I don't know about a direct number, but I would start by calling the Illinois department of transportation. They will get you where you need to talk to. (217) 782-7820
I hope you find it.
(217) 782-7820
I believe the department of highways maintains it. You could check with them.
I believe several have already answered this question. There probably is, but you would need to contact some of the ones already listed. Hope you find what you are looking for.
I am not sure,there is a public pay phone,but I have no numbers.you might try going through the operator.
Thanks! Your answer is awaiting moderation.