With connected-car field trials in the U.S. and Germany assessing how technology can reduce accidents and traffic congestion, it’s only a matter of time before the cars we drive communicate. Volvo says that this connectivity is only five years away, and the safety-minded automaker is working on two fronts to make it happen.

Volvo has been instrumental in the Safe Road Trains for the Environment (SARTRE) project, which allows groups of connected cars to travel autonomously, in close formation, to reduce traffic congestion and fuel consumption.

To that end, the National Highway Traffic Safety Administration said today it would develop a performance rating system for autonomous technology. The agency said it would mandate safety rules for the systems after it completes a research project within the next two to three years, according to the Detroit News.

On Monday, Volvo said that it supported federal mandates for autonomous systems, but that states should not "restrict the use of active safety and support systems" such as automatic braking. Google has logged more than 300,000 miles with its autonomous cars and successfully lobbied three states -- California, Nevada and Florida -- to allow its technology on the road.

Volvo also recently joined the Car 2 Car Communication Consortium, a group of European automakers and suppliers working on technology that allows cars to connect with roadways and other traffic. "In the future, we will have advanced exchange of vital information between vehicles such as their position, speed and direction, Erik Israelsson, Volvo's project leader, said in a statement.

Volvo isn’t involved in the simTD connected-car field trial taking place in Germany, but the Car 2 Car Communication Consortium is promising some of the same capabilities. For example, an application called Green Light Optimum Speed Advisory feeds information from the traffic infrastructure to the car to allow drivers to maintain an optimal speed in order to get all greens through a succession of traffic lights, "thus avoiding unnecessary braking for red," Volvo says. This is a feature we saw in action during a demonstration last week in Frankfurt.

Drivers who do get stopped at a red light would also receive information on how long it will take before the light turns green, the automaker added. For drivers who forget to stop, the car will flash a warning and even alert nearby drivers entering the intersection through a green light.

Volvo's Emergency Vehicle Warning alerts a driver when an emergency vehicle is nearby, allowing the driver "to create free passage well in advance and without being taken by surprise," Volvo says. This is another feature that is being tested in the German field trial and that we saw in Frankfurt.

Motorcyclists will be pleased with the automaker's Motorcycle Approaching Indication. "Motorcyclists are among the most vulnerable road users, and in order to improve safety, Car 2 Car informs other road users if there is a motorcycle nearby," Volvo says.

All drivers can appreciate the Slow Vehicle Warning that Volvo says can "cut the risk of unpleasant surprises in traffic" by alerting the driver to a slow or stopped vehicle ahead (see photo above). Finally, those with a lead foot may also like the In-Vehicle Signage feature, which shows temporary speed limits -- and may warn of potential speed traps where the speed limit suddenly drops.

[Source: Inside Line]