Urban Signalized Intersection Traffic Organization Optimization Research Based On VISSIM

Signalized intersection is an important node in urban road network, and it is the necessary land for all kinds of traffic to collect, turn and pass through. With the rapid development of the city and increasing of vehicle ownerships, coupled with unreasonable road channel and signal timing which makes traffic congestion, blocking and traffic accidents happened very often in signalized intersection, especially at traffic peak time. It not only reduced the traffic capacity of intersection, but also aggravated environmental pollution and energy consumption. Therefore, it is imminent to solve the urban signalized intersection traffic problems, and scientific and reasonable traffic organization optimization study should be done.Firstly, the thesis starts from the characteristics of mixed traffic flow in China, proposes two methods of time separation and space separation through the analysis of mixed traffic flow crossing conflict in the signalized intersection in order to reduce the conflict; analysis and research the role of channelized traffic, the design process, and two kinds of calculation methods of signal timing based on traffic organization, and provide a theoretical basis for the optimization of the signalized intersection.Secondly, this article takes Xi’an Taiyi road-Youyi east road signalized intersection for specific example, investigates the field road geometry, intersection signal phase and timing scheme and traffic flow; analyzes the intersection traffic problems though road channel, signal control, traffic flow conflict and other aspects, and proposed two traffic organization optimization scheme for these problems by combining channelized traffic and signal control optimization.Finally, this article uses the commonly used traffic simulation software VISSIM(Vision Traffic Simulation), models and simulation operates for the existing signalized intersection traffic organization and two kinds of optimization schemes, and use four evaluation indexs of three types(queuing time, travel time, delays and queue length) to evaluate each scheme, shows out the evaluation index values of each scheme in tabular form, gives the evaluation results of each scheme in a graphical form directly, though comparison and analysis, chooses the best traffic organization optimization scheme, effectively to improve the signalized intersection traffic situation.