Train Scheduling

Train schedule design is a critical element of the overall railroad operating plan design problem. It determines the utilization of the network, the train driver or crew requirements, the service received by customers, impacts locomotive requirements, and is a large determinant of network efficiency. This chapter focuses on the role of the train schedules, and describes the data elements making up a train schedule, the process of designing the train schedules, and managing these schedules on a real-time basis. This chapter provides the definitions for the following core OR train design problems: Train routing: how best to generate the routes of each train such that all traffic will be moved, and total train miles will be minimized. Minimizing total train miles also tends to maximize train size subject to a requirement that minimum train frequencies be observed. Block-to-train assignments: which blocks (groups of railcars) will be placed on each train, minimizing overall train complexity and the need to swap blocks en-route from one train to another. Train timing and connections: setting the timing of each train such that the overall transit times for all shipments will be minimized, taking into account the connections of railcars from one train to another, and the associated minimum processing times for such connections. Timing must also take into account the effective numbers of trains per hour that can be processed at each yard and can travel over each line segment.