中文摘要：

合理组织禁左车流能够减少左转车辆的绕行延误．考虑城市道路双向机动车间为隔离栏的情况，采用排队论和概率论方法研究了“右转-掉头-直行”和“直行-掉头-右转”两种间接左转模式下掉头开口距离交叉口停车线距离的计算方法，得到“右转-掉头-直行”模式下右转车辆与相交道路直行车辆协调控制与不协调控制时掉头开口距离交叉口停车线距离的计算模型；得到“直行-掉头-右转”模式下路段设置信号灯与交叉口信号协调控制以及路段不设置信号灯时掉头开口距离交叉口停车线距离的计算模型；提出了协调控制时路段信号的“早断早启”技术及“早断早启”时间的计算方法．实例分析表明：间接左转交通组织方案可行，对于改善交叉口运行状况效果明显．

英文摘要：

Reasonable organization of left-turn forbidden traffic flow could effectively reduce the left-turn vehi- cles delay through signalized intersection. There are barriers between two-direction vehicles, through the queu- ing and probability theory, the distance of two indirect left-turn modes from the road turn-around position to the intersection stop line was studied. To ＂right-turn, turn-around and through＂ mode, considering coordina- tion-control or not for right-turn signal and intersecting-road through signal, the distance calculation model was established. To ＂through, turn-around and right-turn＂ mode, taking the two condition weather setting road median-opening signal to coordinate intersection signal into account, the distance calculation model was ob- tained too. To the ＂through, turn-around and right-turn＂ mode, when the coordination-control policy was a- dopted, the technique of ＂early-startup and early-stop＂ of road median-opening signal was put forward, and the calculation method of the time of ＂early-startup and early-stop＂ was put forward as well. The case study indicated that the indirect left-turn organization scheme was feasible, and had obvious effect on improving the operation of the signalized intersections.