X2 ^
The first time I went there I followed the first directions posted above (coming from Fayetteville I took 87 to 421 to 40, then followed the above directions), but the section from Bristol to Gate City was terrible (my rig and trailer combo is a little top heavy feeling), so I only made about 25-30MPH most of that stretch and pulled over 4 times to let the accumulated traffic by.
This past trip we stayed on 81 till I26 in Kingsport and it actually seemed faster to me as well as not nearly as nervewracking. The advice about not following your GPS 100% is also good as well as the advice about the grades (2 are 7% for 6-8 miles and one is 9% I think for 4-5 miles) Keep a close eye on the engine and tranny temps if its warm out.
