What is the purpose of the whistle signal at grade crossings?

• A. To signal maintenance crews.
• B. To indicate the train is about to depart.
• C. To indicate track maintenance.
• D. To warn pedestrians and vehicles of an approaching train.

Answer: (D)

Whistle signals at grade crossings are a safety alert to people near the tracks. When a train approaches, the engineer sounds the horn to warn pedestrians and drivers who may be crossing or about to cross, giving them time to stop or move away and thus prevent collisions. The horn acts as a clear, audible warning, even if visibility is good or if other warning devices like gates or bells are present. It isn’t about signaling maintenance crews or indicating departure, and it isn’t a signal for track work. In some areas with quiet zones, horn use is restricted, but the purpose remains to warn anyone nearby of an approaching train.