信号交叉口不对称交通流的优化控制方法

为了改善不对称交通流导致信号交叉口进口道交通负荷分布不均、通行效率低下的问题，对交叉口对向交通流的分布形式及其适用的相位方案进行了分析，建立了信号周期动态相位方案的生成规则，并以综合交通效益最大为目标建立了交叉口不对称交通流的动态相位信号控制参数优化模型，并给出了其求解算法.分析了不对称系数大小及其阈值变化、不对称信号周期比例对优化方法的影响，并以哈尔滨市红旗大街-淮河路交叉口为例，VISSIM仿真结果显示，采用动态相位优化方法后，该交叉口的车均延误、平均排队长度和停车率等评价指标下降了27.8%以上，验证了动态相位优化方法的有效性.该方法能减少直行车流的停车等待时间、避免交叉口部分进口方向时空资源的空耗，有利于信号交叉口通行效益的提升.

The Optimal Control Method of Asymmetric Traffic Flow at Signalized Intersection

In order to improve the low traffic efficiency and imbalance traffic loading at signalized intersection approach caused by asymmetric traffic flow in Chinese urban road, the distribution form and its’ applicable phase scheme of the opposing traffic flow at signalized intersection are analyzed, and the generation rules of dynamic phase scheme per signal cycle are established. Then signal control parameter optimization model of dynamic phase directed against asymmetric traffic flow at signalized intersection is established with the aim of maximum comprehensive traffic benefit. Finally, the influence of asymmetry coefficient and its threshold value and the proportion of asymmetric signal cycle on signal control benefit of intersection are analyzed, and the intersection of Hongqi Street and Huaihe Road in Harbin is taken as an example. VISSIM simulation shows that the average delay, queue length and stop rate decrease more than 27.8% after the application of dynamic phase optimization method, which verify the validity of the method. The dynamic phase optimization method can reduce the waiting time of straight traffic flow and avoid the space-time resource wasting at part of intersection approach direction, which is beneficial to the capacity promotion of signalized intersection.