It's not Iowa, but I swear I almost rolled my truck last year going through a construction zone after picking up a Hershey load in Ogden, UT(I think, wherever the Hershey plant is)
They had a sign,trucks stay in right lane. Okay, I stayed in ther right lane. There was an enormous bump in the road and I looked in the mirror and the top of the trailer was rocking back and forth.
I hate it when that happens!! Glad you made it! I almost had a 40 foot dry Van trailer blow over on me once!! Not fun!