What is required if the headlight fails while the train is in motion at night?

In the event that the headlight fails while a train is in motion at night, it is critical to prioritize safety. Stopping before public crossings for safety is essential because these crossings are significant points where trains meet road traffic. A failure of the headlight reduces visibility for both the train crew and surrounding vehicles, increasing the risk of a collision. Hence, the train must halt at these intersections to prevent any potential accidents.

Although other options may seem reasonable, they do not directly address the immediate safety concerns presented by a headlight failure. Turning on all available lights or stopping until repairs are made does not guarantee the safety of the train and nearby vehicles without ensuring a complete stop at vulnerable locations like public crossings. Changing the lead unit might be impractical, especially if it does not directly involve resolving the immediate risks posed by the lack of a functioning headlight. Therefore, stopping before public crossings is the most immediate and appropriate action in this scenario to ensure the safety of all.