Comparing the Effectiveness of Fixed, Virtual, and Moving Block Train Control Systems on a Mixed Single- and Double-Track U.S. Freight Rail Corridor

Abstract

As the nationwide installation of positive train control (PTC) technology has recently been completed, freight railroads are searching for ways to leverage the technology to improve their operations beyond increasing safety. One commonly discussed possibility is developing and installing PTC-based virtual or moving block control systems to increase the capacity of railroad mainlines as a lower-cost alternative to adding costly track infrastructure. Considering that demand for freight rail transportation is expected to increase by 24% by 2045, and that most major mainline routes are operating at their maximum capacity, substantial capacity improvements will become necessary very soon. Since U.S. Class I railroads are for-profit companies, choosing the most cost-efficient way to increase network capacity is a primary objective. Thus, the potential capacity and performance benefits of virtual and moving block train control systems should be evaluated in realistic scenarios. This study utilized a novel dispatching algorithm and detailed railroad corridor simulator to evaluate fixed, virtual, and moving block systems over the full length of a 2,000-mi long U.S. Class I railroad mainline corridor composed of a mix of single- and double-tracks. Moving blocks were found to have the potential to maintain current average train speed under a 40% increase in train traffic, and that five virtual blocks per fixed block achieved most of the performance benefits of moving block control.