Lateral displacement reference positions (LXL, LXR) are provided on the left and right sides in the width direction of the middle in the width direction of a driving lane (L) in which a vehicle is running. When the vehicle is located at least between the left and right lateral displacement reference positions (LXL, LXR), the vehicle is feed-back controlled such that the yaw angle deviation decreases. When the vehicle is located outside the left and right lateral displacement reference positions (LXL, LXR) with respect to the middle of the driving lane, the vehicle is feed-back controlled such that the angle deviation and the lateral displacement deviation decrease.