时间依赖需求下多车型快速公交发车频率优化

Optimization of departure frequency for bus rapid transit with multi-type vehicles under time-dependent demand

以公共交通网络中的单条快速公交线路为研究对象,分析了快速公交车辆的发车间隔特征和沿线乘客出行需求的时间依赖特征;考虑多类型公交车辆协同作业,以所有乘客的累计等待时间最小和车辆的平均满载率最大为目标,以最小、最大发车时间间隔和车辆运能的供需比为约束,建立多类型快速公交车辆协同作业模式下的发车频率优化模型;利用改进的非支配排序遗传算法对模型求解,并应用兰州市快速公交数据进行实例分析。分析结果表明:乘客累计等待时间分别取最大值、中间值和最小值时,优化后的发车次数比实际发车次数分别降低22.9%、16.7%和8.4%,对应的车辆平均满载率分别提高27.4%、15.1%和3.9%;与单一类型的快速公交车辆独立作业相比,2种类型的快速公交车辆协同作业的平均发车次数增加7.9%,平均乘客累计等待时间降低23.8%。可见,根据乘客出行需求的时间依赖特征,合理安排不同类型的快速公交车辆协同作业,对发车频率进行优化,能有效减少乘客等待时间,提高公交车辆利用效率。

Taking the single bus rapid transit line in public transport network as the research object,the departure interval characteristics of bus rapid transit vehicles and time-dependent characteristics of passenger travel demand along the line were analyzed.With consideration of various types of buses working collaboratively,the minimum cumulative waiting time of all passengers and the maximum average load rate of vehicles were taken as the objectives,the minimum,maximum departure time intervals and the ratio of supply to demand for vehicle transport capacity were taken as the constraints,and an optimization model of departure frequency under the collaboratively working mode of bus rapid transit with multi-type vehicles was constructed.An improved non-dominated sorting genetic algorithm was used to solve the model.The bus rapid transit data in Lanzhou City was used to carry out case analysis.Analysis result shows that when the cumulative waiting times of passengers reach to the maximum,intermediate and minimum values,the optimized departure times reduce by 22.9%,16.7%and 8.4%,respectively,compared to the actual departure times,and the corresponding average load rates of vehicles increase by27.4%,15.1%and 3.9%,respectively.Compared to the single type of bus rapid transit vehicle working independently,the average departure time of two types of bus rapid transit vehicles working collaboratively increases by 7.9%,and the average cumulative waiting time of passengers reduces by 23.8%.According to the time-dependent characteristics of passenger travel demand,the optimization of departure frequency with the reasonable arrangement for various types of bus rapid transit vehicles working collaboratively can reduce the waiting time of passengers effectively and increase the utilization efficiency of buses.