Those who study how to monitor and mitigate traffic jams for a living have been experimenting with what will eventually be the killer app for traffic tracking and avoidance - data from cell phones. How does it work? Think about how many cell phones are on the road at any given time; just about every car has one or more on board. What if you could create an anonymous data stream that told you where and how fast (or slow) all of those phones (and the cars they're being transported in) are moving? It's the Holy Grail of real-time traffic data.
TomTom was the first to roll out a public test of the system with its High Definition Traffic service now available only in the Netherlands.
A US-based group, Mobile Millennium (MM) is working on cell phone traffic data also. MM is a partnership between Nokia, NAVTEQ, and UC Berkeley, and is based at the California Center for Innovative Transportation. MM states that it "fuses GPS data from cell phones with data from existing traffic sensors." There are three great advantages of this type of traffic tracking: it costs much less than traditional monitoring methods; it covers many more roads; and it provides real-time data. MM has launched software for beta testers and expects to have 10,000 pilot testers on the road by April, 2009.