts of traffic and rainfall characteristics on heavy metals build-up and wash-off from urban roads.

Science.gov (United States)

Mahbub, Parvez; Ayoko, Godwin A; Goonetilleke, Ashantha; Egodawatta, Prasanna; Kokot, Serge

2010-12-01

An investigation into the effects of changes in urban traffic characteristics due to rapid urbanisation and the predicted changes in rainfall characteristics due to climate change on the build-up and wash-off of heavy metals was carried out in Gold Coast, Australia. The study sites encompassed three different urban land uses. Nine heavy metals commonly associated with traffic emissions were selected. The results were interpreted using multivariate data analysis and decision making tools, such as principal component analysis (PCA), fuzzy clustering (FC), PROMETHEE, and GAIA. Initial analyses established high, low, and moderate traffic scenarios as well as low, low to moderate, moderate, high, and extreme rainfall scenarios for build-up and wash-off investigations. GAIA analyses established that moderate to high traffic scenarios could affect the build-up, while moderate to high rainfall scenarios could affect the wash-off of heavy metals under changed conditions. However, in wash-off, metal concentrations in 1-75 μm fraction were found to be independent of the changes to rainfall characteristics. In build-up, high traffic activities in commercial and industrial areas influenced the accumulation of heavy metal concentrations in particulate size range from 75 - >300 μm, whereas metal concentrations in finer size range of 300 μm can be targeted for removal of Ni, Cu, Pb, Cd, Cr, and Zn from build-up, while organic matter from 300 μm can be targeted for removal of Cd, Cr, Pb, and Ni from wash-off. Cu and Zn need to be removed as free ions from most fractions in wash-off.

An LTE implementation based on a road traffic density model

OpenAIRE

Attaullah, Muhammad

2013-01-01

The increase in vehicular traffic has created new challenges in determining the behavior of performance of data and safety measures in traffic. Hence, traffic signals on intersection used as cost effective and time saving tools for traffic management in urban areas. But on the other hand the signalized intersections in congested urban areas are the key source of high traffic density and slow traffic. High traffic density causes the slow network traffic data rate between vehicle to vehicle and...

From Goods to Traffic:First Steps Toward an Auction-based Traffic Signal Controller

OpenAIRE

Raphael, Jeffery; Maskell, Simon; Sklar, Elizabeth Ida

2015-01-01

Traffic congestion is a major issue that plagues many urban road networks large and small. Traffic engineers are now leaning towards Intelligent Traffic Systems as many physical changes to road networks are costly or infeasible. Multi-Agent Systems (MAS) have become a popular paradigm for intelligent solutions to traffic management problems. There are many MAS approaches to traffic management that utilise market mechanisms. In market-based approaches, drivers “pay” to use the roadways. Howeve...

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.

Outer Synchronization between Two Coupled Complex Networks and Its Application in Public Traffic Supernetwork

Directory of Open Access Journals (Sweden)

Wen-ju Du

2016-01-01

Full Text Available The paper presents a new urban public traffic supernetwork model by using the existing bus network modeling method, consisting of the conventional bus traffic network and the urban rail traffic network. We investigate the synchronization problem of urban public traffic supernetwork model by using the coupled complex network’s outer synchronization theory. Analytical and numerical simulations are given to illustrate the impact of traffic dispatching frequency and traffic lines optimization to the urban public traffic supernetwork balance.

Unravelling hieroglyphs : Urban traffic signs and the League of Nations

Directory of Open Access Journals (Sweden)

Frank Schipper

2009-11-01

Full Text Available Cet article porte sur les enjeux de signalisation routière pendant l'entre-deux-guerres. Il esquisse d'abord la relation souvent difficile entre l'automobile et la ville d'une part et la société en général. Il revient sur le rôle de la signalisation routière dont la mise en place a contribué à encadrer ces rapports. À la veille de la Première Guerre Mondiale, des milliers de panneaux décorent déjà les routes européennes. Depuis la guerre, la nouvelle Société des Nations réussit à s'accaparer les discussions sur la signalisation routière au début des années 1920, puis commence ses travaux sur la signalisation routière spécifiquement urbaine à partir de 1926. La Conférence Européenne sur le Trafic Routier en 1931 est le sommet de ce mouvement. Le système n'a pas changé fondamentalement depuis. A l'inverse des propositions des représentants urbains, la SdN n’est cependant pas devenue le coordinateur central des problèmes de signalisation routière. L’article conclut par nuancer la qualification des panneaux routiers comme des hiéroglyphes par le journaliste français Baudry de Saunier en 1931.This article discusses road traffic signs in the Interwar years. The article first sketches the often difficult relationship between the car and the city and society at large. It proposes road signs were introduced in part to mitigate this antagonistic relation. On the eve of the First World War thousands of signs already adorned European roads. After the war the new League of Nations managed to seize discussions on road signs in the early 1920s, and started to work on specifically urban road signs from 1926 onwards. The European Conference on Road Traffic in 1931 formed the apex of this development. The system has not fundamentally changed since. Contrary to the proposal of urban representatives, the League did not, however, become the supreme arbiter of traffic signs. The article concludes by nuancing a 1931

Monitoring individual traffic flows within the ATLAS TDAQ network

International Nuclear Information System (INIS)

Sjoen, R; Batraneanu, S M; Leahu, L; Martin, B; Al-Shabibi, A; Stancu, S; Ciobotaru, M

2010-01-01

The ATLAS data acquisition system consists of four different networks interconnecting up to 2000 processors using up to 200 edge switches and five multi-blade chassis devices. The architecture of the system has been described in [1] and its operational model in [2]. Classical, SNMP-based, network monitoring provides statistics on aggregate traffic, but for performance monitoring and troubleshooting purposes there was an imperative need to identify and quantify single traffic flows. sFlow [3] is an industry standard based on statistical sampling which attempts to provide a solution to this. Due to the size of the ATLAS network, the collection and analysis of the sFlow data from all devices generates a data handling problem of its own. This paper describes how this problem is addressed by making it possible to collect and store data either centrally or distributed according to need. The methods used to present the results in a relevant fashion for system analysts are discussed and we explore the possibilities and limitations of this diagnostic tool, giving an example of its use in solving system problems that arise during the ATLAS data taking.

Entropy-based heavy tailed distribution transformation and visual analytics for monitoring massive network traffic

Science.gov (United States)

Han, Keesook J.; Hodge, Matthew; Ross, Virginia W.

2011-06-01

For monitoring network traffic, there is an enormous cost in collecting, storing, and analyzing network traffic datasets. Data mining based network traffic analysis has a growing interest in the cyber security community, but is computationally expensive for finding correlations between attributes in massive network traffic datasets. To lower the cost and reduce computational complexity, it is desirable to perform feasible statistical processing on effective reduced datasets instead of on the original full datasets. Because of the dynamic behavior of network traffic, traffic traces exhibit mixtures of heavy tailed statistical distributions or overdispersion. Heavy tailed network traffic characterization and visualization are important and essential tasks to measure network performance for the Quality of Services. However, heavy tailed distributions are limited in their ability to characterize real-time network traffic due to the difficulty of parameter estimation. The Entropy-Based Heavy Tailed Distribution Transformation (EHTDT) was developed to convert the heavy tailed distribution into a transformed distribution to find the linear approximation. The EHTDT linearization has the advantage of being amenable to characterize and aggregate overdispersion of network traffic in realtime. Results of applying the EHTDT for innovative visual analytics to real network traffic data are presented.

Distributed Acoustic Sensing (DAS) Array near a Highway for Traffic Monitoring and Near-Surface Shear-Wave Velocity Profiles

Science.gov (United States)

Wang, H. F.; Fratta, D.; Lancelle, C.; Ak, E. Ms; Lord, N. E.

2017-12-01

Monitoring traffic is important for many technical reasons. It allows for better design of future roads and assessment of the state of current roads. The number, size, weight, and speed of vehicles control deterioration rate. Also, real-time information supplies data to intelligent information systems to help control traffic. Recently there have been studies looking at monitoring traffic seismically as vibrations from traffic are not sensitive to weather and poor visibility. Furthermore, traffic noise can be used to image S-wave velocity distribution in the near surface by capturing and interpreting Rayleigh and Love waves (Nakata, 2016; Zeng et al. 2016). The capability of DAS for high spatial sampling (1 m), temporal sampling (up to 10 kHz), and distributed nature (tens of kilometers) allows for a closer look at the traffic as it passes and how the speed of the vehicle may change over the length of the array. The potential and difficulties of using DAS for these objectives were studied using two DAS arrays. One at Garner Valley in Southern California (a 700-meter array adjacent to CA Highway 74) and another in Brady Hot Springs, Nevada (an 8700-meter array adjacent to Interstate 80). These studies experimentally evaluated the use of DAS data for monitoring traffic and assessing the use of traffic vibration as non-localized sources for seismic imaging. DAS arrays should also be resilient to issues with lighting conditions that are problematic for video monitoring and it may be sensitive to the weight of a vehicle. This study along a major interstate provides a basis for examining DAS' potential and limitations as a key component of intelligent highway systems.

Research on Congestion Pricing in Multimode Traffic considering Delay and Emission

Directory of Open Access Journals (Sweden)

Hongna Dai

2015-01-01

Full Text Available Rapid development of urbanization and automation has resulted in serious urban traffic congestion and air pollution problems in many Chinese cities recently. As a traffic demand management strategy, congestion pricing is acknowledged to be effective in alleviating the traffic congestion and improving the efficiency of traffic system. This paper proposes an urban traffic congestion pricing model based on the consideration of transportation network efficiency and environment effects. First, the congestion pricing problem under multimode (i.e., car mode and bus mode urban traffic network condition is investigated. Second, a traffic congestion pricing model based on bilevel programming is formulated for a dual-mode urban transportation network, in which the delay and emission of vehicles are considered. Third, an improved mathematical algorithm combining successive average method with the genetic algorithm is proposed to solve the bilevel programming problem. Finally, a numerical experiment based on a hypothetical network is performed to validate the proposed congestion pricing model and algorithm.

A wireless computational platform for distributed computing based traffic monitoring involving mixed Eulerian-Lagrangian sensing

KAUST Repository

Jiang, Jiming

2013-06-01

This paper presents a new wireless platform designed for an integrated traffic monitoring system based on combined Lagrangian (mobile) and Eulerian (fixed) sensing. The sensor platform is built around a 32-bit ARM Cortex M4 micro-controller and a 2.4GHz 802.15.4 ISM compliant radio module, and can be interfaced with fixed traffic sensors, or receive data from vehicle transponders. The platform is specially designed and optimized to be integrated in a solar-powered wireless sensor network in which traffic flow maps are computed by the nodes directly using distributed computing. A MPPT circuitry is proposed to increase the power output of the attached solar panel. A self-recovering unit is designed to increase reliability and allow periodic hard resets, an essential requirement for sensor networks. A radio monitoring circuitry is proposed to monitor incoming and outgoing transmissions, simplifying software debug. An ongoing implementation is briefly discussed, and compared with existing platforms used in wireless sensor networks. © 2013 IEEE.

Tradescantia micronucleus test indicates genotoxic potential of traffic emissions in European cities

International Nuclear Information System (INIS)

Klumpp, Andreas; Ansel, Wolfgang; Klumpp, Gabriele; Calatayud, Vicent; Garrec, Jean Pierre; He Shang; Penuelas, Josep; Ribas, Angela; Ro-Poulsen, Helge; Rasmussen, Stine; Sanz, Maria Jose; Vergne, Phillippe

2006-01-01

Urban atmospheres contain complex mixtures of air pollutants including mutagenic and carcinogenic substances such as benzene, diesel soot, heavy metals and polycyclic aromatic hydrocarbons. In the frame of a European network for the assessment of air quality by the use of bioindicator plants, the Tradescantia micronucleus (Trad-MCN) test was applied to examine the genotoxicity of urban air pollution. Cuttings of Tradescantia clone no. 4430 were exposed to ambient air at 65 monitoring sites in 10 conurbations employing a standardised methodology. The tests revealed an elevated genotoxic potential mainly at those urban sites which were exposed to severe car traffic emissions. This bioassay proved to be a suitable tool to detect local 'hot spots' of mutagenic air pollution in urban areas. For its use in routine monitoring programmes, however, further standardisation of cultivation and exposure techniques is recommended in order to reduce the variability of results due to varying environmental conditions. - The Tradescantia micronucleus test can be used to assess genotoxic potential at urban sites

Tradescantia micronucleus test indicates genotoxic potential of traffic emissions in European cities

Energy Technology Data Exchange (ETDEWEB)

Klumpp, Andreas [Institute for Landscape and Plant Ecology (320), University of Hohenheim, 70593 Stuttgart (Germany)]. E-mail: aklumpp@uni-hohenheim.de; Ansel, Wolfgang [Institute for Landscape and Plant Ecology (320), University of Hohenheim, 70593 Stuttgart (Germany); Klumpp, Gabriele [Institute for Landscape and Plant Ecology (320), University of Hohenheim, 70593 Stuttgart (Germany); Calatayud, Vicent [Fundacion CEAM, Parque Tecnologico, c/Charles Darwin 14, 46980 Paterna, Valencia (Spain); Garrec, Jean Pierre [INRA Nancy, Laboratoire Pollution Atmospherique, 54280 Champenoux (France); He Shang [INRA Nancy, Laboratoire Pollution Atmospherique, 54280 Champenoux (France); Penuelas, Josep [Unitat Ecofisiologia CSIC-CEAB-CREAF, Universitat Autonoma de Barcelona, Ed. C, 08193 Bellaterra, Barcelona (Spain); Ribas, Angela [Unitat Ecofisiologia CSIC-CEAB-CREAF, Universitat Autonoma de Barcelona, Ed. C, 08193 Bellaterra, Barcelona (Spain); Ro-Poulsen, Helge [Botanical Institute, University of Copenhagen, Oster Farimagsgade 2D, 1353 Copenhagen K (Denmark); Rasmussen, Stine [Botanical Institute, University of Copenhagen, Oster Farimagsgade 2D, 1353 Copenhagen K (Denmark); Sanz, Maria Jose [Fundacion CEAM, Parque Tecnologico, c/Charles Darwin 14, 46980 Paterna, Valencia (Spain); Vergne, Phillippe [ENS Lyon and Lyon Botanical Garden, 46 Allee d' Italie, 69364 Lyon Cedex 07 (France)

2006-02-15

Urban atmospheres contain complex mixtures of air pollutants including mutagenic and carcinogenic substances such as benzene, diesel soot, heavy metals and polycyclic aromatic hydrocarbons. In the frame of a European network for the assessment of air quality by the use of bioindicator plants, the Tradescantia micronucleus (Trad-MCN) test was applied to examine the genotoxicity of urban air pollution. Cuttings of Tradescantia clone no. 4430 were exposed to ambient air at 65 monitoring sites in 10 conurbations employing a standardised methodology. The tests revealed an elevated genotoxic potential mainly at those urban sites which were exposed to severe car traffic emissions. This bioassay proved to be a suitable tool to detect local 'hot spots' of mutagenic air pollution in urban areas. For its use in routine monitoring programmes, however, further standardisation of cultivation and exposure techniques is recommended in order to reduce the variability of results due to varying environmental conditions. - The Tradescantia micronucleus test can be used to assess genotoxic potential at urban sites.

The range and effectiveness of short-term measures to reduce traffic emissions during high air pollution episodes

International Nuclear Information System (INIS)

Elsom, Derek M.

1999-01-01

Concern for continuing poor urban air quality, caused primarily by motor vehicles emissions, and the slow progress being made towards reducing total vehicle emissions by long-term measures, such as improving fuel and vehicle technologies, has prompted some authorities to try to reduce the severity and duration of high air pollution episodes by implementing short-term traffic restraint measures. This paper reviews the range of episodic air quality management schemes applied in cities around the world and comments on the effectiveness of such schemes. The difficulty of targeting vehicles according to the contribution they make to the air quality problem is highlighted. The problem of some schemes simply causing a displacement of the area of excessive vehicle emissions rather than reducing total emissions is reviewed. Rapid developments in telematics and improved urban air quality and traffic monitoring networks (e.g. Urban Traffic Management and Control systems) may offer significant improvements in the effectiveness of episodic management schemes in the future. (Author)

GIS-BASED ROUTE FINDING USING ANT COLONY OPTIMIZATION AND URBAN TRAFFIC DATA FROM DIFFERENT SOURCES

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M. Davoodi

2015-12-01

Full Text Available Nowadays traffic data is obtained from multiple sources including GPS, Video Vehicle Detectors (VVD, Automatic Number Plate Recognition (ANPR, Floating Car Data (FCD, VANETs, etc. All such data can be used for route finding. This paper proposes a model for finding the optimum route based on the integration of traffic data from different sources. Ant Colony Optimization is applied in this paper because the concept of this method (movement of ants in a network is similar to urban road network and movements of cars. The results indicate that this model is capable of incorporating data from different sources, which may even be inconsistent.

Context-Aware Fusion of RGB and Thermal Imagery for Traffic Monitoring

DEFF Research Database (Denmark)

Alldieck, Thiemo; Bahnsen, Chris Holmberg; Moeslund, Thomas B.

2016-01-01

In order to enable a robust 24-h monitoring of traffic under changing environmental conditions, it is beneficial to observe the traffic scene using several sensors, preferably from different modalities. To fully benefit from multi-modal sensor output, however, one must fuse the data. This paper...... introduces a new approach for fusing color RGB and thermal video streams by using not only the information from the videos themselves, but also the available contextual information of a scene. The contextual information is used to judge the quality of a particular modality and guides the fusion of two...

Estimation and Control of Networked Distributed Parameter Systems: Application to Traffic Flow

KAUST Repository

Canepa, Edward

2016-11-01

The management of large-scale transportation infrastructure is becoming a very complex task for the urban areas of this century which are covering bigger geographic spaces and facing the inclusion of connected and self-controlled vehicles. This new system paradigm can leverage many forms of sensing and interaction, including a high-scale mobile sensing approach. To obtain a high penetration sensing system on urban areas more practical and scalable platforms are needed, combined with estimation algorithms suitable to the computational capabilities of these platforms. The purpose of this work was to develop a transportation framework that is able to handle different kinds of sensing data (e.g., connected vehicles, loop detectors) and optimize the traffic state on a defined traffic network. The framework estimates the traffic on road networks modeled by a family of Lighthill-Whitham-Richards equations. Based on an equivalent formulation of the problem using a Hamilton-Jacobi equation and using a semi-analytic formula, I will show that the model constraints resulting from the Hamilton-Jacobi equation are linear, albeit with unknown integer variables. This general framework solve exactly a variety of problems arising in transportation networks: traffic estimation, traffic control (including robust control), cybersecurity and sensor fault detection, or privacy analysis of users in probe-based traffic monitoring systems. This framework is very flexible, fast, and yields exact results. The recent advances in sensors (GPS, inertial measurement units) and microprocessors enable the development low-cost dedicated devices for traffic sensing in cities, 5 which are highly scalable, providing a feasible solution to cover large urban areas. However, one of the main problems to address is the privacy of the users of the transportation system, the framework presented here is a viable option to guarantee the privacy of the users by design.

Adaptive traffic control systems for urban networks

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Radivojević Danilo

2017-01-01

Full Text Available Adaptive traffic control systems represent complex, but powerful tool for improvement of traffic flow conditions in locations or zones where applied. Many traffic agencies, especially those that have a large number of signalized intersections with high variability of the traffic demand, choose to apply some of the adaptive traffic control systems. However, those systems are manufactured and offered by multiple vendors (companies that are competing for the market share. Due to that fact, besides the information available from the vendors themselves, or the information from different studies conducted on different continents, very limited amount of information is available about the details how those systems are operating. The reason for that is the protecting of the intellectual property from plagiarism. The primary goal of this paper is to make a brief analysis of the functionalities, characteristics, abilities and results of the most recognized, but also less known adaptive traffic control systems to the professional public and other persons with interest in this subject.

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).

The impact of short term traffic forecasting on the effectiveness of vehicles routes planning in urban areas

Energy Technology Data Exchange (ETDEWEB)

Kubek, D.

2016-07-01

An impossibility to foresee in advance the accurate traffic parameters in face of dynamism phenomena in complex transportation system is a one of the major source of uncertainty. The paper presents an approach to robust optimization of logistics vehicle routes in urban areas on the basis of estimated short-term traffic time forecasts in a selected area of the urban road network. The forecast values of optimization parameters have been determined using the spectral analysis model, taking into account the forecast uncertainty degree. The robust counterparts approach of uncertain bi-criteria shortest path problem formulation is used to determining the robust routes for logistics vehicles in the urban network. The uncertainty set is created on the basis of forecast travel times in chosen sections, estimated by means of spectral analysis. The advantages and the characteristics are exemplified in the actual Krakow road network. The obtained data have been compared with classic approach wherein it is assumed that the optimization parameters are certain and accurate. The results obtained in the simulation example indicate that use of forecasting techniques with robust optimization models has a positive impact on the quality of final solutions. (Author)

Monitoring the Urban Tree Cover for Urban Ecosystem Services - The Case of Leipzig, Germany

Science.gov (United States)

Banzhaf, E.; Kollai, H.

2015-04-01

Urban dynamics such as (extreme) growth and shrinkage bring about fundamental challenges for urban land use and related changes. In order to achieve a sustainable urban development, it is crucial to monitor urban green infrastructure at microscale level as it provides various urban ecosystem services in neighbourhoods, supporting quality of life and environmental health. We monitor urban trees by means of a multiple data set to get a detailed knowledge on its distribution and change over a decade for the entire city. We have digital orthophotos, a digital elevation model and a digital surface model. The refined knowledge on the absolute height above ground helps to differentiate tree tops. Grounded on an object-based image analysis scheme a detailed mapping of trees in an urbanized environment is processed. Results show high accuracy of tree detection and avoidance of misclassification due to shadows. The study area is the City of Leipzig, Germany. One of the leading German cities, it is home to contiguous community allotments that characterize the configuration of the city. Leipzig has one of the most well-preserved floodplain forests in Europe.

An Ad-Hoc Opportunistic Dissemination Protocol for Smartphone-based Participatory Traffic Monitoring

NARCIS (Netherlands)

Türkes, Okan; Seraj, Fatjon; Scholten, Johan; Meratnia, Nirvana; Havinga, Paul J.M.

2015-01-01

This study introduces an ad-hoc opportunistic data dissemination protocol, called VADISS, that facilitates participatory traffic monitoring applications with smartphones. As a ubiquitous alternative to existing vehicular networking methods, VADISS uses the default WiFi interfaces universally adopted

Civil engineering support for the traffic monitoring program : final report, January 2010.

Science.gov (United States)

2010-01-01

This project was aimed at providing various civil engineering support services for the telemetered traffic monitoring sites operated by the Statistics Office of the Florida Department of Transportation. This was a companion project to the one that pr...

