A Study On Hierarchical Coordination Method For Traffic Control And Guidance

As important parts in Intelligent Transport System, Urban Traffic Control System and Vehicles Route Guidance System are two main methods to manage real-time traffic flow on urban roads. Traffic control and route guidance should be integrated for their intimate interaction and the complementarities of their function, which becomes the main development direction of ITS.Traffic Control System or Route Guidance System is a very complicated system in itself. To solve their integrated problem, we must turn to Large-scale System theory because of their complicated characteristic. Also the traffic system's structure hierarchical characteristic provides realistic foundation for the integration. Inductive control model is a developed control model, and traffic managers should constitute guidance policy base on system optimization to solve the traffic problem. Based on these facts, this paper proposes a new inductive control-guidance hierarchical coordinated model.Firstly, this paper discusses a developed inductive control model. Then on the base of this model the paper proposes a new hierarchical coordinated mode for traffic control and route guidance. At last, two algorithms and three simulations are given: signal intersection simulation with inductive control, road net simulation on User Equilibrium, road net on the control-guidance hierarchical coordination. Through comparison the results of the simulations, two conclusions are given. One is that the inductive control model can meet the variation of traffic demand through adapting its green time to minimize the delay time of the intersection. The other is the control-guidance hierarchical coordination model can improve the network performance obviously. And it is proved that the hierarchical coordination model in this paper is practical and the algorithm is feasible.