Timetable Optimization Method for Single Bus Line Based on Multiple Vehicle Size Model

Urban bus operation is mainly affected by fluctuations in passenger demand and travel times on the route. Current studies try to find the optimal bus schedule plan with a fixed bus vehicle size. However, this method is not optimal to tackle the stochastic factors of the bus system. The aim of this paper is to develop a new schedule plan optimization model for the bus line with multiple vehicle sizes. The dispatching time of different vehicles are taken as the optimization variables and the total cost of passenger travel time and bus corporation operation minimization are set as the optimization objective. The impacts of bus crowding level and intersection signal control plan on travel time are quantified. Finally, the proposed method is validated using a bus line in Harbin City, China. Comparisons are conducted between the proposed method and traditional method.