Having lived in the northern Indiana area when I was growing up, I can say that there is an unavoidable reason that traffic is so bad in that area.
Think about this. Lake Michigan is a huge barrier for any traffic (both auto and train) going in an east/west direction. Both the interstates and all the railroad lines divert south to the bottom of the lake and then take the shortest distance to get around the lake and to Chicago. It is a "pinch point." With that much traffic (especially cargo hauling trucks) it is almost always busy along I-94.
Having grown up in the area, the non-interstate roads didn't fare much better, because all of the railroad lines also took the same shortest route around Lake Michigan, and so we were always stopped by trains crossing the roads. We would have to leave extra early to any event, because you might get stopped at 2, 3 or 4 different crossings, depending upon where you were going.
My advice, exit Indiana far south of Chicago, then go on the toll roads west of Chicago, and then circle back toward Milwaukee/Cedarburg once you get way north of Chicago. Believe me, you do NOT want to be on the Dan Ryan Expressway in downtown Chicago at any hour of the day. I've been stuck in traffic there sometimes at midnight.