Define Positive Train Control (PTC) and its primary objective.

• A. A safety system that monitors train movements and enforces speed restrictions and prevent collisions or overspeed.
• B. A system to optimize energy usage on trains.
• C. A passenger information system.
• D. A manual signaling protocol.

Answer: (B)

Positive Train Control is a safety system that monitors train movements, enforces speed restrictions, and prevents collisions or overspeed events. It uses onboard equipment, trackside data, and centralized systems to determine the safe movement authority for a train and can automatically apply the brakes if the train approaches or exceeds those limits. The primary objective is to reduce human error by automatically enforcing movement authorities and speed restrictions, thereby preventing train-to-train collisions, overspeed derailments, and incursions into restricted areas. It is not about optimizing energy usage, providing passenger information, or functioning as a manual signaling protocol.