Years ago I made a "real time web based traffic map" for a USDOT/MODOT project. We used traffic sensors made by 3M that sent data to a local 911 center that was also setup under the same project.<p>The sensors sent traffic counts every few minutes and I used that data to draw greeen/yellow/red lines of the areas covered on a road map.<p><a href="http://multimedia.3m.com/mws/media/362275O/3-monitoring-traffic-on-bridges.pdf" rel="nofollow">http://multimedia.3m.com/mws/media/362275O/3-monitoring-traf...</a>
1) Government data <a href="https://opendata.stackexchange.com/questions/1767/data-of-vehicle-traffic" rel="nofollow">https://opendata.stackexchange.com/questions/1767/data-of-ve...</a><p>2) Waze, Google Maps turn-by-turn