We have run the whole trace about three times and parts many more. It is a great road to drive, there is no cross traffic for the 444 miles and there are no trucks, so the road is smooth.
My advice?
When you get to the big visitor center, BUY THE BOOK. There is literally an historic marker every other mile. Yes, 200+ of them and some other great stops too. At least if you read the book ahead, you know what to expect.
We didn't know what to expect the first time. I had done some research, but it was not adequate. We started at Nashville, and I didn't get the book until the south end (there is no visitor center at the north end). The second time we were on a schedule, so it took the third run to see a lot of what we finally got a chance to read about.
If you travel when the trees are full, it will be like a tunnel of trees, but if you get there early enough, you can see things on both sides for a lot of the travel. On the northern half (you have to have someone watching the map) you can see where the actual trace crosses the roadway. - So Neat!!
Next time we are going in that general direction, we will run the
Trace again.
Matt