What does a "prohibit exit" signal do?

The "prohibit exit" signal is a critical safety measure within the context of roadway worker protection. It functions to lock out a signal, which prevents a clear block indication. This means that when the "prohibit exit" signal is active, it is a warning to workers that they should not proceed as it indicates that the area is not safe for entry or exit. The intention behind this signal is to ensure that workers remain within designated safe zones while train operations are taking place, thereby reducing the risk of accidents or injuries.

By locking out a signal, it helps to manage train movement and ensures that workers are aware that the area is potentially hazardous. This is essential in maintaining safety protocols on the railroad and ensuring that all personnel are protected while working in proximity to the tracks. The other options do not accurately reflect the purpose of the "prohibit exit" signal, as they relate to different aspects of rail operations and safety not relevant to this specific signal's function.