Further, at the first display device 3, a virtual vehicle of the own vehicle that performs lane change is displayed as a moving image of a virtual image 46. Similarly, at the second display device 4 as well, a virtual vehicle of the own vehicle that performs lane change is displayed as a moving image of a virtual image 46′. As described later, the virtual image 46, 46′ is displayed so that the virtual vehicle of the own vehicle travels on the arrow of the symbol image 44, 44′ indicating the travel course for lane change as having the arrow as the trajectory therefor.