A target vehicle speed at a predetermined position ahead of a host vehicle is obtained, and a plurality of deceleration patterns with different deceleration schemes is obtained for decelerating the host vehicle to the target vehicle speed. Based on a driving operation for controlling speed of the host vehicle, a deceleration pattern is selected from the plurality of deceleration patterns. Using the selected deceleration pattern as a reference, the vehicle speed of the host vehicle is reduced to the target vehicle speed before the host vehicle reaches the predetermined position.