AVL and Monitoring for Massive Traffic Control System over DDS

Directory of Open Access Journals (Sweden)

Basem Almadani

2015-01-01

Full Text Available This paper proposes a real-time Automatic Vehicle Location (AVL and monitoring system for traffic control of pilgrims coming towards the city of Makkah in Saudi Arabia based on Data Distribution Service (DDS specified by the Object Management Group (OMG. DDS based middleware employs Real-Time Publish/Subscribe (RTPS protocol that implements many-to-many communication paradigm suitable in massive traffic control applications. Using this middleware approach, we are able to locate and track huge number of mobile vehicles and identify all passengers in real-time who are coming to perform annual Hajj. For validation of our proposed framework, various performance matrices are examined over WLAN using DDS. Results show that DDS based middleware can meet real-time requirements in large-scale AVL environment.

Monitoring Pt and Rh in urban aerosols from Buenos Aires, Argentina

Energy Technology Data Exchange (ETDEWEB)

Bocca, Beatrice; Caimi, Stefano; Caroli, Sergio [Istituto Superiore di Sanita, Viale Regina Elena 299, 00161, Rome (Italy); Smichowski, Patricia; Gomez, Dario [Comision Nacional de Energia Atomica, Unidad de Actividad Quimica, Centro Atomico Constituyentes, Av. Gral. Paz 1499, B1650KNA-San Martin, Pcia. de Buenos Aires (Argentina)

2006-04-01

Vehicular traffic is the main source of platinum group elements (PGEs) in highly populated urban areas like Buenos Aires where a traffic density of 1,500,000 vehicles day{sup -1} (corresponding to 7500 vehicles km{sup -2}) is estimated. Since there is no information on the levels of PGEs in Buenos Aires, a pilot study was undertaken to ascertain the amount of two major PGEs, namely Pt and Rh, in the atmosphere of this city. To this end, 49 samples of PM-10 particulate matter were collected during 7 days in seven representative sampling sites located downtown Buenos Aires and spread over an area of about 30 km{sup 2}. The collection of particulate matter was performed on ash-free glass-fiber filters using high volume samplers with PM-10 sampling heads. Filters loaded with the particulate matter were subjected to microwave (MW)-assisted acid digestion using a combination of HNO{sub 3}, HF and HClO{sub 4}. The resulting solutions were evaporated and then diluted with 0.1 mol l{sup -1} HCl. Analyses were performed by sector field inductively coupled plasma-mass spectrometry (SF-ICP-MS) and special attention was paid to the control of mass interferences. Statistical analysis was performed on the experimental data obtained for the element concentrations taking also into account local meteorological data for the monitored period. The highest concentrations of Pt and Rh were detected at two sites (Hospital Aleman and Casa Rapallini) located in streets with traffic consisting mostly of passenger cars. The Pt content (in pg m{sup -3}) in airborne particulate matter was found to vary from 2.3 to 47.7, with a mean value of 12.9+/-7, and that of Rh from 0.3 to 16.8, with a mean value of 3.9+/-2.8. These concentrations are by far below the levels for which adverse health effects might be expected to occur, i.e., around 100 ng m{sup -3}. On the other hand, monitoring of PGEs should be carried out in a systematic fashion to detect possible dramatic increases from today

Calculating the Contribution Rate of Intelligent Transportation System in Improving Urban Traffic Smooth Based on Advanced DID Model

OpenAIRE

Li, Ming-wei; Yun, Jun; Liu, Na

2015-01-01

Recent years have witnessed the rapid development of intelligent transportation system around the world, which helps to relieve urban traffic congestion problems. For instance, many mega-cities in China have devoted a large amount of money and resources to the development of intelligent transportation system. This poses an intriguing and important issue: how to measure and quantify the contribution of intelligent transportation system to the urban city, which is still a puzzle. This paper pro...

Establishing a link between vehicular PM sources and PM measurements in urban street canyons.

Science.gov (United States)

Eisner, Alfred D; Richmond-Bryant, Jennifer; Wiener, Russell W; Hahn, Intaek; Drake-Richman, Zora E; Ellenson, William D

2009-12-01

The Brooklyn Traffic Real-Time Ambient Pollutant Penetration and Environmental Dispersion (B-TRAPPED) study, conducted in Brooklyn, NY, USA, in 2005, was designed with multiple goals in mind, two of which were contaminant source characterization and street canyon transport and dispersion monitoring. In the portion of the study described here, synchronized wind velocity and azimuth as well as particulate matter (PM) concentrations at multiple locations along 33rd Street were used to determine the feasibility of using traffic emissions in a complex urban topography as a sole tracer for studying urban contaminant transport. We demonstrate in this paper that it is possible to link downwind concentrations of contaminants in an urban street canyon to the vehicular traffic cycle using Eigen-frequency analysis. In addition, multivariable circular histograms are used to establish directional frequency maxima for wind velocity and contaminant concentration.

Mortality from road traffic accidents in a rapidly urbanizing Chinese city: A 20-year analysis in Shenzhen, 1994-2013.

Science.gov (United States)

Xie, Shao-Hua; Wu, Yong-Sheng; Liu, Xiao-Jian; Fu, Ying-Bin; Li, Shan-Shan; Ma, Han-Wu; Zou, Fei; Cheng, Jin-Quan

2016-01-01

This study aimed to describe the trends of motorization and mortality rates from road traffic accidents and examine their associations in a rapidly urbanizing city in China, Shenzhen. Using data from the Shenzhen Deaths Registry between 1994 and 2013, we calculated the annual mortality rates of road traffic accidents, in addition to the age- and sex-specific mortality rates and their annual percentage changes (APCs) for the period of 2000-2013. We also examined the associations between mortality rate of road traffic accidents and traffic growth with Spearman's rank correlation analysis and a log-linear model derived from Smeed's law. A total of 20,196 deaths due to road traffic accidents, including 14,391 (71.3%) male deaths and 5,805 (28.7%) female deaths, were recorded in Shenzhen from 1994 to 2013. The annual mortality rates in terms of deaths per population and deaths per vehicle changed in similar patterns, demonstrating an increase since 1994 and peaking in 1997, followed by a steady decrease thereafter. The decrease in mortality was faster in individuals aged 20 year or older compared to those younger than 20 years. The mortality rates in term of deaths per population were positively correlated with the total number of vehicles per kilometer of road but negatively correlated with the motorization rate in term of vehicles per population. The estimated model for deaths due to road traffic accidents in relation to the total population and the number of registered vehicles was ln (deaths/10,000 vehicles) = -1.902 × ln (vehicles/population) - 1.961. The coefficient was statistically significant (P traffic accidents in a rapidly urbanizing Chinese city based observations in the 20-year period from 1994 to 2013. The decreased mortality rate may be explained by the expansion of road network construction, improved road safety regulations and management, as well as more accessible ambulance services in recent years. Nevertheless, road traffic accidents remain a

Network Traffic Monitoring Using Poisson Dynamic Linear Models

Energy Technology Data Exchange (ETDEWEB)

Merl, D. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2011-05-09

In this article, we discuss an approach for network forensics using a class of nonstationary Poisson processes with embedded dynamic linear models. As a modeling strategy, the Poisson DLM (PoDLM) provides a very flexible framework for specifying structured effects that may influence the evolution of the underlying Poisson rate parameter, including diurnal and weekly usage patterns. We develop a novel particle learning algorithm for online smoothing and prediction for the PoDLM, and demonstrate the suitability of the approach to real-time deployment settings via a new application to computer network traffic monitoring.

Botanical environmental monitors for zinc pollution resulting from vehicular traffic

International Nuclear Information System (INIS)

Altaf, W.J.

2007-01-01

Botanical samples were used as monitors for zinc pollution resulting from vehicular traffic. Euphorbia terracina and Calotropis procera were the botanical monitors used in this work. Zinc concentrations were reported alongside a motorway stretch of 50 km. Variations in concentration with respect to the perpendicular distance from the roadside were also reported. The effect of wind turbulence and the wind direction on the concentrations is discussed. In addition, differences between open areas and confined areas with respect to the elemental uptake were also discussed. INAA, using reactor neutrons, was employed for the determination of Zn concentrations in the samples. (author)

A study on traffic weaving segment level of service on Malaysia urban highway

Science.gov (United States)

Abdullah, Rohaya; Sadullah, Ahmad Farhan Mohd

2017-07-01

The objective of this research is to observe weaving problems, analyze the capacity of the weaving segment and to identify the behavior of the Malaysian driver at urban freeway weaving segment. Field data collected during non - peak hours at km. 138.6-138.2 (north bound) Seberang Jaya: Penang Bridge, km.16.8 to km.17.0 Sunway Mentari: Damansara-Puchong Highway and km.21.4 to km.21.9 Puchong Intan: Damansara-Puchong Highway. These segments behave as a bottleneck during peak hour. The data collected are traffic volume, vehicle composition and the road geometry. The drivers behavior pattern at the freeway weaving segment is observed. This research analyses by two different methodologies, the first analysis is by referring to the US Highway Capacity Manual 2010 and the second analysis through a modified method to suit the local traffic composition. The consideration of motorcycle and light heavy vehicle in the analysis lead to a different evaluation of weaving segment capacity. The analysis results show a slight difference between both methods. LOS, weaving speed and density prediction by the modified method is slightly higher than the HCM method. These results, suggest that the numbers of light heavy vehicle and motorcycle contribute to the amount of traffic volume because the value factors of Passenger Car Equivalent (PCE). The adoption of the widely used method without taking consideration of local traffic condition, might lead to improper road planning or design or road operation management.

Traffic planning for non-homogeneous traffic

Indian Academy of Sciences (India)

Vehicles based on similar traffic operating characteristics are grouped into ... of distances to the video monitor involved using a measuring wheel to mark ... Secondly, the observers reviewed the videotape to sample traffic entity ...... makes a strong case for including service lanes for slow moving vehicles for improving the.

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.

Polycyclic aromatic hydrocarbons (PAHs) concentration levels, pattern, source identification and soil toxicity assessment in urban traffic soil of Dhanbad, India.

Science.gov (United States)

Suman, Swapnil; Sinha, Alok; Tarafdar, Abhrajyoti

2016-03-01

Present study was carried out to assess and understand potential health risk and to examine the impact of vehicular traffic on the contamination status of urban traffic soils in Dhanbad City with respect to polycyclic aromatic hydrocarbons (PAHs). Eight urban traffic sites and two control/rural site surface soils were analyzed and the contents of 13 priority PAHs was determined. Total PAH concentration at traffic sites ranged from 1.019 μg g(-1) to 10.856 μg g(-1) with an average value of 3.488 μg g(-1). At control/rural site, average concentration of total PAHs was found to be 0.640 μg g(-1). PAH pattern was dominated by four- and five-ring PAHs (contributing >50% to the total PAHs) at all the eight traffic sites. On the other hand, rural soil showed a predominance of low molecular weight three-ring PAHs (contributing >30% to the total PAHs). Indeno[123-cd]pyrene/benz[ghi]perylene (IP/BgP) ratio indicated that PAH load at the traffic sites is predominated by the gasoline-driven vehicles. The ratio of Ant/(Ant+Phe) varied from 0.03 to 0.44, averaging 0.10; Fla/(Fla+Pyr) from 0.39 to 0.954, averaging 0.52; BaA/(BaA+Chry) from 0.156 to 0.60, averaging 0.44; and IP/(IP+BgP) from 0.176 to 0.811, averaging 0.286. The results indicated that vehicular emission was the major source for PAHs contamination with moderate effect of coal combustion and biomass combustion. Carcinogenic potency of PAH load in traffic soil was nearly 6.15 times higher as compared to the control/rural soil. Copyright © 2015 Elsevier B.V. All rights reserved.

Studies on assessment of traffic noise level in Aurangabad city, India

Directory of Open Access Journals (Sweden)

B J Bhosale

2010-01-01

Full Text Available With the rapid rate of urbanization of Aurangabad city due to the expanding industrialization, the problem of noise pollution has become a concern for urban dwellers and government authority too. Noise pollution due to vehicular traffic is one of the growing environmental problems of urban centers. The study deals with the assessment of traffic noise levels in Aurangabad city. With respect to the total number of vehicles passing the road in unit time, which was surveyed by direct count method, six different sites from Aurangabad city, viz., Nagar Naka, Kranti Chowk, CIDCO bus stand, Railway station area, Dhoot Hospital and Baba petrol pump were selected to study the vehicular noise level. Noise measurements were carried out at these six locations on both working day and holiday during the peak traffic hours, i.e. 8:00 a.m. - 11:a.m., 1:00 p.m. - 4:00 p.m. and 5:00 p.m. - 8:00 p.m., in the morning, afternoon and evening sessions, respectively, after 5 minutes time interval. The noise level was monitored using noise level meter. The results obtained from this investigation showed that the Nagar Naka, Kranti chowk and CIDCO bus stand area have dense traffic zones when compared with the Railway station area, Dhoot Hospital and Baba petrol pump. The minimum and the maximum noise levels are 74 and 86 dB, respectively, on working day and 70 and 81 dB, respectively, on holiday. The measured noise level values exceed the prescribed noise level.

A state of the art regarding urban air quality prediction models

Science.gov (United States)

Croitoru, Cristiana; Nastase, Ilinca

2018-02-01

Urban pollution represents an increasing risk to residents of urban regions, particularly in large, over-industrialized cities knowing that the traffic is responsible for more than 25% of air gaseous pollutants and dust particles. Air quality modelling plays an important role in addressing air pollution control and management approaches by providing guidelines for better and more efficient air quality forecasting, along with smart monitoring sensor networks. The advances in technology regarding simulations, forecasting and monitoring are part of the new smart cities which offers a healthy environment for their occupants.

A state of the art regarding urban air quality prediction models

Directory of Open Access Journals (Sweden)

Croitoru Cristiana

2018-01-01

Full Text Available Urban pollution represents an increasing risk to residents of urban regions, particularly in large, over-industrialized cities knowing that the traffic is responsible for more than 25% of air gaseous pollutants and dust particles. Air quality modelling plays an important role in addressing air pollution control and management approaches by providing guidelines for better and more efficient air quality forecasting, along with smart monitoring sensor networks. The advances in technology regarding simulations, forecasting and monitoring are part of the new smart cities which offers a healthy environment for their occupants.

Limited effect of urban tree vegetation on NO2 and O3 concentrations near a traffic route

International Nuclear Information System (INIS)

Grundström, Maria; Pleijel, Håkan

2014-01-01

Concentrations of NO 2 and O 3 were measured inside and outside a dense broad-leaved forest canopy adjacent to a busy traffic route in the City of Gothenburg, Sweden, with duplicate passive diffusion samplers during six one-week periods starting well before leaf senescence and ending when leaves were largely senescent. Concentrations of NO 2 were lower inside the forest canopy during all periods (representing a significant effect, p = 0.016), on average by 7% or 2.7 μg m −3 . O 3 showed a more variable response with an average non-significant effect of 2% lower in the forest stand. There was no systematic trend of the difference in concentrations inside and outside the forest stand of the pollutants with the progression of autumn leaf senescence. Our study indicates that the effect of urban vegetation on air pollution concentrations is small, although it seems to exist for NO 2 in a traffic polluted environment. - Highlights: • NO 2 was reduced by 7% inside an urban forest stand compared to outside. • The magnitude of the effect was not related to autumn senescence. • For O 3 the effect was smaller and non-significant. - Urban vegetation had limited effect on local air pollution

Evaluation of traffic exhaust contributions to ambient carbonaceous submicron particulate matter in an urban roadside environment in Hong Kong

Science.gov (United States)

Lee, Berto Paul; Kwok Keung Louie, Peter; Luk, Connie; Keung Chan, Chak

2017-12-01

Road traffic has significant impacts on air quality particularly in densely urbanized and populated areas where vehicle emissions are a major local source of ambient particulate matter. Engine type (i.e., fuel use) significantly impacts the chemical characteristics of tailpipe emission, and thus the distribution of engine types in traffic impacts measured ambient concentrations. This study provides an estimation of the contribution of vehicles powered by different fuels (gasoline, diesel, LPG) to carbonaceous submicron aerosol mass (PM1) based on ambient aerosol mass spectrometer (AMS) and elemental carbon (EC) measurements and vehicle count data in an urban inner city environment in Hong Kong with the aim to gauge the importance of different engine types to particulate matter burdens in a typical urban street canyon. On an average per-vehicle basis, gasoline vehicles emitted 75 and 93 % more organics than diesel and LPG vehicles, respectively, while EC emissions from diesel vehicles were 45 % higher than those from gasoline vehicles. LPG vehicles showed no appreciable contributions to EC and thus overall represented a small contributor to traffic-related primary ambient PM1 despite their high abundance (˜ 30 %) in the traffic mix. Total carbonaceous particle mass contributions to ambient PM1 from diesel engines were only marginally higher (˜ 4 %) than those from gasoline engines, which is likely an effect of recently introduced control strategies targeted at commercial vehicles and buses. Overall, gasoline vehicles contributed 1.2 µg m-3 of EC and 1.1 µ m-3 of organics, LPG vehicles 0.6 µg m-3 of organics and diesel vehicles 2.0 µg m-3 of EC and 0.7 µg m-3 of organics to ambient carbonaceous PM1.

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.

Effects of mental workload on physiological and subjective responses during traffic density monitoring: A field study.

Science.gov (United States)

Fallahi, Majid; Motamedzade, Majid; Heidarimoghadam, Rashid; Soltanian, Ali Reza; Miyake, Shinji

2016-01-01

This study evaluated operators' mental workload while monitoring traffic density in a city traffic control center. To determine the mental workload, physiological signals (ECG, EMG) were recorded and the NASA-Task Load Index (TLX) was administered for 16 operators. The results showed that the operators experienced a larger mental workload during high traffic density than during low traffic density. The traffic control center stressors caused changes in heart rate variability features and EMG amplitude, although the average workload score was significantly higher in HTD conditions than in LTD conditions. The findings indicated that increasing traffic congestion had a significant effect on HR, RMSSD, SDNN, LF/HF ratio, and EMG amplitude. The results suggested that when operators' workload increases, their mental fatigue and stress level increase and their mental health deteriorate. Therefore, it maybe necessary to implement an ergonomic program to manage mental health. Furthermore, by evaluating mental workload, the traffic control center director can organize the center's traffic congestion operators to sustain the appropriate mental workload and improve traffic control management. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

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

Directory of Open Access Journals (Sweden)

Jisheng Zhang

2015-06-01

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

Comparative analysis of characteristics and risk factors of traffic injury in aged people from urban and rural areas in Chongqing.

Science.gov (United States)

Zhang, Liang; Zhou, Ji-Hong; Qiu, Jun; Zhang, Xiu-Zhu; Yuan, Dan-Feng; Gao, Zhi-Ming; Dai, Wei

2012-01-01

To study the epidemiologic characteristics of traffic injuries among people over 60 years old in the Nan'an district (urban) and Jiangjin district (rural) of Chongqing, and to discuss the corresponding strategies for its prevention and cure. Records of traffic injuries in people over 60 years old registered by the traffic police between 2000 and 2006 in Nan'an district and Jiangjin district were collected in the Database of Road Traffic Accidents and Traffic Injuries. Epidemiologic characteristics of traffic injuries among the aged people were analyzed and compared. Between the year 2000 and 2006, the average annual incidence of traffic injuries and mortality rate in the aged people in Nan'an district were 124.62/100 000 and 13.85/ 100 000 respectively, higher than that in Jiangjin district (27.49/ 100 000, 7.13/100 000, P less than 0.01). However, the mortality rate for the aged people who were involved in traffic injuries in Jiangjin district was 20.60%, higher than that in Nan'an district (10.00%, P less than 0.01). Head injury was the primary cause of death. Totally 76.58% of casualties were pede-strians. Over 90% of the traffic accidents occurred in the areas with no traffic signal or traffic control system. The traffic environment is unfavorable to the aged people. It is important to enhance traffic safety consciousness of drivers and the elderly and to strengthen traffic safety system and traffic law, so as to provide a safe road traffic environment for the aged people.

Spoofing cyber attack detection in probe-based traffic monitoring systems using mixed integer linear programming

KAUST Repository

Canepa, Edward S.

2013-01-01

Traffic sensing systems rely more and more on user generated (insecure) data, which can pose a security risk whenever the data is used for traffic flow control. In this article, we propose a new formulation for detecting malicious data injection in traffic flow monitoring systems by using the underlying traffic flow model. The state of traffic is modeled by the Lighthill-Whitham- Richards traffic flow model, which is a first order scalar conservation law with concave flux function. Given a set of traffic flow data, we show that the constraints resulting from this partial differential equation are mixed integer linear inequalities for some decision variable. We use this fact to pose the problem of detecting spoofing cyber-attacks in probe-based traffic flow information systems as mixed integer linear feasibility problem. The resulting framework can be used to detect spoofing attacks in real time, or to evaluate the worst-case effects of an attack offline. A numerical implementation is performed on a cyber-attack scenario involving experimental data from the Mobile Century experiment and the Mobile Millennium system currently operational in Northern California. © 2013 IEEE.

Spoofing cyber attack detection in probe-based traffic monitoring systems using mixed integer linear programming

KAUST Repository

Canepa, Edward S.

2013-09-01

Traffic sensing systems rely more and more on user generated (insecure) data, which can pose a security risk whenever the data is used for traffic flow control. In this article, we propose a new formulation for detecting malicious data injection in traffic flow monitoring systems by using the underlying traffic flow model. The state of traffic is modeled by the Lighthill- Whitham-Richards traffic flow model, which is a first order scalar conservation law with concave flux function. Given a set of traffic flow data generated by multiple sensors of different types, we show that the constraints resulting from this partial differential equation are mixed integer linear inequalities for a specific decision variable. We use this fact to pose the problem of detecting spoofing cyber attacks in probe-based traffic flow information systems as mixed integer linear feasibility problem. The resulting framework can be used to detect spoofing attacks in real time, or to evaluate the worst-case effects of an attack offliine. A numerical implementation is performed on a cyber attack scenario involving experimental data from the Mobile Century experiment and the Mobile Millennium system currently operational in Northern California. © American Institute of Mathematical Sciences.

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.

Isotopic Recorders of Pollution in Heterogeneous Urban Areas

Science.gov (United States)

Pataki, D. E.; Cobley, L.; Smith, R. M.; Ehleringer, J. R.; Chritz, K.

2017-12-01

A significant difficulty in quantifying urban pollution lies in the extreme spatial and temporal heterogeneity of cities. Dense sources of both point and non-point source pollution as well as the dynamic role of human activities, which vary over very short time scales and small spatial scales, complicate efforts to establish long-term urban monitoring networks that are relevant at neighborhood, municipal, and regional scales. Fortunately, the natural abundance of isotopes of carbon, nitrogen, and other elements provides a wealth of information about the sources and fate of urban atmospheric pollution. In particular, soils and plant material integrate pollution sources and cycling over space and time, and have the potential to provide long-term records of pollution dynamics that extend back before atmospheric monitoring data are available. Similarly, sampling organic material at high spatial resolution can provide "isoscapes" that shed light on the spatial heterogeneity of pollutants in different urban parcels and neighborhoods, along roads of varying traffic density, and across neighborhoods of varying affluence and sociodemographic composition. We have compiled numerous datasets of the isotopic composition of urban organic matter that illustrate the potential for isotopic monitoring of urban areas as a means of understanding hot spots and hot moments in urban atmospheric biogeochemistry. Findings to date already reveal the critical role of affluence, economic activity, demographic change, and land management practices in influencing urban pollution sources and sinks, and suggest an important role of stable isotope and radioisotope measurements in urban atmospheric and biogeochemical monitoring.

