Simulation and analysis of railroad hump yards in North America

Freight railroad terminals receive inbound trains, classify or regroup railcars, and build outbound trains. There are two types of terminals: hump yard which uses gravity to sort railcars and flat switching yard. In general, a hump yard is more productive than a flat switching yards. Due to the complexity of terminal operations, computer simulation offers a flexible and credible technique to identify opportunities for yard performance improvements. However, the use of simulation technique to model terminal operations is not a common practice in freight railroads. In this paper, we introduce a simulation model which depicts the typical operations in a railroad hump yard and present key performance measurements that are used to gauge the efficiency of yard operations and infrastructure. Finally, we illustrate the use of simulation model to improve terminal operations.