Optimizing Transport Scheme of High Value-Added Shipments in Regions without Express Train Services

In railway transportation, high value-added shipments in regions with large traffic volumes are generally delivered by express train services, since these freights need to be delivered in a short time. However, there are also high value-added shipments in areas where express train services are not available. If these freights are delivered by the traditional approaches (i.e., the freight cars are delivered to the adjacent classification yard by local trains, combined with other freight cars to form a train, and finally sent to the destination according to the transportation plan) with multiple reclassifications (a reclassification is when wagons are separated from their original train and then join another train in a classification yard), it will lead to delivery delays and economic losses to shippers and contribute to severe carbon emissions. In this context, this paper proposes an innovative method to deliver high value-added shipments in regions without express train services, which is called the method of reserving axle loads. The differences in assembling and transfer costs achieved by the method of reserving axle loads and traditional method are analyzed, especially the car-hours saved for the accumulation process of freight cars in a classification yard. Then, a corresponding mathematical model is established, which involves four scenarios: reserving axle loads for departing; reserving axle loads for arriving; reserving axle loads for both departing and arriving; and not reserving axle loads. Finally, the practicability and feasibility of the model was verified by two numerical experiments.