How long must train crews retain written authorities that are no longer in effect?

Train crews are required to retain written authorities that are no longer in effect until the end of their tour of duty. This practice ensures that all relevant documentation is available for review and accountability, which is crucial for safety and operational efficiency. By keeping these documents until their shift concludes, it allows crews to refer back to any previously issued authorities if necessary, supports orderly handovers between shifts, and maintains a high standard of operational awareness.

This retention policy is a key part of the operational protocols in train dispatching as it helps avoid confusion about train movements and ensures that every crew member is aligned with the last known instructions until their duty is complete. This can be particularly important in events where clarifications or issues arise, as previous authorities may contain valuable context or information.