What does a non-illuminated sign signify in train operations?

A non-illuminated sign in train operations typically signifies a state where the train should coast. This means the operator can allow the train to continue moving without having to exert power, as the absence of illumination indicates no immediate action or change in speed is required. In train signaling, non-illuminated signs are often interpreted as a normal or neutral indication, guiding the operator to maintain their current course of action without needing to alter speed or prepare for a stop.

In general, illuminated signs convey more urgent messages or require immediate responses, while non-illuminated signs suggest that conditions are stable. Thus, understanding the meaning of signs in this context is critical for safe and efficient train operation, particularly in recognizing when to allow the train to coast.