I'm wondering how feasible it would be to extract useful information from cell phone GPS data. Given a bird's eye view heat map of the ground, would it be possi

I'm wondering how feasible it would be to extract useful information from cell phone GPS data. Given a bird's eye view heat map of the ground, would it be possible to approximate road curvature? This, of course, wouldn't correlate street names with paths taken by people; that would have to be done elsewhere.