First, the virtual image 46″ starts, on the actual scenery as a virtual image 461″ in FIG. 14A illustrating a virtual vehicle having approximately the same size as the picture image 40 of the own vehicle and moving out of the picture image 40 toward the cruising lane 45′. As illustrated by a virtual image 462″ in FIG. 14B, the virtual vehicle moves to the cruising lane 45′ to be apart therefrom while changing orientation of the vehicle body as being similar to the actual vehicle along the travel course of the symbol image 44″. Then, as illustrated in FIG. 14C, the virtual vehicle completes movement to be the virtual image 463″ that is oriented to straightly travel on the cruising lane 45′. Since the rest of description regarding the virtual image 46″ is similar to that in the case of FIGS. 13A to 13D, description thereof will not be repeated.