综合考虑车道划分和流量分布的交叉口相位结构优选方法

Optimization Method of Phase Pattern in Intersection with Considering Lane Division and Flow Distribution

相位结构的合理选取是进行交叉口信号配时的基础.文中综合考虑进口道车道功能划分和流量方向分布两个因素,给出了一套面向关键车流总流量比最小的交叉口相位结构优选流程.对相位结构优选流程中的关键步骤—关键车流总流量比计算,给出了两种典型车道功能划分情况下的关键车流总流量比计算方法.以南通市某交叉口为例,利用所提相位结构优选方法给出了该交叉口的最佳相位结构.同时,利用Webster配时理论分别给出最佳相位结构、非最佳相位结构下的信号方案,并与该交叉口实际运行信号方案进行对比分析.结果表明:(1)无论是仅考虑机动车通行需求还是同时考虑机动车和行人过街通行需求,最佳相位结构下的周期时长均比非最佳相位结构下的周期时长小;(2)利用所提相位结构优选方法设计出的信号方案可以同时满足机动车和行人过街的通行需求,而现有信号方案却无法同时满足,若要满足则需要较大幅度扩大其周期时长.以上结果分析验证了所提方法的有效性与实用性.

Reasonable selection of phase is the basis of intersection signal timing. In this paper, considering the two factors of lane function division and flow direction distribution of the entrance lane, a set of phase pattern optimization process for intersections with minimum total flow ratio of key traffic flow was presented. For the calculation of the total flow ratio of key traffic flow in the phase pattern optimization process, the calculation methods of the total flow ratio of key traffic flow under two typical lane functions were given. Taking an intersection in Nantong as an example, the optimal phase pattern of the intersection was given by using the proposed phase structure optimization method. Meanwhile, using Webster’s timing theory, the signal schemes under the optimal phase pattern and the non-optimal phase pattern were analyzed respectively, and compared with the actual signal schemes of the intersection. The results show that:(1)The cycle time under the optimal phase pattern is shorter than that under the non-optimal phase pattern, whether only considering the traffic demand of motor vehicles or considering the traffic demand of both motor vehicles and pedestrians.(2)The signal scheme designed by the proposed phase pattern optimization method can meet the traffic demand of motor vehicles and pedestrians crossing the street at the same time, but the existing signal scheme cannot meet it at the same time. If it is to be satisfied, it needs to greatly expand its cycle time. The above analysis verifies the effectiveness and practicability of the proposed method.