| This dissertation proposes and develops a process for managed booking of intermodal services to improve the reliability of railroad service commitments, increase asset utilization, and broaden the service options available to customers. These benefits stem from two substantial innovations to current intermodal service: managed reservation of intermodal traffic, and differentiated service based on different guaranteed trip times for each service class.; Emphasis is placed on improved service reliability and cost reduction rather than on revenue maximization. The link between booking and service quality stems from the two-tiered nature of intermodal operations. Most traffic travels fully planned and scheduled operations, but demand in excess of planned capacity 'overflows' from the planned system, requiring ad hoc adjustments to the plan. The motivation for booking control is the observation that planned service is typically more reliable and less resource intensive than unplanned service. The proposed pEMR system (postponement Expected Marginal Revenue) approach selectively postpones low priority traffic while maintaining customer service commitments in order to smooth traffic volumes on scheduled services and thereby reduce the incidence of overflows.; The study approach was to demonstrate how managed booking and differentiated service apply to intermodal service, to develop the pEMR design, and to measure the performance of alternative policies in a series of simulation tests. The simulations show that managed booking and differentiated service can improve service quality and operating efficiency, and demonstrate real-time performance with a moderate amount of computing power.; In the tests conducted, the pEMR booking system generated large improvements in the reliability of service commitments and the utilization of capacity, as well as moderate gains in profitability for nearly every case tested. Postponement added the most value when demand was less regular and when a reasonably high percentage of demand was postponeable. Typical performance improvements in the simulation tests were five to ten percentage point increases in utilization, 2% to 10% increases in profitability, and 30% to 98% reductions in overflow traffic. |
