Traffic Optimization Methods of Urban Multi-leg Intersections

The research on the organization of intersections has always been the key and difficult point of road optimization, especially for multi-leg intersections. Since the traffic flow direction and the number of conflict points of multi-leg intersection are more than that of ordinary intersection, the difficulty of organization and optimization increases accordingly. At present, the research on multi-leg intersections is not much or deep enough at home and abroad. In general, it is transformed into a roundabout when the traffic volume is small, and the signal lamp is set with the increase of traffic volume. However, the signalized roundabout is not applicable when the traffic flow at the signal roundabout increases to a certain extent. Therefore, this paper introduces Huangsha six import signal free roundabout in Dianjiang County of Chongqing as the research case, takes the traffic delay and queue length as the evaluation index, and two new optimization methods are proposed on the basis of the original methods, namely improved the signalized roundabout and the signalized intersection. To assess the feasibility of these methods, VISSIM is used for simulation comparison. The simulation results show that compared with the current traffic situation, the average delay time of vehicles in the signalized intersection optimization method is reduced by 9.3 s, the average queue length decreased by 3.7 m, and its indicators are better than the signalized roundabout. Therefore, the method of signalized intersection not only provides a good mirror for the reconstruction of multi-leg intersections, but also offers relevant theoretical and practical exploration.