Giving Drivers Enough Data To Avoid The Worst Traffic Jams

Drivers in Atlanta, Georgia, spend an average of 60 hours a year stuck in traffic on their way to and from work. During these delays, they waste 40 gallons of gas per person and spew tons of carbon into the atmosphere. With Atlanta sprawling larger all the time, engineers at the Georgia Department of Transportation began wracking their brains for a solution. Better informed drivers, they reasoned, would be able to avoid traffic snags. The problem was finding an inexpensive way of keeping track of how many cars are on the road at any given moment, and where.

Making traffic flow more efficiently isn't just a problem for car-obsessed America: cities all over the world have struggled with it. Most high-tech solutions usually involve putting myriad cameras and sensors on the highways and back streets, which makes them expensive. Georgia, for instance, had already expanded the traffic monitoring system it created for the 1996 Olympics to about 225 kilometers of roadway. Underground fiber optic cables linked together 1,400 traffic monitoring cameras, and electronic signs directed drivers around traffic tie-ups. But the system costs $1 million per mile to build, and it needed constant repairs as vehicles struck equipment, storms took down cameras, and workers dug up cables.

To keep track of cars without having to build a lot of new infrastructure, Georgia's engineers turned to a transmitting device that already exists on almost every car on the road. It's called the cell phone.

As long as a mobile phone is turned on, it continuously sends signals to local cellular towers so that the telephone company--in this case, Sprint/Nextel--knows where to route your calls. The phone company provides this information, raw, to AirSage, a traffic-monitoring firm in Atlanta, which lays the information over a digital map. Commuters log onto a Web site to see real-time travel speed and congestion information gathered anonymously from thousands of drivers, or they can get automated e-mails or text messages about traffic conditions along a particular route.

When the city officially incorporated the cell-phone information into its traffic Web site in July, the number of kilometers covered jumped to 764. Getting information on those 483 additional kilometers required no extra hardware, won't need extensive maintenance or repairs, and cost one tenth of a traditional traffic monitoring system, according to Georgia.

Atlanta and other U.S. cities are playing catch-up to Europe. As far back as 2001, several cities began using GPS devices installed in commercial vehicles to track them. Later, they began combining that information with cell phone transmissions, figuring more sources would enable more accurate data. Cell-phone-based monitoring systems are now in place throughout the United Kingdom and Belgium, and are being rolled out in Prague and Barcelona. One reason Europeans were quick off the mark is because their freeways aren't as extensive as American ones. Europeans also aren't spooked by the privacy implications of having their cell phone transmissions monitored.

In America, by contrast, privacy may hold up adoption of the technology. A traffic-monitoring project in Baltimore, announced in 2004, has stalled, in part because customers may be skittish about the privacy implications. "Privacy issues can create bad publicity for telecoms, and even the hint of that isn't worth it for them," says Stan Young, a research engineer at the Center for Advanced Transportation Technology Laboratory at the University of Maryland.

AirSage and Georgia's transportation department are convinced that their technology, which aggregates all the cell-phone data and keeps it anonymous, has few implications for drivers' privacy. And because the firm has entered into an exclusive revenue-sharing agreement with Sprint/Nextel, the telephone company has an incentive to keep the service going.

Real-time traffic technology potentially could be fed to GPS devices to provide real-time traffic maps in the car, say AirSage execs. The company plans to open up the data they've collected to the public by the spring of 2008, allowing others to create their own applications. If the technology truly helps drivers avoid traffic, they may not mind being a tiny dot in a digital map.

BYLINE: By Jesse Ellison, SECTION: THE TECHNOLOGIST; Technology Vol. 150 No. 21 ISSN: 0163-7053. For more information about Newsweek visit their website.

November 19, 2007