The vast majority of car accidents occur because a human driver failed to see and react to something like a traffic light or another car. Let's face it, we kind of suck like that. It's a good thing that computers are so much smarter than we are, and by setting up cars to talk to each other, accidents could (mostly) be a thing of the past.
Cars are getting smarter and smarter every year, as manufacturers add more and more sensors to enable slick automated systems like parallel parking assist, adaptive cruise control, and lane departure warnings. But even when you're not using these systems, they're still capable of collecting all kinds of useful data, and the U.S. Department of Transportation wants to know whether cars can put all those data to work by communicating it to other cars.
The idea behind this is sort of like what's already going on with automated traffic re-routing in your GPS, except much more immediate. Your car will be getting a continuous feed of sensor data from all the cars around it, so it'll know when it's safe to change lanes, how much space you have to pass someone on a two lane road, if some jerk a few cars ahead of you just slammed on their breaks for no reason, and even where there's a free parking spot. All it takes to implement a system like this is a GPS receiver hooked up to a radio that transmits location, direction and speed data. Simple.
The first trial of this system is big, and it has to be in order to allow for test cars to randomly encounter each other in day-to-day city driving. 64 cars in Ann Arbor, Michigan will be outfitted with receivers, while about 3,000 other cars will be set up with GPS radio transmitters. The trial will run until 2013, and if enough data are collected that demonstrate that the system provides a tangible benefit to drivers, the DOT's National Highway Safety Traffic Administration will implement a rollout of the technology to all cars over the next 10 years.