No description available.

This dissertation analyzes two unsolved problems to fulfill the gap in the literature: (1). What is the vehicle delay and intersection capacity considering left-turn traffic at a pre-timed signal? (2). What are the mean and variance of delay to vehicles at a vehicle-actuated signal? The first part of this research evaluates the intersection performance in terms of capacity and delay at an isolated pre-timed signal intersection. Despite of a large body of literature on pre-timed signals, few work has examined the interactions be- tween left-turn and through vehicles. Usually a protected left-turn signal phase, before (leading) or after (lagging) through signal, is applied to a signalized inter- section when the traffic demand is relatively high. A common problem for leading left-turn operation is the blockage to left-turn vehicles by through traffic, particularly at an intersection with a short left-turn bay. During the peak hour, some vehicles on the through lane might not be able to depart at the end of a cycle, resulting in an increased probability of left-turn blockage. In turn, the blocked left-turn vehicles may also delay the through traffic to enter the intersection during the following cycle. Those problems may not exist for a lagging left-turn operation, since left-turn vehicles intend to spill out of the bay under heavy traffic. In this case, the through capacity is reduced, leading to an increase of total delay. All of these factors contribute to the difficulties of estimating the delay and capacity for an isolated intersection. In order to examine this missing part of study on the signalized intersection, two probabilistic models are proposed to deal with the left-turn bay blockage and queue spillback in a heuristic manner. Numerical case studies are also provided to test the proposed models. The second part of this research studies an isolated intersection with vehicle-actuated signal. Typically an advanced detector is located at a distance prior to the intersection such that an arriving vehicle triggers a green time extension in or- der to pass through without any stop. This extended time period actuated by the vehicle is called unit extension in this study. If no vehicle actuation occurs during a unit extension, the green phase would terminate in order to clear queues in other approaches. In this way, the actuated system dynamically allocates the green time among multiple approaches according to vehicle arrivals. And the unit extension is the only control parameter in this case. We develop a model to study the vehicle delay under a general arrival distribution with a given unit extension. Our model allows optimizing the intersection performance over the unit extension. The third part of this research applies graphical methods and diffusion approximations to the traffic signal problems. We reinterpret a graphical method which is originally proposed by Newell in order to directly measure the variance of the time for the queue clearance at a signalized intersection, which remains yet to be carefully examined in practice and would be rather challenging if only using the conventional queuing techniques. Our results demonstrate that graphical method explicitly presents both the deterministic and stochastic delay. We also illustrate that the theoretical background for the graphical methods in this particular application is inherently the diffusion approximation. Furthermore, we investigate the problems of disruptions occurred during a pre-timed traffic signal cycle. By diffusion approximation, we provide quantitative estimation on the duration that the effects of disruptions would dissipate.

No description available.

The research analyzes the operating performance of three vehicle detection technologies for use in the City of Winnipeg. The technologies were: Autoscope Encore (video sensor), Iteris Vantage Edge2 (video sensor) and Matrix Wavetronix (microwave sensor). The sensors were tested in the tow eastbound lanes and two turning lanes on the intersection of Bishop Grandin Blvd and St.Mary's Road in Winnipeg, Manitoba. The research considered 24 weather, illumination, wind and traffic conditions. Testing and analysis was completed at the stop bar, and advance zone as well as for count performance. Sensitivity is a measure of the number of calls missed by the sensor. In terms of sensitivity, Iteris performed best overall, performing with greater sensitivity than Autoscope and Matrix in 17 of 24 conditions at the stop bar and outperforming in 11 of 12 conditions for advanced zone detection in this research. For count performance the Iteris had better accuracy when compared to ground truth established by Miovision Technologies, than Autoscope and Matrix.

The research analyzes the operating performance of three vehicle detection technologies for use in the City of Winnipeg. The technologies were: Autoscope Encore (video sensor), Iteris Vantage Edge2 (video sensor) and Matrix Wavetronix (microwave sensor). The sensors were tested in the tow eastbound lanes and two turning lanes on the intersection of Bishop Grandin Blvd and St.Mary's Road in Winnipeg, Manitoba. The research considered 24 weather, illumination, wind and traffic conditions. Testing and analysis was completed at the stop bar, and advance zone as well as for count performance. Sensitivity is a measure of the number of calls missed by the sensor. In terms of sensitivity, Iteris performed best overall, performing with greater sensitivity than Autoscope and Matrix in 17 of 24 conditions at the stop bar and outperforming in 11 of 12 conditions for advanced zone detection in this research. For count performance the Iteris had better accuracy when compared to ground truth established by Miovision Technologies, than Autoscope and Matrix.

Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 156-168). Also available in electronic version. Access restricted to campus users.

Thesis (Ph. D.)--University of Chicago, Dept. of Mathematics, August 2000. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--Duke University, 2008.

Thesis (Ph. D.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains vi, 76 p. Includes abstract. Includes bibliographical references (p. 75-76).

La presente tesis evalúa los niveles de servicio de la intersección de la Av. La Marina con la Av. Sucre, debido al incremento de la congestión vehicular. Para ello se elaboró un modelo microscópico de la intersección donde se presentaron propuestas de mejora de la situación actual. El análisis de las propuestas se realizó en base al software Vissim 9.0. La presente investigación consta de 5 capítulos. El Capítulo 1, plantea la problemática del tráfico vehicular. Asimismo, se presentan antecedentes de investigaciones similares, la justificación del estudio, la hipótesis y los objetivos del estudio. El Capítulo 2, desarrolla el marco teórico de la investigación. Aquí se toma en cuenta estudios previos realizados e información correspondiente a microsimulación. Se presentan los tipos de modelos de tráfico, fundamentos de microsimulación, modelos de seguimiento vehicular y se explica el funcionamiento del software Vissim V9. El Capítulo 3, describe la metodología empleada en la presente investigación, además del procesamiento de la información, la construcción del modelo de microsimulación debidamente calibrado y validado. El Capítulo 4, presenta los resultados de la microsimulación, determinando el nivel de servicio actual de la intersección en “F” y que al implementar las propuestas de mejora se puede mejorar hasta un nivel “D”. El Capítulo 5, presenta las conclusiones y las recomendaciones. De lo indicado se puede concluir que el uso adecuado del software de simulación de tránsito, permite evaluar y optimizar de manera real los niveles de servicio de una intersección sin necesidad de intervenir de manera real en el área de estudio. / This thesis evaluates the service levels of the intersection of Av. La Marina with Av. Sucre, due to the increase in vehicular congestion. To do this, a microscopic model of the intersection was developed and proposals were made to improve the current situation. The analysis of the proposals was carried out based on Vissim 9.0 software. The present investigation consists of 5 chapters. Chapter 1, raises the issue of vehicular traffic. Likewise, similar research background, the justification of the study, the hypothesis and the objectives of the study are presented. Chapter 2 develops the theoretical framework of the investigation. Here, previous studies and information corresponding to microsimulation are taken into account. The types of traffic models, microsimulation fundamentals, vehicle tracking models are presented and the operation of the Vissim V9 software is explained. Chapter 3 describes the methodology used in this research, in addition to information processing, the construction of the properly calibrated and validated microsimulation model. Chapter 4 presents the results of the microsimulation, determining that the current service level of the intersection is "F" and that by implementing the improvement proposals it can be improved to a "D" level. Chapter 5 presents the conclusions and recommendations. From the aforementioned, it can be concluded that the proper use of traffic simulation software allows for the real evaluation and optimization of the service levels of an intersection without the need to actually intervene in an intersection. / Tesis