Car route map?

I'd love to see a map generated that would take an average weekday - surely, one can pick a day that would give something generally applicable as a result - and an average weekend day ---- plot in some graphically compelling way where cars go in the course of that day. In other words, a certain number of cars come from Chatham County and go up 15-501 to UNC; what number turn off on 54 and go to I-40? Where do cars leaving Pittsboro or Carrboro go in the course of time they area away during that day. A number of assumptions would have to be made - such as that cars leaving in the early morning likely are based at the point of departure, but that later in the day, they are returning. Anyway, a color-enabled map would be a fascinating thing to watch. Why do it? Because it would help us determine where people go and then try to sort through what it might take to get them to go to other places or not to go at all.