Scheduling Direct and Indirect Trains and Containers in an Intermodal Setting

Abstract

The focus of our research is on rail transportation of intermodal containers. We address the problem of determining day-of-week schedules for both direct and indirect (via a hub) trains and allocating containers to these trains for the rail (linehaul) portion of the intermodal trip. The goal is to minimize operating costs, including a fixed charge for each train, variable transportation and handling costs for each container and yard storage costs, while meeting on-time delivery requirements. We formulate the problem as an integer program and develop a novel decomposition procedure to find near-optimal solutions. We also develop a method to provide relatively tight bounds on the objective function values. Finally, we compare our solutions to those obtained with heuristics designed to mimic current operations, and show that a savings of between 5 and 20% can be gained from using our solution procedure.