中文摘要：

为了在左转许可相位下比较左转专用和直左共用车道的延误,分析了2种左转交通组织方式下交通流在交叉口运行的规律,基于可接受空当理论,以到达率和左转车辆比例为变量,分别建立了在泊松分布到达情况下2种左转交通组织方式下的延误模型,以西安市某交叉口的几何设计和信号控制数据为例进行了延误分析。计算结果表明：总延误随着到达率和左转车辆比例的增大而增大;到达率较小时设置左转专用车道的延误较大,随着到达率的增大设置直左共用车道的延误逐渐接近甚至超过设置左转专用车道的延误;直左共用车道适用于较小交通需求,左转专用车道适用于较大交通需求;当到达率不大于0.12pcu·s^-1,或到达率为0.12~0.18pcu·s^-1、左转车辆比例不大于0.2时,建议设置直左共用车道;当到达率不小于0.18pcu·s^-1,或到达率为0.12~0.18pcu·s^-1、左转车辆比例大于0.2时,建议设置左转专用车道。

英文摘要：

In order to compare the delays of exclusive left turn lane and through-left shared lane in permitted left turn phase, the operation laws of traffic flow under two left turn traffic organization modes were analyzed. Based on the gap acceptance theory, the arrival rate and the left turn vehicle percentage were taken as variables to build the delay models for two left turn traffic organization modes with Poisson arrival londition respectively. The geometric design and signal control data of a intersection in Xi＇an were taken as example to analyze the delays. Calculation result shows that total delays increase with the increase of arrival rate and left turn vehicle percentage. When arrival rate is smaller, the delay with exclusive left turn lane is larger. The delay with through-left shared lane gradually approaches or even overtakes the delay with exclusive left turn lane with the increase of arrival rate. Through-left shared lane is suitable for smaller traffic demand, and exclusive left turn lane is suitable for larger traffic demand. When arrival rate is no more than 0. 12 pcu·s^-1, or arrival rate is 0. 12-0. 18 pcu·s^-1 and left turn vehicle arrival vehicle 9 figs, percentage is no more than O. 2, through-left shared lane layout is recommended. When rate is no less than O. 18 pcu ·s^-1 , or arrival rate is O. 12-0. 18 pcu ·s^-1 and left turn percentage is more than 0. 2, exclusive left turn lane layout is recommended. 2 tabs, 33 refs.