行人-自行车对两种交叉口设计模式通行能力的影响

Impact of Pedestrian and Bicycle on Capacity of Two Design Types of Intersection

为了更准确地估算信号控制交叉口的通行能力,分析了行人-自行车在自行车左转一次过街和自行车左转二次过街这两种交叉口设计模式条件下,对机动车通行能力的影响。首先,针对我国交叉口信号控制和交通运行的实际情况,将行人-自行车影响分为绿灯信号期间冲突和清空上一相位滞留行人-自行车的时间损失两种类型。然后,运用理论解析与关键参数实际调查标定相结合的方法,对两种交叉口设计模式的两类行人-自行车影响,分别给出了通行能力折减系数计算模型。最后,基于敏感性分析对两种交叉口设计模式进行了对比。研究表明:在信号配时设计中已设置行人自行车清空时间的情况下,自行车左转二次过街设计模式的机动车交通受行人-自行车的影响较自行车左转一次过街设计模式略有增加,但差异不大;若信号配时设计中没有考虑行人-自行车清空时间,则自行车左转二次过街设计模式下行人-自行车对机动车通行的影响较小。

In order to estimate the capacity of signalized intersection more exactly, we analyzed the pedestrian-bicycle impacts on vehicular capacity under 2 intersection design patterns, i. e. , one-step crossing for left-turn bicycle and two-step crossing for left-turn bicycle. First, aiming the actual signal control and traffic operation condition in China, the pedestrian-bicycle impacts are divided into 2 types, i.e. , the conflict during the green time and the lost time for clearing the stranded pedestrians and bicycles in the previous phase. Then, the calculation models of capacity reduction factor for the impacts of 2 types of pedestrian-bicycle under 2 intersection design types are presented respectively by the combination of theoretical analysis and key parameters calibration based on field data. Finally, the comparison is made between the 2 design types of signalized intersection based on sensitivity analysis. The result shows that （ 1 ） the pedestrian and bicycle may impact the vehicular traffic of design type 2 （left-turn bicycle turns circuitously） is slightly greater than that of design type 1 （ left-turn bicycle turns directly） in the case that the clearance time of pedestrian and bicycle has properly considered in the signal timing; （2） the impact under design type 2 is much smaller when the clearance time of pedestrian and bicycle is not considered.