非机动车影响下考虑不均衡车流的信号控制方案优化方法

Optimization method for signal control scheme consideringunbalanced traffic flow with the effect of non- motorized vehicles

针对目前信号交叉口相位设计过于依赖实践经验、未充分考虑机非交通流特性和非机动车过街模式的影响,导致通行效率低和时空资源利用不足的问题,基于机动车交通流不均衡性提出一种信号交叉口动态放行方案。建立不同放行方案的延误估计模型,综合考虑机非载客性差异,以减小交叉口人均延误为优化目标,采用灵敏度分析方法给出传统相位方案的定量设置条件,以北京市平安里西大街与赵登禹路交叉口为例,对模型的适用性进行验证,利用改进蚁群算法求解得到不同放行方案对应的最佳信号配时。结果表明:当机动车交通流不均衡系数aj>0.25时,采用轮转放行+二次过街;当aj<0.25、左转和直行流量之比大于1∶3,且非机动车左转流量在100~500辆/h时,采用对称放行+一次过街;当流量之比小于1∶3时,适宜采用对称放行+二次过街。与传统放行相位相比,采用对称搭接放行相位方案能使人均延误下降13.6 s,降幅为25.81%,有效提高交叉口的通行效率。

The current design of intersection signal phase relies heavily on practical experience.Without thorough consideration of the impact of the non-traffic flow characteristics and non-motorized vehicles’street-crossing mode,it often causes poor use of time and space resources.This paper proposes an intersection signal dynamic release scheme which takes into account the phase traffic flow imbalance and the impacts of non-motorized vehicle expansion effect on motorized vehicles.A delay estimation model based on different release methods is built,and a sensitivity analysis method is employed to present quantitative setting conditions for different release schemes.An intersection in Beijing is taken as an example.The signal timing schemes corresponding to different release schemes are obtained by improving the ant colony algorithm.The results show“rotation release+twice crossing”is used when a j is greater than 0.25.When a j is less than 0.25,the ratio of left-turn and direct flow is greater than 1∶3,and the left-turn flow of non-motorized vehicles is 100~500 veh·h-1,“symmetrical release+once crossing”is adopted.When the ratio of flow is less than 1∶3,“symmetrical release+twice crossing”is adopted accordingly.Compared to the traditional release scheme,the use of symmetrical lap release results in a reduction of 13.6s in delay per person,down by 25.81%.Therefore,the release scheme proposed in this paper effectively improves the traffic efficiency at intersections.