According to this site, Wisconsin drivers are the 4th best drivers in the country.
Illinois drivers are 45th.
That explains a lot. Illinoians seem to think the Wisconsin state motto is "Wisconsin - Illinois' playground!"
Take the drivers test yourself, and let me know how you do. I scored 80%, which is above the national average (77%) and would be 4 wrong; note, however, that I took a phone call in the middle of taking the test, distracting me. I'd never take a phone call while driving (truly - I pull over, annoying both me and the car behind me)