单口轮放策略下借道左转交叉口优化设计

Optimal Design of Left-Turn Intersection with Single Wheel Release Strategy

针对高峰时段交叉口左转车流大、部分相位空放及部分出口道闲置问题,从相位优化和出口道资源最大化利用出发,分析单口轮放预信号设置时间和交通流不对称性,研究交叉口应用单口轮放—借道左转优化方案和不同信号配时方案后,交叉口车均延误、排队长度改善情况。以兰州市天水路—东岗西路交叉口为例,通过VISSIM仿真建模,比较优化前后交叉口各项指标优劣。结果表明:设置优化方案后,高峰时段该交叉口车辆平均延误、平均排队长度分别减少了44.91%、50.61%,平峰时段车辆平均延误、平均排队长度分别降低了40.91%、48.42%;采取Webster配时方法和多目标信号配时优化方法皆可优化信号配时方案,多目标信号配时优化方法优于Webster配时方法。在交通流不对称性明显的交叉口,单口轮放策略优于对称放行。研究成果为城市道路交叉口交通管理和控制提供一定的设计参考。

Aiming at the problems of large left turn traffic flow,partial phase idle and partial exit lane idle at the intersection during peak hours,from the perspective of phase optimization and maximum utilization of exit lane resources,the pre-signal setting time and traffic flow asymmetry of the single wheel release were analyzed,and the optimization scheme of the single wheel release-exit turn turn and different signal timing schemes were studied.Traffic delay and queue length improvement at intersection.Taking the intersection of Tianshuihuan-Donggang West Road in Lanzhou City as an example,the advantages and disadvantages of various indexes of the intersection before and after optimization are compared by VISSIM simulation modeling.The results show that the average delay and queue length of vehicles at the intersection during peak hours are reduced by 44.91%and 50.61%,respectively,and the average delay and queue length during peak hours are reduced by 40.91%and 48.42%,respectively.Both Webster timing method and multi-target signal timing optimization method can optimize the signal timing scheme,and the multi-target signal timing method is superior to Webster timing method.At the intersection where the traffic flow asymmetry is obvious,the single wheel release strategy is better than the symmetrical strategy.The research results provide reference for the design of urban traffic management and control.