From Technology Review…

Researchers at the University of California, Berkeley, hope that drivers with GPS-enabled smart phones will help them gather more-accurate and up-to-date traffic data. Starting Monday, volunteers in the San Francisco Bay Area and around Sacramento will be invited to participate in a pilot program by downloading software that tracks their movements and transmits this information, via the phone network, back to a server at the university. In return, the volunteers will receive personalized traffic information on their cell phones.

The idea is simple, says Alex Bayen, a professor of civil and environmental engineering at the university. “Smart phones with GPS collect data from a regular commute and send it to a central system,” he says. “The system puts the data into a mathematical model that estimates traffic in real time and then broadcasts it back to the Internet and phones.”

The researchers’ model combines traffic data collected from static road sensors as well as from volunteers’ cell phones. Participants will receive personalized information such as travel-time estimates and traffic speeds along relevant routes.