I've been on the mailing list for COTA for quite some time and had a dialog going with some of the track's representatives. They invited me to tour the facility and take a lap of the track.
Caught the last tour before they closed the facility to visitors. They're entering the final stages of construction...don't know if they plan to open it back up for tours before race day.
They had just completed the asphalt on the start/finish straight and I was told that we were the first "civilians" to get a full lap in. I don't think we were even supposed to be there--the guide gave a look around first to see if the foreman was watching before allowing us to drive down it. We stopped at the pole grid slot (no paint yet of course) and fired up the Turn 1 hill...pretty flippin' sweet if I'm honest.
AFAIK there isn't public access to the track right now.