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%.
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 fixed- dwelling bus stop is about 0.96 and this factor is one percent increase over the factor of free-dwelling bus stop.