PERANGKAT LUNAK TRAFFIC CONFIGURATOR DAN TRAFFIC MONITOR UNTUK PENGATURAN TRAFIK JARINGAN BERBASIS PROTOKOL TCP/IP DAN LIBRARY PACKET CAPTURE

Directory of Open Access Journals (Sweden)

Royyana M. Ijtihadie

2005-01-01

Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Dengan semakin banyaknya orang yang mengakses internet untuk mendapatkan informasi dan tidak adanya pengaturan pada trafik data maka akan mengakibatkan jaringan menjadi lambat. Pengaturan trafik jaringan yang ada di Linux selama ini masih menggunakan scripts yang relatif lebih sulit untuk digunakan dan dimengerti oleh sebagian orang sehingga diperlukan alat bantu untuk mengkonfigurasikannya. Paper ini menjelaskan tentang pembuatan Traffic Management Configurator untuk mempermudah pengaturan traffic dalam gateway yang menghubungkan jaringan yang berbeda Aplikasi Network Monitoring digunakan untuk menghitung utilitas dan statistik jaringan. Kedua aplikasi tersebut menggunakan web sebagai interface kepada pengguna.   Kata Kunci : Network Monitoring, PCAP, Traffic Control, HTB, HTB GUI.

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

Traffic represents the main source of pollution in small Mediterranean urban areas as seen by lichen functional groups.

Science.gov (United States)

Llop, Esteve; Pinho, Pedro; Ribeiro, Manuel C; Pereira, Maria João; Branquinho, Cristina

2017-05-01

The land-use type (residential, green areas, and traffic) within relatively small Mediterranean urban areas determines significant changes on lichen diversity, considering species richness and functional groups related to different ecological factors. Those areas with larger volume of traffic hold lower species diversity, in terms of species richness and lichen diversity value (LDV). Traffic areas also affect the composition of the lichen community, which is evidenced by sensitive species. The abundance of species of lichens tolerant to low levels of eutrophication diminishes in traffic areas; oppositely, those areas show a higher abundance of species of lichens tolerating high levels of eutrophication. On the other hand, residential and green areas have an opposite pattern, mainly with species highly tolerant to eutrophication being less abundant than low or moderate ones. The characteristics of tree bark do not seem to affect excessively on lichen composition; however, tree species shows some effect that should be considered in further studies.

Distributed intelligent urban environment monitoring system

Science.gov (United States)

Du, Jinsong; Wang, Wei; Gao, Jie; Cong, Rigang

2018-02-01

The current environmental pollution and destruction have developed into a world-wide major social problem that threatens human survival and development. Environmental monitoring is the prerequisite and basis of environmental governance, but overall, the current environmental monitoring system is facing a series of problems. Based on the electrochemical sensor, this paper designs a small, low-cost, easy to layout urban environmental quality monitoring terminal, and multi-terminal constitutes a distributed network. The system has been small-scale demonstration applications and has confirmed that the system is suitable for large-scale promotion

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.

Modelling NOX concentrations through CFD-RANS in an urban hot-spot using high resolution traffic emissions and meteorology from a mesoscale model

Science.gov (United States)

Sanchez, Beatriz; Santiago, Jose Luis; Martilli, Alberto; Martin, Fernando; Borge, Rafael; Quaassdorff, Christina; de la Paz, David

2017-08-01

Air quality management requires more detailed studies about air pollution at urban and local scale over long periods of time. This work focuses on obtaining the spatial distribution of NOx concentration averaged over several days in a heavily trafficked urban area in Madrid (Spain) using a computational fluid dynamics (CFD) model. A methodology based on weighted average of CFD simulations is applied computing the time evolution of NOx dispersion as a sequence of steady-state scenarios taking into account the actual atmospheric conditions. The inputs of emissions are estimated from the traffic emission model and the meteorological information used is derived from a mesoscale model. Finally, the computed concentration map correlates well with 72 passive samplers deployed in the research area. This work reveals the potential of using urban mesoscale simulations together with detailed traffic emissions so as to provide accurate maps of pollutant concentration at microscale using CFD simulations.

Mobile Phone Data from GSM Networks for Traffic Parameter and Urban Spatial Pattern Assessment

NARCIS (Netherlands)

Steenbruggen, J.G.M.; Borzacchiello, M.T.; Nijkamp, P.; Scholten, H.J.

2013-01-01

The use of wireless location technology and mobile phone data appears to offer a broad range of new opportunities for sophisticated applications in traffic management and monitoring, particularly in the field of incident management. Indeed, due to the high market penetration of mobile phones, it

Satellite-aided coastal zone monitoring and vessel traffic system

Science.gov (United States)

Baker, J. L.

1981-01-01

The development and demonstration of a coastal zone monitoring and vessel traffic system is described. This technique uses a LORAN-C navigational system and relays signals via the ATS-3 satellite to a computer driven color video display for real time control. Multi-use applications of the system to search and rescue operations, coastal zone management and marine safety are described. It is emphasized that among the advantages of the system are: its unlimited range; compatibility with existing navigation systems; and relatively inexpensive cost.

Effective Density and Mixing State of Aerosol Particles in a Near-Traffic Urban Environment

DEFF Research Database (Denmark)

Rissler, Jenny; Nordin, Erik Z; Eriksson, Axel C

2014-01-01

-range transport from polluted continental areas. The effective density of each group was relatively stable over time, especially of the soot aggregates, which had effective densities similar to those observed in laboratory studies of fresh diesel exhaust emissions. When heated to 300 °C, the soot aggregate......In urban environments, airborne particles are continuously emitted, followed by atmospheric aging. Also, particles emitted elsewhere, transported by winds, contribute to the urban aerosol. We studied the effective density (mass-mobility relationship) and mixing state with respect to the density...... and more dense particles. Both groups were present at each size in varying proportions. Two types of temporal variability in the relative number fraction of the two groups were found: soot correlated with intense traffic in a diel pattern and dense particles increased during episodes with long...

Influences of population, building, and traffic densities on urban heat island intensity in Chiang Mai City, Thailand

Directory of Open Access Journals (Sweden)

Kammuang-Lue Niti

2015-01-01

Full Text Available This research aims to evaluate the Urban Heat Island Intensity (UHII and study the influences of population density, building density, and traffic density on the UHII in Chiang Mai city on each season and time. The surrounding air temperature was measured by thermocouples at a constant height of 2 m above the road by mobile surveying approach. The surveyed routes were divided into urban routes and rural routes. The UHII was calculated from the average surrounding air temperature difference between the urban and the rural areas. Experimental investigations were carried out in two seasons, consisting of summer (March-May, 2014 and winter (December 2013-February 2014. Experimental investigations were carried out in two periods, which were a daytime period (01.00-03.00 pm and a nighttime period (10.00 pm-00.00 am on Mondays, Wednesdays, and Sundays. The results show that the UHII in summer day, summer night, winter day, and winter night were 1.07°C, 1.27°C, 0.58°C, and 1.34°C, respectively. This implies that the temperature in Chiang Mai city’s urban area is higher than that in the rural area the entire year. Moreover, it was found that the UHII in summer day, winter day, and winter night were primarily affected by the traffic density with the sensitivity percentage of 87.50%, 72.73%, and 63.33%, respectively. In contrast, the UHII in summer night was mainly affected by the building density with the sensitivity percentage of 50.00%.

Determination of REE in urban park soils from Sao Paulo city for fingerprint of traffic emission contamination

International Nuclear Information System (INIS)

Figueiredo, Ana Maria G.; Camargo, Sonia P.; Sigolo, Joel B.

2009-01-01

The study of rare earth elements (REE) distribution in urban environments has become very interesting in the last years, due to the increasing industrial use of these elements. The REE La, Ce and Nd are used in automobile converter catalysts to stabilize the catalyst support and to enhance the oxidation of pollutants. The honeycomb structure has a typical association of a high Ce (and often also La) concentration combined with high concentrations of Platinum Group Elements. Due to thermal and mechanical wear of catalysts, fine particles enriched in REE are released to the environment. These catalyst particles can accumulate in urban soils, mainly in soils located near high density traffic roads. The aim of this paper was to study the REE distribution and ratios in surface soil samples collected in fourteen urban public parks of Sao Paulo city, to assess the influence of vehicular emissions. Instrumental Neutron Activation Analysis (INAA) was used for the REE analysis. The diagrams normalized to chondrite values showed an enrichment of the light REE (La to Sm), in contrast to the heavy REE (Eu to Lu), with a negative anomaly of Eu. The results obtained indicated that the enrichment in REE is not clearly attributed to vehicular traffic, because of high background values associated to the natural geological composition of the soils. (author)

Estimation of urban traffic density from street camera images

OpenAIRE

Chandrakaladharan, Shreyas

2017-01-01

Traffic is a very real problem in today’s world. Elon Musk, CEO of SpaceX and Tesla, has created a start-up which aims to bore tunnels to better manage traffic. While we do not dare to challenge him, we propose to better manage traffic on roads by leveraging currently available technologies in a novel way. Our project aims to give accurate real-time predictions of traffic, so that prospective commuters can choose routes that are free of traffic, thereby automatically balanci...

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...

A Visual Analytics Approach for Extracting Spatio-Temporal Urban Mobility Information from Mobile Network Traffic

Directory of Open Access Journals (Sweden)

Euro Beinat

2012-11-01

Full Text Available In this paper we present a visual analytics approach for deriving spatio-temporal patterns of collective human mobility from a vast mobile network traffic data set. More than 88 million movements between pairs of radio cells—so-called handovers—served as a proxy for more than two months of mobility within four urban test areas in Northern Italy. In contrast to previous work, our approach relies entirely on visualization and mapping techniques, implemented in several software applications. We purposefully avoid statistical or probabilistic modeling and, nonetheless, reveal characteristic and exceptional mobility patterns. The results show, for example, surprising similarities and symmetries amongst the total mobility and people flows between the test areas. Moreover, the exceptional patterns detected can be associated to real-world events such as soccer matches. We conclude that the visual analytics approach presented can shed new light on large-scale collective urban mobility behavior and thus helps to better understand the “pulse” of dynamic urban systems.

Can weekly noise levels of urban road traffic, as predominant noise source, estimate annual ones?

Science.gov (United States)

Prieto Gajardo, Carlos; Barrigón Morillas, Juan Miguel; Rey Gozalo, Guillermo; Vílchez-Gómez, Rosendo

2016-11-01

The effects of noise pollution on human quality of life and health were recognised by the World Health Organisation a long time ago. There is a crucial dilemma for the study of urban noise when one is looking for proven methodologies that can allow, on the one hand, an increase in the quality of predictions, and on the other hand, saving resources in the spatial and temporal sampling. The temporal structure of urban noise is studied in this work from a different point of view. This methodology, based on Fourier analysis, is applied to several measurements of urban noise, mainly from road traffic and one-week long, carried out in two cities located on different continents and with different sociological life styles (Cáceres, Spain and Talca, Chile). Its capacity to predict annual noise levels from weekly measurements is studied. The relation between this methodology and the categorisation method is also analysed.

Congestion Tolling for Mixed Urban Freight and Passenger Traffic

Directory of Open Access Journals (Sweden)

Xie Chaoda

2017-01-01

Full Text Available This paper investigates the welfare effects of optimal tolling on urban traffic congestion, in a bottleneck model, with mixed freight and passenger users. The users’ marginal utility of time is considered to be varying with time. Under both no-toll equilibrium and socially optimal tolling, the users are found to sort their arrival time according to the increasing rates of marginal utility at the destination. The optimal toll that maximizes social welfare does not change each user's indirect utilit y relative to the no-toll equilibrium, but completely removes the queue, which also removes the barrier of freight carriers to accept congestion pricing by relating their marginal utilities directly to the toll. When the toll is equally rebated, the proposed social optimal tolling is a Pareto improvement relative to the no-toll equilibrium. Those more productive users also suffer more in both no-toll equilibrium and optimal tolling, which indicates that a differentiated redistribution of toll revenues could be an incentive to improve productivity.

Monitor Network Traffic with Packet Capture (pcap) on an Android Device

Science.gov (United States)

2015-09-01

administrative privileges . Under the current design Android development requirement, an Android Graphical User Interface (GUI) application cannot directly...build an Android application to monitor network traffic using open source packet capture (pcap) libraries. 15. SUBJECT TERMS ELIDe, Android , pcap 16...Building Application with Native Codes 5 8.1 Calling Native Codes Using JNI 5 8.2 Calling Native Codes from an Android Application 8 9. Retrieve Live

Road traffic emission monitoring on motorways

NARCIS (Netherlands)

Dittrich, M.G.; Beek, P.J.G. van

2006-01-01

Road traffic noise is one of the major environmental noise sources that is known to cause health problems. Despite existing noise reception items, the continuing growth of traffic causes higher levels than the lims allow. Consequently, excessive costs are incurred for noise barriers along roads and

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...

Urban traffic pollution and citizens information; Misure anti inquinamento da traffico urbano e partecipazione del cittadino. Uno studio di caso

Energy Technology Data Exchange (ETDEWEB)

Giuntarelli, P; Borrelli, G; Brini, S [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

1999-07-01

The following report is strictly connected to studies for introducing certain actions useful to effort the problem of urban traffic pollution. Technologies are today available to reduce traffic pollution and it is possible to verify effectiveness during the implementation. On the other hand it is not always possible to verify effectiveness of these measures on the citizen customs and quality of life. Frequently policies aiming to limit environmental risk are viewed by citizens as an insupportable coercion. In the case of urban traffic it is particularly true because the measures in this field are limited to a certain numbers of prohibitions limiting the moving freedom of citizens inside urban areas. This research, realised via a questionnaire on citizens representative of two roman districts, analyses the social acceptability degree of actions for reducing atmospheric pollution produced by automobile traffic in the city of Rome. [Italian] Il lavoro presentato di seguito si inserisce in un filone di studi che tendono a individuare quelle azioni capaci di sciogliere il nodo ormai cruciale dell'inquinamento da traffico nelle aree urbane. Azioni efficaci ne sono state individuate numerose ma, mentre per quanto riguarda le misure tecnologiche l'efficacia intrinseca della misura viene verificata nell'applicazione, non sempre si puo' dire la stessa cosa per quanto riguarda le misure che incidono sulle abitudini di vita dei cittadini. Sempre piu' spesso le politiche tese a limitare i danni ambientali sono vissute dal cittadino come una insopportabile coercizione. Nel caso del traffico urbano cio' e' particolarmente vero proprio perche' le misure di questo settore si limitano spesso a una serie di divieti che oggettivamente limitano la liberta' di movimento del cittadino. I blocchi del traffico, le zone blu, sono gli esempi piu' lampanti di questo tipo di limitazione. Questa ricerca sul campo, svolta tramite questionario e su un campione di cittadini di due quartieri di

Urban Noise Recorded by Stationary Monitoring Stations

Science.gov (United States)

Bąkowski, Andrzej; Radziszewski, Leszek; Dekýš, Vladimir

2017-10-01

The paper presents the analysis results of equivalent sound level recorded by two road traffic noise monitoring stations. The stations were located in Kielce (an example of a medium-size town in Poland) at the roads in the town in the direction of Łódź and Lublin. The measurements were carried out through stationary stations monitoring the noise and traffic of motor vehicles. The RMS values based on A-weighted sound level were recorded every 1 s in the buffer and the results were registered every 1 min over the period of investigations. The registered data were the basis for calculating the equivalent sound level for three time intervals: from 6:00 to 18:00, from 18:00 to 22:00 and from 22:00 to 6:00. Analysis included the values of the equivalent sound level recorded for different days of the week split into 24h periods, nights, days and evenings. The data analysed included recordings from 2013. The agreement of the distribution of the variable under analysis with normal distribution was evaluated. It was demonstrated that in most cases (for both roads) there was sufficient evidence to reject the null hypothesis at the significance level of 0.05. It was noted that compared with Łódź Road, in the case of Lublin Road data, more cases were recorded for which the null hypothesis could not be rejected. Uncertainties of the equivalent sound level measurements were compared within the periods under analysis. The standard deviation, coefficient of variation, the positional coefficient of variation, the quartile deviation was proposed for performing a comparative analysis of the obtained data scattering. The investigations indicated that the recorded data varied depending on the traffic routes and time intervals. The differences concerned the values of uncertainties and coefficients of variation of the equivalent sound levels.

An Adaptive Traffic Signal Control in a Connected Vehicle Environment: A Systematic Review

OpenAIRE

Peng Jing; Hao Huang; Long Chen

2017-01-01

In the last few years, traffic congestion has become a growing concern due to increasing vehicle ownerships in urban areas. Intersections are one of the major bottlenecks that contribute to urban traffic congestion. Traditional traffic signal control systems cannot adjust the timing pattern depending on road traffic demand. This results in excessive delays for road users. Adaptive traffic signal control in a connected vehicle environment has shown a powerful ability to effectively alleviate u...

Modeling annual benzene, toluene, NO2, and soot concentrations on the basis of road traffic characteristics

International Nuclear Information System (INIS)

Carr, David; Ehrenstein, Ondine von; Weiland, Stephan; Wagner, Claudia; Wellie, Oliver; Nicolai, Thomas; Mutius, Erika von

2002-01-01

The investigation of potential adverse health effects of urban traffic-related air pollution is hampered by difficulties encountered with exposure assessment. Usually public measuring sites are few and thereby do not adequately describe spatial variation of pollutant levels over an urban area. In turn, individual monitoring of pollution exposure among study subjects is laborious and expensive. We therefore investigated whether traffic characteristics can be used to adequately predict benzene, NO 2 , and soot concentrations at individual addresses of study subjects in the city area of Munich, Germany. For all road segments with expected traffic volumes of at least 4000 vehicles a day (n=1840), all vehicles were counted manually or a single weekday in 1995. The proportion of vehicles in 'stop-go' mode, n estimate of traffic jam, was determined. Furthermore, annual concentrations of benzene, NO 2 , and soot from 18 high-concentration sites means: 8.7, 65.8, and 12.9 μg/m 3 , respectively) and from 16 school sites with moderate concentrations (means: 2.6, 32.2, and 5.7 μg/m 3 , respectively) were measured from 1996 to 1998. Statistical analysis of the data was performed using components of two different statistical models recently used to predict air pollution levels in comparable settings. Two traffic characteristics, traffic volume and traffic jam percentage, adequately described air pollutant concentrations (R 2 : 0.76-0.80, P=0.0001). This study shows that air pollutant concentrations can be accurately predicted by two traffic characteristics and that these models compare favorably with other more complex models in the literature

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

Deployment Strategy for Car-Sharing Depots by Clustering Urban Traffic Big Data Based on Affinity Propagation

Directory of Open Access Journals (Sweden)

Zhihan Liu

2018-01-01

Full Text Available Car sharing is a type of car rental service, by which consumers rent cars for short periods of time, often charged by hours. The analysis of urban traffic big data is full of importance and significance to determine locations of depots for car-sharing system. Taxi OD (Origin-Destination is a typical dataset of urban traffic. The volume of the data is extremely large so that traditional data processing applications do not work well. In this paper, an optimization method to determine the depot locations by clustering taxi OD points with AP (Affinity Propagation clustering algorithm has been presented. By analyzing the characteristics of AP clustering algorithm, AP clustering has been optimized hierarchically based on administrative region segmentation. Considering sparse similarity matrix of taxi OD points, the input parameters of AP clustering have been adapted. In the case study, we choose the OD pairs information from Beijing’s taxi GPS trajectory data. The number and locations of depots are determined by clustering the OD points based on the optimization AP clustering. We describe experimental results of our approach and compare it with standard K-means method using quantitative and stationarity index. Experiments on the real datasets show that the proposed method for determining car-sharing depots has a superior performance.

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

Directory of Open Access Journals (Sweden)

Arina Negoitescu

2013-09-01

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

Long-Term Marine Traffic Monitoring for Environmental Safety in the Aegean Sea

Science.gov (United States)

Giannakopoulos, T.; Gyftakis, S.; Charou, E.; Perantonis, S.; Nivolianitou, Z.; Koromila, I.; Makrygiorgos, A.

2015-04-01

The Aegean Sea is characterized by an extremely high marine safety risk, mainly due to the significant increase of the traffic of tankers from and to the Black Sea that pass through narrow straits formed by the 1600 Greek islands. Reducing the risk of a ship accident is therefore vital to all socio-economic and environmental sectors. This paper presents an online long-term marine traffic monitoring work-flow that focuses on extracting aggregated vessel risks using spatiotemporal analysis of multilayer information: vessel trajectories, vessel data, meteorological data, bathymetric / hydrographic data as well as information regarding environmentally important areas (e.g. protected high-risk areas, etc.). A web interface that enables user-friendly spatiotemporal queries is implemented at the frontend, while a series of data mining functionalities extracts aggregated statistics regarding: (a) marine risks and accident probabilities for particular areas (b) trajectories clustering information (c) general marine statistics (cargo types, etc.) and (d) correlation between spatial environmental importance and marine traffic risk. Towards this end, a set of data clustering and probabilistic graphical modelling techniques has been adopted.

The development of area wide traffic management scenarios

NARCIS (Netherlands)

Van Zuylen, H.J.; Lu, S.; Li, J.; Yusen, C.

2014-01-01

Traffic management in cities with congestion is a big challenge with still unused opportunities. Intersection control is a corner stone but this should be done in an area-wide context. The dominant traffic process on urban roads is the traffic flow on the intersections. Spill back is a most

Multiagent reinforcement learning for urban traffic control using coordination graphs

NARCIS (Netherlands)

Kuyer, L.; Whiteson, S.; Bakker, B.; Vlassis, N.

2008-01-01

Since traffic jams are ubiquitous in the modern world, optimizing the behavior of traffic lights for efficient traffic flow is a critically important goal. Though most current traffic lights use simple heuristic protocols, more efficient controllers can be discovered automatically via multiagent

Towards a monitoring strategy to assess the anthropogenic signature of traffic derived pollution

Science.gov (United States)

Ojha, G.; Appel, E.; Magiera, T.; Wawer, M.

