采用延误分析法研究路口拓宽后信号交叉口的服务通行能力 ,利用交通仿真软件VISSIM对拓宽交叉口进行交通流微观仿真 ,从而得到拓宽车道的延误曲线 ,建立了基于交通仿真的拓宽交叉口延误流量模型 .依据该模型提出了拓宽左转车道的基本服务通行能力的建议值 ,并给出了各修正系数以及实用服务通行能力的确定方法 The delay analysis method is used to study the traffic capacity of signalized intersections after widening intersections. The traffic flow simulation software VISSIM is used to simulate the traffic flow at the widened intersections. The delay curves of the widened intersections are obtained, and the delay traffic is broadened based on traffic simulation Model.According to the model, the proposed value of broadening the basic service capacity of the left-turn lane is proposed and the method of determining each correction coefficient and the practical service capacity is given