With vehicle miles traveled growing about 15 percent faster than the U.S. roadway network, and the trend likely to continue this year as fuel prices stabilize and more drivers take to the roadways, we need to look for more creative—and smarter—ways of easing congestion.

New projects from German automakers Audi and BMW promise to ease congestion simply by looking at traffic signals and driving style, in an effort to smooth the flow of traffic.

One likely start is by replacing our outdated traffic-signal system with one that's networked—or, better yet, one that can communicate with vehicles in real time.

Last fall we reported that BMW is working on such a system, through its Traffic Technology and Traffic Management group, of better synchronizing traffic signals with vehicle traffic and vice versa. Through a test course in Munich, vehicles were able to post phenomenal fuel-efficiency gains simply by adjusting the timing of traffic lights depending on traffic volume—to whatever speed provides a so-called 'green wave' of four or more synchronized signals.

Now, in the city of Ingolstadt, in Germany, Audi is showing the latest version of its 'travolution' concept, which also aims to preserve a smoother traffic flow through the city.

Audi claims to have reduced overall fuel consumption by 17 percent with the algorithm, which was developed through a partnership with local colleges.

Audi 'travolution' concept for traffic signals

The Audi system—interfaced with Audi's Multi-Media Interface (MMI) screen—uses wireless LAN and UMTS links, enabling vehicles to communicate directly with traffic-light systems as they're approaching. The signal systems transmit data—displayed in graphic form—regarding when the light is going to change to green. Likewise, if the light is about to change to yellow, the system prompts the driver and momentarily cuts power.

In the test vehicles, the adaptive cruise control system can be used to maintain an ideal speed and conserve momentum for the best fuel efficiency.

Such a method sounds ripe for deployment on U.S.-style boulevards, where obsolete signals, each running on their own cycle, can bring light traffic to a congested snarl. As for car-to-car communication—or more complicated traffic patterns with pedestrians, bikes, and side streets—that's still a longer-range work-in-progress.

[Audi]