2013-12-01

Soil contamination along roadsides is one important factor of anthropogenic linear pollution source. In our present study we focus on typical traffic pollutants like heavy metals (HM), platinum group elements (PGEs), polycyclic aromatic hydrocarbons (PAHs) and investigate the use of magnetic parameters, in particular to discriminate the distribution of contaminants by surface runoff, splash-water and airborne transport. For monitoring we removed 10-15 cm of top soil at 1 m distance from the roadside edge and replaced it by 30 plastic boxes, and installed pillars at 1 m and 2 m distances to the roadside with samplers in different heights (ground, 0.5 m, 2 m) as well as 4 m long u-channels (surface and 2.5 cm above ground) perpendicular to the road. Clean quartz sand was used as collector material. Mass-specific magnetic susceptibility (χ) and the concentration of pollutants (HM, PAH) all show a significant increase with time in the box samples, however, there are obviously also seasonal and site-dependent effects which lead to more stable values over several months or even some decrease in the upper few cm due to vertical migration. Similar significant differences of χ, PAH and HM concentrations and an importance of splash-water were noticed in pillars and u-channels within one year of monitoring. Magnetic results revealed that magnetite-like phases are responsible for the enhancement of magnetic concentration. A good correlation between χ and semi-volatile and particle-bound PAH phases as well as HM suggests that χ can be used as a proxy for traffic derived PAH and HM pollution. SEM observations and EDX analyses identified a dominance of angular and aggregates-shaped particles with composition of Fe-Cr-Ni derived from traffic-specific activities (abrasion of tyres, exhausts and brake linings). The results from our monitoring studies will be utilized to develop new innovative roadside pollution monitoring concepts.

Identifying common practices and challenges for local urban tree monitoring programs across the United States

Science.gov (United States)

Lara A. Roman; E. Gregory McPherson; Bryant C. Scharenbroch; Julia. Bartens

2013-01-01

Urban forest monitoring data are essential to assess the impacts of tree planting campaigns and management programs. Local practitioners have monitoring projects that have not been well documented in the urban forestry literature. To learn more about practitioner-driven monitoring efforts, the authors surveyed 32 local urban forestry organizations across the United...

Estimation of Carbon Dioxide Emissions Generated by Building and Traffic in Taichung City

Directory of Open Access Journals (Sweden)

Chou-Tsang Chang

2018-01-01

Full Text Available The emissions of carbon dioxide generated by urban traffic is generally reflected by urban size. In order to discuss the traffic volume generated in developed buildings and road crossings in a single urban block, with the metropolitan area in Taichung, Taiwan as an example, this study calculates the mutual relationship between the carbon dioxide generated by the traffic volume and building development scale, in order to research energy consumption and relevance. In this research, the entire-day traffic volume of an important road crossing is subject to statistical analysis to obtain the prediction formula of total passenger car units in the main road crossing within 24 h. Then, the total CO2 emissions generated by the traffic volume in the entire year is calculated according to the investigation data of peak traffic hours within 16 blocks and the influential factors of the development scale of 95 buildings are counted. Finally, this research found that there is a passenger car unit of 4.72 generated in each square meter of land in the urban block every day, 0.99 in each square meter of floor area in the building and the average annual total CO2 emissions of each passenger car unit is 41.4 kgCO2/yr. In addition, the basic information of an integrated road system and traffic volume is used to present a readable urban traffic hot map, which can calculate a distribution map of passenger car units within one day in Taichung. This research unit can be used to forecast the development scale of various buildings in future urban blocks, in order to provide an effective approach to estimate the carbon dioxide generated by the traffic volume.

Space-based monitoring of land-use/land-cover in the Upper Rio Grande Basin: An opportunity for understanding urbanization trends in a water-scarce transboundary river basin.

Science.gov (United States)

Mubako, S. T.; Hargrove, W. L.; Heyman, J. M.; Reyes, C. S.

2016-12-01

Urbanization is an area of growing interest in assessing the impact of human activities on water resources in arid regions. Remote sensing techniques provide an opportunity to analyze land cover change over time, and are useful in monitoring areas undergoing rapid urban growth. This case study for the water-scarce Upper Rio Grande River Basin uses a supervised classification algorithm to quantify the rate and evaluate the pattern of urban sprawl. A focus is made on the fast growing El-Paso-Juarez metropolitan area on the US-Mexico border and the City of Las Cruces in New Mexico, areas where environmental challenges and loss of agricultural and native land to urban development are major concerns. Preliminary results show that the land cover is dominantly native with some significant agriculture along the Rio Grande River valley. Urban development across the whole study area expanded from just under 3 percent in 1990, to more than 11 percent in 2015. The urban expansion is occurring mainly around the major urban areas of El Paso, Ciudad Juarez, and Las Cruces, although there is visible growth of smaller urban settlements scattered along the Rio Grande River valley during the same analysis period. The proportion of native land cover fluctuates slightly depending on how much land is under crops each analysis year, but there is a decreasing agricultural land cover trend suggesting that land from this sector is being lost to urban development. This analysis can be useful in planning to protect the environment, preparing for growth in infrastructure such as schools, increased traffic demands, and monitoring availability of resources such as groundwater as the urban population grows.

Automatic road traffic safety management system in urban areas

Directory of Open Access Journals (Sweden)

Oskarbski Jacek

2017-01-01

Full Text Available Traffic incidents and accidents contribute to decreasing levels of transport system reliability and safety. Traffic management and emergency systems on the road, using, among others, automatic detection, video surveillance, communication technologies and institutional solutions improve the organization of the work of various departments involved in traffic and safety management. Automation of incident management helps to reduce the time of a rescue operation as well as of the normalization of the flow of traffic after completion of a rescue operation, which also affects the reduction of the risk of secondary accidents and contributes to reducing their severity. The paper presents the possibility of including city traffic departments in the process of incident management. The results of research on the automatic incident detection in cities are also presented.

Urban cyclist exposure to fine particle pollution in a rapidly growing city

Science.gov (United States)

Luce, B. W.; Barrett, T. E.; Ponette-González, A.

2017-12-01

Urban cyclists are exposed to elevated atmospheric concentrations of fine particulate matter (particles vehicle exhaust, which is emitted directly into cyclists' "breathing zone." In cities, human exposure to PM2.5 is a concern because its small size allows it to be inhaled deeper into the lungs than most particles. The aim of this research is to determine "hotspots" (locations with high PM2.5 concentrations) within the Dallas-Fort Worth Metroplex, Texas, where urban cyclists are most exposed to fine particle pollution. Recent research indicates that common exposure hotspots include traffic signals, junctions, bus stations, parking lots, and inclined streets. To identify these and other hotspots, a bicycle equipped with a low-cost, portable, battery-powered particle counter (Dylos 1700) coupled with a Trimble Geo 5T handheld Global Positioning System (GPS; ≤1 m ± resolution) will be used to map and measure particle mass concentrations along predetermined routes. Measurements will be conducted during a consecutive four-month period (Sep-Dec) during morning and evening rush hours when PM2.5 levels are generally highest, as well as during non-rush hour times to determine background concentrations. PM2.5 concentrations will be calculated from particle counts using an equation developed by Steinle et al. (2015). In addition, traffic counts will be conducted along the routes coinciding with the mobile monitoring times. We will present results on identified "hotspots" of high fine particle concentrations and PM2.5 exposure in the City of Denton, where particle pollution puts urban commuters most at risk, as well as average traffic counts from monitoring times. These data can be used to determine pollution mitigation strategies in rapidly growing urban areas.

Approaches for Intelligent Traffic System: A Survey

OpenAIRE

Pratishtha Gupta; G.N Purohit; Amrita Dadhich

2012-01-01

This survey presents various approaches for intelligent traffic systems. The potential research fields in which Intelligent Traffic System emerges as an important application area are highlighted andvarious issues have been identified which need to be handled while developing such a system for an urban area, where an efficient traffic management has become the need of hour.A model is also proposed capable of managing intelligent traffic system using CCTV cameras and WAN. The proposed model wi...

Traveler oriented traffic performance metrics using real time traffic data from the Midtown-in-Motion (MIM) project in Manhattan, NY.

Science.gov (United States)

2013-10-01

In a congested urban street network the average traffic speed is an inadequate metric for measuring : speed changes that drivers can perceive from changes in traffic control strategies. : A driver oriented metric is needed. Stop frequency distrib...

Urban traffic pollution and citizens information; Misure anti inquinamento da traffico urbano e partecipazione del cittadino. Uno studio di caso

Energy Technology Data Exchange (ETDEWEB)

Giuntarelli, P.; Borrelli, G.; Brini, S. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

1999-07-01

The following report is strictly connected to studies for introducing certain actions useful to effort the problem of urban traffic pollution. Technologies are today available to reduce traffic pollution and it is possible to verify effectiveness during the implementation. On the other hand it is not always possible to verify effectiveness of these measures on the citizen customs and quality of life. Frequently policies aiming to limit environmental risk are viewed by citizens as an insupportable coercion. In the case of urban traffic it is particularly true because the measures in this field are limited to a certain numbers of prohibitions limiting the moving freedom of citizens inside urban areas. This research, realised via a questionnaire on citizens representative of two roman districts, analyses the social acceptability degree of actions for reducing atmospheric pollution produced by automobile traffic in the city of Rome. [Italian] Il lavoro presentato di seguito si inserisce in un filone di studi che tendono a individuare quelle azioni capaci di sciogliere il nodo ormai cruciale dell'inquinamento da traffico nelle aree urbane. Azioni efficaci ne sono state individuate numerose ma, mentre per quanto riguarda le misure tecnologiche l'efficacia intrinseca della misura viene verificata nell'applicazione, non sempre si puo' dire la stessa cosa per quanto riguarda le misure che incidono sulle abitudini di vita dei cittadini. Sempre piu' spesso le politiche tese a limitare i danni ambientali sono vissute dal cittadino come una insopportabile coercizione. Nel caso del traffico urbano cio' e' particolarmente vero proprio perche' le misure di questo settore si limitano spesso a una serie di divieti che oggettivamente limitano la liberta' di movimento del cittadino. I blocchi del traffico, le zone blu, sono gli esempi piu' lampanti di questo tipo di limitazione. Questa ricerca sul campo, svolta tramite questionario e

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

Directory of Open Access Journals (Sweden)

Salvatore Cafiso

2017-02-01

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

The Coupling Strategy Research of Urban Public Space and Traffic for Improving the Residents’ Low-Carbon Travel Accessibility: A Case Study of Hexi New City Central Area in Nanjing

Directory of Open Access Journals (Sweden)

Caiyun Qian

2017-11-01

Full Text Available Under the current model of advocating urban intensive development and updating built-up areas, promoting the coupling optimization of space and public transport in built-up areas is an important way to realize sustainable urban development. Apart from researching the space and accessibility of the central area in Hexi new city of Nanjing and analyzing problems from various aspects, i.e., urban land use, road network planning, bus station distribution, non-motorized traffic, and space and environment design, combining with the OD (Origin & Destination survey, this paper further put forward the corresponding improvement strategy for the public space accessibility of different levels and optimized design of non-motorized traffic.

A Simplified Approach to Estimate the Urban Expressway Capacity after Traffic Accidents Using a Micro-Simulation Model

Directory of Open Access Journals (Sweden)

Hong Chen

2013-01-01

Full Text Available Based on the decomposition of the evolution processes of the urban expressway capacity after traffic accidents and the influence factors analysis, an approach for estimating the capacity has been proposed. Firstly, the approach introduces the Decision Tree ID algorithm, solves the accident delay time of different accident types by the Information Gain Value, and determines congestion dissipation time by the Traffic Flow Wave Theory. Secondly, taking the accident delay time as the observation cycle, the maximum number of the vehicles through the accident road per unit time was considered as its capacity. Finally, the attenuation simulation of the capacity for different accident types was calculated by the VISSIM software. The simulation results suggest that capacity attenuation of vehicle anchor is minimal and the rate is 30.074%; the next is vehicles fire, rear-end, and roll-over, and the rate is 38.389%, 40.204%, and 43.130%, respectively; the capacity attenuation of vehicle collision is the largest, and the rate is 50.037%. Moreover, the further research shows that the accident delay time is proportional to congestion dissipation time, time difference, and the ratio between them, but it is an inverse relationship with the residual capacity of urban expressway.

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...

Safety analysis of urban signalized intersections under mixed traffic.

Science.gov (United States)

S, Anjana; M V L R, Anjaneyulu

2015-02-01

This study examined the crash causative factors of signalized intersections under mixed traffic using advanced statistical models. Hierarchical Poisson regression and logistic regression models were developed to predict the crash frequency and severity of signalized intersection approaches. The prediction models helped to develop general safety countermeasures for signalized intersections. The study shows that exclusive left turn lanes and countdown timers are beneficial for improving the safety of signalized intersections. Safety is also influenced by the presence of a surveillance camera, green time, median width, traffic volume, and proportion of two wheelers in the traffic stream. The factors that influence the severity of crashes were also identified in this study. As a practical application, the safe values of deviation of green time provided from design green time, with varying traffic volume, is presented in this study. This is a useful tool for setting the appropriate green time for a signalized intersection approach with variations in the traffic volume. Copyright © 2014 Elsevier Ltd. All rights reserved.

Urban air quality, meteorology and traffic linkages: Evidence from a sixteen-day particulate matter pollution event in December 2015, Beijing.

Science.gov (United States)

Hu, Dongmei; Wu, Jianping; Tian, Kun; Liao, Lyuchao; Xu, Ming; Du, Yiman

2017-09-01

A heavy 16-day pollution episode occurred in Beijing from December 19, 2015 to January 3, 2016. The mean daily AQI and PM 2.5 were 240.44 and 203.6μg/m 3 . We analyzed the spatiotemporal characteristics of air pollutants, meteorology and road space speed during this period, then extended to reveal the combined effects of traffic restrictions and meteorology on urban air quality with observational data and a multivariate mutual information model. Results of spatiotemporal analysis showed that five pollution stages were identified with remarkable variation patterns based on evolution of PM 2.5 concentration and weather conditions. Southern sites (DX, YDM and DS) experienced heavier pollution than northern ones (DL, CP and WL). Stage P2 exhibited combined functions of meteorology and traffic restrictions which were delayed peak-clipping effects on PM 2.5 . Mutual information values of Air quality-Traffic-Meteorology (ATM-MI) revealed that additive functions of traffic restrictions, suitable relative humidity and temperature were more effective on the removal of fine particles and CO than NO 2 . Copyright © 2017. Published by Elsevier B.V.

The traffic crisis and a tale of two cities: Traffic and air quality in Bangkok and Mexico City

Energy Technology Data Exchange (ETDEWEB)

Pendakur, V.S.; Badami, M.G.

1995-12-31

This paper focuses on congestion management techniques, traffic congestion levels and air quality. By using data from Bangkok and Mexico City, it illustrates the need for drastic changes in transportation policy tools and techniques for congestion management and for improving environmental quality. New approaches to investment and regulatory policy analysis and implementation are suggested. This requires the inclusion of all costs and benefits (economic and ecological) in the policy matrix so that investment and regulatory policies act in unison. Megacities are dominant in social, political and economic terms. 30 to 60% of national GDP is typically produced in these cities. Their human and motor vehicle populations have been doubling every 15-20 and 6-10 years respectively. They also have the most severe traffic congestion and air quality problems. They have the nation`s highest incidence of poverty and absolute poverty. Large portions of their populations endure severely unhealthy housing and sanitation conditions. Following are important characteristics of urban transportation systems in the megacities: the city centres are heavily congested with motorized traffic; traffic crawl rates vary from 2 to 10 km/hr; car and motorcycle ownership are increasing at annual rates of 10-12% and 15-20% respectively; significant air pollution with no relief in sight; TDM strategies are primarily creating new supply of road capacity; fairly high transit trips with substantial transit investments; weak air pollution monitoring and enforcement; and fairly cheap fuel and high costs of vehicles.

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

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

URBAN TRAFFIC ACCIDENT ANALYSIS BY USING GEOGRAPHIC INFORMATION SYSTEM

Directory of Open Access Journals (Sweden)

Meltem SAPLIOĞLU

2006-03-01

Full Text Available In recent years, traffic accidents that cause more social and economic losses than that of natural disasters,have become a national problem in Turkey. To solve this problem and to reduce the casualties, road safety programs are tried to be developed. It is necessary to develop the most effective measures with low investment cost due to limited budgets allocated to such road safety programs. The most important program is to determine dangerous locations of traffic accidents and to improve these sections from the road safety view point. New Technologies are driving a cycle of continuous improvement that causes rapid changes in the traffic engineering and any engineering services within it. It is obvious that this developed services will be the potential for forward-thinking engineering studies to take a more influence role. In this study, Geographic Information System (GIS was used to identify the hazardous locations of traffic accidents in Isparta. Isparta city map was digitized by using Arcinfo 7.21. Traffic accident reports occurred between 1998-2002 were obtained from Directory of Isparta Traffic Region and had been used to form the database. Topology was set up by using Crash Diagrams and Geographic Position Reference Systems. Tables are formed according to the obtained results and interpreted.

A multi-model approach to monitor emissions of CO2 and CO from an urban-industrial complex

Science.gov (United States)

Super, Ingrid; Denier van der Gon, Hugo A. C.; van der Molen, Michiel K.; Sterk, Hendrika A. M.; Hensen, Arjan; Peters, Wouter

2017-11-01

Monitoring urban-industrial emissions is often challenging because observations are scarce and regional atmospheric transport models are too coarse to represent the high spatiotemporal variability in the resulting concentrations. In this paper we apply a new combination of an Eulerian model (Weather Research and Forecast, WRF, with chemistry) and a Gaussian plume model (Operational Priority Substances - OPS). The modelled mixing ratios are compared to observed CO2 and CO mole fractions at four sites along a transect from an urban-industrial complex (Rotterdam, the Netherlands) towards rural conditions for October-December 2014. Urban plumes are well-mixed at our semi-urban location, making this location suited for an integrated emission estimate over the whole study area. The signals at our urban measurement site (with average enhancements of 11 ppm CO2 and 40 ppb CO over the baseline) are highly variable due to the presence of distinct source areas dominated by road traffic/residential heating emissions or industrial activities. This causes different emission signatures that are translated into a large variability in observed ΔCO : ΔCO2 ratios, which can be used to identify dominant source types. We find that WRF-Chem is able to represent synoptic variability in CO2 and CO (e.g. the median CO2 mixing ratio is 9.7 ppm, observed, against 8.8 ppm, modelled), but it fails to reproduce the hourly variability of daytime urban plumes at the urban site (R2 up to 0.05). For the urban site, adding a plume model to the model framework is beneficial to adequately represent plume transport especially from stack emissions. The explained variance in hourly, daytime CO2 enhancements from point source emissions increases from 30 % with WRF-Chem to 52 % with WRF-Chem in combination with the most detailed OPS simulation. The simulated variability in ΔCO :  ΔCO2 ratios decreases drastically from 1.5 to 0.6 ppb ppm-1, which agrees better with the observed standard

Detectability Analysis of Road Vehicles in Radarsat-2 Fully Polarimetric SAR Images for Traffic Monitoring

Directory of Open Access Journals (Sweden)

Bo Zhang

2017-02-01

Full Text Available By acquiring information over a wide area regardless of weather conditions and solar illumination, space-borne Synthetic Aperture Radar (SAR has the potential to be a promising application for traffic monitoring. However, the backscatter character of a vehicle in a SAR image is unstable and varies with image parameters, such as aspect and incidence angle. To investigate vehicle detectability in SAR images for traffic monitoring applications, images of four common types of vehicles in China were acquired using the fully polarimetric (FP SAR of Radarsat-2 in our experiments. Methods for measuring a vehicle’s aspect angle and backscatter intensity are introduced. The experimental FP SAR images are used to analyze the detectability, which is affected by factors such as vehicle size, vehicle shape, and aspect angle. Moreover, a new metric to improve vehicle detectability in FP SAR images is proposed and compared with the well-known intensity metric. The experimental results show that shape is a crucial factor in affecting the backscatter intensity of vehicles, which also oscillates with varying aspect angle. If the size of a vehicle is smaller than the SAR image resolution, using the intensity metric would result in low detectability. However, it could be improved in an FP SAR image by using the proposed metric. Compared with the intensity metric, the overall detectability is improved from 72% to 90% in our experiments. Therefore, this study indicates that FP SAR images have the ability to detect stationary vehicles on the road and are meaningful for traffic monitoring.

Nighttime road-traffic noise and arterial hypertension in an urban population.

Science.gov (United States)

Belojević, Goran A; Jakovljević, Branko D; Stojanov, Vesna J; Slepcević, Vesna Z; Paunović, Katarina Z

2008-04-01

Commonly used daytime measurements in previous investigations on community noise and arterial hypertension (AH) may be a source of exposure bias, as urban residents spend most of their daytime hours out of the home on workdays. For this reason, we focused on the relation of nighttime noise and AH. A cross-sectional study was performed on a sample of 2,503 (995 men and 1,508 women) adult residents of a downtown Belgrade municipality. The inclusion criteria were a period of residence longer than 10 years and a bedroom oriented toward the street. The exclusion criteria were a high level of noise annoyance at work and diseases related to AH. Noise measurements were performed in all 70 streets of the municipality. The streets were grouped into noisy areas (equivalent noise level [Leq]>45 dB(A)) and quiet areas (Leqquiet areas were 23.6% and 17.5%, respectively. The adjusted odds ratio (OR) for AH was 1.58; the 95% confidence interval (CI) ranged from 1.03-2.42; and the probability value was 0.038, when men living in quiet streets were taken as a reference category. This relation was statistically insignificant for women: adjusted OR: 0.90; 95% CI: 0.59-1.38; p: 0.644. This cross-sectional study showed that nighttime urban road-traffic noise might be related to occurrence of AH in men.

Mosses Are Better than Leaves of Vascular Plants in Monitoring Atmospheric Heavy Metal Pollution in Urban Areas.

Science.gov (United States)

Jiang, Yanbin; Fan, Miao; Hu, Ronggui; Zhao, Jinsong; Wu, Yupeng

2018-05-29

Mosses and leaves of vascular plants have been used as bioindicators of environmental contamination by heavy metals originating from various sources. This study aims to compare the metal accumulation capabilities of mosses and vascular species in urban areas and quantify the suitability of different taxa for monitoring airborne heavy metals. One pleurocarpous feather moss species, Haplocladium angustifolium , and two evergreen tree species, Cinnamomum bodinieri Osmanthus fragrans , and substrate soil were sampled in the urban area of different land use types in Wuhan City in China. The concentrations of Ag, As, Cd, Co, Cr, Cu, Mn, Mo, Ni, V, Pb, and Zn in these samples were analyzed by inductively coupled plasma mass spectrometry. The differences of heavy metals concentration in the three species showed that the moss species was considerably more capable of accumulating heavy metals than tree leaves (3 times to 51 times). The accumulated concentration of heavy metals in the moss species depended on the metal species and land use type. The enrichment factors of metals for plants and the correlations of metals in plants with corresponding metals in soil reflected that the accumulated metals in plants stemmed mostly from atmospheric deposition, rather than the substrate soil. Anthropogenic factors, such as traffic emissions from automobile transportation and manufacturing industries, were primarily responsible for the variations in metal pollutants in the atmosphere and subsequently influenced the metal accumulation in the mosses. This study elucidated that the moss species H. angustifolium is relatively more suitable than tree leaves of C. bodinieri and O. fragrans in monitoring heavy metal pollution in urban areas, and currently Wuhan is at a lower contamination level of atmospheric heavy metals than some other cities in China.

