Traffic Control System's technology

[SaimsChiki]

Need suggestions about which technology is best to use to create a traffic control and driver guidance application with reference to cost, accuracy and convenience? e.g. GSM, GPS, Infrared, UMTS or some other one? Need immediate responses plz with references

[Salem]

> Need immediate responses plz with references
Sure, anything else you would like?

This perhaps ?

Governments spend millions trying to answer that question, and generally end up making a pig's ear out of it.

Did you expect you could just roll into a forum and get an answer just like that?

This answer fits into the "fast / cheap / good - pick two" framework.
You chose "fast and cheap".

[jwenting]

and the government chooses slow and expensive, and still doesn't get "good" :)