Although it was among their most far-reaching proposals in the Plan of Chicago, Burnham and Bennett’s plan for metropolitan highways receives little attention from modern commentators. This map shows that they had given considerable thought to the opportunities created by the automobile in the outer reaches of the metropolitan area and for providing better communications between city and country. Using language that could have been taken directly out of the tracts published by advocates of good automobile roads, they wrote that “[w]hile good highways are of great value to the terminal cities, they are of even greater value to the outlying towns, and of greatest value to the farming communities through which they pass. Good roads add an element of better living to an agricultural community; they afford ready communication with the city and reduce materially the cost of handling farm products of all kinds; and they also promote communication between farms” (p. 39). A system of state highways, they argued, could serve not only as a working road, but also as a pleasure to drive for urban and suburban residents. Most importantly, a plan for metropolitan highways would extend the ideas they applied in the central city. Circumferential and diagonal highways would improve circulation between outlying suburbs and farming communities without the necessity of routing traffic through the urban core. Here they anticipated the bypass highway, though not quite the expressways that came to define suburban life in the second half of the twentieth century. The map and the plans it outline carried no legal weight, but it was unusually prescient in its prediction of the development of metropolitan Chicago’s highways. By the early 1920s, the state of Illinois was actively constructing circumferential and radial highways in metropolitan Chicago following geographical alignments similar to those called for on this map.
Hugill, P. J. "Good Roads and the Automobile in the United States, 1880-1929." Geographical Review 72 (1982): 327-49. http://www.jstor.org/stable/214531
Eldridge, Maurice O. "Good Roads for Farmers." In The Future of Road-Making in America, edited by Archer B. Hulbert. New York: AMS Press, 1971.
“Chicago: General Diagram of Exterior Highways Encircling and Radiating From the City,” from Plan of Chicago (Chicago: The Commercial Club, 1909), pl. XL. The Newberry Library, Case folio W 999 .182