Positive Train Control (PTC)

Category: infrastructure

An advanced, integrated safety system designed to automatically prevent train-to-train collisions, over-speed derailments, and unauthorized track entry.

PTC relies on a highly resilient network of GPS tracking, onboard locomotive computers, wayside interface units, and centralized database servers. The system dynamically monitors train coordinates, track speeds, and active switch alignments. If an engineer fails to respond to an over-speed warning or an approaching stop signal, the PTC system automatically overrides the manual control ledger and engages the air brakes.

Common Examples

• Implementing Positive Train Control across the commuter network required full synchronization between our wayside transponders and the centralized dispatch server.
• The locomotive computer triggered an automatic service brake application because the PTC system detected an unacknowledged speed restriction zone ahead.