As Wikipedia will tell you
Roadway noise is the most widespread environmental component of noise pollution worldwide.Among the various suggestions our group came up with, was an alternative to vehicle horns (which is a major part of roadway noise in India). Rather than using loud horns, a radio horn was to be used. The radio horn was rather simple in design. The horn emitted a signal with the exact location of the vehicle (obtained by GPS-Global Positioning System) along with the exact time with an accuracy of a Milli-second.
All the vehicles will have to carry a radio receiver which will catch these radio waves, and after comparing it with the location of the vehicle and the time , it would decide if that horn was meant for it. (A computer program or still better a IC will do it in real time) As soon as the radio set learn t that it was being honked, it would produce some kind of warning which either involved a blinking light on the dashboard or a horn of much lower magnitude to be heard only within the vehicle that received the honk.
And this became a rather controversial suggestion in the report, the main arguments against it were-
- What about human beings and stray cattle on the road-they cant have radio receivers! we are talking about INDIA
- The economic viability of having all this high tech stuff installed. (A legislation ought to solve this problem and the cost should come down drastically when mass produced)