Abstract: A controlled gate system is comprised of a barrier arm which is pivotally connected to a first fixed support. A motion detector is secured to a second fixed support spaced a predetermined distance from the first fixed support and in alignment therewith to create a restricted passageway with the barrier arm normally resting in an obstructing position within the passageway. The barrier arm is arrested at the obstructing position by a solenoid actuated latch which is disengaged by the motion detector. The arc of displacement of the barrier arm is also restricted to permit passage through the passageway in a single direction. Under certain conditions a controller will permit the barrier arm to be disengaged to permit passage in the passageway in opposed directions. The motion detector of the preferred embodiment is constituted by a further barrier arm.