When is the dead-man feature on subway cars inoperative?

The dead-man feature on subway cars is designed to ensure that the operator remains alert and in control while the train is in motion. It requires the operator to actively engage with the controls, such as by maintaining pressure on a pedal or handle.

When the reverser key is centered, it indicates that the train is not in a direction of travel and effectively disables the propulsion of the train. This means that the dead-man feature isn't required to engage since the train cannot move forward or backward while the reverser is centered. Thus, the system is considered inoperative because it is not necessary for the safety of the operation when the train is not actively in motion.

In contrast, the other scenarios highlight situations where the dead-man feature is operational. If the operator is not at the controls, the feature should activate to prevent movement. Likewise, when the train is in motion, the dead-man feature serves its crucial function of maintaining operator engagement. During maintenance checks, procedures typically ensure that systems like the dead-man feature are operational to maintain safety standards.