I had EXACTLY the same experience coming home from St. Louis to Chicago! I had the option of stopping in Springfield IL (right off the highway), or Bloomington Normal IL. I picked the later bc it fit my trip better, but it turns out the later was In The City, , several miles off the highway, in a parking deck! No signage, just faith so you drive and drive to the top until you find it. Huge hassle and waste of time. And at least at that time it dod NOT specify that it was not on the highway.