定点停靠公交站的路段通行能力计算方法

路段通行能力不仅与公交站的设置形式有关，同时受到公交车停靠方式的影响.本文引入经典的c_M/M/1排队模型，结合概率论得出定点停靠公交站的进站排队时间.在此基础上，从时间占用的角度计算定点停靠公交站的路段通行能力.结果表明，与自由停靠相比，定点停靠公交站有效泊位数的边际效用递减规律更为显著.一方面，定点停靠排队溢出概率较大引起路段通行能力降低；另一方面定点停靠公交车服务时长减小导致路段通行能力变大.当公交到达率接近饱和值时，定点停靠公交站的路段通行能力约为普通路段通行能力的96%，比自由停靠公交站提高了1%.

Calculation Method of Road Link Capacity with Fixed-dwelling Bus Stop

There is no doubt that the road link capacity is affected by the layout of bus-stop. Meanwhile, the impact of dwelling way on road link capacity cannot be ignored to some extent. In this paper, a typical c_M/ M/1 queueing model is proposed to analyze the waiting time for entering the fixed-dwelling bus stop. Based on this, road link capacity is estimated from the view of time occupation. Results show that compared with free-dwelling bus stop, the effective berth number of fixed-dwelling bus stop has a more distinct marginal decreasing law of value. On the one hand the increasing failure rate at fixed-dwelling bus stop reduces link capacity, on the other hand the less service time caused by fixed-dwelling compensates link capacity. When the bus arrival rate is getting close to saturation, the adjustment factor of road link capacity with fixeddwelling bus stop is about 0.96 and this factor is one percent increase over the factor of free-dwelling bus stop.