What action is required if a fixed signal is absent from a location where it is usually displayed?

When a fixed signal is absent from a location where it is typically found, the procedure demands that the crew assume the signal is displaying the most restrictive aspect and notify the dispatcher. This approach ensures that train operations prioritize safety above all. By proceeding with the assumption of the most restrictive aspect, it helps to prevent potential accidents or miscommunications that could arise if a train were to assume a more favorable signal aspect in the absence of any indication.

The rationale behind notifying the dispatcher is to maintain communication and allow the proper authorities to investigate the situation, ensuring that the integrity of the signaling system is upheld. This practice fosters a thorough standardization in operations, providing an additional layer of security in the absence of visual indicators.

In contrast, assuming that the signal is displaying a proceed aspect disregards the uncertainty surrounding the situation and can lead to unsafe conditions. Ignoring the absence of the signal and proceeding as normal also compromises safety and raises operational risks. Contacting the nearest signal maintainer, while potentially helpful, is not the immediate required action and does not conform to established protocol that emphasizes notifying the dispatcher first in such situations.