What does a blue signal represent?

A blue signal is specifically used in railroad operations to indicate that workmen are on or near the equipment, ensuring that the area is safe for employees to conduct their duties. This signal is critical for maintaining safety on the tracks and around operating equipment, as it alerts train operators and other personnel to the presence of workers. The use of a blue signal helps prevent accidents by communicating that extra caution is required in that area, thus ensuring both the safety of the workers and the efficiency of train operations.

While other signals may serve different functions—such as indicating high speeds, warning of hazards, or signaling track maintenance—the key feature of a blue signal is its direct relation to the presence of workmen, emphasizing the importance of workplace safety in rail operations.