The use of Global Positioning System receivers installed on locomotives or railcars to provide continuous real-time location data independent of wayside AEI readers. GPS tracking is standard on locomotives and is increasingly deployed on railcars and intermodal containers for enhanced visibility. It provides location data in areas between AEI readers and within yards.
A system of passive RFID tags mounted on every railcar and locomotive and read by wayside readers at strategic locations throughout the network, automatically recording the car number, direction, and time of passage. AEI data is the backbone of real-time car location and train tracking for both operational and customer visibility purposes. The system was mandated by the FRA and deployed network-wide in the 1990s.
The integrated use of telecommunications and informatics to remotely monitor and transmit data from railcars and locomotives, including GPS location, temperature, shock events, door open/close status, and mechanical sensor readings. Telematics devices enable proactive management of car condition and cargo integrity without physical inspection. They are increasingly standard on tank cars, refrigerator cars, and high-value equipment.
The process of locating a specific railcar by querying the railroad's information system or the industry-wide Railinc car location network. Car traces provide current location, status, and estimated arrival information. Shippers use car traces to plan unloading schedules and manage inventory.
The predicted date and time at which a railcar or intermodal shipment is expected to arrive at its destination, based on current location, train plan, and historical performance data. ETAs are published through railroad customer portals and EDI transactions. Predictive ETA models increasingly use machine learning to improve accuracy.
A safety system mandated by Congress after the 2008 Chatsworth collision that automatically enforces speed limits, prevents train-to-train collisions, and enforces temporary speed restrictions, overriding human error. PTC uses GPS, wireless communications, and digital track maps to monitor and control train movements in real time. All Class I railroads completed PTC implementation by the 2020 deadline.