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

Yellow-red flags serve as an essential safety tool in notifying train crews of upcoming restricted areas. The correct answer highlights that yellow-red flags may be displayed less than two miles in advance of a restricted area when the area is close to a terminal or junction. This is based on the operational needs and the specific conditions surrounding terminals or junctions, where the speed and traffic patterns differ from more remote locations.

In these situations, it is crucial that train crews are aware of upcoming restrictions as they approach, enabling them to appropriately adjust their speed and prepare for any operational changes. Terminals and junctions typically have unique operational demands, which may justify the reduced distance for warning flags.

Other options do not align with the established protocols. For instance, the presence of a green flag, while indicating a clear condition, does not account for the need for advance warning of restrictions. Similarly, lacking equipment hazards does not inherently affect the distance at which yellow-red flags must be displayed. Lastly, while a directive from a train dispatcher may alter various operational protocols, it is not a standard condition that would universally apply to the flag display rule related to distances from restricted areas.