Well, from Madison, you could take I-39 south to I-80 east and miss all but the lower end of Chicago. Then pick up I-94 into Michigan. You still have to worry about the mix-match on I-80 where traffic is always heavy, but to me, it's not so much the route you take as it is the time you take it. Avoid driving within 50 miles of Chicago any time between 6 AM and 10 AM on weekdays. The best time to drive around/through Chicago is early Sunday morning. Then you only have to compete with truck traffic which is always present. This year, I'll be traveling from Kenosha, WI to Michigan on Thursday July 2nd and I intend to take the tri-state toll way but I won't leave Kenosha until 9 so I get to Chicago around 10. Hope this helps a little bit.