At the first display device 3, the symbol image 68 is formed as an arrow mark curved along a trajectory on which the own vehicle is previously noticed to make a U-turn from a position on the cruising lane 66 in the actual scenery 36 to a position on the adjacent opposing lane 67. At the second display device 4 as well, the symbol image 68′ is formed as an arrow mark curved along a trajectory on which the own vehicle is previously noticed to make a U-turn from a position on a cruising lane 66′ in the taken scenery 39 to a position on an adjacent opposing lane 67′. Here, the symbol images 68, 68′ may be displayed instead of the symbol image 37, 37′.