U.S. Route 41 (US 41) in the U.S. state of Illinois runs north from the Indiana border beneath the Chicago Skyway on Indianapolis Boulevard to the Wisconsin border north of the northern terminus of the Tri-State Tollway with Interstate 94. It is the only north–south U.S. Route to travel through a significant portion of the city of Chicago, carrying Lake Shore Drive through the central portion of the city along the lakefront. US 41 in Illinois is 64.81 miles (104.30 km) in length.

Interstate 90 (I-90) in the US state of Illinois runs roughly northwest-to-southeast through the northern part of the state. From the Wisconsin state line at South Beloit, it heads south to Rockford before heading east-southeast to the Indiana state line at Chicago. I-90 traverses 124 miles (200 km) through a variety of settings, from farmland west of the Fox River Valley through the medium-density suburbs west of O'Hare International Airport, through Downtown Chicago, and through the heart of the industrial southeast side of Chicago before entering Indiana.