信号交叉口上游公交站点对饱和流率影响分析

Impact of Upstream Linear Bus Stop on Saturated Flow Rate at Signalized Intersection

针对公交车辆在交叉口上游直线式公交站点停靠时对交叉口饱和流率的影响问题,以元胞传输模型为基础,并将其扩展,建立信号交叉口处的元胞车辆运行迭代规则,以及公交站点处公交停靠时的元胞车辆运行规则,进而将路段上游直线式站点公交到达的情况进行分类讨论,运用元胞传输模型对公交停靠造成的流率影响进行建模,并设定信号交叉口处饱和流率判定方式。最后对所提出的饱和流率影响模型进行数值分析,分别以交叉口信号周期、绿信比、公交停靠时间、交通流量等因素为变量研究对交叉口饱和流率的影响大小。结果表明,公交停靠时间、绿信比和站点位置对交叉口饱和流率折减影响较大。随着公交停靠时间、绿信比增大和站点到交叉口距离减小,饱和流率减小。

Aiming at the influence to the saturation flow rate of the intersection when the bus stops at the straight-line bus stop upstream of the intersection,based on the cellular transmission model and its extension,the iterative rules of the cellular vehicle operation at the signal intersection and the cellular vehicle operation rules at the bus stop are established.Then the arrival of the bus at the straight-line bus stop upstream of the road section is classified.The influence to flow rate caused by bus stop is modeled by cell transmission model,and the determination method of saturation flow rate at signalized intersection is set.Finally,the influence of signal period,green signal ratio,dwell time,traffic flow and other factors on the saturation flow rate is analyzed.The results show that dwell time,green signal ratio and station location have great influence on the reduction of saturation flow rate.With the increase of dwell time,green signal ratio and the decrease of distance from station to intersection,saturation flow rate decreases.