The push by high-tech firms coincides with a decades-long effort in many cities to squeeze more capacity out of existing roads because it has proved difficult to find the money, space and public support for building new ones. As a result, one strategy has been to encourage motorists to use roads more efficiently.
Since the 1970s, the California Department of Transportation has installed thousands of sensors below freeways to monitor traffic. Information from those sensors allows the extrapolation of traffic speeds, which are displayed on traffic websites.
But sensors, which are expensive to install and can break down, are in short supply on some freeways. And that has led many to believe that the better way to electronically measure traffic is to put monitoring equipment inside vehicles. The other big advantage is that GPS also allows vehicles to be tracked on surface streets.
If such data can be sufficiently crunched and combined with existing sensor data, researchers hope to build a service that tells people how to get from point A to point B in the shortest time.
"As a user you are not only contributing to the data, but you are benefiting from it by looking at it in real time on your phone," said Alexandre Bayen, an assistant professor in civil engineering at UC Berkeley who is heading the project.
As part of Friday's experiment, which Bayen said was successful, the cellphone data was stripped of personal information to alleviate concerns that Big Brother -- or perhaps a divorce attorney -- could ever use the information to show that a person who said he was driving to the grocery actually strayed off-course.
Iannucci, of Nokia, said smaller-scale experiments have been successful and the next step would likely involve a road test on an even larger scale for a longer time. As to how soon the company could bring a product to market, Iannucci said he couldn't predict, but that Nokia's research arm generally works in two- to seven-year time frames.
It remains to be seen if cellphones will be the device that consumers favor. The Sunnyvale-based firm will soon begin selling an in-car directional system -- with a screen much larger than a cellphone's.
It also uses similar technology to recommend to motorists the three best ways to get to their destination, based on real-time highway speeds gathered from road sensors and other Dash system users.
