I too really dislike I24 around Chattanooga. One would think, after all these years, that the drivers there would know about the hills and sharpe curves - but nooooooo - they insist on speeding and, eventually, wrecking. And one would think TN might widen that road a bit - but, again, nooooo.
Anyhow. Try this....
I-65 To Birmingham
US280 from Birmingham all the way to Tifton, GA.
Then back to I-75
We drive to/from Columbus from the Fl east coast a lot. US280 between Columbus and Tifton is mostly 4 lane divided, just adhere to the speed limits, every small town seems to have a local cop just looking for speeders.
We've also driven US280 between Columbus and Birmingham a few times. Easy road.
oh - Monteagle, TN - big downhill on I-24 from North to South. Use a low gear.
2018 F350, 2019 Grand Design 310GKR