Having to start over, the cat deleted the entire post............. yes, the cat. (lots of cussing ensued)
The parkway south end is at Cherokee, no where near Gatlinburg, and runs to I-64 at Afton VA milepost zero, where the Skyline Drive continues for another 100 miles to Front Royal VA.
If you are thinking about crossing over to Cherokee from Gatlinburg on US441, its doable but it has some tight switch backs, one 360 degree spiral, about three tight 180's, and one tunnel, plus lots of bear and elk jams, and virtually no place to get off the road. I saw a Ranger with a semi stopped who was heading from Cherokee. He didn't get far past the Oconaluftee Visitor Center. We were headed to Smokemont campground. Not sure how he got turned around.
I answered a similar query about the BRP just a while back
HERE. There are 17 tunnels between the south end at milepost 469.1 and Ashville alone, there are more north of there. The low ones are between US 19 and US 441 at the south end. I have driven this entire distance from Ashville to Cherokee (but not north of Ashville) and can easily say it is no place for a big rig. Period. Find a campground somewhere nearby and use the toad to drive the parkway.
The very few campgrounds on the parkway are only suited for smaller campers. Mt Pisgah has possibly a half dozen that handle a 30 ft something and some of them have so much slope that you put the wheels on blocks and the trailer tongue on the pavement to get level. I've camped at Mt Pisgah in a trailer and a 23 ft class C, I've camped at Mile High and Balsam Mtn Campground in the trailer.
I don't think any of the tunnels are straight, they all curve, some rather tightly. Most you cannot see from one end to the other. The road has a 20 ft roadbed, not the 24 ft you are used to seeing. This means 10 ft lanes. Many of the overlooks are small with not much room to park, some are large, but getting in and out can be tricky with any vehicle. Many of the overlooks are on the outside of curves and if you have to cross the road to get to them, you are doing so in a blind curve. Access on and off the parkway is limited and the roads leading up to the access points (in mountain gaps) are fairly steep and somewhat narrow and winding themselves. Been up and down some that i won't go back to again.
Its just no place for a big rig.
Charles