Integrated Optimization of Train Formation Plan and Rolling Stock Scheduling with Multiple Turnaround Operations Under Uneven Demand in an Urban Rail Transit Line

The passenger demand of urban rail transit is dynamic and uneven in time and space, and traditional train plan of single train formation cannot adapt to dynamic passenger demand. In order to solve the redundancy of train capacity caused by uneven passenger demand in bi-directions, we proposed a mixed-integer linear programing model (MILP) to optimize the train formation plan and rolling stock scheduling integrally based on known passenger demand and timetable for an urban rail transit line. The turnaround operation, coupling/decoupling operation, the entering/exiting depot operation of train services, the number of available trains and the capacity of depot are involved. The model is solved by the CPLEX solver. As illustration, the model is applied to Beijing Batong line to verify its effectiveness and performance. The results show that through this integrated approach the number of operation formations can reduce 44% and the number of rolling stocks can reduce 20%. It demonstrated that the proposed model can effectively reduce the operation cost while satisfy the uneven demand.