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A unified optimization framework for traffic signal priority scheduling based on the phasetime network models is presented in this research work with two mathematical programming formulations: (i) Mixed Integer Linear Programming (MILP) formulation and resilient MILP formulation (R-MILP). A heuristic algorithm is developed using the delay generated by the cumulative arrival and departure curves for searching optimum solution in phase-time network. An acceptance and rejection policy is also developed based on the proposed R-MILP. A set of numerical experiment with the proposed policy is conducted for fully adapted and coordinated phase-time network. The third set of numerical experiment is destined for the comparison of the performance of proposed phase-time network with the signal timing given by traditional traffic engineering method and Multi-Modal Intelligent Traffic Signal System (MMITSS) (1). The results show that in each case, the proposed formulation gives shorter delay and arterial travel time than the other two methods.

During a signal malfunction, traffic signals are operated in the flash mode. During this event, drivers are presented with one of two possible scenarios: (1) flashing yellow on the major street and flashing red on the minor street or (2) flashing red on all approaches. Yellow/red flash is typically the default mode utilized based on the expectation that red/red flash would produce an intolerable amount of delay. However, little research has been conducted to date on flashing operations, with exception of low-volume nighttime conditions. A traffic signal malfunction can occur during any time of the day, potentially placing the signal into flash mode under moderate to peak traffic volume conditions. In order to assess the safety implications of these events and improve the process by which the mode of flash (yellow/red versus red/red) is selected, the research contained in this study evaluated driver behavior and the operational characteristics of intersections operating in malfunction flash mode under a wide spectrum of traffic demands. Analysis of field data collected at thirteen study intersections in the Atlanta, Georgia area found that confusion exists among drivers approaching a signal in flash mode. The analysis found that a significant percentage of vehicles stop on a yellow indication. It was seen that an intersection flashing yellow/red could operate as a two-way stop or four-way stop, potentially transitioning between these two alternatives on a minute-by-minute basis. This creates an increased potential for crashes and further compounds the problem of driver expectancy by creating a constantly changing control environment. The stopping on yellow also introduces additional delay, which reduces the operational benefit of utilizing the yellow/red flash mode. Furthermore, a high level of traffic violations was observed for the flashing red indications for both yellow/red and red/red flashing operation. Based upon the study results, providing one consistent mode of flashing operation may be a reasonable solution to improving driver expectancy and safety. Red/red flashing operation is the preferred mode as it reduces vehicle speeds and the variability in the number of vehicles stopping, while improving driver expectancy.

The traffic signal optimization problem is to find a traffic signal setting in a traffic network such that vehicles could arrive at their destination with minimum waiting time. The design of traffic signal setting to decrease waiting time for vehicles moving on the roads in urban city is important but difficult. In this thesis, we use a graph model to represent a traffic network. We propose two signal setting algorithms, a fast heuristic approach and an evolutionary algorithm based on the ant colony optimization (ACO) method, to give a good traffic signal setting. The results show that we could find better solutions by ACO algorithms, and the heuristic algorithm is faster but gets more total waiting time for vehicles. Furthermore, we transform the traffic network data of Kaohsiung city in Taiwan into our traffic graph model and test our algorithm on this traffic graph.

Highway traffic control systems have been deployed to provide emergency vehicle preemption (EVP) at signalized intersections. Industry and transportation researchers have worked to develop analytical methods to establish the degree of benefit of emergency vehicle preemption to the emergency vehicle (EV) community and the impact on other road user groups. This thesis report illustrates the use of an analytical method to evaluate the potential impacts of EVP related to EV safety, and the potential delay to EVs and vehicles on the side street. The method uses EV-specific conflict point and delay analysis with video and other data collected in a field study conducted in Northern Virginia at the intersection of Southgate Drive and U.S. 1. EV related conflict points are characterized in terms of the EV/auto interaction geometry, the signal display, and the severity of potential crashes. EV related delay is characterized in terms of the EV/auto interaction geometry, the signal display, the level of service and the amount of delay to the EV. The EV/auto interaction, the queue length and the signal display characterize increase in delay to vehicles on the side street. The analysis indicates that the severity of EV-specific conflict points is significantly reduced with EVP. The delay to EV does not change significantly and the delay to the vehicles on the side street auto traffic increases. / Master of Science

Bluetooth Data collection technique is recently proven as a reliable data collection technique that provides the opportunity to modify traditional methodologies to improve system performance. Actual volume in the network is a result of the timing plans which are designed and modified based on the volume which is generated using existing timing plans in the system. This interdependency between timing plan and volume on the network is a dynamic process and should be captured to obtain actual traffic states in the network. The current practice is to calculate synthetic origin destination information based on detector volume that doesn't necessarily represent the volume scenario accurately. The data from Bluetooth technology can be utilized to calculate dynamic volume on the network which can be further used as input for signal timing design. Application of dynamic volume improves the system performance by providing the actual volume in system to design optimal timing plans. This thesis proposes a framework that can be used to integrate data obtained from the Bluetooth technology with the traditional methods to design timing plans. The proposed methodology utilizes the origin destination information obtained from Bluetooth data, detector data, characteristics of intersections such as number of lanes, saturation flow rate and existing timing plans as a basis for the calculation of the dynamic volume for the various movements at each intersection. The study shows that using the Bluetooth based OD matrix to calculate accurate dynamic volumes results in better system performance compared to the traditional way of using the static detector volume alone. / Master of Science

