What is indicated by the display of a yellow-red flag less than two miles before a restricted area?

The display of a yellow-red flag less than two miles before a restricted area serves as an important warning to employees, indicating that they should prepare for a stop. This flag is a visual signal meant to alert train crews to an upcoming condition that requires caution, often related to track work, maintenance, or other hazards ahead.

In this context, the yellow-red flag acts as a proactive measure, giving crews sufficient notice to reduce speed and be ready for potential restrictions in movement. This is particularly crucial in maintaining safety, as it allows time for the crew to respond appropriately to the signal and the conditions ahead. Understanding this warning is vital for ensuring that train operations are conducted safely and efficiently in areas where caution is required.

The other options do not accurately reflect the purpose of the yellow-red flag, as the train must not proceed at normal speed, there are indeed restrictions in the area that necessitate a stop, and train movements are not entirely prohibited but must be approached with caution and preparation for a stop.