. "In step S1602, the distance y0 to the obstacle is compared with a distance obtained by multiplying a predetermined collision prediction time TTC1 by the relative speed Vr0 of the obstacle (that is, the value of (TTC1???Vr0)), and, by using the distance y0 to the obstacle and the relative speed Vr0, a judgment is made as to whether the obstacle is an object belonging to the region where the possibi" . . .