Abstract: A housing and telescoping arm are supported by a shaft pivot pivotally mounted in the ground. The telescoping arm includes a rotating rod actuator journalled for rotation in a bearing mounted atop the shaft. The rod includes a threaded portion extending longitudinally from the shaft to the gate. A traveling tubular member is mounted concentrically with the rod and includes a block having a threaded bore for receiving the threads of the rod. The arm is connected to the gate through a pinned connection between one end of the traveling member and a lower rail of the gate. Relative rotation between the rod an the traveling member is prevented by the pinned connection. As a result, the traveling member extends outwardly and retracts inwardly in response to the counter-clockwise and clockwise rotation respectively of the rod. A motor and transmission for driving the rod in rotation are mounted in the housing along with a motor control circuit.