There are two companies who say they have a system that can monitor traffic on roads and highways. They say their systems are based on tracking the signals of cellphones that are inside cars while on the road.
IntelliOne and AirSage rely on data provided by wireless companies from their respective cellular towers that calculate the position of each phone about twice a second when its being used and once every 30 seconds when its not. Of course, there are some nuances to each system that sets them apart, but the basic concept is the same.
The services are currently being used in a number of markets with more to come in the next year. Certainly a number of wireless providers will look to offer a service to customers that would allow them to get alternate route data sent to them in case of heavy traffic for a monthly fee, but there are privacy advocates who say that cellular providers should not be allowed to track their customers while on the road or anywhere else.
News source: The Wireless Report