In this study a methodology using a computer simulation model for the design or redesign of rail classification yards was formulated, refined, tested and analyzed. The procedure concentrated upon developing both process and measures for evaluating the performance and efficiency of alternative yard configurations. The methodology addresses large scale yard systems analysis and properly assesses operating policy decisions.; The evaluation is divided into three hierarchical levels of analysis that are integrated with traditional yard layout design. The approach involves using a computer model to evaluate multiple alternatives under the same overall traffic loads. In the first two levels, individual yards are assessed using volume, speed and cost as the measures of effectiveness. The selection of a preferred alternative (the evaluation of the terminal as a whole) is based on three measures of performance, cost, transit time and reliability.; The process is formulated for complete terminal evaluation involving all possible yard configurations. Nevertheless, its structured input requirements and the type of output produced make it applicable for all types of analysis from the simple task of evaluating the operational efficiency of an existing yard to complete terminal design.; The model was developed and tested using data on the Terminal Railroad Association (TRRA) Madison Yard and the Alton and Southern Railway (A&S) Gateway Yard in East St. Louis, Illinois. The analysis showed that the model adequately evaluates yard operations and is sensitive to the independent policy variable. The process was shown to be comprehensive and can be used for any level of analysis or design. The methodology allows the inclusion of the no-build alternative and compares alternatives under the internal rate of return method.; It was suggested that the procedure developed in this paper helps to quantify and make rational a process that previously was largely intuitive and persuasive. Its potential contribution would be mainly in comprehensive analysis of large rail yard evaluation projects.
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