In another embodiment, for providing prior notice of the next unscheduled travel behavior for the own vehicle with automated driving, it is possible to emit a prior notice sound to inform the occupant on the own vehicle of that prior notice has been displayed, in addition to displaying visual images described above at the first and second display devices 3, 4. Such a sound may be a signal sound such as a single beep and double beeps or a voice such as “lane change is to be performed”.