In relation to track safety, what are blue flags used for?

Blue flags are specifically used to signal that track work is in progress. This system is a critical safety measure that alerts both train operators and workers in the area that work is taking place on or near the tracks, ensuring that trains do not enter that section and that the individuals involved are protected from accidents. The use of blue flags is part of standard operating procedures to maintain a safe environment during maintenance or repair activities, clearly indicating to all parties that the area is restricted for active train operations.

Other options, such as indicating train approaches or marking personnel areas, do not accurately reflect the specific role of blue flags in the context of track safety. Understanding the purpose of blue flags is essential for engineers and safety personnel to effectively manage and communicate safety protocols during track maintenance activities.