Which elements must be present for a route through an interlocking to be considered cleared?

• A. The route indication is active.
• B. The interlocking shows locked settings.
• C. Dispatcher has cleared the route.
• D. All of the above.

Answer: (D)

Cleared means the route is fully authorized and protected for movement. It requires three things to be true at once: the route indication is active, showing the path that has been set; the interlocking shows locked settings, meaning the points and signals are secured to prevent conflicting movements; and the dispatcher has cleared the route, giving official authorization to proceed. If any one of these isn’t present, there’s no complete clearance, because there would be either no visible path, no physical protection of that path, or no formal authority to move. That’s why all three elements—active route indication, locked interlocking, and dispatcher clearance—are needed.