What is the significance of a "limited speed" signal under NORAC rules?

The significance of a "limited speed" signal under NORAC rules is that it requires a train to operate at a speed that allows it to stop within half the range of vision. This means that the train crew must reduce the train's speed to ensure it can halt safely if a hazard appears on the track or if the signal changes unexpectedly. The concept of stopping within half the range of vision is crucial for maintaining safety, as it provides the necessary time and distance for the engineer to react to any situation that might pose a risk.

Operating at limited speed not only enhances safety but also aligns with general practices for managing train movements in areas where there may be obstructions, track work, or other conditions that warrant caution. This regulation ensures that trains can respond effectively to any potential hazards, thereby preventing accidents and ensuring the overall safety of operations on the rail network.