Illinois Truck Parking

I would like to know if any of the truckers here have issues with parking in Illinois, more specifically the Chicagoland Area. I am working on a research parking to create more parking lots for long term parking, but we must first find out where there are issues, where are you guys parking that isn't allowed... more so we can figure out the places that need a legal location most. If a lot of truckers are parking in a general vicinity then that might be our target place. Thank you all for your help.

Also if you have any suggestions as to where I can find more about this.