Positive Train Location

FRA PTL: Supporting Next-Generation Train Operations

The ability to precisely locate and track train movement on the rail network is the cornerstone of modern train control systems. The Interoperable Electronic Train Management System (I-ETMS) and Positive Train Control (PTC) systems currently used by Class I railroads, operational on approximately 54,000 route-miles, rely on the Global Positioning System (GPS) to identify the location of the train lead locomotive, crew-entered track information, and switch position. The location of the rear of the train is then derived from the location of the lead locomotive using the train length, typically provided by the railroad’s management information systems (MIS) and confirmed or updated by the locomotive engineer.