Radar senses when a car is approaching too quickly, closing within the parameters of a collision, and the horn is activated alerting both drivers of the potential collision allowing the rear driver more time to hit their brakes.

Easily retrofittable, you could buy a pair of these and strap them to the front and back of your car. A simple, relatively cheap solution that could prevent a lot of rear end collisions.
-- doctorremulac3, Oct 01 2016

Cairo traffic https://www.youtube...watch?v=GnzxMjrBCTQ
[not_morrison_rm, Oct 02 2016]

Bonus if the horn noise comes from the cell phone -- it's about the only thing drivers pay much attention to these days.
-- whatrock, Oct 01 2016


Sort of like Cairo, nobody indicates,just beeping the horn all the time...
-- not_morrison_rm, Oct 02 2016


Yea, to keep this from being just a bunch of noisemakers on the street, there would be a very precisely adjusted trigger point.

The horn would sound just before the pint when the current closing rate will cause a collision with the approaching car in the front or back if brakes aren't applied within the second or so reaction time needed from when a driver hears the horn.

So there would be an x y graph of when the horn sounds. x being speed, y being distance between cars. Also there would be no sounding of horns below a certain speed, say 15 miles per hour such as during heavy traffic jams.
-- doctorremulac3, Oct 02 2016


//The horn would sound just before the pint // Now that would be a useful innovation.
-- MaxwellBuchanan, Oct 02 2016



random, halfbakery