http://www.cmap.illinois.gov/uploadedFiles/planning_activities/transportation/sp2030/historic/CATSPlan_1962.pdf (http://www.cmap.illinois.gov/uploadedFiles/planning_activities/transportation/sp2030/historic/CATSPlan_1962.pdf) (Large PDF)
Notes/pages of interest:
* (Page 66/154): 1939 highway Plan
* (Page 69/154): 1946 highway Plan
* (Page 70/154): It appears I-65 was originally planned to go around Lafayette, IN on the west side. In addition, I-69 appears to have undergone an alignment change from the yellow book map so it still kind of followed the US 36 corridor, but would intersect I-70 east of I-465.
* ( Page82/154): Recommended highway plan
That is rather interesting. I ran across this once before, but didn't look through the whole document, so I didn't see the recommended highway plan, I almost wonder if this ever given any real thought, I could certainly a few of the proposal being helpful, such as the freeway between the Tri-Sate and I-57.
That freeway between the Chicago Skyway and Des Plaines near O'Har would have helped sooo much it's unbelievable.