Abstract: Through mathematical analysis of traffic flow parameters (volume, saturationflowrate, spacing), quantitive research of the length of widening lane with left-turn signal is carried out.Furthermore, the mathematical model is founded,and the computing software is also developed.The reduction factors of capacity at different widening lengths are obtained.vissim simulation is adopted to compare the results before and after optimization, which is verified the correctness and feasibility of the model.

Key words: widened intersection, left-turn lane, reduction factor of capacity, vissim simulation

摘要： 通过对交通量、饱和流率、平均车头间距交通流参数的数理分析,定量地研究了有专左相位的左转专用拓宽 车道长度。建立了数学模型,开发了计算软件,得出不同拓宽长度下的通行能力损失系数。经比选,得出车道长度 的优化值。实例分析,运用vissim仿真对优化前后进行对比,验证了模型的正确性、可操作性。

关键词: 拓宽车道, 左转专用车道长度, 通行能力损失系数, vissim仿真