Simulation And Optimization Study On Urban Traffic Signal

With the rapid development of economy and urbanization and increase of quantity of private car, unbalance conflict between traffic supply and demand becomes more and more sharpen. People have been gotten into a hobble by traffic congestion while enjoying convenient transportation. It is the effective measure to solve traffic congestion that improvement of urban traffic management and development of public transit. Optimization of signal timing plan of urban intersection is the most economic and effective method to improve efficiency of traffic and also is the main content of modern urban traffic management. Public transit also has been given more priority to pass through intersection by optimization of signal timing plan. It is helpful to decrease delay time and improve schedule of public transit. In order to understand existing question of signal timing optimization, the thesis begins with study of current advanced traffic management system and then develops up Urban Traffic Microscopic Simulation and Optimization System. The main contents are list as follow:(1) Improvement on Urban Traffic Microscopic Simulation Model developed by Dr.Shanglei has been finished in order to make it more reality and accuracy. Validity and calibration of Urban Traffic Microscopic Simulation Model has been tested through experimental data of Heping road of Wuhan city;(2) Study on heuristic optimization algorithm. Through performance comparison of simple Genetic Algorithm, adaptive Genetic Algorithm and Chaos-Genetic Algorithm (CGA) on test function, Convergence of Chaos-Genetic Algorithm is better than others.(3) Chaos-Genetic Algorithm has been used on optimization of traffic signal timing. Urban Traffic Microscopic Simulation and Optimization System have been developed and Urban Traffic Microscopic Simulation Model is used as the tool of evaluation of different signal timing plans.(4) Active Transit Signal Priority System has been developed and it supplies three priority strategy, that is:Green time extension, Early green (red truncation) and Priority phase insertion. Different priority strategy is adapted according to arriving stop line time of transit. The system is used to evaluate influence on intersection delay of non-priority vehicle and priority transit.(5) Evaluating performance index of Transit Signal Priority (TSP) is been put forward. Passive Transit Signal Priority System has been developed with Urban Traffic Microscopic Simulation and Optimization System. Optimization of Passive Transit Signal Priority has been tested for under-satuated and over-satuated traffic based on the performance index.of TSP(6) Sensitivity of traffic signal scheme to traffic has been studied that cycle length, offset and green split has impact on traffic. It is proved that the same cycle length is the base and precondition of steady traffic stream. Multi-intersection and multi-phase of signal simulation and optimization has been built and it has been used to study on signal timing optimization of arterial line and area system.