If a fixed signal is absent from its usual position, how should movement be governed?

When a fixed signal is absent from its usual position, the appropriate response is to govern movement by the most restrictive indication possible. This principle ensures safety by treating the situation with caution, minimizing the risk of accidents resulting from potential misinterpretation of the track conditions.

In the absence of a signal, it is prudent to adopt a conservative approach. By following the most restrictive indication, crews are positioned to reduce speed significantly, check their surroundings carefully, and prepare for unexpected conditions that may not be indicated by a signal.

Other options may present a more flexible interpretation of the situation, but they could lead to unintended hazards. Relying on the last signal encountered could lead to unsafe speeds or actions based on outdated information. Governing by the next signal displayed is not reliable either, as it presupposes that future indications will be clear and that there are no unforeseen obstacles or changes in track conditions before the next signal is reached. Following the criteria of the surrounding area might introduce ambiguity and subjectivity, which could create inconsistencies in safety protocol. Hence, the safest route is to always act based on the most restrictive indication possible when a fixed signal is missing.