Some city transit buses may have a brake-door interlock system, this system:

Question

Accepted Answer

A: Works when the passenger exit doors are open.. The brake and accelerator interlock system holds the throttle in the idle position while applying the brakes whenever the exit door is opened. This safety procedure ensures that the vehicle does not move as passengers enter and exit. This feature should never be used as a parking brake.

Some city transit buses may have a brake-door interlock system, this system:

Alabama CDL Passenger Test Info