Study On Traffic Congestion And Vehicle Delay Model At Road Intersectionin Urban

With the rapid development of social economy, people’s living standard has remarkably improved. Travel modes have become diversified, by way of walking for short destination, and by trains, cars, planes and other vehicles to reach further destination. Therefore, activity space and scope of travel is greatly expanded. However, traffic congestion, traffic accidents, and energy consumption and air pollution caused by motor vehicles in the big cities all over the world have aroused widely public concern. The problems and difficulties about vehicles traffic flow have drawn wide interest in scientific researchers. A large number of experimental data indicates that more than80%time delay concentrates on the urban intersection and road bottleneck, and traffic capacity of plane intersection is often less than70%. So the city’s traffic congestion is caused because of lacking of traffic capacity of intersection. Solving the problem of traffic capacity at urban intersection is the key to solve the urban traffic congestion. The works of this paper are as follows:(1) Applying to Jiang-Wu model, the typical intersection is simulated, in order to look for the factors of traffic jams and investigate the large area congestion which forms in the upstream of main road. Directing at GuangXi University-HuoJu road, simulation results show that turning traffic is too large and residence time of vehicles is too long in traffic interchange are the main factors causing congestion. Suggestion:restrict turning traffic in the rush hour, and reasonably set isolation belt that avoid all directions of traffic flow to twist together, and improve traffic capacity.(2) The two-lane velocity gradient model with road reduction is proposed, which could analyze the movement rule and evolution process of traffic flow when slow lane have bottleneck because of road reduction. It is found when free speed of slow lane is small or initial density of fast lane is low, traffic flow of fast lane are easier to produce large disturbance in the bottleneck. It forms clusters, leading to vehicle speed vibration frequently. At the same time, the clusters spread to the upstream over time. Due to fast and slow lane is associated, slow lane also appears the density fluctuation. In fast and slow lane, there will be a "shift" phenomenon.(3) Through investigating and analyzing Australian delay model and Canadian delay model, we improve delay model based on the existing of the two models. The improved delay model is close to Canadian and Australian delay model when the saturation is low and high. When the saturation is close to1, improved delay model is better agreement with the measured results and improves the precision.Finally, the work of this paper is summarized. Furthermore the deficiency and improved methods are put forward about the content of the article. We point out further work in the future.