Properties of Phase Transition of Traffic Flow on Urban Expressway Systems with Ramps and Accessory Roads

International Nuclear Information System (INIS)

Mei Chaoqun; Liu Yejin

2011-01-01

In this paper, we develop a cellular automaton model to describe the phase transition of traffic flow on urban expressway systems with on-off-ramps and accessory roads. The lane changing rules are given in detailed, the numerical results show that the main road and the accessory road both produce phase transitions. These phase transitions will often be influenced by the number of lanes, lane changing, the ramp flow, the input flow rate, and the geometry structure. (interdisciplinary physics and related areas of science and technology)

A Unified Monitoring Framework for Energy Consumption and Network Traffic

Directory of Open Access Journals (Sweden)

Florentin Clouet

2015-08-01

Full Text Available Providing experimenters with deep insight about the effects of their experiments is a central feature of testbeds. In this paper, we describe Kwapi, a framework designed in the context of the Grid'5000 testbed, that unifies measurements for both energy consumption and network traffic. Because all measurements are taken at the infrastructure level (using sensors in power and network equipment, using this framework has no dependencies on the experiments themselves. Initially designed for OpenStack infrastructures, the Kwapi framework allows monitoring and reporting of energy consumption of distributed platforms. In this article, we present the extension of Kwapi to network monitoring, and outline how we overcame several challenges: scaling to a testbed the size of Grid'5000 while still providing high-frequency measurements; providing long-term loss-less storage of measurements; handling operational issues when deploying such a tool on a real infrastructure.

Temporal-Spatial Analysis of Traffic Congestion Based on Modified CTM

Directory of Open Access Journals (Sweden)

Chenglong Chu

2015-01-01

Full Text Available A modified cell transmission model (CTM is proposed to depict the temporal-spatial evolution of traffic congestion on urban freeways. Specifically, drivers’ adaptive behaviors and the corresponding influence on traffic flows are emphasized. Two piecewise linear regression models are proposed to describe the relationship of flow and density (occupancy. Several types of cellular connections are designed to depict urban rapid roads with on/off-ramps and junctions. Based on the data collected on freeway of Queen Elizabeth, Ontario, Canada, we show that the new model provides a relatively higher accuracy of temporal-spatial evolution of traffic congestions.

Remotely Accessed Vehicle Traffic Management System

Science.gov (United States)

Al-Alawi, Raida

2010-06-01

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

Traffic characterization and Internet usage in rural Africa

CSIR Research Space (South Africa)

Johnson, D

2011-03-01

Full Text Available significantly from the developed world. We observe dominance of web-based traffic, as opposed to peer-to-peer traffic common in urban areas. Application-wise, online social networks are the most popular, while the majority of bandwidth is consumed by large...

Use of CFD modeling for estimating spatial representativeness of urban air pollution monitoring sites and suitability of their locations

International Nuclear Information System (INIS)

Santiago, J. L.; Martin, F.

2015-01-01

A methodology to estimate the spatial representativeness of air pollution monitoring sites is applied to two urban districts. This methodology is based on high resolution maps of air pollution computed by using Computational Fluid Dynamics (CFD) modelling tools. Traffic-emitted NO 2 dispersion is simulated for several meteorological conditions taking into account the effect of the buildings on air flow and pollutant dispersion and using a steady state CFD-RANS approach. From these results, maps of average pollutant concentrations for January -May 2011 are computed as a combination of the simulated scenarios. Two urban districts of Madrid City were simulated. Spatial representativeness areas for 32 different sites within the same district (including the site of the operative air quality stations) have been estimated by computing the portion of the domains with average NO 2 concentration differing less than a 20% of the concentration at each candidate monitoring site. New parameters such as the ratio AR between the representativeness area and the whole domain area or the representativeness index (IR) has been proposed to discuss and compare the representativeness areas. Significant differences between the spatial representativeness of the candidate sites of both studied districts have been found. The sites of the Escuelas Aguirre district have generally smaller representativeness areas than those of the Plaza de Castilla. More stations are needed to cover the Escuelas Aguirre district than for the Plaza de Castilla one. The operative air quality station of the Escuelas Aguirre district is less representative than the station of the Plaza de Castilla district. The cause of these differences seems to be the differences in urban structure of both districts prompting different ventilation. (Author)

Use of CFD modeling for estimating spatial representativeness of urban air pollution monitoring sites and suitability of their locations

Energy Technology Data Exchange (ETDEWEB)

Santiago, J. L.; Martin, F.

2015-07-01

A methodology to estimate the spatial representativeness of air pollution monitoring sites is applied to two urban districts. This methodology is based on high resolution maps of air pollution computed by using Computational Fluid Dynamics (CFD) modelling tools. Traffic-emitted NO{sub 2} dispersion is simulated for several meteorological conditions taking into account the effect of the buildings on air flow and pollutant dispersion and using a steady state CFD-RANS approach. From these results, maps of average pollutant concentrations for January -May 2011 are computed as a combination of the simulated scenarios. Two urban districts of Madrid City were simulated. Spatial representativeness areas for 32 different sites within the same district (including the site of the operative air quality stations) have been estimated by computing the portion of the domains with average NO{sub 2} concentration differing less than a 20% of the concentration at each candidate monitoring site. New parameters such as the ratio AR between the representativeness area and the whole domain area or the representativeness index (IR) has been proposed to discuss and compare the representativeness areas. Significant differences between the spatial representativeness of the candidate sites of both studied districts have been found. The sites of the Escuelas Aguirre district have generally smaller representativeness areas than those of the Plaza de Castilla. More stations are needed to cover the Escuelas Aguirre district than for the Plaza de Castilla one. The operative air quality station of the Escuelas Aguirre district is less representative than the station of the Plaza de Castilla district. The cause of these differences seems to be the differences in urban structure of both districts prompting different ventilation. (Author)

Use of CFD modeling for estimating spatial representativeness of urban air pollution monitoring sites and suitability of their locations

Energy Technology Data Exchange (ETDEWEB)

Santiago, J.L.; Martin, F.

2015-07-01

A methodology to estimate the spatial representativeness of air pollution monitoring sites is applied to two urban districts. This methodology is based on high resolution maps of air pollution computed by using Computational Fluid Dynamics (CFD) modelling tools. Traffic-emitted NO2 dispersion is simulated for several meteorological conditions taking into account the effect of the buildings on air flow and pollutant dispersion and using a steady state CFD-RANS approach. From these results, maps of average pollutant concentrations for January–May 2011 are computed as a combination of the simulated scenarios. Two urban districts of Madrid City were simulated. Spatial representativeness areas for 32 different sites within the same district (including the site of the operative air quality stations) have been estimated by computing the portion of the domains with average NO2 concentration differing less than a 20% of the concentration at each candidate monitoring site. New parameters such as the ratio AR between the representativeness area and the whole domain area or the representativeness index (IR) has been proposed to discuss and compare the representativeness areas. Significant differences between the spatial representativeness of the candidate sites of both studied districts have been found. The sites of the Escuelas Aguirre district have generally smaller representativeness areas than those of the Plaza de Castilla. More stations are needed to cover the Escuelas Aguirre district than for the Plaza de Castilla one. The operative air quality station of the Escuelas Aguirre district is less representative than the station of the Plaza de Castilla district. The cause of these differences seems to be the differences in urban structure of both districts prompting different ventilation. (Author)

Assessment of road traffic noise indices in urban residential areas of Klang Valley, Malaysia

Science.gov (United States)

Halim, Herni; Abdullah, Ramdzani; Nor, Mohd Jailani Mohd; Aziz, Hamidi Abdul; Rahman, Noorhazlinda Abd

2017-10-01

Traffic noise has been recognized as a serious threat to the quality of life in most industrialised nations. Klang valley is rapidly emerging as industrialized and urbanized city and has started facing severe noise pollution problems. Urban noise quality assessment is studied in three residential areas; Desa Tun Razak, Kinrara Court and Taman Sentul Utama. Noise pollution indices of L10, L50, L90, Lmax and Lmin as well as equivalent continuous noise level (Leq) were measured for all dwellings. Noise indices results illustrate that Desa Tun Razak recorded the highest values of noise levels among three studied sites. Results also indicate that the highest Leq of 75.7 dB(A) was observed in Desa Tun Razak followed by 74.3 dB(A) in Kinrara Court, and 72.1 dB(A) in Taman Sentul Utama. The noise assessment study clearly reveals the alarming condition of noise pollution in residential areas of Klang Valley as the noise level measured exceeded permissible limit by WHO and Malaysia Guidelines.

Geochemistry and carbon isotopic ratio for assessment of PM10 composition, source and seasonal trends in urban environment.

Science.gov (United States)

Di Palma, A; Capozzi, F; Agrelli, D; Amalfitano, C; Giordano, S; Spagnuolo, V; Adamo, P

2018-08-01

Investigating the nature of PM 10 is crucial to differentiate sources and their relative contributions. In this study we compared the levels, and the chemical and mineralogical properties of PM 10 particles sampled in different seasons at monitoring stations representative of urban background, urban traffic and suburban traffic areas of Naples city. The aims were to relate the PM 10 load and characteristics to the location of the monitoring stations, to investigate the different sources contributing to PM 10 and to highlight PM 10 seasonal variability. Bulk analyses of chemical species in the PM 10 fraction included total carbon and nitrogen, δ 13 C and other 20 elements. Both natural and anthropogenic sources were found to contribute to the exceedances of the EU PM 10 limit values. The natural contribution was mainly related to marine aerosols and soil dust, as highlighted by X-ray diffractometry and SEM-EDS microscopy. The percentage of total carbon suggested a higher contribution of biogenic components to PM 10 in spring. However, this result was not supported by the δ 13 C values which were seasonally homogeneous and not sufficient to extract single emission sources. No significant differences, in terms of PM 10 load and chemistry, were observed between monitoring stations with different locations, suggesting a homogeneous distribution of PM 10 on the studied area in all seasons. The anthropogenic contribution to PM 10 seemed to dominate in all sites and seasons with vehicular traffic acting as a main source mostly by generation of non-exhaust emissions Our findings reinforce the need to focus more on the analysis of PM 10 in terms of quality than of load, to reconsider the criteria for the classification and the spatial distribution of the monitoring stations within urban and suburban areas, with a special attention to the background location, and to emphasize all the policies promoting sustainable mobility and reduction of both exhaust and not

An Adaptive Traffic Signal Control in a Connected Vehicle Environment: A Systematic Review

Directory of Open Access Journals (Sweden)

Peng Jing

2017-08-01

Full Text Available In the last few years, traffic congestion has become a growing concern due to increasing vehicle ownerships in urban areas. Intersections are one of the major bottlenecks that contribute to urban traffic congestion. Traditional traffic signal control systems cannot adjust the timing pattern depending on road traffic demand. This results in excessive delays for road users. Adaptive traffic signal control in a connected vehicle environment has shown a powerful ability to effectively alleviate urban traffic congestions to achieve desirable objectives (e.g., delay minimization. Connected vehicle technology, as an emerging technology, is a mobile data platform that enables the real-time data exchange among vehicles and between vehicles and infrastructure. Although several reviews about traffic signal control or connected vehicles have been written, a systemic review of adaptive traffic signal control in a connected vehicle environment has not been made. Twenty-six eligible studies searched from six databases constitute the review. A quality evaluation was established based on previous research instruments and applied to the current review. The purpose of this paper is to critically review the existing methods of adaptive traffic signal control in a connected vehicle environment and to compare the advantages or disadvantages of those methods. Further, a systematic framework on connected vehicle based adaptive traffic signal control is summarized to support the future research. Future research is needed to develop more efficient and generic adaptive traffic signal control methods in a connected vehicle environment.

Air Pollution Monitoring and Mining Based on Sensor Grid in London

OpenAIRE

Ma, Yajie; Richards, Mark; Ghanem, Moustafa; Guo, Yike; Hassard, John

2008-01-01

In this paper, we present a distributed infrastructure based on wireless sensors network and Grid computing technology for air pollution monitoring and mining, which aims to develop low-cost and ubiquitous sensor networks to collect real-time, large scale and comprehensive environmental data from road traffic emissions for air pollution monitoring in urban environment. The main informatics challenges in respect to constructing the high-throughput sensor Grid are discussed in this paper. We pr...

Passive monitoring for near surface void detection using traffic as a seismic source

Science.gov (United States)

Zhao, Y.; Kuzma, H. A.; Rector, J.; Nazari, S.

2009-12-01

In this poster we present preliminary results based on our several field experiments in which we study seismic detection of voids using a passive array of surface geophones. The source of seismic excitation is vehicle traffic on nearby roads, which we model as a continuous line source of seismic energy. Our passive seismic technique is based on cross-correlation of surface wave fields and studying the resulting power spectra, looking for "shadows" caused by the scattering effect of a void. High frequency noise masks this effect in the time domain, so it is difficult to see on conventional traces. Our technique does not rely on phase distortions caused by small voids because they are generally too tiny to measure. Unlike traditional impulsive seismic sources which generate highly coherent broadband signals, perfect for resolving phase but too weak for resolving amplitude, vehicle traffic affords a high power signal a frequency range which is optimal for finding shallow structures. Our technique results in clear detections of an abandoned railroad tunnel and a septic tank. The ultimate goal of this project is to develop a technology for the simultaneous imaging of shallow underground structures and traffic monitoring near these structures.

Urban Seismology: on the origin of earth vibrations within a city.

Science.gov (United States)

Díaz, Jordi; Ruiz, Mario; Sánchez-Pastor, Pilar S; Romero, Paula

2017-11-10

Urban seismology has become an active research field in the recent years, both with seismological objectives, as obtaining better microzonation maps in highly populated areas, and with engineering objectives, as the monitoring of traffic or the surveying of historical buildings. We analyze here the seismic records obtained by a broad-band seismic station installed in the ICTJA-CSIC institute, located near the center of Barcelona city. Although this station was installed to introduce visitors to earth science during science fairs and other dissemination events, the analysis of the data has allowed to infer results of interest for the scientific community. The main results include the evidence that urban seismometers can be used as a easy-to-use, robust monitoring tool for road traffic and subway activity inside the city. Seismic signals generated by different cultural activities, including rock concerts, fireworks or football games, can be detected and discriminated from its seismic properties. Beside the interest to understand the propagation of seismic waves generated by those rather particular sources, those earth shaking records provide a powerful tool to gain visibility in the mass media and hence have the opportunity to present earth sciences to a wider audience.

Solutions to Improve Road Circulation in the Pitesti City Based on Analysis-Diagnostics of Road Traffic

Science.gov (United States)

Vîlcan, A.; Neagu, E.; Badarau Suster, H.; Boroiu, A. A.

2017-10-01

Road traffic congestion has become a daily phenomenon in the central area of Pitesti in the peak traffic periods. In order to achieve the mobility plan of Pitesti, an important stage is the diagnostic analysis of the road traffic. For this purpose, the urban road network was formalized through a graph containing the most important 40 intersections and traffic measurements were made at all these intersections and on the main roads connecting the peri-urban area. The data obtained by traffic macrosimulation confirmed the overloading of the street network during peak traffic hours and the analyzes made for various road traffic organization scenarios have shown that there are sustainable solutions for urban mobility only if the road network is fundamentally reconfigured (a belt outside the city and a median ring). Thus, the necessity of realizing the road passage in the Prundu neighbourhood and the finishing of the city belt by realizing the “detour West” of the city is argued. The importance of the work is that it brings scientific arguments for the realization of these road infrastructure projects, integrated in the urban mobility plan, which will base the development strategy of the Pitesti municipality.

Classification of Global Urban Centers Using ASTER Data: Preliminary Results From the Urban Environmental Monitoring Program

Science.gov (United States)

Stefanov, W. L.; Stefanov, W. L.; Christensen, P. R.

2001-05-01

Land cover and land use changes associated with urbanization are important drivers of global ecologic and climatic change. Quantification and monitoring of these changes are part of the primary mission of the ASTER instrument, and comprise the fundamental research objective of the Urban Environmental Monitoring (UEM) Program. The UEM program will acquire day/night, visible through thermal infrared ASTER data twice per year for 100 global urban centers over the duration of the mission (6 years). Data are currently available for a number of these urban centers and allow for initial comparison of global city structure using spatial variance texture analysis of the 15 m/pixel visible to near infrared ASTER bands. Variance texture analysis highlights changes in pixel edge density as recorded by sharp transitions from bright to dark pixels. In human-dominated landscapes these brightness variations correlate well with urbanized vs. natural land cover and are useful for characterizing the geographic extent and internal structure of cities. Variance texture analysis was performed on twelve urban centers (Albuquerque, Baghdad, Baltimore, Chongqing, Istanbul, Johannesburg, Lisbon, Madrid, Phoenix, Puebla, Riyadh, Vancouver) for which cloud-free daytime ASTER data are available. Image transects through each urban center produce texture profiles that correspond to urban density. These profiles can be used to classify cities into centralized (ex. Baltimore), decentralized (ex. Phoenix), or intermediate (ex. Madrid) structural types. Image texture is one of the primary data inputs (with vegetation indices and visible to thermal infrared image spectra) to a knowledge-based land cover classifier currently under development for application to ASTER UEM data as it is acquired. Collaboration with local investigators is sought to both verify the accuracy of the knowledge-based system and to develop more sophisticated classification models.

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.

On the Impact of Anomalous Noise Events on Road Traffic Noise Mapping in Urban and Suburban Environments.

Science.gov (United States)

Orga, Ferran; Alías, Francesc; Alsina-Pagès, Rosa Ma

2017-12-23

Noise pollution is a critical factor affecting public health, the relationship between road traffic noise (RTN) and several diseases in urban areas being especially disturbing. The Environmental Noise Directive 2002/49/EC and the CNOSSOS-EU framework are the main instruments of the European Union to identify and combat noise pollution, requiring Member States to compose and publish noise maps and noise management action plans every five years. Nowadays, the noise maps are starting to be tailored by means of Wireless Acoustic Sensor Networks (WASN). In order to exclusively monitor the impact of RTN on the well-being of citizens through WASN-based approaches, those noise sources unrelated to RTN denoted as Anomalous Noise Events (ANEs) should be removed from the noise map generation. This paper introduces an analysis methodology considering both Signal-to-Noise Ratio (SNR) and duration of ANEs to evaluate their impact on the A-weighted equivalent RTN level calculation for different integration times. The experiments conducted on 9 h of real-life data from the WASN-based DYNAMAP project show that both individual high-impact events and aggregated medium-impact events bias significantly the equivalent noise levels of the RTN map, making any derived study about public health impact inaccurate.

Bangkok: Anatomy of a traffic disaster

Energy Technology Data Exchange (ETDEWEB)

Poboon, C.; Kenworthy, J.; Barter, P.

1995-12-31

Traditional urban and transport policy which relies on road-base planning has been proven inadequate for tackling Bangkok`s traffic chaos. After employing such policy for more than three decades Bangkok traffic has become a disaster and the city has become notorious world-wide for its traffic congestion and air pollution. The simplistic application of theses largely American models took little consideration if any of the walking city and transit city structure of Bangkok. The policies recommended by the authors rely on the awareness of Bangkok`s unique characteristics and also encompass social and environmental aspects. The worldwide comparison has contributed substantially to more insight in selecting the appropriate measures for Bangkok. The introduction of a mass rapid transit system, water transport improvement, control of car use, provision of infrastructure for walking and cycling, improvement in paratransit together with transit-oriented land use development are believed to be able to work effectively in Bangkok. Nevertheless, institutional improvement including public participation is very necessary to achieve these urban planning and transport strategies. With the combination of these sustainable urban and transport policies, it is possible for Bangkok to be converted into a city for people again, though it will take probably 10 to 20 years or more for substantial improvements.

[Reduction of automobile traffic: urgent health promotion policy].

Science.gov (United States)

Tapia Granados, J A

1998-03-01

During the last few decades, traffic injuries have become one of the leading causes of death and disability in the world. In urban areas, traffic congestion, noise, and emissions from motor vehicles produce subjective disturbances and detectable pathological effects. More than one billion people are exposed to harmful levels of environmental pollution. Because its combustion engine generates carbon dioxide (CO2), the automobile is one of the chief sources of the gases that are causing the greenhouse effect. The latter has already caused a rise in the average ambient temperature, and over the next decades it will predictable cause significant climatic changes whose consequences, though uncertain, are likely to be harmful and possibly catastrophic. Aside from the greenhouse effect, the relentless growth of parking zones, traffic, and the roadway infrastructure in urban and rural areas is currently one of the leading causes of environmental degradation. Urban development, which is nearly always "planned" around traffic instead of people, leads to a significant deterioration in the quality of life, while it also destroys the social fabric. Unlike the private automobile, public transportation, bicycles, and walking help reduce pollution, congestion, and traffic volume, as well as the morbidity and mortality resulting from injuries and ailments related to pollution. Non-automobile transportation also encourages physical activity--with its positive effect on general health--and helps reduce the greenhouse effect. The drop in traffic volume and the increased use of alternate means of transportation are thus an integrated health promotion policy which should become an inherent part of the movement for the promotion of healthy cities and of transportation policies and economic policy in general.

Validation of a multi-objective, predictive urban traffic model

NARCIS (Netherlands)

Wilmink, I.R.; Haak, P. van den; Woldeab, Z.; Vreeswijk, J.

2013-01-01

This paper describes the results of the verification and validation of the ecoStrategic Model, which was developed, implemented and tested in the eCoMove project. The model uses real-time and historical traffic information to determine the current, predicted and desired state of traffic in a

A comparative study of the effect of automobile pollution on pulmonary function tests of people who reside in high traffic density urban areas and relatively traffic free rural areas

Directory of Open Access Journals (Sweden)

Amrith Pakkala

2014-01-01

Full Text Available Background: Motor vehicle emissions constitute the most significant source of ultra particles in an urban environment. Traffic related air pollution is an occupational health hazard to individuals who live and work in an environment close to traffic. The present study intends to study the effect of air pollution on the pulmonary system in people who reside in areas exposed to automobile exhaust. Material and Methods: This study was conducted by performing pulmonary function tests (PFT on 20 people who are exposed to automobile exhaust by virtue of their residence nearer to traffic junctions and comparing them with 20 others of age and gender matched and similar anthropometric profile people, who reside in a rural setting free from vehicular air pollution. Statistical analysis was done by Student′s t-test (two-tailed, independent for inter group analysis. Results: There was a statistically significant difference between the two groups as far as parameters like FVC, FEV 1 , PEFR, FEV 1 /FVC, FEF 25-75% . It can be seen that there is decline in dynamic pulmonary function parameters in the study group when compared to controls, which is statistically significant. Conclusion: The respiratory system are particulate matter (PM 10 and sulphur dioxide (SO 2 produced by the combustion of fossil fuels. These pollutants react with each other, forming hazardous acid sulfate particles, which are capable of reaching deep inside the tracheo-bronchial tree producing a bronchoconstrictor response, as their predominant site of action are the small airways. This was a comparative study to demonstrate the effect of air pollution due to automobile exhaust on pulmonary functions of people who reside in areas exposed to a polluted urban environment with a similar group in the rural relatively pollution free environment.