Less than 1% of work and school trips are completed by bicycle in the United States. Comprehensive bicycle facilities improve bicycle ridership by including a diverse set of strategies that accommodate the bicycle mode and seek to minimize the Level of Traffic Stress experienced by riders. Traffic Signal Operational Strategies for Bicycles (TSOSB) are an integral component of comprehensive bicycle facilities. This research presents a methodology to identify critical zones for implementation of TSOSB. After identifying critical zones a process for assessment of gaps in bicycle safety and comfort and convenience for signalized intersections within the critical zones is conducted. The outcome of the methodology is a prioritized list of signalized intersection that could benefit from the application of Traffic Signal Operational Strategies for Bicycles

Adaptive traffic signal control is the process by which the timing of a traffic signal is continuously adjusted based on the changing arrival patterns of vehicles at an intersection, usually with the goal of optimizing a given measure of effectiveness. Herein, a methodology is developed in which the characteristics of a traffic signal cycle are optimized at the conclusion of every phase based on the arrival times of vehicles to an intersection, using stopped delay as the measure of effectiveness. This optimization is solved using metaheuristic search procedures, namely tabu search, and embedded in an algorithm in which current vehicle arrival times are detected, arrival patterns over a specified horizon are predicted, the traffic signal timing is optimized, and the timings are sent to a traffic signal controller. The methodology is shown to provide improvement in performance for a number of intersection configurations and traffic regimes over traditional forms of traffic signal control, and the metaheuristic search is demonstrated to significantly reduce the computation time for a solution as compared with other search procedures. / text

CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / A utilizaÃÃo de mecanismos que auxiliem a tomada de decisÃo à cada vem mais difundida no meio tÃcnico, o uso destes ferramentais por Engenheiros de TrÃfego auxiliam na anÃlise do desempenho de novos cenÃrios urbanos, definiÃÃo de novas estratÃgias de coordenaÃÃo, isolamento de semÃforos, dentre outros, de forma a contribuir para a eficÃcia do sistema de trÃnsito. Com o aumento da problemÃtica relacionada ao trÃnsito nas grandes cidades, a implantaÃÃo de semÃforos surge como uma das medidas mitigadoras. Devido à existÃncia de vÃrios mÃtodos de implantaÃÃo de semÃforos, nacionais e estrangeiras, conforme as caracterÃsticas das cidades que os originaram, à necessÃrio alÃm da identificaÃÃo dos locais onde se devem implantar os semÃforos, utilizar outros mÃtodos, a exemplo de um otimizador e um simulador de trÃfego, que atravÃs de medidas de desempenho, auxiliem à anÃlise dos impactos operacionais no trÃnsito, de forma a verificar quais as reais melhorias resultantes das implantaÃÃes, considerando outras realidades. Este trabalho terà como estudo de caso um trecho viÃrio da Ãrea central da cidade de Fortaleza-Ce. Na concepÃÃo deste estudo, foram definidas as seguintes etapas: aplicaÃÃo das metodologias de implantaÃÃo de semÃforos estudadas, definiÃÃo do modo de operaÃÃo e coordenaÃÃo e avaliaÃÃo operacional. Optou-se por utilizar o simulador de trÃfego Integration que atravÃs de suas medidas de desempenho auxiliou na definiÃÃo do cenÃrio que apresentou os maiores ganhos operacionais em relaÃÃo ao cenÃrio atual. / Decision making techniques have become increasingly widespread in the technical field. The use of such tools by Traffic Engineers assists in analyzing the performance of new urban settings, the definition of new coordination strategies, traffic signal isolation, among others, as to contribute to the effectiveness of the traffic control system. With increasing problems related to traffic in large cities, the implementation of traffic control signals emerges as one of the mitigating measures. As there are several national and international methods used in the implementation of traffic signals, depending on the characteristics of the cities in which they originate, it is necessary not only to identify the sites where traffic signals should be installed, but also to utilize different methods. Such methods include traffic signal optimization and simulation tools, which assist in the analysis of operational impacts through performance measures, indentifying which are the real improvements resulting from the implementations, considering other realities. The present work will study a road section from the central area of the city of Fortaleza, in the state of CearÃ, Brazil. The following stages were defined: application of the studied methodologies of traffic control signal implementation, mode of operation, and operational coordination and evaluation. The traffic simulator Integration was used, and through its performance measurements it was possible to define the setting that exhibited the highest operational gains in relation to the current setting.