When trains receive authority to occupy the main track after the arrival of a train or to follow a train, how must they ascertain the train's location?

• A. By GPS signals.
• B. Through the dispatcher or direct communication with a crew member of the train.
• C. By visual signals only.
• D. By previous timetable entry.

Answer: (B)

When a train is given authority to occupy the main track after another train or to follow it, you must confirm the preceding train’s exact location through direct communication with the dispatcher or with a crew member of that train. This provides real-time, authoritative information about where the train is and whether the block is actually clear, which is essential for safe sequencing and routing.

GPS data isn’t relied upon as the sole means of determining train location in this context because position information can be delayed or mistaken and doesn’t by itself confirm track occupancy or clearance. Visual signals can help, but they don’t give precise, timely location information over distance or in poor visibility. A timetable entry represents planned timing, not the current position or status of the train. Direct communication ensures accurate, up-to-the-moment knowledge of the train’s location and status before proceeding.