信号交叉口利用中央分隔带左转的优化研究

Optimum of left-turn with partition at the signalized intersection

对于有中央分隔带的交叉口,利用分隔带实现左转,可以减少交叉口的冲突点,减少其他相位上车流的延误,提高通行能力,但也相应地增加左转车流的延误.本文基于对利用中央分隔带的渠化设置的各车流延误计算,以交叉口总延误最小为目标,计算得到具体的交叉口设置形式.并比较设置前后的交叉口总延误,得到渠化设置的交叉口流量条件,为交叉口利用中央分隔带实现左转的优化设计提供了理论基础.最后通过具体的交叉口应用,得到了该交叉口利用中央分隔带左转设置的具体指标和方法,计算结果也证明了该交叉口渠化设置的实用性.

At the signalized intersection with central dividing strip, if the left-turn vehicles turn through the median, the number of conflict points can be reduced, capacity improved. As traffic delay of other phases is reduced, the left-turn traffic delay increased. Based on the traffic delay calculation of each phase, and aiming to reach the least delay, this paper calculates the traffic flow qualifications of channelization in getting to know the detailed position of left-turn portal, which provides the theoretical foundation for optimum design of left-turn with median in signalized intersections. In the end, a practical example is demonstrated. It also attains the detailed traffic flow qualifications and channelized method at intersections.