Abstract: A system and method are provided to detect an impending contact or collision between a subject vehicle, which may be an aircraft, a watercraft or a load-handling vehicle, and stationary objects or other vehicles in the vicinity of the subject vehicle, comprising distance or motion-detecting sensors mounted at positions on the subject vehicle at risk of such collision or contact, and alerting means, responsive to said sensors, to notify the operator of the subject vehicle and/or the operators of such other vehicles in the vicinity of the subject vehicle of the risk of a collision. Preferred embodiments comprise alerting means which indicate to the operator of the subject vehicle which, if any, sensors detect an object closer too the subject vehicle than a predetermined distance of safe approach.