When may yellow-red flags be displayed less than two miles in advance of a restricted area?

The correct answer relates to the operational procedures for signaling and ensuring safety around restricted areas on the railway. Yellow-red flags are used to indicate that a restricted area is approaching, and typically, they need to be displayed a sufficient distance in advance—generally two miles—to provide crews with ample time to react.

When the area is close to a terminal or junction, it's often necessary to adjust standard practices due to the unique operational needs in these environments. Terminals and junctions commonly involve more frequent stopping, switching, and potential train interactions, where immediate awareness of restricted areas is crucial. Hence, the requirement for displaying yellow-red flags can be modified, allowing them to be shown less than the standard two-mile distance. This flexibility is important to maintain efficient operations while ensuring safety and awareness for train crews navigating complex areas.

The other options involve scenarios that do not directly pertain to operational flexibility in the same way. For instance, tasks regarding safety protocols around equipment hazards or the presence of green flags do not inherently justify reducing the standard distance for yellow-red flag displays. Additionally, simply following directives from the train dispatcher does not automatically imply that adjustments can be made regarding flag display distances without considering the context of the restricted area.