"I think this is an interesting direction, though I wonder to what extent the real problem in urban planning is not having the resources—money—to do anything about it," says Sam Madden, an associate professor at the MIT Computer Science and Artificial Intelligence Laboratory who studies wireless sensor networks, including GPS units.
Resources-- and political will. It doesn't matter what your data shows if the residents won't let you build roads through their neighborhoods. In Cambridge, MA there are roads that actually already exist but rush hour traffic is deliberately blocked from using them. (eg Whitemore ave / Seagrave Road between Alewife Brook Parkway and Mass Ave)