Progress has been made in the development of sensor systems for detecting obstacles behind a car before engaging reverse gear, other cars in the blind spot, and for maintaining a driver-set spacing to the vehicle ahead. Demonstration systems have been created, but there is very little hardware available to the general public. No one sensor technology has been shown superior to its competitors for the several sensing functions.Advances in sensor, component, and computer technology will make it possible to have systems that scan the space around a vehicle and warn of potential or imminent collisions coming from any direction. Future sensors might be linked to restraints in such a way that, when an unavoidable collision is about to occur, the restraints will be activated before the collision so that vehicle occupants receive maximum protection.For sensors to be effective, they should be integrated into the overall vehicle design at the beginning of design. It is conceivable that the importance of sensors may become so great that designers may modify the appearance of a vehicle to accommodate them. For example, mounting a sensor on the roof of a car would be practically unthinkable today. This might not be the case ten years from now.