The Car-2-Car Consortium's system, which includes GM's Vehicle-to-Vehicle project, combines three technologies - a Global Positioning Satellite (GPS) antenna, a wireless data system and a computer that interprets the information it receives.
GPS tracks the position of the car while sensor data from the car - such as speed, direction, road conditions and if the windscreen wipers are on and if the brakes have been stamped on - is monitored by the on-board computer. A wireless system similar to existing wi-fi technology - based on the 802.11p protocol - transmits and receives data to and from nearby cars, creating an ad-hoc network.
Data hops from car to car and the on-board computers can build a picture of road and traffic conditions based on information from multiple vehicles across a great distance. Cars travelling in opposite directions can share information about where they have been and so informing each other about where they are going.
Read in full at - 'Connected cars 'promise safer roads'