Which of the following conditions triggers the requirement for an announcement of a train stopping?

The requirement for an announcement of a train stopping is triggered specifically when the train is stopped on a controlled track. This is important in ensuring safety and effective communication among train crews, dispatchers, and other individuals involved in railroad operations. When a train stops on controlled track, it may not be immediately clear to approaching trains or personnel that it has halted. Announcing the stop helps prevent misunderstandings, ensures appropriate actions can be taken, and maintains situational awareness.

In contrast, stopping at any location, within yard limits, or during crew changes may not necessitate the same level of communication regarding safety or control because these situations might be considered standard or understood within specific operational contexts. Consequently, the emphasis is placed on stopping in potentially hazardous or less predictable areas, like controlled tracks, where communication is critical to safety protocols.