Under which condition is napping permitted for train crews?

Napping is permitted for train crews when the crew is waiting for departure. This condition allows crew members to rest during periods of inactivity before the train begins its journey. Adequate rest is vital for maintaining alertness and safety when operating the train.

In situations where the crew is actively engaged in managing the train or operational activities, such as waiting for a signal to proceed or when all crew members are present but not in a state of wait for departure, napping would not be appropriate. Additionally, while long routes without stops may seem to allow for rest, safety protocols typically dictate that crew members must be alert and ready to act during the entirety of their duties, especially on active routes. Thus, waiting for departure creates a clear context in which napping is both acceptable and advantageous for the crew's preparedness.