When is the use of an SSD required?

The requirement to use a Site Safety Device (SSD) comes into play when foul time exceeds 5 minutes. This specific regulation is crucial for maintaining a safe work environment for roadway workers. The SSD acts as a protective measure to ensure that workers are alerted and safeguarded against oncoming trains or any other hazards while they are working on or near the tracks.

This requirement is particularly important because longer periods of foul time indicate that the risk of trains approaching the work area remains elevated. By mandating the use of an SSD in such situations, the program aims to minimize the risk of accidents and enhance the overall safety of all personnel present in the work zone. The use of an SSD serves as a clear reminder of the ongoing potential hazards and reinforces safety protocols.

The other options do not align with the specific scenarios that necessitate the deployment of an SSD. For instance, safety briefings, changes in train schedules, and night shifts might be important considerations for workers, but they do not have the same direct correlation to the use of Site Safety Devices as the duration of foul time does.