I agree with Likes...US 23 is the way to go. We have used that route from Charleston, WV to Alabama several times. Sometimes with the TC and boat...sometimes just the boat. Once just for a day trip to the Natural Bridge State Park in VA. If you have a few minutes to kill, stop there. They have a tram to the bottom of the gorge and the tunnel is amazing. It is not too far off the highway if memory serves me correctly. Try to wait for a train to come through.
This road is great (in my opinion). A few congested areas but the scenery is worth it! Amazing feats of engineering cut this road from the mountains.
Enjoy your trip!