TRAVEL CONTROL DEVICE, AND TRAVEL CONTROL SYSTEM

An object of the invention is to provide a traveling control system capable of reducing discomfort or uneasiness felt by a driver or an occupant in automatic traveling control of a vehicle. [0002] The invention provides a traveling control system including an on-vehicle control device that is mounted on a vehicle and performs traveling control on the vehicle and an on-vehicle display device that is connected to be communicable with the on-vehicle control device and presents information to an occupant of the vehicle through screen display or audio output. The on-vehicle control device acquires externality recognition information recognized by an externality sensor and/or out-of-vehicle communication, decides driving behavior content to be taken by the vehicle based on the externality recognition information, specifies a driving behavior cause which is a reason why the driving behavior content is decided, and outputs the driving behavior content and the specified driving behavior cause. The on-vehicle display device acquires the driving behavior content and the driving behavior cause output by the on-vehicle control device and notifies of the driving behavior content and the driving behavior cause through screen display or audio output.