Railyard Modeling: Part II. The Effect of Yard Facilities on Congestion

Abstract

After previously demonstrating that queueing models could be used to describe the classification, connection and train assembly operations in railyards, here is described how the service rates for these operations can be related to the physical characteristics of the yard and the traffic handled. Based on the number of classification tracks, the configuration of switching leads, the available yard engines, the marshaling rules and the traffic intensities, the switching workload is estimated. From unit operating times for these switching operations, the rates at which trains can be classified and assembled are calculated. These rates are then modified by standing capacity limitations of the yard. An example of the use of the model is presented.