Blindspot Warning System
Blind spot warning systems detect the distance and closing speed of objects in adjacent lanes and alert the driver if a collision is imminent.
On a highway, a car which is far behind can be clearly seen in the rear view mirrors. However, as the car approaches, a point is reached where the car cannot be seen in either the interior or exterior mirrors. Typically this occurs when the car is just behind and to one side of the vehicle it is overtaking. It is a common mistake for drivers to change lanes when there is a vehicle in this so-called "blind spot", a manoeuvre which causes many crashes.
Several manufacturers have developed systems which monitor the blind spot and help a driver to change lanes safely. Some systems are camera-based, others rely on radar.