信号交叉口行人二次过街下右转车通行能力与延误估计模型

Capacity and Delay of Right-turn Vehicles at Signalized Intersections Under Influence of Pedestrian Two-stage Crossing

在充分分析典型四相位交叉口行人二次过街设置前、后的行人流与右转车流冲突的前提下,以行人过街时间占有率和行人群到达分布作为分析指标,利用可插车间隙理论得出行人单向通行和双向通行条件下的右转车通行能力计算公式;根据行人流随机消散和集中消散的不同特征,应用随机分布理论推导出右转车穿越行人流的延误模型;并通过算例对比分析行人二次过街设置前、后右转车通行能力和延误的变化值。结果表明,除了在少数行人流量比较大的情况下,行人二次过街的设置会小幅度减少右转车的延误;在其他大多数情况下,行人二次过街设置后,右转车的通行能力将受到限制,延误增大,其中,平均通行能力降低了16.68%,平均延误时间增大了21%,所以,当右转车交通需求较大时,需同时考虑行人和右转车的交通运行状态,优化设计是否采用行人二次过街,避免右转车超出极限忍耐时间而增大与行人冲突的概率。

This paper analyzes the impact of pedestrian two-stage crossing on right-turn vehicles at signalized intersections.Based on the gap acceptance theory and random distribution,this paper develops the capacity and delay models for right-turn vehicles considering the conflicts with one-way and two-way pedestrian flows.Taking a typical four-phase signal release mode as an example,the study also evaluates the right-turn movement capacity and delay when pedestrian use two-stage crossing or one time crossing.The occupancy of pedestrian crossing time and the arrival distribution of pedestrians are used as the comparison indexes.The results show that compared to the pedestrian one time crossing,the average capacity of right-turn movement is reduced by 16.68%and the average delay is increased by 21%after installation of pedestrian two-stage crossing.Therefore,when the traffic demand for right-turn vehicles is heavy,it is necessary to consider the traffic operation of both pedestrians and right-turn vehicles to determine whether to use pedestrian two-stage crossing.This would avoid right-turn vehicles exceeding the tolerance limit and increasing the probability of conflicting with pedestrians.