Research On Coordination Control Methods Of Traffic Bottlenecks Under Queue Length Restriction

The growing traffic congestion in China is an indisputable fact. With the development of economy and city size, the traffic congestion becomes more and more serious. In essence, the occurrence of congestion is due to the traffic imbalance between demand and supply. The point is often located at the road network which began a traffic bottleneck, and the time is the peak of residents going out. When the traffic demand to a certain extent, the traffic bottleneck will form a long queue of vehicles, leading to a small scope congestion. If we do not take measures to control in time, it will affect the normal operation of vehicles in different directions when the vehicles constantly reach the upstream intersection. This situation will lead to road network traffic flow locked, and cause large traffic jams or road network traffic gridlock, the traffic of this so-called "domino" phenomenon. "Domino" phenomenon is the extreme performance of urban traffic jams form, the consequences and effects are most serious. Therefore, traffic control measures must be taken to prevent this phenomenon.The purpose of this paper is to prevent the "domino" phenomenon. The queue length is used as the index of control system evaluation. At first, the calculation model of equivalent queue length based on traffic wave theory and traffic flow theory is built. The accuracy of the model has been verified by VISSIM software. According to the simulation results, the accuracy of the equivalent queue length model can meet the requirements of theoritical research.Secondly, this paper propose the coordination control method for the bottleneck intersections, the focus is on the selection of the control connection and the building process of the coordination control model of bottleneck intersections. It make full use of the road network space resources, traffic pressure will shift to less stressful control connection intersections to prevent traffic "Domino" phenomenon.Finally, there are simulations on the coordination control model in this paper. The results show that coordination control under queue length constraint is more conducive to prevent "domino" phenomenon, thus the purpose of coordination control is achieved.