基于实地收集数据,针对我国大城市主道路上公交车流量普遍较大的情况,考虑公交车有别于小汽车的特有的运行特性,引入公交车停站平均延误参数,利用截断正态分布建立了相邻交叉口有停靠站的公交车队密度离散模型,分析了上游交叉口的排队公交车辆在绿灯放行后往下游道路行驶过程中的离散特性,利用分段函数方式构造了公交车队在时空坐标上的交通流密度分布函数.针对相邻交叉口有一个停靠站的信号协调控制实例,提出了在某一时刻公交车队头部驶过和尾部未驶过下游断面的车辆数计算公式,推导了上下游交叉口断面处的流量分布模式,结合实测数据分析验证了该模型的有效性.
On the basis of field collected data and aiming at the large amount of bus traffic flow in urban arterials in China, this paper investigates the special operation characteristics of buses different from cars. Then, by using the truncated normal distribution of speed and by adopting the average stop time of buses in the station, a density dis- persion model of bus platoon in the presence of bus station in adjacent intersections is proposed. The dispersion characteristics of the bus platoon that moves down along the road during the green time are analyzed, and a piece- wise density distribution function of the bus flow is constructed in time-space coordinates. Moreover, by taking the signal coordination control of an intersection with a bus station as the example, an expression is deduced to calcu- late the number of cars in the conditions in which the front of the platoon has passed but the rear of the platoon has not passed a downstream point. Besides, the flow distribution mode in the upstream and downstream intersections is analyzed. Case study and numerical analysis show that the proposed model is effective.