Abstract: The operating mechanism of a railroad crossing gate employs a variable mechanical advantage connection to transmit force from the drive motor to the gate member to raise and lower the same. The main shaft of the mechanism serves as a mount for the gate member and its counterweights, and an operating arm is fixed to the shaft and extends radially therefrom. A crank is driven by reduction gearing and is connected to the arm by a sliding coupling which reciprocates on the arm longitudinally thereof as the crank rotates. The axis of rotation of the crank is located such that the mechanical advantage is high when the gate member is in either its raised or its lowered position, decreasing to a ratio approaching unity at the midpoint of travel in either direction. Accordingly, the starting load is minimized, the gate member is accelerated once it is in motion, and its speed is then reduced as it nears the end of its travel.