When you get to Chattanooga, Tn areas at Hwy 153 intersection, you may and probably will encounter heavy backed up traffic. If you get there before 3:00 traffic will be moving easier.
From Hwy 153 exit to I75/I24 junction will be backed up after 3:00 generally and on west on I24 will be heavy through Chattanooga.
There is some construction on I24 near hwy 127 intersection.
If you are camping off I75 south of Chattanooga,at KOA or Holiday park after the intersection traffic will be heavy but not backed up or stopped like going north and west.