基于通行效率最优的交叉口调头选位
Location of U-Turn Openings at Signalized Intersections Based on Optimal Traffic Capacity

针对信号交叉口调头区域设置不合理的问题，选择传统四相位控制交叉口为研究对象，基于通行效率最优提出了最佳调头位置的计算方法。该方法首先通过建立左转与调头共用车道的损失时间模型，揭示了左转和调头车流在不同交通条件下的相互影响机理；其次基于不同流向车辆的概率分布函数，构建了信号交叉口左转与调头共用车道的通行能力计算模型，揭示了调头位置对共用车道通行能力的影响特征；最后以淄博市中心城区为例进行了实例分析。实验结果表明，该方法能使左转与调头共用车道的通行能力由432 pcu/h提升到509 pcu/h，提高了17.82%。
： In order to solve the unreasonable deployment of U-turn openings at signalized intersections, a method is proposed to calculate locations of optimal U-turn openings based on the optimal traffic capacity by taking the traditional four-phase control intersection as an object. Firstly, a loss time model of lanes shared by left-turn and U-turn vehicles is built to reveal the interaction mechanism between left-turn and U-turn traffic flows in different traffic conditions. Then, a capacity calculation model of lanes shared by left-turn and U-turn vehicles is established using the probability distribution function of vehicles in different flow directions. The capacity-location (C-L) curve drawn by the model can fully reveal the capacity characteristics of the shared lanes under influence of the U-turn openings. Based on the maximum capacity, the optimal location of U-turn openings is finally determined. In addition, the validity of the method was verified through a case study in the central area of Zibo City. The result shows that the proposed method can improve the traffic capacity of the shared lane of left-turn and U-turn vehicles from 432 to 509 pcu/h by 17.82%