What should be the acceptable position of the ATC Bypass switch when leaving the cab?

The acceptable position of the ATC Bypass switch when leaving the cab is the ATC position. In this setting, the Automatic Train Control (ATC) system is engaged and operational, ensuring that all safety functions are active and that the train is under proper control. This is crucial for maintaining safe train operations and adhering to established protocols.

When the ATC is engaged, it monitors various aspects of train movement, including speed, braking, and adherence to signals, which helps to prevent accidents. Leaving the cab with the switch in the ATC position means that the engineer is ensuring that the safety systems remain active and can intervene if necessary. It is important to remember that other positions, such as bypass or emergency, would disable these critical safety functions and could lead to hazardous situations if the train were to be operated after leaving the cab.