Southwest Michigan to Joliet, Illinois

No good way around it. We drive it quite a bit, but haven't in the past two months. I just put in New Buffalo to Joliet in Google Maps with traffic, and it says 86 miles, 1 hr 36 minutes. So that is not bad at all. Maybe sitting in traffic for what, 10-15 minutes. Not fun, but you can see why you can't be taking stoplight infested state routes and expect to do any better.

If you were going a bit farther south than Joliet, then maybe. But in my experience, not even then. It's more for peace and tranquility than time savings. To Joliet, no way, just take the interstate.