城市信号交叉口左转待行区设置及效益评价研究

目前，左转待行区已经在很多城市得到推广。介绍左转待行区设置的一般步骤，结合交叉口几何条件、左转车流、直行车流分析左转待行区设置的量化条件，根据最短绿灯间隔计算左转待行区长度的临界值，选取通行能力、停车延误、停车次数等参数来评价左转待行区设置对交通效益的影响，并结合南京市新建交叉口实测数据进行分析。结果表明：南京市汉中路-虎踞南路交叉口满足左转待行区设置条件，在不改变其他条件的前提下，较之左转待行区使用前通行能力大幅增加，车均延误略有降低，停车次数有所增加。因此，在满足设置条件的前提下，设置左转待行区能够有效提高交叉口行车效率，改善运行环境。

Research on Setup of Left-turn Stay Line Area at Urban Signal Intersections and Benefit Evaluation

As of now the left turning stay line area has been popularized in many cities. This paper introduces general steps of setting the left turning stay line area, analyzes the quantum conditions for setup of the left turning stay line area in combination with geometrical conditions, left-turn flow and straight flow, calculates the critical value of the length of left turning stay line area according to the shortest green light interval, evaluates the influences of setup of left-turn stay line area on traffic benefits by selecting parameters including traffic capacity, stop delay and stop times, etc. , and analyzes in combination with the measured data at new intersection in Nanjing. The results show that the intersection between Hanzhong Road-Huju South Road in Nanjing satisfies the conditions for setup of left-turn stay line area, and the traffic capacity increases remarkably, the average stop delay slightly reduces and the stop times increase in comparison with those before use of left-turn stay line area in the precondition of not changing other conditions. Therefore, in the prerequisite of satisfying the setup conditions, setting left-turn stay line area can effectively promote traffic efficiency at the intersections and improve operating environment.