Overtake Warning System

One problem I have noticed which becomes much more pronounced during poor lighting or atmospheric conditions is a reduced ability to judge the speed of another vehicle when you come up behind it from a distance.

More than once I have been surpised by a vehicle moving much slower than expected.

I propose a system that would be installed in the rear end of a vehicle. This would consist of a rear facing Radar or Lidar detector with a fairly narrow focus(say 10 feet wide at 300 feet) This sensor would watch for overtaking vehicles and monitor the relative difference in speed. If the overtake difference exceeded say 15mph the sensor would trigger a set of warning flasher type strobes if the approaching vehicle got too close without changing speed. perhaps even a staged warning(first trigger blinkers if over 15mph at 150 to 300 feet, then strobes at 150 or less)

This would act to warn over taking drivers of the slower vehicle and prevent potentially hazardous emergency maneuvers or even accidents.