FIG. 6B exemplifies a configuration of the display screen 34 in a case that the monitor device 24 is used as the second display device 4. The display screen 34 in FIG. 6B is divided into two areas being a behavior display area 35a, similarly to the main display area 31 of the first display device 3, for displaying an image indicating a scheduled travel course on a road during travelling with automated driving and an image providing prior notice of an unscheduled travel behavior such as deviating from a scheduled travel course on a road and a navigation display area 35b for displaying map data as the display device of the car navigation system.