An Efficient PageRank Approach for Urban Traffic Optimization

Directory of Open Access Journals (Sweden)

Florin Pop

2012-01-01

to determine optimal decisions for each traffic light, based on the solution given by Larry Page for page ranking in Web environment (Page et al. (1999. Our approach is similar with work presented by Sheng-Chung et al. (2009 and Yousef et al. (2010. We consider that the traffic lights are controlled by servers and a score for each road is computed based on efficient PageRank approach and is used in cost function to determine optimal decisions. We demonstrate that the cumulative contribution of each car in the traffic respects the main constrain of PageRank approach, preserving all the properties of matrix consider in our model.

Test and assessment method of Automotive Safety Systems (SSB) particularly to monitor traffic incidents

Science.gov (United States)

Pijanowski, B.; Łukjanow, S.; Burliński, R.

2016-09-01

The rapid development of telematics, particularly mobile telephony (GSM), wireless data transmission (GPRS) and satellite positioning (GPS) noticeable in the last decade, resulted in an almost unlimited growth of the possibilities for monitoring of mobile objects. These solutions are already widely used in the so-called “Intelligent Transport Systems” - ITS and affect a significant increase for road safety. The article describes a method of testing and evaluation of Car Safety Systems (Polish abbreviation - SSB) especially for monitoring traffic incidents, such as collisions and accidents. The algorithm of SSB testing process is also presented. Tests are performed on the dynamic test bench, part of which is movable platform with car security system mounted on it. Crash tests with a rigid obstacle are carried out instead of destructive attempts to crash test of the entire vehicle which is expensive. The tested system, depending on the simulated traffic conditions, is mounted in such a position and with the use of components, indicated by the manufacturer for the automotive safety system installation in a vehicle, for which it is intended. Then, the tests and assessments are carried out.

An efficient statistical-based approach for road traffic congestion monitoring

KAUST Repository

Abdelhafid, Zeroual

2017-12-14

In this paper, we propose an effective approach which has to detect traffic congestion. The detection strategy is based on the combinational use of piecewise switched linear traffic (PWSL) model with exponentially-weighted moving average (EWMA) chart. PWSL model describes traffic flow dynamics. Then, PWSL residuals are used as the input of EWMA chart to detect traffic congestions. The evaluation results of the developed approach using data from a portion of the I210-W highway in Califorina showed the efficiency of the PWSL-EWMA approach in in detecting traffic congestions.

An efficient statistical-based approach for road traffic congestion monitoring

KAUST Repository

Abdelhafid, Zeroual; Harrou, Fouzi; Sun, Ying

2017-01-01

In this paper, we propose an effective approach which has to detect traffic congestion. The detection strategy is based on the combinational use of piecewise switched linear traffic (PWSL) model with exponentially-weighted moving average (EWMA) chart. PWSL model describes traffic flow dynamics. Then, PWSL residuals are used as the input of EWMA chart to detect traffic congestions. The evaluation results of the developed approach using data from a portion of the I210-W highway in Califorina showed the efficiency of the PWSL-EWMA approach in in detecting traffic congestions.

Urban observatories opportunities for environmental monitoring: solid wastes.

Science.gov (United States)

Rojas-Caldelas, R I; Corona Zambrano, E A

2008-01-01

Towns concentrate around 50% of world-wide population and the trend is oriented to underscore an urban profile of population. In addition, towns have become important for their economic contribution to the Gross Internal Product. The negative side of towns is the environmental and social impacts as a result of productive and domestic activities, besides the lack of available data. In order to overcome these shortcomings, the United Nations has established a project of urban monitoring throughout the Global Network of Urban Observatories; Mexico joined the project in 2005. The Local Urban Observatory of Mexicali has the task to produce information about cities that is useful to design public policies. Some of this information deals with a set of environmental indicators in the United Nations Habitat Agenda, which includes solid wastes. Therefore, this paper deals with two main topics; firstly, from the Habitat Agenda, a comparative urban analysis of waste production and coverage of domestic waste collection services; secondly, from the Local Agenda, the identification and ranking of environmental problems according to public perception coming from people involved in the municipal planning and decision making process. Results will be used to develop local indicators and public environmental policies.

Potential effects of using biodiesel in road-traffic on air quality over the Porto urban area, Portugal

Science.gov (United States)

Ribeiro, Isabel; Monteiro, Alexandra; Lopes, Myriam

2016-01-01

This work aims to assess the impacts of biodiesel blends use in road-traffic on air quality. In this frame, the air quality numerical modelling system WRF-EURAD was applied over Portugal and the Porto urban area, forced by two emission scenarios (including CO, NOx, PM10, PM2.5, NMVOC, formaldehyde, acetaldehyde, acrolein and benzene): a reference scenario, without biofuels, and a scenario where a B20 fuel (20% biodiesel/80% diesel, v/v) is used by the diesel vehicle fleet. Regarding carbonyl compounds, emission scenarios pointed out that B20 fuel can promote an increase of 20% on formaldehyde, acetaldehyde and acrolein emissions, leading to increments on equivalent ozone production. On the other hand, through the air quality modelling exercise, it was verified that the use of B20 helps in controlling air pollution, improving CO and NO2 concentrations in urban airshed in about 20% and 10%, respectively, taking into account a regional simulation grid. However, according to the urban scale simulation, NO2 levels can increase in about 1%, due to the use of B20, over the Porto urban area. For the remaining studied pollutants, namely PM10 and PM2.5, mean concentrations will be reduced all over the territory, however in a negligible amount of <1%.

Determinant of Road Traffic Crash Fatalities in Iran: A Longitudinal Econometric Analysis.

Science.gov (United States)

Rezaei, Satar; Bagheri Lankarani, Kamran; Karami Matin, Behzad; Bazyar, Mohammad; Hamzeh, Behrooz; Najafi, Farid

2015-01-01

Injuries and deaths from road traffic crashes are one of the main public health problems throughout the world. This study aimed to identify determinants of fatality traffic accident in Iran for the twenty-span year from 1991 to 2011. A time series analysis (1991-2011) was used to examine the effects of some of the key explanatory factors (GDP per capita, number of doctors per 10,000 populations, degree of urbanization, unemployment rate and motorization rate) on deaths from road traffic in Iran. In order to examine long- and short-run effects of variables, we employed autoregressive distributed lag (ARDL) approach and error correction method (ECM). The data for the study was obtained from the Central Bank of Iran (CBI), Iranian Statistical Center (ISC) and Legal medical organizations (LMO). GDP per capita, doctor per 10,000 populations, degree of urbanization and motorization rate had a significant impact on fatality from road traffic in Iran. We did not observe any short- and long-term effects of the unemployment rate on fatality from road traffic. GDP per capita, doctor per 10,000 populations, degree of urbanization and motorization rate were identified as main determinant of fatality from road traffic accidents in Iran. We hope the results of the current study enable health policy-makers to understand better the factors affecting deaths from road traffic accidents in the country.

Comparison of land use regression models for NO2 based on routine and campaign monitoring data from an urban area of Japan.

Science.gov (United States)

Kashima, Saori; Yorifuji, Takashi; Sawada, Norie; Nakaya, Tomoki; Eboshida, Akira

2018-08-01

Typically, land use regression (LUR) models have been developed using campaign monitoring data rather than routine monitoring data. However, the latter have advantages such as low cost and long-term coverage. Based on the idea that LUR models representing regional differences in air pollution and regional road structures are optimal, the objective of this study was to evaluate the validity of LUR models for nitrogen dioxide (NO 2 ) based on routine and campaign monitoring data obtained from an urban area. We selected the city of Suita in Osaka (Japan). We built a model based on routine monitoring data obtained from all sites (routine-LUR-All), and a model based on campaign monitoring data (campaign-LUR) within the city. Models based on routine monitoring data obtained from background sites (routine-LUR-BS) and based on data obtained from roadside sites (routine-LUR-RS) were also built. The routine LUR models were based on monitoring networks across two prefectures (i.e., Osaka and Hyogo prefectures). We calculated the predictability of the each model. We then compared the predicted NO 2 concentrations from each model with measured annual average NO 2 concentrations from evaluation sites. The routine-LUR-All and routine-LUR-BS models both predicted NO 2 concentrations well: adjusted R 2 =0.68 and 0.76, respectively, and root mean square error=3.4 and 2.1ppb, respectively. The predictions from the routine-LUR-All model were highly correlated with the measured NO 2 concentrations at evaluation sites. Although the predicted NO 2 concentrations from each model were correlated, the LUR models based on routine networks, and particularly those based on all monitoring sites, provided better visual representations of the local road conditions in the city. The present study demonstrated that LUR models based on routine data could estimate local traffic-related air pollution in an urban area. The importance and usefulness of data from routine monitoring networks should be

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

OpenAIRE

Wei Wu; Yang Liu; Yue Xu; Quanlun Wei; Yi Zhang

2017-01-01

Autonomous vehicle is able to facilitate road safety and traffic efficiency and has become a promising trend of future development. With a focus on highways, existing literatures studied the feasibility of autonomous vehicle in continuous traffic flows and the controllability of cooperative driving. However, rare efforts have been made to investigate the traffic control strategies in autonomous vehicle environment on urban roads, especially in urban intersections. In autonomous vehicle enviro...

Control of Networked Traffic Flow Distribution - A Stochastic Distribution System Perspective

Energy Technology Data Exchange (ETDEWEB)

Wang, Hong [Pacific Northwest National Laboratory (PNNL); Aziz, H M Abdul [ORNL; Young, Stan [National Renewable Energy Laboratory (NREL); Patil, Sagar [Pacific Northwest National Laboratory (PNNL)

2017-10-01

Networked traffic flow is a common scenario for urban transportation, where the distribution of vehicle queues either at controlled intersections or highway segments reflect the smoothness of the traffic flow in the network. At signalized intersections, the traffic queues are controlled by traffic signal control settings and effective traffic lights control would realize both smooth traffic flow and minimize fuel consumption. Funded by the Energy Efficient Mobility Systems (EEMS) program of the Vehicle Technologies Office of the US Department of Energy, we performed a preliminary investigation on the modelling and control framework in context of urban network of signalized intersections. In specific, we developed a recursive input-output traffic queueing models. The queue formation can be modeled as a stochastic process where the number of vehicles entering each intersection is a random number. Further, we proposed a preliminary B-Spline stochastic model for a one-way single-lane corridor traffic system based on theory of stochastic distribution control.. It has been shown that the developed stochastic model would provide the optimal probability density function (PDF) of the traffic queueing length as a dynamic function of the traffic signal setting parameters. Based upon such a stochastic distribution model, we have proposed a preliminary closed loop framework on stochastic distribution control for the traffic queueing system to make the traffic queueing length PDF follow a target PDF that potentially realizes the smooth traffic flow distribution in a concerned corridor.

Competitive Traffic Assignment in Road Networks

Directory of Open Access Journals (Sweden)

Krylatov Alexander Y.

2016-09-01

Full Text Available Recently in-vehicle route guidance and information systems are rapidly developing. Such systems are expected to reduce congestion in an urban traffic area. This social benefit is believed to be reached by imposing the route choices on the network users that lead to the system optimum traffic assignment. However, guidance service could be offered by different competitive business companies. Then route choices of different mutually independent groups of users may reject traffic assignment from the system optimum state. In this paper, a game theoretic approach is shown to be very efficient to formalize competitive traffic assignment problem with various groups of users in the form of non-cooperative network game with the Nash equilibrium search. The relationships between the Wardrop’s system optimum associated with the traffic assignment problem and the Nash equilibrium associated with the competitive traffic assignment problem are investigated. Moreover, some related aspects of the Nash equilibrium and the Wardrop’s user equilibrium assignments are also discussed.

An Integrated GPS/PDA/GIS Telegeoprocessing System for Traffic and Environment

Directory of Open Access Journals (Sweden)

Ana Luísa Ramos

2009-12-01

Full Text Available The development of sustainable urban transport networks is a present priority for world leaders, national governors and local authorities. The challenge is to increase mobility reducing the adverse impacts of transport. The potential of Intelligent Transportation Systems (ITS to provide solutions for the 21 st century sustainable urban transport system has already been demonstrated in several piecewise applications. An integrated framework that addresses the needs of municipal authorities, that integrates the data spread through different sources, that supports the intelligent traffic and environment operations, and that provides information to the citizens steering their involvement and commitment is of critical importance and can be the enabler towards the creation of more efficient, safety, and environmental-friendly transport networks that promote the citizens' quality of life. This work describes an integrated GPS (Global Positioning System / PDA (Personal Digital Assistant / GIS (Geographical Information System system which is part of the mentioned framework. The system includes prototypes for mobile urban traffic data acquisition, with a GPS -equipped vehicle, a PDA application and wireless communications, and for a geodatabase with a related Web application for urban traffic and environment. Their integrated operation is exemplified for a real urban transport system.

Police Enforcement Policy and Programmes on European Roads (PEPPER). Workpackage WP4 `Good Practices in Traffic Enforcement', Working paper 24: Good practice in data and data collection for monitoring and evaluating traffic law enforcement.

NARCIS (Netherlands)

Schagen, I.N.L.G. van Bernhoft, I.M. Erke, A. Ewert, U. Kallberg, V.-P. & Skladana, P.

2007-01-01

This working paper describes the good practice requirements regarding data and data collection for monitoring and evaluating Traffic Law Enforcement (TLE). The aim is at, eventually, individual police forces/countries put the identified ’good practice’ data into a European TLE monitoring database

Time resolved aerosol monitoring in the urban centre of Soweto

Science.gov (United States)

Formenti, P.; Annegarn, H. J.; Piketh, S. J.

1998-03-01

A programme of aerosol sampling was conducted from 1982 to 1984 in the urban area of Soweto, Johannesburg, South Africa. The particulate matter (aerodynamic diameter source apportionment of crustal elements between coal smoke and traffic induced road dust, based on chemical elemental measurements. A novel technique is demonstrated for processing PIXE-derived time sequence elemental concentration vectors. Slowly varying background components have been extracted from sulphur and crustal aerosol components, using alternatively two digital filters: a moving minimum, and a moving average. The residuals of the crustal elements, assigned to locally generated aerosol components, were modelled using surrogate tracers: sulphur as a surrogate for coal smoke; and Pb as a surrogate for traffic activity. Results from this source apportionment revealed coal emissions contributed between 40% and 50% of the aerosol mineral matter, while 18-22% originated from road dust. Background aerosol, characteristic of the regional winter aerosol burden over the South African Highveld, was between 12% and 21%. Minor contributors identified included a manganese smelter, located 30 km from the sampling site, and informal trash burning, as the source of intermittent heavy metals (Cu, Zn). Elemental source profiles derived for these various sources are presented.

Data management for urban tree monitoring -- software requirements

Science.gov (United States)

Deborah J. ​Boyer; Lara A. Roman; Jason G. Henning; Matthew McFarland; Dana Dentice; Sarah C. Low; Casey Thomas; Glen. Abrams

2016-01-01

The creation of this report was organized by the Pennsylvania Horticultural Society (PHS) and the USDA Forest Service Philadelphia Field Station to explore how technology could be used to support the longterm systematic monitoring of urban trees by trained professionals, student interns and volunteers; assist with tree planting and maintenance data processes; and...

Development of Seasonal ARIMA Models for Traffic Noise Forecasting

Directory of Open Access Journals (Sweden)

Guarnaccia Claudio

2017-01-01

Full Text Available In this paper, a time series analysis approach is adopted to monitor and predict a traffic noise levels dataset, measured in a site of Messina, Italy. In general, acoustical noise shows a high prediction complexity, since its slope is strongly related to the variability of the sources and to intrinsic randomness. In the analysed site the predominant source is road traffic, that has a periodic and non-stationary behaviour. The study of the time evolution of this hazardous agent is very useful to assess the impact to human health and activities. The time series models adopted in this paper are of the stochastic seasonal ARIMA class; these types of model are based on the strong periodicity registered in the acoustical equivalent levels. The observed periodicity is related to the highly variability of urban traffic in the different days of the week. Three different seasonal ARIMA models are proposed and calibrated on a rich dataset of 800 sound level measurements. The predictive capabilities of these techniques are encouraging. The implemented models show a good forecasting performances in terms of low residuals, i.e. difference between observed and estimated noise values. The residuals are analysed by means of statistical indexes, plots and tests.

A Survey of Soil Enzyme Activities along Major Roads in Beijing: The Implications for Traffic Corridor Green Space Management

Directory of Open Access Journals (Sweden)

Tianxin Li

2015-10-01

Full Text Available Soil quality is critical to the management of urban green space, in particular, along traffic corridors where traffic-related air pollution is significant. Soil quality can be evaluated by soil enzyme activities, which show quick responses to both natural and anthropogenic disturbances. In this study, we investigated three soil enzyme activities (i.e., dehydrogenase, catalase and urease along the major roads in urban areas of Beijing. Results show the activities of dehydrogenase, catalase and urease in urban samples were 58.8%, 68.2% and 48.5% less than the rural sample, respectively. The content of fluorescent amino acids as indicators of microbial activities was also consistently lower in urban samples than the rural. We observed two times greater exposure of particulate material along the roadsides in urban areas than rural areas. Although traffic air pollutants provide some nutrient sources to stimulate the URE activity, the exposure to traffic-related air pollution leads to the substantial decrease in enzyme activities. There were significant negative correlations for exposure to PM10 with DHA (r = −0.8267, p = 0.0017 and CAT (r = −0.89, p = 0.0002 activities. For the urban soils URE activity increased with the increasing of PM. We conclude that the degraded soil quality can negatively affect the target of developing plants and green spaces along the traffic corridors to mitigate the traffic impact. This study suggests the investigation of integrated strategies to restore the soil quality, reinforce the ecological service functions of green spaces along the traffic corridors and reduce the traffic pollutants.

Impact Analysis of Land Use on Traffic Congestion Using Real-Time Traffic and POI

Directory of Open Access Journals (Sweden)

Tianqi Zhang

2017-01-01

Full Text Available This paper proposed a new method to describe, compare, and classify the traffic congestion points in Beijing, China, by using the online map data and further revealed the relationship between traffic congestion and land use. The data of the point of interest (POI and the real-time traffic was extracted from an electronic map of the area in the fourth ring road of Beijing. The POIs were quantified based on the architectural area of the land use; the congestion points were identified based on real-time traffic. Then, the cluster analysis using the attributes of congestion time was conducted to identify the main traffic congestion areas. The result of a linear regression analysis between the congestion time and the land use showed that the influence of the high proportion of commercial land use on the traffic congestion was significant. Also, we considered five types of land use through performing a linear regression analysis between the congestion time and the ratio of four types of land use. The results showed that the reasonable ratio of land use types could efficiently reduce congestion time. This study makes contributions to the policy-making of urban land use.

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.

An Assessment of the Relationship between Urban Air Quality and Environmental Urban Factors in Urban Regeneration Areas

Directory of Open Access Journals (Sweden)

Yakup Egercioglu

2016-06-01

Full Text Available Urban air pollution has been increasing due to ever increasing population, rapid urbanization, industrialization, energy usage, traffic density. The purpose of the study is to examine the relation between urban air quality and urban environmental factors in urban regeneration areas. Two common air polluters (SO2 and PM10 are considered in the study. The data are collected for Cigli district, including the level of air pollutants, the local natural gas service lines and planning decisions for the years between 2007 and 2011. According to the examinations, urban environmental factors and planning decisions affect the urban air quality in urban regeneration areas.

Monitoring of urban heat island over Shenzhen, China using remotely sensed measurements

Science.gov (United States)

Wang, Weimin; Hong, Liang; Yang, Lijun; He, Lihuan; Dong, Guihua

2016-05-01

In the past three decades, the Shenzhen city, which is located in south of China, has experienced a rapid urbanization process characterized by sharp decrease in farmland and increases in urban area. This rapid urbanization is one of the main causes of many environmental and ecological problems including urban heat island (UHI). Therefore, the monitoring of rapid urbanization regions and the environment is of critical importance for their sustainable development. In this study, Landsat-8 OLI and TIR images, which were acquired on 2013, are used to monitor urban heat island. After radiometric calibration and atmospheric correction with a simplified method for the atmospheric correction (SMAC) are applied to OLI image, an index-based build-up index (IBI), which is based on the soil adjusted vegetation index (SAVI), the modified normalized difference water index (MNDWI) and the normalized difference built-up index (NDBI), is employed to extract the build-up land features with a given thresholds. A single-channel algorithm is used to retrieve land surface temperature while the land surface emissivity is derived from a normalized differential vegetation index (NDVI) thresholds method. Surface urban heat island index (SUHII) and urban heat island ratio index (URI) are computed for ten districts of Shenzhen based on build-up land distribution and land surface temperature data. A correlation analysis is conducted between heat island index (including SUHII and URI) and socio-economic statistics (including total population and population density) also are included in this analysis. The results show that, a weak relationship between urban heat island and socio-economic statistics are found.

Monitoring urban growth

DEFF Research Database (Denmark)

Møller-Jensen, Lasse; Kofie, Richard; Yankson, Paul

2007-01-01

The extent of the urbanized areas of Accra is assessed from Landsat-TM satellite images for the year 2002 and compared to similar information for the years 1985 and 1991. A texture-based classification method is applied. The results show that the urbanization of the fringe areas of Accra is occur......The extent of the urbanized areas of Accra is assessed from Landsat-TM satellite images for the year 2002 and compared to similar information for the years 1985 and 1991. A texture-based classification method is applied. The results show that the urbanization of the fringe areas of Accra...

The effects of redundancy and information manipulation on traffic networks

OpenAIRE

Özel, Berk; Ozel, Berk

2014-01-01

Traffic congestion is one of the most frequently encountered problems in real life. It is not only a scientific concern of scholars, but also an inevitable issue for most of the individuals living in urban areas. Since every driver in traffic networks tries to minimize own journey length, and volume of the traffic prevents coordination between individuals, a cooperative behavior will not be provided spontaneously in order to decrease the total cost of the network and the time spent on traffic...

Modelling urban travel times

NARCIS (Netherlands)

Zheng, F.

