Now this is a different way to get road construction warnings out to the Illinois driving public. It is in Mongomery County along I-55.
Montgomery County encompasses Litchfield and Hillsboro, etc and was named after Richard Montgomery, a Revolutionary War hero who was killed while trying to capture Quebec City in Canada in 1775. Must have been a number of Illinois settlers who were a part of that event back then.
Katie and Charlie live in Montgomery County Maryland and I'd bet it's named after the same guy.