I live in Apple Valley, MN and will be traveling down to Jacksonville, IL this weekend. Here is the route Google Maps
I've traveled back and forth over a dozen times, but never taken the bottom half of this route. I always take the first half of the highlighted route ([Apple Valley down to Iowa City) so I know that's all four-lane. But from Iowa City I normally take all Interstate Highways (Iowa City-Davenport-Galesburg-Peoria-Springfield-Jacksonville). But I've of the thought about going down thru Missouri before crossing over to Illinois. The only thing stopping me is a fear that I'll end up traveling on a lot of two-line highways. (I avoid two-lane roads on long trips because I'm just too impatient.)
I know I'm good from my starting point down to Iowa City. This Wiki link
indicates that it's four-lane from Iowa City to the Missouri border:
the parts of US 218 that follow the Avenue have been completely upgraded to four lanes…. When 218 is part of the Avenue of the Saints, it is co-signed with Iowa Highway 27
So I think I'm good all the way down to Missouri. That just leaves Highway 61 from the border down to Quincy. Can anyone tell me whether or not this is all (or mostly) four-lane?