Study Of Area Delay Model And Coordination Control Of Urban Traffic

Since 21st century, urban traffic construction has been developing rapidly, the amount of vehicle increases every year and it leads to serious traffic congestion problem. The economic losses, time losses, and environmental pollution caused by traffic congestion become more and more serious. In order to alleviate traffic congestion, intelligent traffic control technology is introduced. Area coordination control is one of the most important components of intelligent traffic control technology. The model and algorithm are the core of area coordination control. In this work, area coordination control is realized by three steps:collection, modeling and optimization.Firstly, to solve the problem that area traffic flow distribution cannot be acquired directly, the advantages and disadvantages of traditional traffic assignment models are analyzed, stochastic user equilibrium is introduced, and an algorithm for solving traffic assignment model is presented. The traffic flow is distributed to the various links of the area by using the algorithm.Secondly, according to the analysis of correlation between intersections and traffic flow characteristics, the delays of external entrance and internal entrance are obtained, then traffic flow distribution is acquired by solving the stochastic user equilibrium model. We build the relationship among area delay, cycle, split and offset. By microscopic traffic simulation software, the accuracy of the model is proved.Finally, the particle swarm optimization algorithm (PSO) is used to optimize cycle, split and offset based on the proposed area delay model. In order to prevent the algorithm trap in local optimal, PSO with mutation operator is used to improve the accuracy of the algorithm and the global search capability. This area coordination optimization algorithm is proved to relieving area congestion and improving traffic capacity effectively by an actual case.