What are Interlocking Signals?

Interlocking signals refer to fixed signals that are part of a system designed to prevent conflicting movements through track junctions and crossings. This system ensures that signals operate in a coordinated manner, so that when one track section is occupied, other tracks cannot be accessed until it is safe to do so. This coordination helps to maintain safety and efficiency in rail operations by managing the flow of trains on the network.

The correct choice emphasizes the nature of these signals being fixed components of an interlocking system, which is critical for controlling train movements and preventing accidents. It is this integration into a larger signaling and track control system that distinguishes interlocking signals from other types of signals that may operate without regard to track configurations or other trains on the line.