What indicates that a route clearance has been issued?

• A. A handwritten note left in the control room.
• B. An audible alarm in the locomotive.
• C. Dispatcher authorization and a route indicator on the signal system.
• D. A calendar entry in the timetable.

Answer: (C)

Route clearance means the dispatcher has officially authorized a train to move along a defined route, and the signaling system reflects that authorization. The best indicator is both the dispatcher’s authorization and the route indicator on the signal system showing the chosen route set for that train. A handwritten note is not an official, real-time clearance; an audible alarm is a warning, not a clearance; and a calendar entry in the timetable is just a plan, not active authorization.