Which system prevents conflicting train routes by coordinating signals and track switches?

• A. Block signaling.
• B. Overhead catenary.
• C. Interlocking.
• D. Pantograph.

Answer: (C)

Interlocking coordinates signals with track switches to prevent two trains from moving onto conflicting paths. It uses locking mechanisms that tie the position of signals to the alignment of turnouts, so a route can only show a proceed aspect if the required switches are correctly set and secured. If anything isn’t safe, the system blocks the route and keeps signals in a safe state, ensuring that only one valid path through a junction can be used at a time. Block signaling, by contrast, mainly handles dividing track into sections and controlling trains based on occupancy, while overhead catenary and pantograph relate to power delivery, not routing coordination.