INTERMODAL TERMINAL CAPACITY MODELING

摘要

Growing demand for freight transportation heightens the need for expanding capacity and developing effective operations at intermodal facilities (IMF). The need for operations analysis and capacity modeling can range from a high-level assessment for planning, to detailed simulation modeling to understand the impact of design elements and operating strategies on terminal efficiency. This paper will describe various IMF capacity models, their development and recommended applications. A planning model can be used to size a proposed facility with minimal data collection requirements. Historically, this assessment was done with rule-of-thumb calculations, but a need exists for a model to assess the capacity benefits of terminal features such as working track length, support track length, mainline connections, yard arrangement and lift equipment. Development of such a model requires extensive data collection and facility benchmarking to be processed through multi-variant regression analysis, which lead to a correlation-based/kinematic-based spreadsheet capacity model. Such a model has been developed and validated against terminal operating near their capacity and against dynamic simulation modeling. When more detailed modeling is required, discrete event simulation (DES) models are employed. This paper will describe several DES models including: a basic train movement/intermodal lift operation; detailed terminal operations with container yard handling; and highly detailed wide-span gantry IMF operations. Simulation is especially valuable when evaluating automation in these terminals. The authors have developed terminal capacity models to address this range of requirements based on their experience managing intermodal operations, benchmarking terminal performance, performing industrial operations analyses and designing traditional and automated intermodal terminals.