Encyclopedia o f Chicago
Historical Source
Historical Source
P
Plan of Chicago Promotional Campaign (Diagram of Proposed Superhighway System), 1927

Plan of Chicago Promotional Campaign (Diagram of Proposed Superhighway System), 1927
As this slide indicates, with the advance of the popularity of the automobile beyond the original planner's expectations, the Chicago Plan Commission was thinking of turning certain roads into "superhighways" in a manner that anticipated today's interstate system.