Nope, none of the above. Here is what happens to some of the most valuable, expensive, real-time, real-world traffic data on the planet:

” The data beep and shine on screens in a state-of-the-art traffic control center that looks like something out of a science fiction movie. The information — Wilshire Boulevard jammed in Westwood, Broadway wide-open through downtown — is used to adjust the timing of traffic lights, easing the flow of vehicles through the city’s busy streets. The data are instantly placed on the Internet, available to commuters and traffic reporters.

But although the sensors and computers collect massive amounts of data about traffic patterns and congestion, they do little to help engineers plan for the city’s growing transportation needs — or determine how development is affecting traffic.

That’s because the city does not save the information for more than a few days, using it only to direct traffic in real time by adjusting the speed at which lights turn from green to amber to red.

Because the information is discarded, it cannot be used to determine over time where traffic is increasing — or by how much.”

http://articles.latimes.com/2007/oct/01/local/me-traffic1