2011-01-01

Urban travel times are intrinsically uncertain due to a lot of stochastic characteristics of traffic, especially at signalized intersections. A single travel time does not have much meaning and is not informative to drivers or traffic managers. The range of travel times is large such that certain

Ultrastructural alterations in the mouse lung caused by real-life ambient PM10 at urban traffic sites

International Nuclear Information System (INIS)

Samara, Constantini; Kouras, Athanasios; Kaidoglou, Katerina; Emmanouil-Nikoloussi, Elpida-Niki; Simou, Chrysanthi; Bousnaki, Maria; Kelessis, Apostolos

2015-01-01

Current levels of ambient air particulate matter (PM) are associated with mortality and morbidity in urban populations worldwide. Nevertheless, current knowledge does not allow precise quantification or definitive ranking of the health effects of individual PM components and indeed, associations may be the result of multiple components acting on different physiological mechanisms. In this paper, healthy Balb/c mice were exposed to ambient PM 10 at a traffic site of a large city (Thessaloniki, northern Greece), in parallel to control mice that were exposed to filtered air. Structural damages were examined in ultrafine sections of lung tissues by Transmission Electronic Microscopy (TEM). Ambient PM 10 samples were also collected during the exposure experiment and characterized with respect to chemical composition and oxidative potential. Severe ultrastructural alterations in the lung tissue after a 10-week exposure of mice at PM 10 levels often exceeding the daily limit of Directive 2008/50/EC were revealed mainly implying PM-induced oxidative stress. The DTT-based redox activity of PM 10 was found within the range of values reported for traffic sites being correlated with traffic-related constituents. Although linkage of the observed lung damage with specific chemical components or sources need further elucidation, the magnitude of biological responses highlight the necessity for national and local strategies for mitigation of particle emissions from combustion sources. - Highlights: • Animal exposure to PM10 was conducted at a traffic site of a large city. • Chemical and toxicological characterization of PM10 was carried out. • Severe degenerative alterations in alveolar cells were revealed. • PM induced oxidative stress from carbonaceous species was suggested

Persistent Monitoring of Urban Infrasound Phenomenology. Report 1: Modeling an Urban Environment for Acoustical Analyses using the 3-D Finite-Difference Time-Domain Program PSTOP3D

Science.gov (United States)

2015-08-01

ER D C TR -1 5- 5 Remote Assessment of Critical Infrastructure Persistent Monitoring of Urban Infrasound Phenomenology Report 1...ERDC TR-15-5 August 2015 Persistent Monitoring of Urban Infrasound Phenomenology Report 1: Modeling an Urban Environment for Acoustical Analyses...Figure 5.1. Main spreadsheet containing problem setup. ..................................................................... 74 Figure 5.2. Definition

Urban Seismology: on the origin of earth vibrations within a city

OpenAIRE

Díaz, Jordi; Ruiz, Mario; Sánchez-Pastor, Pilar S.; Romero, Paula

2017-01-01

Urban seismology has become an active research field in the recent years, both with seismological objectives, as obtaining better microzonation maps in highly populated areas, and with engineering objectives, as the monitoring of traffic or the surveying of historical buildings. We analyze here the seismic records obtained by a broad-band seismic station installed in the ICTJA-CSIC institute, located near the center of Barcelona city. Although this station was installed to introdu...

Impacts of Traffic Noise and Traffic Volume on Birds of Roadside Habitats

Directory of Open Access Journals (Sweden)

Kirsten M. Parris

2009-06-01

Full Text Available Roadside habitats are important for a range of taxa including plants, insects, mammals, and birds, particularly in developed countries in which large expanses of native vegetation have been cleared for agriculture or urban development. Although roadside vegetation may provide suitable habitat for many species, resident animals can be exposed to high levels of traffic noise, visual disturbance from passing vehicles, and the risk of collision with cars and trucks. Traffic noise can reduce the distance over which acoustic signals such as song can be detected, an effect known as acoustic interference or masking. Studies from the northern hemisphere show that the singing behavior of birds changes in the presence of traffic noise. We investigated the impact of traffic noise and traffic volume on two species of birds, the Grey Shrike-thrush (Colluricincla harmonica and the Grey Fantail (Rhipidura fuliginosa, at 58 roadside sites on the Mornington Peninsula, southeastern Australia. The lower singing Grey Shrike-thrush sang at a higher frequency in the presence of traffic noise, with a predicted increase in dominant frequency of 5.8 Hz/dB of traffic noise, and a total effect size of 209 Hz. In contrast, the higher singing Grey Fantail did not appear to change its song in traffic noise. The probability of detecting each species on a visit to a site declined substantially with increasing traffic noise and traffic volume, with several lines of evidence supporting a larger effect of traffic noise. Traffic noise could hamper detection of song by conspecifics, making it more difficult for birds to establish and maintain territories, attract mates and maintain pair bonds, and possibly leading to reduced breeding success in noisy roadside habitats. Closing key roads during the breeding season is a potential, but untested, management strategy to protect threatened bird species from traffic noise and collision with vehicles at the time of year when they are most

Long-term exposure to road traffic noise and incident diabetes

DEFF Research Database (Denmark)

Sørensen, Mette; Andersen, Zorana Jovanovic; Nordsborg, Rikke B

2013-01-01

Road traffic noise at normal urban levels can lead to stress and sleep disturbances. Both excess of stress hormones and reduction in sleep quality and duration may lead to higher risk for type 2 diabetes.Objective: We investigated whether long-term exposure to residential road traffic noise...

The trend of road traffic crashes at urban signalised intersection

Science.gov (United States)

Farhana Nasarrudin, Nurul; Razelan, Intan Suhana Mohd

2018-04-01

Road traffic crash is one of the main contributing factors for deaths in the world. Intersection is listed as the second road type which road crashes occurred frequently. Hence, the traffic light was installed to minimise the road crashes at intersection. However, the crashes are still occurring and arising. The objective of this study was to exhibit the trend of road crashes at the signalised intersections. The data of road crashes for the past 6 years were analysed using descriptive analysis. The results showed that the road traffic crashes at three- and four-legged signalised intersection recorded the increasing trend. In conclusion, this finding shows that the road traffic crashes for these types of signalised intersection in Malaysia is rising. It is also one the contributors to the increasing number of crashes in Malaysia. This finding will encourage the local authority to conduct awareness programs on the safety at the signalised intersection.

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

Directory of Open Access Journals (Sweden)

Rodolfo I Meneguette

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

The impact of the Thai motorcycle transition on road traffic injury: Thai Cohort Study results.

Science.gov (United States)

Berecki-Gisolf, Janneke; Yiengprugsawan, Vasoontara; Kelly, Matthew; McClure, Roderick; Seubsman, Sam-ang; Sleigh, Adrian

2015-01-01

The aim of this study was to investigate the impact of motorcycle to car transitioning and urbanisation on traffic injury rates in Thailand. Analysis of two consecutive surveys of a large national cohort study. Thailand. The data derived from 57,154 Thai Cohort Study (TCS) participants who provided relevant data on both the 2005 and 2009 surveys. Motorcycle and car traffic crash injury self-reported in 2009, with twelve months' recall. In 2009, 5608(10%) participants reported a traffic crash injury. Most crashes involved a motorcycle (74%). Car access increased and motorcycle use decreased between 2005 and 2009. Among those who used a motorcycle at both time points, traffic injury incidence was 2.8 times greater compared to those who did not use a motorcycle at either time point. Multivariable logistic regression models were used to test longitudinal and cross sectional factors associated with traffic crash injury: in the adjusted model, cars were negatively and motorcycles positively associated with injury. Living in an urban area was not injury protective in the adjusted model of traffic crash injury. Ongoing urbanisation in Thailand can be expected to lead to further reductions in road traffic injuries based on transition from motorcycles to cars in urban areas. Cities, however, do not provide an intrinsically safer traffic environment. To accommodate a safe transition to car use in Thailand, traffic infrastructural changes anticipating the growing car density in urban areas is warranted.

Google Earth Visualizations of the Marine Automatic Identification System (AIS): Monitoring Ship Traffic in National Marine Sanctuaries

Science.gov (United States)

Schwehr, K.; Hatch, L.; Thompson, M.; Wiley, D.

2007-12-01

The Automatic Identification System (AIS) is a new technology that provides ship position reports with location, time, and identity information without human intervention from ships carrying the transponders to any receiver listening to the broadcasts. In collaboration with the USCG's Research and Development Center, NOAA's Stellwagen Bank National Marine Sanctuary (SBNMS) has installed 3 AIS receivers around Massachusetts Bay to monitor ship traffic transiting the sanctuary and surrounding waters. The SBNMS and the USCG also worked together propose the shifting the shipping lanes (termed the traffic separation scheme; TSS) that transit the sanctuary slightly to the north to reduce the probability of ship strikes of whales that frequent the sanctuary. Following approval by the United Nation's International Maritime Organization, AIS provided a means for NOAA to assess changes in the distribution of shipping traffic caused by formal change in the TSS effective July 1, 2007. However, there was no easy way to visualize this type of time series data. We have created a software package called noaadata-py to process the AIS ship reports and produce KML files for viewing in Google Earth. Ship tracks can be shown changing over time to allow the viewer to feel the motion of traffic through the sanctuary. The ship tracks can also be gridded to create ship traffic density reports for specified periods of time. The density is displayed as map draped on the sea surface or as vertical histogram columns. Additional visualizations such as bathymetry images, S57 nautical charts, and USCG Marine Information for Safety and Law Enforcement (MISLE) can be combined with the ship traffic visualizations to give a more complete picture of the maritime environment. AIS traffic analyses have the potential to give managers throughout NOAA's National Marine Sanctuaries an improved ability to assess the impacts of ship traffic on the marine resources they seek to protect. Viewing ship traffic

Methodology for setup and data processing of mobile air quality measurements to assess the spatial variability of concentrations in urban environments

International Nuclear Information System (INIS)

Van Poppel, Martine; Peters, Jan; Bleux, Nico

2013-01-01

A case study is presented to illustrate a methodology for mobile monitoring in urban environments. A dataset of UFP, PM 2.5 and BC concentrations was collected. We showed that repeated mobile measurements could give insight in spatial variability of pollutants at different micro-environments in a city. Streets of contrasting traffic intensity showed increased concentrations by a factor 2–3 for UFP and BC and by 2.5 . The first quartile (P25) of the mobile measurements at an urban background zone seems to be good estimate of the urban background concentration. The local component of the pollutant concentrations was determined by background correction. The use of background correction reduced the number of runs needed to obtain representative results. The results presented, are a first attempt to establish a methodology for setup and data processing of mobile air quality measurements to assess the spatial variability of concentrations in urban environments. -- Highlights: ► Mobile measurements are used to assess the variability of air pollutants in urban environments. ► PM 2.5 , BC and UFP concentrations are presented for zones with different traffic characteristics. ► A methodology for background correction based on the mobile measurements is presented. ► The background concentration is estimated as the 25th percentile of the urban background data. ► The minimum numbers of runs for a representative estimate is reduced after background correction. -- This paper shows that the spatial variability of air pollutants in an urban environment can be assessed by a mobile monitoring methodology including background correction

Traffic flow behavior at a single-lane urban roundabout

Science.gov (United States)

Lakouari, N.; Oubram, O.; Ez-Zahraouy, H.; Cisneros-Villalobos, L.; Velásquez-Aguilar, J. G.

In this paper, we propose a stochastic cellular automata model to study the traffic behavior at a single-lane roundabout. Vehicles can enter the interior lane or exit from it via N intersecting lane, the boundary conditions are stochastic. The traffic is controlled by a self-organized scheme. It has turned out that depending on the rules of insertion to the roundabout, five distinct traffic phases can appear, namely, free flow, congestion, maximum current, jammed and gridlock. The transition between the free flow and the gridlock is forbidden. The density profiles are used to study the traffic pattern at the interior lane of the roundabout. In order to quantify the interactions between vehicles in the interior lane of the roundabout, the velocity correlation coefficient (VCC) is also studied. Besides, the spatiotemporal diagrams corresponding to the entry/exit lanes are derived numerically. Furthermore, we have investigated the effect of displaying signal (PIn), as the PIn decreases, the maximum current increases at the expense of the free flow and the jamming phase. Finally, we have investigated the effect of the braking probability P on the interior lane of the roundabout. We have found that the increase of P raises the spontaneous jam formation on the ring. Thus, enlarges the maximum current and the jamming phase while the free flow phase decreases.

Citizen Sensing for Improved Urban Environmental Monitoring

Directory of Open Access Journals (Sweden)

Qijun Jiang

2016-01-01

Full Text Available Citizen science is increasingly being used in diverse research domains. With the emergence and rapid development of sensor technologies, citizens potentially have more powerful tools to collect data and generate information to understand their living environment. Although sensor technologies are developing fast, citizen sensing has not been widely implemented yet and published studies are only a few. In this paper, we analyse the practical experiences from an implementation of citizen sensing for urban environment monitoring. A bottom-up model in which citizens develop and use sensors for environmental monitoring is described and assessed. The paper focuses on a case study of Amsterdam Smart Citizens Lab using NO2 sensors for air quality monitoring. We found that the bottom-up citizen sensing is still challenging but can be successful with open cooperation and effective use of online and offline facilities. Based on the assessment, suggestions are proposed for further implementations and research.

Effect of Traffic Noise and Relaxations Sounds on Pedestrian Walking Speed

Directory of Open Access Journals (Sweden)

Marek Franěk

2018-04-01

Full Text Available Exposure to noise in everyday urban life is considered to be an environmental stressor. A specific outcome of reactions to environmental stress is a fast pace of life that also includes a faster pedestrian walking speed. The present study examined the effect of listening to annoying acoustical stimuli (traffic noise compared with relaxation sounds (forest birdsong on walking speed in a real outdoor urban environment. The participants (N = 83 walked along an urban route of 1.8 km. They listened to either traffic noise or forest birdsong, or they walked without listening to any acoustical stimuli in the control condition. The results showed that participants listening to traffic noise walked significantly faster on the route than both the participants listening to forest birdsong sounds and the participants in the control condition. Participants who listened to forest birdsong walked slightly slower than those under control conditions; however, this difference was not significant. Analysis of the walk experience showed that participants who listened to forest birdsong during the walk liked the route more than those who listened to traffic sounds. The study demonstrated that exposure to traffic noise led to an immediate increase in walking speed. It was also shown that exposure to noise may influence participants’ perception of an environment. The same environment may be more liked in the absence of noise or in the presence of relaxation sounds. The study also documented the positive effect of listening to various kinds of relaxation sounds while walking in an outdoor environment with traffic noise.

Polycyclic aromatic hydrocarbons levels evaluation in urban area after October 23rd 1998 promulgation

International Nuclear Information System (INIS)

Galimberti, E.; Baroni, R.; Villa, V.; Sesana, G.

1999-01-01

This paper reports the result concerning the air quality evaluation in an urban centre in the hinterland of Milan., with an high population density and an intense road traffic, relatively to polycyclic aromatic hydrocarbons (PAH) concentration levels. The data, referred to the annual season, indicate that, near high traffic road, the above compounds are always present in the concentration level analytically detectable and that the concentration of benzo(a)pyrene is 2.7 ng/m 3 . The reported study is an useful instruments both for a road town planning, in order to people disease prevention, and for monitoring the evolution of PAH concentration levels in the future [it

Decentralized Traffic Management: A Synchronization-Based Intersection Control --- Extended Version

OpenAIRE

Tlig , Mohamed; Buffet , Olivier; Simonin , Olivier

2014-01-01

Controlling the vehicle traffic in large networks remains an important challenge in urban environments and transportation systems. Autonomous vehicles are today considered as a promising approach to deal with traffic control. In this paper, we propose a synchronization-based intersection control mechanism to allow the autonomous vehicle-agents to cross without stopping, i.e., in order to avoid congestions (delays) and energy loss. We decentralize the problem by managing the traffic of each in...

Passive monitoring using traffic noise recordings - case study on the Steinachtal Bridge

Science.gov (United States)

Salvermoser, Johannes; Stähler, Simon; Hadziioannou, Céline

2015-04-01

Civil structures age continuously. The early recognition of potentially critical damages is an important economical issue, but also one of public safety. Continuous tracking of small changes in the medium by using passive methods would offer an extension to established active non-destructive testing procedures at relatively low cost. Here we present a case study of structural monitoring using continuous recordings of traffic noise on a 200 meter long reinforced concrete highway bridge in Germany. Over two months of continuos geophone records are used in the frequency range of 2-8 Hz. Using passive image interferometry, evaluation of hourly cross-correlations between recordings at pairs of receivers yield velocity variations in the range of -1.5% to +2.1%. We were able to correlate our outcomes with temperature measurements of the same two month period. The measured velocity changes scale with the temperature variations with on average a dv/v of 0.064% per degree Celsius. This value is in accordance with other studies of concrete response to temperature, confirming that we are able to observe subtle changes with physical origin. It is shown that traffic noise is temporally homogenenous enough to fulfill the requirements of passive image interferometry.

Review of methods and indicators in sustainable urban transport studies overview from 2000 to 2016

Directory of Open Access Journals (Sweden)

Puji Adiatna Nadi

2017-12-01

Full Text Available The attention of countries either the developed or developing countries on sustainable urban transport is becoming more popular. The purpose of paper is to review the methods and the indicators used for measuring performance of sustainable urban transport. This study is based on the literature review and the case study observation and also uses the quantitative assessment. It reviews the theoretical aspects of sustainability factors at various research works and performance indicator in urban transportation. The indicators were classified into two major categories: (i assessment methods in sustainable urban transport (SUT, and (ii basic of sustainability indicators for urban transport. This study found several types of analytical techniques for measuring sustainability indicators in urban transport. It also identify five indicators as basic element to measure sustainable urban transport performance i.e. traffic congestion, traffic air pollution, traffic noise pollution, traffic accidents and land consumption for transport infrastructure.

Modeling the Short-Term Effect of Traffic and Meteorology on Air Pollution in Turin with Generalized Additive Models

Directory of Open Access Journals (Sweden)

Pancrazio Bertaccini

2012-01-01

Full Text Available Vehicular traffic plays an important role in atmospheric pollution and can be used as one of the key predictors in air-quality forecasting models. The models that can account for the role of traffic are especially valuable in urban areas, where high pollutant concentrations are often observed during particular times of day (rush hour and year (winter. In this paper, we develop a generalized additive models approach to analyze the behavior of concentrations of nitrogen dioxide (NO2, and particulate matter (PM10, collected at the environmental monitoring stations distributed throughout the city of Turin, Italy, from December 2003 to April 2005. We describe nonlinear relationships between predictors and pollutants, that are adjusted for unobserved time-varying confounders. We examine several functional forms for the traffic variable and find that a simple form can often provide adequate modeling power. Our analysis shows that there is a saturation effect of traffic on NO2, while such saturation is less evident in models linking traffic to PM10 behavior, having adjusted for meteorological covariates. Moreover, we consider the proposed models separately by seasons and highlight similarities and differences in the predictors’ partial effects. Finally, we show how forecasting can help in evaluating traffic regulation policies.

Integrated monitoring and assessment of air pollution

Energy Technology Data Exchange (ETDEWEB)

Hertel, O.

2009-09-15

Improved quality, better understanding of processes and optimisation of allocated resources, these are the main advantages of applying Integrated Monitoring and Assessment (IMA) in air quality management. The IMA is defined as the combined use of measurements and model calculations. The use of IMA is demonstrated with examples with different aims: to obtain data for air pollution in urban streets, to assess human exposure to traffic air pollution, and to assess atmospheric deposition of nitrogen compounds to marine and terrestrial ecosystems. (author)

Variability of multifractal parameters in an urban precipitation monitoring network

Science.gov (United States)

Licznar, Paweł; De Michele, Carlo; Dżugaj, Dagmara; Niesobska, Maria

2014-05-01

Precipitation especially over urban areas is considered a highly non-linear process, with wide variability over a broad range of temporal and spatial scales. Despite obvious limitations of rainfall gauges location at urban sites, rainfall monitoring by gauge networks is a standard solution of urban hydrology. Often urban precipitation gauge networks are formed by modern electronic gauges and connected to control units of centralized urban drainage systems. Precipitation data, recorded online through these gauge networks, are used in so called Real-Time-Control (RTC) systems for the development of optimal strategies of urban drainage outflows management. As a matter of fact, the operation of RTC systems is motivated mainly by the urge of reducing the severity of urban floods and combined sewerage overflows, but at the same time, it creates new valuable precipitation data sources. The variability of precipitation process could be achieved by investigating multifractal behavior displayed by the temporal structure of precipitation data. There are multiply scientific communications concerning multifractal properties of point-rainfall data from different worldwide locations. However, very little is known about the close variability of multifractal parameters among closely located gauges, at the distances of single kilometers. Having this in mind, here we assess the variability of multifractal parameters among gauges of the urban precipitation monitoring network in Warsaw, Poland. We base our analysis on the set of 1-minute rainfall time series recorded in the period 2008-2011 by 25 electronic weighing type gauges deployed around the city by the Municipal Water Supply and Sewerage Company in Warsaw as a part of local RTC system. The presence of scale invariance and multifractal properties in the precipitation process was investigated with spectral analysis, functional box counting method and studying the probability distributions and statistical moments of the rainfall

Pedestrian Urban Safety System and Comfort at Traffic Signals PUSSYCATS : new pedestrian facilities : technique, observations and opinions, a drive-project in France, the UK and The Netherlands.

NARCIS (Netherlands)

Levelt, P.B.M.

