Just drove from Central Texas to Birmingham AL. The Interstate (20) is the worst in Mississippi. constant bumping from holes in the road surface, very large potholes.
Two conditions for Interstates: In need of construction, and under construction.
All Interstates are running at capacity. In major cities interstates are either at or just over capacity or completely gridlocked.
Secondary highways in Texas are almost as fast as open Interstates. Most cities have a loop to bypass the city center, and the roads have large shoulders.
Limited at 70 and sometimes 75 MPH!.
Interstates in cities like Birmingham are way over used, heavily potted, and under construction almost all the time.