VEHICLE COLLISION WARNING SYSTEM

An apparatus for facilitating avoidance of a vehicle collision with an object, comprises a vision sensor providing image data, and an image analyzer, operable to provide an estimated time to collision of the vehicle with the object. The estimated time to collision is determined from a rate of expansion of an image element corresponding to the object within the image data, and the apparatus provides a warning if the estimated time to collision is less than or approximately equal to a predetermined time.