Illinois is the heart of the U.S. interstate system

  • Interstate highways and tollways move millions of drivers around the Chicago area.

    Interstate highways and tollways move millions of drivers around the Chicago area. Associated Press, 2013

  • Traffic on the Kennedy Expressway in Chicago, once dubbed the nation's worst traffic bottleneck in terms of hours of delays.

    Traffic on the Kennedy Expressway in Chicago, once dubbed the nation's worst traffic bottleneck in terms of hours of delays. Associated Press, 2015

By Shane Nicholson
Of the Rock River Times
Updated 3/24/2018 5:43 PM

Illinois' neighbor to the east might claim "The Crossroads of America" title, but by nearly any measure, our state is the heart of the U.S. interstate system.

Illinois has the third-highest total of interstate routes and mileage. Only New York, with 7 million more residents than Illinois, and California, with 25 million more people, have more I-designated roadways. Only Texas, with five times more territory than Illinois, and California, which is three times larger, have more mileage.


And the importance of the routes -- many of which were designed to pass through or near Chicago, with its access to the global economy -- further spell out the significance of Illinois as a hub of trans-U. S. travel. The two longest treks of the interstate system, I-90 and I-80, pass through Illinois on their coast-to-coast journeys. Two key connections to the Gulf States, I-55 and I-65, reach their nadir in the Chicago area.

"Illinois is at the heart of the country's interstate highway system," the Illinois Department of Transportation boasts. That was not without intent: When the Dwight D. Eisenhower National System of Interstate and Defense Highways was authorized in 1956, Illinois was the fourth-most-populous state in the nation (Texas and Florida leapt over Illinois in the rankings during the second-half of the 20th century).

Illinois was a key part of the economic structure of the country: Its endless fields a critical part of the food supply; its inland port a means for the Midwest industrial centers to reach the outside world; its train yards the center around which the entire U.S. rail system operated.

It was natural, then, that the original Interstate plan released in 1955 saw key arteries originate and pass through Illinois, including I-55, I-57, I-64, I-70, I-74, I-80, I-90 and I-94. Illinois was cementing its place as the heart of the nation's roads.

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Throughout this rapid transition of Illinois's highway system, the bane of existence for commuters in and around the Chicago area came into existence: the Illinois Tollway.

As the state struggled to complete modern highways during World War II, the first tollway commission was established, becoming the Illinois State Toll Highway Commission in 1953. The initial three toll roads, completed by 1958 -- the Jane Addams, Tri-State and East-West Tollways -- all were eventually rolled into the Interstate system as the nationwide spiderweb of superhighways began to take shape. Today, the re-christened Toll Authority has added I-355 and state Route 390 among the ranks of its administered roads.

By the early 1990s, the majority of the modern Illinois interstate system was complete. Route 5, the original moniker of the East-West Tollway, saw a re-designation to I-88 in 1987 as Illinois sought to raise the speed limit on the toll road connecting Chicago to the Quad Cities.

I-39 from U.S. 20 outside Rockford to Bloomington was completed in 1992. Since then, Illinois has seen only one new Interstate: the 9/10ths of a mile I-41 on the northern edge of Lake County. That roadway came about as a construct of the Wisconsin DOT re-purposing U.S. 41, from the north suburbs of Chicago to Green Bay, into an interstate of its own. Its brief stint in Illinois sees it paired with I-94 as it crosses the state line.

All told, 24 routes -- 13 primary and 11 secondary -- compose the modern Illinois interstate, covering some 2,500 miles. And while Indiana might continue to lay claim to that "crossroads" crown, as Illinois celebrates 200 years -- with nearly 1,000 more miles of blue-and-red-signed roadways than its eastern neighbor -- its residents should know that it is still the true heart of America's fascination with the highway.

• Illinois 200 is a project of the Illinois Press Association and the Illinois Associated Press Media Editors. Shane Nicholson can be reached at Find previous stories at

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