What is the purpose of the yellow-red flag?

The yellow-red flag serves a specific purpose in railway operations, particularly as a warning signal. When this flag is displayed, it alerts train crews and dispatchers to prepare for a stop due to potential hazards or issues ahead on the track. It acts as a precautionary measure to ensure the safety of trains, crew members, and any passengers by signaling that there may be an obstruction or something that requires caution.

In contrast, other choices imply different functions that do not align with the established use of the yellow-red flag. For instance, a flag indicating a signal for departure would typically be a different color or type, focused on movement rather than the cautionary alert provided by the yellow-red combination. Marking the end of a section typically involves other visual indicators that denote boundaries rather than caution, and signaling for safe passage would not require a cautionary color like yellow-red, which inherently suggests potential dangers ahead. Therefore, the choice related to preparing for a stop due to hazards accurately reflects the flag’s intended purpose.