I drove across Iowa... seems like it would get a bit boring after the first few hours, unless they keep really interesting bits away from the highway in order to persuade passers-by to just keep passing.
60-80 miles a day almost sounds fun!
Well the super highway is on a pretty flat route. The pick a new route every year and it is all on smaller roads. Iowa is not nearly as flat as you might think. A lot of rivers run through it that have carved broad rolling valleys. Also it slopes up from east to west by several hundred feet. But yeah, 60 miles in 8 - 12 hours is pretty darn tame. Just the butt getting sore for the sitting so long on the seat.