Abstract: An electromechanical rotary switch actuator for the operation of doors of mass transit vehicles. The switch actuator discloses a crew switch actuator that incorporates the features of a rotary switch while at the same time provides low cost manufacturing of the switch actuator apparatus. The invention is a simple, yet innovative, apparatus whereby rotational control of the switch assembly is provided by a retaining member which mates with a slot grooved into a shaft mounted for rotation in the actuator body. The longitudinally axial dimension of the actuator body is small which enables the apparatus to be flush mounted to the outside walls of the transit vehicles. The crew switch actuator disclosed is operated not only by a detachable key which is also disclosed, but also may be actuated with the same keys currently being used to operate the door control switches of most mass transit systems.