When an own vehicle is highly likely to collide with an obstacle, a notification of prompting a driver to carry out a collision avoidance operation is appropriately given. When an output request for collision avoidance support information exists, a notification ECU notifies of the collision avoidance support information irrespective of absence/presence of an output request for vehicle-infrastructure cooperation support information. When the output request for the collision avoidance support information does not exist and the output request for the vehicle-infrastructure cooperation support information exists, the notification ECU notifies of the vehicle-infrastructure cooperation support information. Thus, when the conditions for the notification of the vehicle-infrastructure cooperation support information and the collision avoidance support information are simultaneously satisfied, the vehicle-infrastructure cooperation support information is inhibited from being notified and the collision avoidance support information is notified.