Interstate 294 (I-294) is a tolled auxiliary Interstate Highway in northeastern Illinois. It forms the southern portion of the Tri-State Tollway in Illinois. I-294 runs from South Holland at I-80/I-94 and Illinois Route 394 (IL 394) to Northbrook at I-94. I-294 is 53.42 miles (85.97 km) long; 5.32 miles (8.56 km) are shared with I-80. It serves as a bypass around the city of Chicago. I-294 is also the longest auxiliary route of I-94, at 10 miles (16 km) longer than I-494 in Minneapolis–Saint Paul. In addition, the tollway is the longest auxiliary Interstate Highway in Illinois, and it intersects the most primary Interstate Highways at six.
Illinois Route 58, also known as Golf Road for most of its route, is a state highway in northeast Illinois. It runs from Illinois Route 25 in Elgin east to U.S. Route 41 in Skokie. This is a distance of 27.88 miles (44.87 km).
Illinois Route 83 (IL 83) is a 91.73-mile-long (147.63 km) major north–south state highway in northeast Illinois. It stretches from U.S. Route 30 by Lynwood and Dyer, Indiana, north to the Wisconsin border by Antioch at Wisconsin Highway 83 (WIS 83).
Illinois Route 43 is a 60.30-mile-long (97.04 km) major north–south state highway in the U.S. state of Illinois. It runs from U.S. Route 30 (US 30) in Frankfort north to the large intersection of IL 120 and US 41 in Waukegan.
Illinois Route 40 is a 112.05-mile-long (180.33 km) north–south route in central portion of the U.S. state of Illinois. It runs from Interstate 74 (I-74) in East Peoria north to IL 78 at Mt. Carroll, just south of U.S. Route 52 and IL 64.
Illinois Route 171 (IL 171) is a 38.61-mile-long (62.14 km) north–south state highway in northeastern Illinois. It runs from U.S. Route 6 (US 6) in Joliet north to Illinois Route 72 at the Chicago–Park Ridge border. The section of IL 171 on Archer Avenue from Joliet to Summit is historically significant, originating as a Native American trail, and later serving for a time as part of the first numbered highway between St. Louis and Chicago.
Illinois Route 31 (IL 31) is a 58.41-mile-long (94.00 km) north–south state highway in northeastern Illinois, United States. It travels from U.S. Route 34 (US 34) in Oswego north to US 12, near the Wisconsin state line, just south of Richmond.
Illinois Route 60 is a 17.22-mile-long (27.71 km) east–west state highway in Lake County, in northeastern Illinois. It connects the village of Volo at Illinois Route 120 just east of Illinois Route 59 with the city of Lake Forest at U.S. Highway 41.
Illinois Route 390 (IL 390), previously known as the Elgin–O'Hare Expressway, now known as the Elgin–O'Hare Tollway, is a 9.8-mile-long (15.8 km) electronic toll highway in northeastern Illinois. IL 390 currently connects U.S. Route 20 in Hanover Park to the intersection with Illinois Route 83 and Thorndale Avenue in Wood Dale. The only other towns it borders are Schaumburg and Roselle. Construction is underway to extend the road from IL 83 to the western edge of O'Hare International Airport.
Illinois Route 4 is a major north–south highway that runs south from the Interstate 55 business loop around the state capital of Springfield, south to Illinois Route 13 just north of Murphysboro. This is a distance of 170.44 miles (274.30 km).
Lake Street is an east–west street in Chicago and part of its suburbs. A portion of Lake Street is designated as U.S. Route 20. Lake Street begins in downtown Chicago and travels west to the eastern terminus of the Elgin Bypass around suburban Elgin. The street travels west through the city and then begins to travel in a northwest fashion through several suburbs. The street is a distance of roughly 34.4 miles (55.4 km).
Illinois Route 137 is a 23.49-mile-long (37.80 km) state highway in northeast Illinois. It runs from the Wisconsin Border north of Winthrop Harbor south to North Chicago, west to Libertyville, and then back northwest to Grayslake, terminating at IL 83 just south of IL 120.
Interstate 490 (I-490), also known as O'Hare West Bypass and Western O'Hare Beltway, is a proposed electronic toll highway and a beltway near Chicago, Illinois, that would run along the west side of O'Hare International Airport. The tollway would connect I-294 to a western access point to the airport. From there, it would continue northward to an extension of the Illinois Route 390 (IL 390) and I-90. The O'Hare Western Bypass is part of the Elgin–O'Hare Western Access (EOWA) project. Building the highway would affect the villages of Elk Grove Village, Wood Dale, Itasca, and Bensenville. The proposed route runs through the American Airlines Flight 191 crash site, the deadliest aviation accident in US history.
U.S. Route 20 in the U.S. state of Illinois is a major arterial highway that runs from the Iowa state line at East Dubuque at the northwestern tip of Illinois, to the Indiana state line at Chicago south of the Chicago Skyway, a distance of 233.93 miles (376.47 km). For its entire length, US 20 is designated as the General Ulysses S. Grant Highway, often abbreviated the U.S. Grant Memorial Highway. However, this name is only commonly used west of Elgin. US 20 bypasses the city of Elgin on a freeway known as the Elgin Bypass or Dr. Martin Luther King Jr. Memorial Highway. From Elgin to Melrose Park, US 20 follows Lake Street. It then follows Mannheim Road, and further south La Grange Road. US 20 also follows 95th Street as it turns east through Chicago's southwestern suburbs. It ultimately leaves Illinois on Indianapolis Boulevard.
U.S. Route 12 (US 12) in the U.S. state of Illinois is an arterial highway that runs northwest to southeast through the Chicago metropolitan area. It enters Illinois at the Wisconsin border north of Richmond, and exits into Hammond, Indiana from Chicago near the foot of the onramp to the Indiana Toll Road ; as it exits Illinois, the route is also concurrent with US 20 and US 41. Within Illinois, US 12 runs for a distance of 85.14 miles (137.02 km).
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.
U.S. Route 54 (US 54) in Illinois is a 23.9-mile-long (38.5 km) east–west highway that travels from the Champ Clark Bridge on the Missouri state line to I-72/US 36/IL 107 south of Griggsville. At its greatest extent, US 54 used to continue east to Springfield, then northeast to Onarga, and then north all the way to Downtown Chicago.
U.S. Route 45 in the state of Illinois is a major north–south U.S. Highway that runs from the Brookport Bridge over the Ohio River at Brookport north through rural sections of eastern Illinois and then through the suburbs of Chicago to the Wisconsin state line east of Antioch. This is a distance of 428.99 miles (690.39 km). US 45 is the longest numbered route in Illinois.
U.S. Route 14 (US 14) in the state of Illinois is a major arterial that runs southeast from the Wisconsin state line north of Harvard, Illinois, to the north side of Chicago at US 41.
Several special routes of U.S. Route 20 exist. In order from west to east they are as follows.
IL 25 in Elgin 
IL 390 Toll in Schaumburg 
US 12 / US 45 in Schiller Park 
I-294 Toll in Schiller Park
I-90 / I-94 in Chicago 
US 41 in Chicago
