What is the first step in responding to a yellow-red flag?

The appropriate initial action when encountering a yellow-red flag is to move at restricted speed. This strategy is essential for ensuring safety in the event of a warning that there may be a need for caution or that conditions ahead require the train to be prepared to stop. Moving at restricted speed allows the crew to control the train's movement more effectively, ensuring they can respond to any developing situations while still being able to stop safely within the distance they can see.

In this context, recognizing the need for a cautious approach is critical, as yellow-red flags are typically indicative of an in-progress or potential hazard ahead on the track. The implementation of restricted speed helps to maximize reaction time and minimizes risks associated with unexpected obstacles or conditions.