What is a Controlled Signal?

A Controlled Signal is defined as a fixed signal displaying a Stop indication that is managed by the Rail Traffic Controller. This type of signal is significant in maintaining safe operations on the rail track, especially in situations where trains are approaching areas that require immediate stopping or slowing down. The Rail Traffic Controller's role is crucial because they actively monitor train movements and can authorize a controlled signal to indicate when a train must halt. This ensures that there is a coordinated effort in traffic management, particularly at busy junctions or areas with potentially conflicting train paths.

In contrast, the other options describe different types of signals. A variable signal indicating the current position of a train would likely change based on real-time data but does not inherently control train movements as strictly as a controlled signal. A signal that only provides caution warnings lacks the definitive stop indication required to enforce train passage safety. Lastly, a signal indicating the direction a train should take relates more to directional signaling rather than a controlled stopping mechanism. Thus, the focus on active management by a Rail Traffic Controller fundamentally differentiates the controlled signal from the other signal types.