A heartbeat sensor obtains a heartbeat of a driver. A concentration level computing unit estimates a concentration level of the driver at a time later than a timing of obtaining the heartbeat by the heartbeat sensor, on the basis of the heartbeat obtained by the heartbeat sensor. A state determining unit controls driving assistance for a vehicle on the basis of a comparison of the concentration level of the driver estimated by the concentration level computing unit with a target concentration level of the driver that is set in association with a position or an environment in which the vehicle driven by the driver is predicted to travel.