中文摘要：

在道路交叉口中,采用禁止左转方式可以消除交叉口的左转车流冲突点,提高交叉口的通行效率和行车安全,但同时也会增加邻接路段和交叉口的交通压力。采用VISSIM交通仿真系统对相邻2主路与2次路相交组成的4交叉口区域在禁止左转条件下进行仿真分析,研究主路交叉口禁止左转对区域交通的影响。分别采用韦伯斯特法计算各交叉口的信号配时参数,在此基础上对2主路交叉口进行协调控制,得到交通区域在禁左前后的仿真数据。分别对交通区域的行程时间、排队队长、行车延误进行分析研究,结果表明：主路交叉口禁左后,周期时长得以降低,交叉口延误有明显降低;主次交叉口与次路交叉口的延误均有所增加;交叉口区域的总行程时间和行车延误也有微小增长。

英文摘要：

At road intersections no left turn can eliminate conflict points in left- turning flow at intersections and improve passing efficiency and driving safety at intersections, but meanwhile will increased traffic pressure at adjacent sections and intersections. This paper carries out simulated analysis for a 4- intersection area composed by adjacent 2 main roads and 2 side roads under the condition of no left turn by means of VISSIM traffic simulation system, and studies influences of no left turn at intersections of main roads on area traffic. The paper adopts the Webster method to calculate signal timing parameters at all intersections and on this basis performs coordinative control of intersections between 2main roads to obtain simulated data of traffic area before and after no left turn. The paper analyzes and studies travel time,queue length and driving delay in traffic area,the results show that the cycle time is reduced and delay at intersections is reduced remarkably after no left turn at intersections of main roads;delay at intersections between main and side roads and at intersections of side roads is increased; and total travel time and driving delay in the area of intersections are increased slightly.