Abstract: Considering the phenomenon that T-type intersections traffic flow is greatly influenced by the left-turning vehicles, the traffic organization method that left-turning traffic flow of main road adopts U-turn at intersections was proposed to improve the traffic efficiency and driving safety. The applicable conditions and traffic organization method of T-type plane intersections far-leading of left-turning vehicles were analyzed. The relation model between lane volume and operating range of lanes changing was established. The location calculation model about U-turn of far-leading left-turning was constructed by taking minimum average delay of vehicles at intersections as the evaluation index, and the effect of adjacent intersections functional area was also considered. The model covered some parameters of intersections, such as geometric dimensioning and traffic flow. In addition, the delay calculation method of T-type intersections after far-leading and channelization was dissected. The example shows that, under certain conditions, the far-leading of left-turning at T-type intersections can effectively reduce the number of signal phase and average vehicle delay. The feasibility of the above method is verified by traffic simulation.

Key words: traffic engineering, U-turn followed by right-turn；delay；traffic simulation；intersection

摘要： 针对左转交通流对T型交叉口车辆运行影响较大的现象，提出了交叉口主路左转车流远引掉头的交通组织方式，以提高交通效率和行车安全。分析了T型平面交叉口主路左转远引的适用条件与车流组织方法，建立了车道流量与换道行驶距离之间的关系模型。以交叉口车辆平均延误最小为评价指标，考虑对相邻交叉口功能区的影响，构建了远引回转车流掉头位置计算模型，模型参数涵盖了交叉口的几何尺寸和交通流量等，并分析了远引渠化后T型交叉口的延误计算方法。实例应用分析表明，在一定条件下T型平面交叉口主路左转远引可有效减少信号相位数和车辆平均延误，交通仿真也验证了上述方法的有效性。

关键词: 交通工程, 远引掉头, 延误, 交通仿真, 交叉口