A command calculation unit calculates a target speed at each point on a road ahead of the own vehicle, and calculates a drive command for driving the own vehicle in the longitudinal direction of the own vehicle, based on the target speed and a current speed of the own vehicle. When output of the drive command that has been stopped is restarted, the command calculation unit adjusts the drive command, using an acceleration limit limiting acceleration of the own vehicle, or a jerk limit that limits jerk of the own vehicle. An output control unit controls output of the drive command, based on an input from at least one of a driver's operation of the own vehicle, and from another control system of the own vehicle. The output control unit temporarily reduces the value of at least one of the acceleration limit, the jerk limit and the drive command when restarting output of the drive command that was previously stopped.