Northern Illinois

Northern Illinois is a region generally covering the northern third of the U.S. state of Illinois.

Northern Illinois is dominated by the metropolitan areas of Chicago, the Quad Cities, and Rockford, which contain a majority (over 75%) of Illinois' population and economic activity, including numerous Fortune 500 companies and a heavy manufacturing, commercial, retail, service, and office based economy. Much of the economic activity of the region is centered in the Chicago Loop, the Illinois Technology and Research Corridor, and the Golden Corridor. However, rural sections of this region are highly productive agriculturally, and are part of the Corn Belt. The headquarters for John Deere farming equipment are located in Moline. Additional smaller cities in this area include Kankakee, LaSalle-Peru, Ottawa, Freeport, Dixon, and Sterling-Rock Falls, which still have predominantly manufacturing and agricultural economies. Northern Illinois is also one of the world's busiest freight railroad and truck traffic corridors.

Interstate 80 is sometimes referenced as the informal southern boundary of Northern Illinois, and is often used in weather reports as a reference point, as in "south of Interstate 80 will see sleet and rain, but north of Interstate 80 can expect mostly snow."

Interstate 88 (the Ronald Reagan Memorial Tollway) connects the region, east-west, stretching from the Quad Cities, eastward through Sterling-Rock Falls, Dixon, DeKalb, Aurora, Naperville, and into Chicago. Northern Illinois is also the only region of the state in which there are tollways, which are run by the Illinois State Toll Highway Authority, another trait separating this region from Central and Southern Illinois.

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