Which activity can a utility employee perform without blue signal protection?

The option indicating that a utility employee can perform air brake tests without blue signal protection is correct because air brake testing is generally considered part of routine maintenance and safety checks that can be conducted safely in controlled conditions. Blue signal protection is specifically designed to ensure workers are safe from moving equipment, primarily applicable when employees are working on or near track equipment that poses a risk of moving vehicles or machinery operating.

Air brake tests typically involve checking the functionality of the braking systems on rail vehicles and do not require employees to be in close proximity to moving equipment in the same way that coupling and uncoupling cars, or working on heavy machinery does. Utility employees performing air brake tests are usually operating within established safety protocols that do not necessitate the added protection of a blue signal, as they are not in a position that places them in immediate danger from moving trains.

In contrast, the other activities such as operating heavy machinery, moving equipment between stations, or coupling and uncoupling cars typically present a greater risk of injury from the movement of rail cars or equipment, necessitating formal blue signal protection to ensure the safety of workers in those scenarios.