Final answer:
High visibility clothing must be worn when working this distance from any rail to ensure safety and visibility.
Step-by-step explanation:
High visibility clothing must be worn when working this distance from any rail to ensure safety. This is because high visibility clothing is designed to make the wearer easily visible, especially in low-light or hazardous environments. By wearing high visibility clothing, workers can increase their visibility to other individuals and vehicles, reducing the risk of accidents or collisions. Therefore, it is crucial to follow the safety protocols and wear high visibility clothing when working near rails.