What is one condition for a dispatcher to issue a Form D line 4 or line 13 authority for track removal?

The correct answer revolves around the requirement that the track must be clear of non-work movements for a dispatcher to issue a Form D line 4 or line 13 authority for track removal. This condition is crucial because ensuring the track is free from any interfering movements is essential for maintaining safety during maintenance operations.

When the track is clear, it allows the maintenance crew to perform their work without the risk of encountering trains or other equipment that could compromise their safety or the integrity of the work being done. The dispatcher is responsible for coordinating and ensuring that the safe working conditions are met prior to granting authority for track removal, and having no non-work movements is part of that essential safety check.

The other options, while potentially related to safe operations, do not address the direct requirements necessary for issuing Form D authority in this context. For example, having signals operating normally or all trains stopped might contribute to overall safety but are not specifically necessary conditions for granting track removal authority. Similarly, the presence of a maintenance crew is important, but if the track is not clear, issuing the authority would still pose safety risks. Hence, the requirement for the track to be clear is the pivotal condition.