Cutting Down the Commute

Each day at five o'clock, the highways of Northern Virginia fill with hundreds of thousands of cars and trucks. Under the best of circumstances, these vehicles add thousands of tons of carbon dioxide and other pollutants to the atmosphere every evening. When there is a bottleneck, the amount of carbon dioxide and other harmful substances injected into the atmosphere skyrockets.

Companies like Atlanta-based AirSage have developed a technology that uses cell phone traffic to spot congestion in real time. It collects the positioning information that all active cell phones generate to determine how long it takes drivers with cell phones to traverse a specific section of road. With this information, transportation agencies could urge motorists to take alternative routes.

The Virginia Department of Transportation is considering adopting the AirSage system. Its research arm, the Virginia Transportation Research Council, has asked Associate Civil and Environmental Engineering Professor Brian Smith, an expert on intelligent transportation networks, to validate AirSage's information. Undergraduate Christopher Foley (CE '09) is assisting Smith.

Foley's first job was to take a GPS-equipped car and join commuters along specified routes in Northern Virginia. He spent the better part of two weeks driving in rush-hour traffic. “Fortunately, the car we used came with XM Satellite Radio, so I had something interesting to listen to,” he says. Foley then compared the GPS data for each segment to the cell phone data AirSage generated for the same period. To do this, he had to cull any erroneous data from his database and use a statistical software package.

“It was a challenge,” Foley says. “I got support from Professor Smith and his graduate students, but I also liked having the responsibility for getting the work done correctly and on time.”