A system determines a dynamic collision awareness envelope for a vehicle. The system includes at least one vehicle motion sensor, an operator Line-Of-Sight detector and a processor. The vehicle motion sensor periodically provides measurements relating to the motion of the vehicle in a reference coordinate system. The operator Line-Of-Sight detector periodically provides information relating to the direction of the Line-Of-Sight of an operator of the vehicle, in a vehicle coordinate system. The processor is coupled with the at least one vehicle motion sensor, and with the operator Line-Of-Sight detector. The processor determines an operator vector from the direction of the Line-Of-Sight of the operator. The processor further determines an operational vector at least from the motion of the vehicle. The processor periodically determines a collision awareness envelope respective of each of the operational vectors, from the operator vector and the respective operational vector.