远引平面交叉口中央分向岛开口位置探讨

Research About the Location of Median U-turn Openings on Roadways

在城市交通系统中,解决好交叉口的左转交通具有举足轻重的作用。近年来许多地方和政府考虑在中央分隔带上开口采用迂线回转来代替交叉口直接左转以减少交叉口的交通冲突。在设置中央分隔带回转路口时,其位置对回转车流的安全及其运行效率有着直接的影响。作者结合远引平面交叉口的交通特性,道路通行能力与左转车辆延误,建立了确定中央分向岛开口位置的模型。计算表明其对远引平面交叉口的运营及安全设计具有一定的指导意义。

The problems of intersections left-turn have played important roles in the system of urban traffic.Many government and local transportation agencies planed to reduce the conflict of traffic by U-turn median openings instead of the direct left-turn in the intersection.The location of these U-turn median openings will have has a direct relationship to highway efficiency and traffic progression and operations of U-turn vehicles.The author developed the model which calculated the location of median openings based on the character of traffic in the intersection,capacity and left-turn delay.A case study demonstrated the model was developed to guide U-turn median operations and safety design.