This video
https://www.youtube.com/watch?v=Vm6aPPf-vxcwas filmed on the road track, which was built a Bob Lutz's insistence. It is located on your left as you drive up the access road to the grounds. It used to be the truck loop, where the medium duty trucks were tested. It is now restricted and you need special training for access. unfortunately, i haven't had the opportunity to get the training yet.
They just completed a multi million dollar building where the cars were parked and wire spools were in this video, it is for observation and traffic control on the track. How cool would it be to be the dude whose job it is to chauffeur these press dude around the track, trying to make them blow lunch?