A gateway control apparatus for vehicles includes a receiver configured to receive vehicle state information from vehicle ECUs and a vehicle-to-vehicle distance from an intelligent cruise control unit. The gateway control apparatus also includes a first memory to store the vehicle state information, a calculation unit to calculate a relative velocity and a relative acceleration from the vehicle state information, and to calculate a collision index. A determination unit determines if the collision index exceeds a predetermined value. A vehicle information management unit determines an accident occurrence time point when the collision index exceeds the predetermined value, and allows the first memory to store pre-accident and post-accident vehicle state information. The gateway control apparatus stores the pre-accident and post-accident vehicle state information even in the case of a fender bender or minor collision to use the stored information for post-accident judgment.