What is required of a train encountering a displayed red flag?

When a train encounters a displayed red flag, the requirement is to stop and await further instructions. This action is crucial because a red flag indicates a potential hazard or issue on the track that requires immediate attention. By stopping, the train crew ensures the safety of the train operations, allowing for proper assessment of the situation.

Proceeding slowly and cautiously could lead to misunderstandings or misjudgments regarding the nature of the situation ahead. Continuing if the track is clear overlooks the warning associated with the red flag, which is meant to indicate that there is something that needs to be addressed before moving forward. Additionally, while calling the crew of the flagging team might seem useful, the priority remains to stop the train first to prevent any accidents or unsafe situations from occurring.