A vehicle speed setting of cruise control is changed based on an operation by a driver. At this time, it is determined whether the vehicle is traveling in a passing lane or a traveling lane (S202). If the vehicle is traveling in a passing lane, the speed at which the vehicle speed setting is changed is increased (S206). If a blinker on the passing lane side of the vehicle is on (S205), the speed at which the vehicle speed setting is changed is also increased (S206) even if the vehicle is traveling in the traveling lane.