Abstract: A revolving door system has a central axis defining a center shaft and three wing hangers rigidly joined and extending in a equidistant spaced apart relationship about the center shaft's upper portion.A pair of facing substantially semicircular walls, spaced apart to define regions of ingress and egress, partially surrounds the wings and shaft on opposite sides.The system allows free passage of persons in an authorized direction while preventing, and driving out, intruders attempting to pass in an unauthorized direction. If an intruder enters the system in an unauthorized direction, the door stops before the intruder has free passage to the other side, reverses direction and forces the intruder back toward the entrance. In one configuration, the door then rotates in its forward direction to permit the authorized passenger to escape the system, but not far enough to allow the intruder to pass. In another configuration, the reversal of the door allows the passenger to escape from the side in which it entered.