In restricted speed operation, what distance-related preparation must the crew maintain?

• A. Be prepared to stop within one quarter of the range of vision
• B. Be prepared to stop within one half of the range of vision
• C. Stop only at the next signal without regard to vision
• D. Maintain a constant speed regardless of vision

Answer: (B)

In restricted speed operation, you must be able to bring the train to a stop within the portion of the track you can clearly see ahead. Specifically, you should be prepared to stop within half of the range of vision. This gives a safety margin for your reaction time and the train’s braking distance, which can vary with train weight, track condition, weather, and visibility. If you can see farther, you still limit your speed so that you can stop within that visible distance, rather than risking an unexpected obstacle appearing before you can react.

This is why stopping within half the range of vision is the best standard: it accounts for imperfect sight, variable braking performance, and the need to respond to hazards that may become visible only at the last moment. The other ideas—stopping within a quarter of the range, stopping only at the next signal regardless of what you can see, or maintaining constant speed regardless of vision—do not provide the safety buffer and would not align with restricted speed practices.