The present invention is an article carrier assembly for mounting on an exterior surface of a motor vehicle The article carrier includes a pair of elongated side rails constructed and arranged to be mounted on an exterior surface of the motor vehicle. The side rails extend generally parallel to one another in a spaced apart relation. An elongated cross rail assembly is constructed and arranged to be mounted transversely between and releaseably lockable along the side rails in a range of operating positions. The cross rail assembly has rail locking structures mounted on opposite ends thereof. A rotatable rod gangs the rail locking structures together for cooperative movement thereof between locked positions wherein the rail locking structures engage the side rails to lock the cross rail assembly in one of the operating positions and disengage positions permitting longitudinal travel of the cross rail assembly along the side rails. An actuator is operatively connected to the rotatable rod for effecting the cooperative movement. The cross rail assembly is constructed and arranged such that an operator standing on one side of the vehicle can manipulate the actuator and move the cross rail assembly between the operating positions.