Optimizing rail-truck intermodal drayage operations

This thesis presents a case study of the trucking (or drayage) portion of rail-truck intermodal freight transportation. The approach used was to examine in detail the current costs and potential for improvement at one New Jersey intermodal terminal. The analysis is conducted using a mathematical programming model to find an optimal scheduling plan for the drayage operation. To solve the model more efficiently, a modification is made to explore the special structure of the original problem which has a sparse constraint matrix. The model is solved first with an objective function that minimizes the total cost of the operation, and then with an objective function that minimizes the total tractor fleet size required to move the containers. The model results indicate a 19.2% and 52.7% reduction in overall costs respectively for the objectives of minimizing total cost and minimizing fleet size. This reduction is achieved by repositioning and reloading containers, after they have been unloaded at consignees