1994-01-01

PUSSYCATS (Pedestrian Urban Safety System and Comfort at Traffic Signals) is a new system incorporating technical improvements better adapted to pedestrians needs and behaviour. A Kerb-side detector mat replaces the push buttons, with infrared sensors detecting the presence of pedestrians on the

Understanding how roadside concentrations of NOx are influenced by the background levels, traffic density, and meteorological conditions using Boosted Regression Trees

Science.gov (United States)

Sayegh, Arwa; Tate, James E.; Ropkins, Karl

2016-02-01

Oxides of Nitrogen (NOx) is a major component of photochemical smog and its constituents are considered principal traffic-related pollutants affecting human health. This study investigates the influence of background concentrations of NOx, traffic density, and prevailing meteorological conditions on roadside concentrations of NOx at UK urban, open motorway, and motorway tunnel sites using the statistical approach Boosted Regression Trees (BRT). BRT models have been fitted using hourly concentration, traffic, and meteorological data for each site. The models predict, rank, and visualise the relationship between model variables and roadside NOx concentrations. A strong relationship between roadside NOx and monitored local background concentrations is demonstrated. Relationships between roadside NOx and other model variables have been shown to be strongly influenced by the quality and resolution of background concentrations of NOx, i.e. if it were based on monitored data or modelled prediction. The paper proposes a direct method of using site-specific fundamental diagrams for splitting traffic data into four traffic states: free-flow, busy-flow, congested, and severely congested. Using BRT models, the density of traffic (vehicles per kilometre) was observed to have a proportional influence on the concentrations of roadside NOx, with different fitted regression line slopes for the different traffic states. When other influences are conditioned out, the relationship between roadside concentrations and ambient air temperature suggests NOx concentrations reach a minimum at around 22 °C with high concentrations at low ambient air temperatures which could be associated to restricted atmospheric dispersion and/or to changes in road traffic exhaust emission characteristics at low ambient air temperatures. This paper uses BRT models to study how different critical factors, and their relative importance, influence the variation of roadside NOx concentrations. The paper

Ultrastructural alterations in the mouse lung caused by real-life ambient PM{sub 10} at urban traffic sites

Energy Technology Data Exchange (ETDEWEB)

Samara, Constantini, E-mail: csamara@chem.auth.gr [Environmental Pollution Control Laboratory, Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thesaloniki (Greece); Kouras, Athanasios; Kaidoglou, Katerina [Environmental Pollution Control Laboratory, Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thesaloniki (Greece); Emmanouil-Nikoloussi, Elpida-Niki; Simou, Chrysanthi; Bousnaki, Maria [Laboratory of Histology-Embryology and Anthropology, School of Medicine, Aristotle University of Thessaloniki, 541 24 Thesaloniki (Greece); Kelessis, Apostolos [Environmental Department, Municipality of Thessaloniki, Kleanthous 18, 54 642 Thessaloniki (Greece)

2015-11-01

Current levels of ambient air particulate matter (PM) are associated with mortality and morbidity in urban populations worldwide. Nevertheless, current knowledge does not allow precise quantification or definitive ranking of the health effects of individual PM components and indeed, associations may be the result of multiple components acting on different physiological mechanisms. In this paper, healthy Balb/c mice were exposed to ambient PM{sub 10} at a traffic site of a large city (Thessaloniki, northern Greece), in parallel to control mice that were exposed to filtered air. Structural damages were examined in ultrafine sections of lung tissues by Transmission Electronic Microscopy (TEM). Ambient PM{sub 10} samples were also collected during the exposure experiment and characterized with respect to chemical composition and oxidative potential. Severe ultrastructural alterations in the lung tissue after a 10-week exposure of mice at PM{sub 10} levels often exceeding the daily limit of Directive 2008/50/EC were revealed mainly implying PM-induced oxidative stress. The DTT-based redox activity of PM{sub 10} was found within the range of values reported for traffic sites being correlated with traffic-related constituents. Although linkage of the observed lung damage with specific chemical components or sources need further elucidation, the magnitude of biological responses highlight the necessity for national and local strategies for mitigation of particle emissions from combustion sources. - Highlights: • Animal exposure to PM10 was conducted at a traffic site of a large city. • Chemical and toxicological characterization of PM10 was carried out. • Severe degenerative alterations in alveolar cells were revealed. • PM induced oxidative stress from carbonaceous species was suggested.

Determinants of Traffic Congestion in the Metropolis of Douala ...

African Journals Online (AJOL)

On the other hand, urban agglomeration used as a proxy for traffic congestion has a negative effect on urban growth and economic growth. Based on the above results, it is recommended that a remedial infrastructural development plan and a sustainable polycentric land use pattern with alternative efficient mode of public ...

Remote sensing based approach for monitoring urban growth in Mexico city, Mexico: A case study

Science.gov (United States)

Obade, Vincent

The world is experiencing a rapid rate of urban expansion, largely contributed by the population growth. Other factors supporting urban growth include the improved efficiency in the transportation sector and increasing dependence on cars as a means of transport. The problems attributed to the urban growth include: depletion of energy resources, water and air pollution; loss of landscapes and wildlife, loss of agricultural land, inadequate social security and lack of employment or underemployment. Aerial photography is one of the popular techniques for analyzing, planning and minimizing urbanization related problems. However, with the advances in space technology, satellite remote sensing is increasingly being utilized in the analysis and planning of the urban environment. This article outlines the strengths and limitations of potential remote sensing techniques for monitoring urban growth. The selected methods include: Principal component analysis, Maximum likelihood classification and "decision tree". The results indicate that the "classification tree" approach is the most promising for monitoring urban change, given the improved accuracy and smooth transition between the various land cover classes

Intelligent transportation systems in improving traffic flow in tourism destinations

OpenAIRE

Mrnjavac, Edna; Marsanic, Robert

2007-01-01

The rapid growth and development of motorisation combined with relatively small investments made to improving transportation infrastructure in cities, as well as in tourism destinations, has led to serious problems in the unobstructed movement of vehicles in public traffic areas. Traffic congestion on roadways, in ferryboat ports and at state borders during the summer months and year-round lines of cars going to or returning from work are a regular presence in traffic in most urban and touris...

Temporal dynamics of urbanization-driven environmental changes explored by metal contamination in surface sediments in a restoring urban wetland park

Energy Technology Data Exchange (ETDEWEB)

Ma, Jun; Liu, Yi; Yu, Guangbin; Li, Hongbo [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Yu, Shen, E-mail: syu@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Jiang, Yueping [The Management Committee of the National Xixi Wetland Park, Hangzhou 310013 (China); Li, Guilin [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Lin, Jinchang [The Management Committee of the National Xixi Wetland Park, Hangzhou 310013 (China)

2016-05-15

Highlights: • Urban-rural distribution pattern of metals in sediment faded out with urbanization. • Urban emissions were identified as sources of metal elevation in surface sediment. • Metal level homogenization with urbanization posed a moderate risk to the public. - Abstract: Spatial patterns of metal distribution along urban-rural or multi-city gradients indicate that the urbanization process directly lead to metal enrichment and contamination in the environments. However, it has not yet looked at homogenization dynamics of an urban-rural gradient pattern over time with urbanization process in an area. This study monitored anthropogenic metals (Cr, Cu, Pb, and Zn) in surface sediments from channels of a newly-opened National Wetland Park to elucidate the urbanization-driven dissolution of urban-rural gradient pattern between 2008 and 2011. Sixty-eight surface sediment samples were taken from these channels in July of both 2008 and 2011. Results showed that a spatial distribution pattern of total metal contents along the gradient of urbanization influence, evident in 2008, was homogenized in 2011 with the area development. The lead stable isotope ratio analysis identified anthropogenic Pb origins from vehicular exhausts, cements, and coal flying ashes, which elevated metal contents in the inner channels via atmospheric deposition. Specific hazard quotients of the metal contamination in surface sediment were also assessed and enhanced over time in the study wetland park. These findings suggest that emissions from traffic, construction, and energy generation contribute metal loadings in the urbanizing environment.

Temporal dynamics of urbanization-driven environmental changes explored by metal contamination in surface sediments in a restoring urban wetland park

International Nuclear Information System (INIS)

Ma, Jun; Liu, Yi; Yu, Guangbin; Li, Hongbo; Yu, Shen; Jiang, Yueping; Li, Guilin; Lin, Jinchang

2016-01-01

Highlights: • Urban-rural distribution pattern of metals in sediment faded out with urbanization. • Urban emissions were identified as sources of metal elevation in surface sediment. • Metal level homogenization with urbanization posed a moderate risk to the public. - Abstract: Spatial patterns of metal distribution along urban-rural or multi-city gradients indicate that the urbanization process directly lead to metal enrichment and contamination in the environments. However, it has not yet looked at homogenization dynamics of an urban-rural gradient pattern over time with urbanization process in an area. This study monitored anthropogenic metals (Cr, Cu, Pb, and Zn) in surface sediments from channels of a newly-opened National Wetland Park to elucidate the urbanization-driven dissolution of urban-rural gradient pattern between 2008 and 2011. Sixty-eight surface sediment samples were taken from these channels in July of both 2008 and 2011. Results showed that a spatial distribution pattern of total metal contents along the gradient of urbanization influence, evident in 2008, was homogenized in 2011 with the area development. The lead stable isotope ratio analysis identified anthropogenic Pb origins from vehicular exhausts, cements, and coal flying ashes, which elevated metal contents in the inner channels via atmospheric deposition. Specific hazard quotients of the metal contamination in surface sediment were also assessed and enhanced over time in the study wetland park. These findings suggest that emissions from traffic, construction, and energy generation contribute metal loadings in the urbanizing environment.

Transit Traffic Analysis Zone Delineating Method Based on Thiessen Polygon

Directory of Open Access Journals (Sweden)

Shuwei Wang

2014-04-01

Full Text Available A green transportation system composed of transit, busses and bicycles could be a significant in alleviating traffic congestion. However, the inaccuracy of current transit ridership forecasting methods is imposing a negative impact on the development of urban transit systems. Traffic Analysis Zone (TAZ delineating is a fundamental and essential step in ridership forecasting, existing delineating method in four-step models have some problems in reflecting the travel characteristics of urban transit. This paper aims to come up with a Transit Traffic Analysis Zone delineation method as supplement of traditional TAZs in transit service analysis. The deficiencies of current TAZ delineating methods were analyzed, and the requirements of Transit Traffic Analysis Zone (TTAZ were summarized. Considering these requirements, Thiessen Polygon was introduced into TTAZ delineating. In order to validate its feasibility, Beijing was then taken as an example to delineate TTAZs, followed by a spatial analysis of office buildings within a TTAZ and transit station departure passengers. Analysis result shows that the TTAZs based on Thiessen polygon could reflect the transit travel characteristic and is of in-depth research value.

A review of urban air pollution monitoring and exposure assessment methods

OpenAIRE

Xie, Xingzhe; Semanjski, Ivana; Gautama, Sidharta; Tsiligianni, Evaggelia; Deligiannis, Nikos; Rajan, Raj; Pasveer, Frank; Philips, Wilfried

2017-01-01

The impact of urban air pollution on the environments and human health has drawn increasing concerns from researchers, policymakers and citizens. To reduce the negative health impact, it is of great importance to measure the air pollution at high spatial resolution in a timely manner. Traditionally, air pollution is measured using dedicated instruments at fixed monitoring stations, which are placed sparsely in urban areas. With the development of low-cost micro-scale sensing technology in the...

Nonlinear stability of traffic models and the use of Lyapunov vectors for estimating the traffic state

Science.gov (United States)

Palatella, Luigi; Trevisan, Anna; Rambaldi, Sandro

2013-08-01

Valuable information for estimating the traffic flow is obtained with current GPS technology by monitoring position and velocity of vehicles. In this paper, we present a proof of concept study that shows how the traffic state can be estimated using only partial and noisy data by assimilating them in a dynamical model. Our approach is based on a data assimilation algorithm, developed by the authors for chaotic geophysical models, designed to be equivalent but computationally much less demanding than the traditional extended Kalman filter. Here we show that the algorithm is even more efficient if the system is not chaotic and demonstrate by numerical experiments that an accurate reconstruction of the complete traffic state can be obtained at a very low computational cost by monitoring only a small percentage of vehicles.

Synchronization between Different Networks with Time-Varying Delay and Its Application in Bilayer Coupled Public Traffic Network

Directory of Open Access Journals (Sweden)

Wenju Du

2016-01-01

Full Text Available In order to study the dynamic characteristics of urban public traffic network, this paper establishes the conventional bus traffic network and the urban rail traffic network based on the space R modeling method. Then regarding these two networks as the subnetwork, the paper presents a new bilayer coupled public traffic network through the transfer relationship between subway and bus, and this model well reflects the connection between the passengers and bus operating vehicles. Based on the synchronization theory of coupling network with time-varying delay and taking “Lorenz system” as the network node, the paper studies the synchronization of bilayer coupled public traffic network. Finally, numerical results are given to show the impact of public traffic dispatching, delayed departure, the number of public bus stops between bus lines, and the number of transfer stations between two traffic modes on the bilayer coupled public traffic network balance through Matlab simulation.

Appreciation of the traffic effects on the RST by infrared thermography

Science.gov (United States)

Khalifa, Abderrahmen; Marchetti, Mario; Buès, Michel

2014-09-01

Road surface temperature forecast is a key component of winter maintenance strategy in many developed countries. Numerical tools exist to help road managers to organize services and consequently to trigger de-icing operations. Forecasting strategies have been commonplace since the 1980s, and often based on numerical models. Traffic is one of the influencing parameters, specifically in urban areas. This work was undertaken to evaluate to which extent an accurate description of traffic might improve numerical model dedicated to road surface temperature forecasting. Two sets of experiments were run to detect and to quantify traffic effects on RST. First one consisted in driving above an infrared radiometer, a pyrgeometer and other atmospheric probes to measure the radiative contribution of a passing vehicle at various speeds. In the second set, an infrared camera was installed on a vehicle in an urban traffic flow. This camera was mounted on the roof and focused the pavement right behind the vehicle ahead, both circulating at the same speed. Infrared thermography indicated a fleeting contribution of traffic to RST. The temperature increase in circulated areas, with respect to uncirculated ones, does not last according to collected measurements. Measurements with atmospheric and radiometric probes provided elements to properly take into account traffic in a numerical model and to appreciate its contribution.

Ergodicity of Traffic Flow with Constant Penetration Rate for Traffic Monitoring via Floating Vehicle Technique

Science.gov (United States)

Gunawan, Fergyanto E.; Abbas, Bahtiar S.; Atmadja, Wiedjaja; Yoseph Chandra, Fajar; Agung, Alexander AS; Kusnandar, Erwin

2014-03-01

Traffic congestion in Asian megacities has become extremely worse, and any means to lessen the congestion level is urgently needed. Building an efficient mass transportation system is clearly necessary. However, implementing Intelligent Transportation Systems (ITS) have also been demonstrated effective in various advanced countries. Recently, the floating vehicle technique (FVT), an ITS implementation, has become cost effective to provide real-time traffic information with proliferation of the smartphones. Although many publications have discussed various issues related to the technique, none of them elaborates the discrepancy of a single floating car data (FCD) and the associated fleet data. This work addresses the issue based on an analysis of Sugiyama et al's experimental data. The results indicate that there is an optimum averaging time interval such that the estimated velocity by the FVT reasonably representing the traffic velocity.

The Traffic Noise Index: A Method of Controlling Noise Nuisance.

Science.gov (United States)

Langdon, F. J.; Scholes, W. E.

This building research survey is an analysis of the social nuisance caused by urban motor ways and their noise. The Traffic Noise Index is used to indicate traffic noises and their effects on architectural designs and planning, while suggesting the need for more and better window insulation and acoustical barriers. Overall concern is for--(1)…

Measuring the Complexity of Self-Organizing Traffic Lights

Directory of Open Access Journals (Sweden)

Darío Zubillaga

2014-04-01

Full Text Available We apply measures of complexity, emergence, and self-organization to an urban traffic model for comparing a traditional traffic-light coordination method with a self-organizing method in two scenarios: cyclic boundaries and non-orientable boundaries. We show that the measures are useful to identify and characterize different dynamical phases. It becomes clear that different operation regimes are required for different traffic demands. Thus, not only is traffic a non-stationary problem, requiring controllers to adapt constantly; controllers must also change drastically the complexity of their behavior depending on the demand. Based on our measures and extending Ashby’s law of requisite variety, we can say that the self-organizing method achieves an adaptability level comparable to that of a living system.

Apparatus, System, And Method For Roadway Monitoring

KAUST Repository

Claudel, Christian G.

2015-06-02

An apparatus, system, and method for monitoring traffic and roadway water conditions. Traffic flow and roadway flooding is monitored concurrently through a wireless sensor network. The apparatus and system comprises ultrasound rangefinders monitoring traffic flow, flood water conditions, or both. Routing information may be calculated from the traffic conditions, such that routes are calculated to avoid roadways that are impassable or are slow due to traffic conditions.

Apparatus, System, And Method For Roadway Monitoring

KAUST Repository

Claudel, Christian G.

2015-01-01

An apparatus, system, and method for monitoring traffic and roadway water conditions. Traffic flow and roadway flooding is monitored concurrently through a wireless sensor network. The apparatus and system comprises ultrasound rangefinders monitoring traffic flow, flood water conditions, or both. Routing information may be calculated from the traffic conditions, such that routes are calculated to avoid roadways that are impassable or are slow due to traffic conditions.

Android-based E-Traffic law enforcement system in Surakarta City

Science.gov (United States)

Yulianto, Budi; Setiono

2018-03-01

The urban advancement is always overpowered by the increasing number of vehicles as the need for movement of people and goods. This can lead to traffic problems if there is no effort on the implementation of traffic management and engineering, and traffic law enforcement. In this case, the Government of Surakarta City has implemented various policies and regulations related to traffic management and engineering in order to run traffic in an orderly, safe and comfortable manner according to the applicable law. However, conditions in the field shows that traffic violations still occurred frequently due to the weakness of traffic law enforcement in terms of human resources and the system. In this connection, a tool is needed to support traffic law enforcement, especially in relation to the reporting system of traffic violations. This study aims to develop an Android-based traffic violations reporting application (E-Traffic Law Enforcement) as part of the traffic law enforcement system in Surakarta City. The Android-apps records the location and time of the traffic violations incident along with the visual evidence of the infringement. This information will be connected to the database system to detect offenders and to do the traffic law enforcement process.

Estimation of the Impact of Traveler Information Apps on Urban Air Quality Improvement

Directory of Open Access Journals (Sweden)

Wenke Huang

2018-04-01

Full Text Available With the rapid growth of vehicle population and vehicle miles traveled, automobile emission has become a severe issue in the metropolitan cities of China. There are policies that concentrate on the management of emission sources. However, improving the operation of the transportation system through apps on mobile devices, especially navigation apps, may have a unique role in promoting urban air quality. Real-time traveler information can not only help travelers avoid traffic congestion, but also advise them to adjust their departure time, mode, or route, or even to cancel trips. Will such changes in personal travel patterns have a significant impact in decreasing emissions? If so, to what extent will they impact urban air quality? The aim of this study is to determine how urban traffic emission is affected by the use of navigation apps. With this work, we attempt to answer the question of whether the real-time traffic information provided by navigation apps can help to improve urban air quality. Some of these findings may provide references for the formulation of urban traffic and environmental policies. Keywords: Real-time traffic information, Mobile devices, Environmental benefits, Agent-based model

Valuing attributes of enhanced traffic information: an experience in Kolkata

Directory of Open Access Journals (Sweden)

D. Basu

2007-10-01

Full Text Available Most of the traffic information considers a single item like travel time or delay. In the present work, enhanced traffic information displaying instantaneous travel time and its variation from the previous interval to the present, is considered. An initial investigation is made on the effectiveness of such traffic information on route choice behavior of trip makers by valuation of attributes of the traffic information. Taking a case study of two urban corridors in the Kolkata metro city, India, the valuation is done separately for private car and taxi trip makers. The stated preference (choice based data collected from trip makers are analyzed using both multinomial logit (MNL and mixed logit (ML modeling techniques. Assuming sparsely used constrained triangular distribution of random parameters, two different types of ML model are developed: one with independent choice sets and the other one by accounting heterogeneity around the mean of random parameter(s. Both family income and trip purpose are found to decompose heterogeneity around the mean estimate(s. The values of travel time and their variation presented in the paper encourage further investigation on such type of traffic information for management of congestion on alternative urban corridors both spatially and temporally.

Urban air quality in Europe

Energy Technology Data Exchange (ETDEWEB)

Viana, Mar (ed.) [Spanish Research Council - CSIC, Barcelona (Spain). Inst. for Environmental Assessment and Water Research

2013-07-01

This book provides an overview of air quality in urban environments in Europe, focusing on air pollutant emission sources and formation mechanisms, measurement and modeling strategies, and future perspectives. The emission sources described are biomass burning, vehicular traffic, industry and agriculture, but also African dust and long-range transport of pollutants across the European regions. The impact of these emission sources and processes on atmospheric particulate matter, ozone, nitrogen oxides and volatile and semi-volatile organic compounds is discussed and critical areas for particulate matter and nitrogen dioxide in Europe are identified. Finally, this volume presents future perspectives, mainly regarding upcoming air quality monitoring strategies, metrics of interest, such as submicron and nanoparticles, and indoor and outdoor exposure scenarios.

Reducing automobile traffic: an urgent policy for health promotion

Directory of Open Access Journals (Sweden)

Tapia Granados José A.

1998-01-01

Full Text Available In recent decades traffic injuries have become a leading cause of death and disability the world over. In congested urban areas, the noise and emissions from vehicle engines cause discomfort and disease. More than one billion people are exposed daily to harmful levels of atmospheric contamination. Because internal combustion generates carbon dioxide (CO2 , the automobile is a principal contributor to the greenhouse effect, which has significantly raised the temperature of the atmosphere. Scientists anticipate that in coming decades the greenhouse effect will produce alterations in climate that are very likely to be harmful and possibly catastrophic. Meanwhile, burgeoning traffic and rural and urban highway infrastructures are already among the principal causes of environmental degradation. Urban development, because it is nearly always "planned" to accommodate automobiles rather than people, reduces the quality of life and tears the social fabric. In contrast to private automobiles, public transportation, bicycles, and walking produce little environmental contamination or injury-related morbidity and mortality. These modes of transport involve more physical activity, with its positive health effects, and avoid contributing to the greenhouse effect. The reduction of automobile traffic and substitution of alternative modes of transport are essential policies for health promotion. They should be incorporated in "healthy cities" programs and general economic policies.

The Brooklyn traffic real-time ambient pollutant penetration and environmental dispersion (B-TRAPPED) field study methodology.

Science.gov (United States)

Richmond-Bryant, Jennifer; Hahn, Intaek; Fortune, Christopher R; Rodes, Charles E; Portzer, Jeffrey W; Lee, Sangdon; Wiener, Russell W; Smith, Luther A; Wheeler, Michael; Seagraves, Jeremy; Stein, Mark; Eisner, Alfred D; Brixey, Laurie A; Drake-Richman, Zora E; Brouwer, Lydia H; Ellenson, William D; Baldauf, Richard

2009-12-01

The Brooklyn Traffic Real-Time Ambient Pollutant Penetration and Environmental Dispersion (B-TRAPPED) field study examined indoor and outdoor exposure to traffic-generated air pollution by studying the individual processes of generation of traffic emissions, transport and dispersion of air contaminants along a roadway, and infiltration of the contaminants into a residence. Real-time instrumentation was used to obtain highly resolved time-series concentration profiles for a number of air pollutants. The B-TRAPPED field study was conducted in the residential Sunset Park neighborhood of Brooklyn, NY, USA, in May 2005. The neighborhood contained the Gowanus Expressway (Interstate 278), a major arterial road (4(th) Avenue), and residential side streets running perpendicular to the Gowanus Expressway and 4(th) Avenue. Synchronized measurements were obtained inside a test house, just outside the test house façade, and along the urban residential street canyon on which the house was located. A trailer containing Federal Reference Method (FRM) and real-time monitors was located next to the Gowanus Expressway to assess the source. Ultrafine particulate matter (PM), PM(2.5), nitrogen oxides (NO(x)), sulfur dioxide (SO(2)), carbon monoxide (CO), carbon dioxide (CO(2)), temperature, relative humidity, and wind speed and direction were monitored. Different sampling schemes were devised to focus on dispersion along the street canyon or infiltration into the test house. Results were obtained for ultrafine PM, PM(2.5), criteria gases, and wind conditions from sampling schemes focused on street canyon dispersion and infiltration. For comparison, the ultrafine PM and PM(2.5) results were compared with an existing data set from the Los Angeles area, and the criteria gas data were compared with measurements from a Vancouver epidemiologic study. Measured ultrafine PM and PM(2.5) concentration levels along the residential urban street canyon and at the test house façade in Sunset Park