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

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.

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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The history of newspapers in Illinois (even before it was a state)

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

Interstate timeline

1916: The Federal Aid Road Act is passed to establish a nationwide system of modern highways. World War I prevents most of its funds from being disbursed, and the Act passes out of law in 1921.

1918: A civil engineer during a presentation at The Congress Hotel in Chicago proposes a 50,000-mile system of transnational highways.

1921: The Phipps Act, a reconstruct of the 1916 act, targets funding for a nationwide series of interconnected highways. Gen. John J. Pershing follows up with a proposed map of roads considered important to the national defense, with 20,000 miles of interconnected primary highways.

1939: The Bureau of Public Roads Division under President Franklin Roosevelt issues a report, "Toll Road and Free Roads," now considered the first blueprint of the Interstate Highway System.

1941: The Toll Highway Authority is established as highway construction around Chicago stalls during World War II.

1951: The Edens Expressway, the state's first expressway and now part of I-94, opens north of Chicago.

1953: The Illinois State Toll Highway Commission is established, replacing the THA.

1955: Inspired by his travel across the United States as a young Army officer and his time in Germany during World War II, President Dwight D. Eisenhower announces plans for the modern Interstate system.

1956: The Federal-Aid Highway Act of 1956 is signed into law, establishing the Interstate Highway System.

1957: Construction of I-80 begins, with the modern Kingery Expressway being the first section of Interstate open in Illinois.

1958: The Northwest, Tri-State and East-West tollways open.

1959: The original five tollway oases are opened.

1964: The Stevenson Expressway, one of the first portions of I-55 completed near Chicago, opens. The earliest stretch of I-55 was a reclaimed portion of U.S. 66. The St. Louis-Chicago connection was part of the second phase of interstates finished in the 1970s.

1968: I-80 is completed.

1969: I-180, a 13-mile spur in the center of the state, is completed, connecting I-80 to the Jones & Laughlin steel plant in Hennepin. The plant closes soon after I-180's completion and doesn't reopen until 2002.

1971: I-57, Illinois' longest Interstate at 386 miles, is completed near Paxton.

1972: IDOT is formed following a decadelong study of Illinois' transportation system.

1978: The Eisenhower Expressway is redesignated as I-290. It was formerly considered part of I-90, which was moved to the Northwest Tollway and Kennedy Expressway.

1984: I-39 from Rochelle to Rockford is opened.

1987: I-88, the former East-West Tollway renamed in honor of President Ronald Reagan, is completed, reaching its west end at I-80 in East Moline.

1989: I-355 is opened in the western suburbs, alleviating traffic on the Tri-State Tollway and creating another bypass route around Chicago.

1992: I-39 is completed.

2009: I-490, a bypass around the west side of O'Hare International Airport, is proposed. Construction is expected to begin in 2018.

2015: I-41 is completed in northeast Lake County. The road runs only 9/10ths of a mile in Illinois.

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