A collision prediction ECU of a collision prediction apparatus estimates a state of presence of a detected front obstacle. At this time, the collision prediction ECU estimates the state of presence on the basis of road shape data supplied from a navigation ECU of a navigation apparatus. Further, the collision prediction ECU checks and corrects the calculated road gradient value. At this time, the collision prediction ECU corrects the gradient value on the basis of road gradient data supplied from the navigation ECU. Further, the collision prediction ECU changes a collision avoidance time on the basis of travel environment data supplied from the navigation ECU. Moreover, the collision prediction ECU obtains an ETC gate pass-through signal from the navigation ECU and determines whether the vehicle is passing through the gate. The collision prediction apparatus performs collation prediction on the basis of the corrected values.