As one of factors that causes requirement for lane change in FIGS. 11A and 11B, it is considered to be a case that another vehicle is getting closer from the rear at a high speed. It is considered that an occupant in travelling with automated driving has a less degree of concern and/or attention to following vehicles compared to travelling with manual driving. Accordingly, it is preferable to perform displaying at the first and/or second display devices 3, 4 for calling attention on rapid approaching of a following vehicle at the same time to perform displaying of prior notice of lane change.