Just came through Iowa ( northern part ) last month and used side , state roads almost exclusively. We like taking our time and seeing the small towns etc. The roads were tar sealed as in your photo and aren't glass smooth but our rig had no problems. I watch all bridges as that's where your going to find any rough uneven spots. The freeways we were on weren't any better. Chose your poison!!!! We prefer the back roads.
2003 Beaver Marquis
2016 25' (20'box) CargoMate car hauler