Soon, cars that can "talk" to each other!

The technology that allows vehicles and highway infrastructure to communicate with each other is undergoing trials in a giant experiment on the streets of Ann Arbor, Michigan.

Wireless devices will allow these "smart cars" to send signals to each other, warning their drivers of potential dangers such as stopped traffic or cars that might be blowing through a red light. They can even get traffic lights to turn green if no cars are coming the other way.

The US Department of Transportation and the University of Michigan are hoping the year long, USD 25 million project generates data that show the devices can cut down on traffic crashes.

Eventually this could lead to the devices going in every car. About 500 vehicles with the devices are now on the roads. That will rise to 2,800 in about six weeks, officials said.

"This is a big moment for automotive safety," said US Transportation Secretary Ray LaHood in a statement.

"This cutting-edge technology offers real promise for improving both the safety and efficiency of our roads. That is a winning combination for drivers across America," said LaHood.

Motor vehicle crashes are the largest single public health crisis in the United States. Their number has fallen in recent years as automakers added safety devices such as air bags, antilock brakes and stability control, which helps drivers keep cars under control in emergency situations.

As many as 80 per cent of crashes in which the drivers aren't impaired by drugs or alcohol could be prevented or the severity reduced if cars could talk to each other.

"This is a tremendous opportunity, and we are very excited to be able to support the USDOT's demonstration of cutting-edge transportation technologies in our community," said program manager Jim Sayer.

No one knows exactly when the technology will make its way into cars and trucks everywhere.