When a lane-width-direction lateral position (X2obst+X0) of a vehicle (MM) reaches a predetermined control start position (60) being a lane-width-direction lateral position (X2obst+X0) serving as an approach prevention indicator for the vehicle (MM), a control start is determined and a yaw moment (Ms) toward the center of a vehicle traveling lane (200) is applied to the vehicle (MM) to control the vehicle (MM). Then, when the lane-width-direction lateral position (X2obst+X0) of the vehicle (MM) moves from the outside to the inside of the control start position (60), the determination of control start is suppressed for a predetermined period, compared to a period before the movement to the inside of the control start position (60).