| Interstate Highway System in Illinois | |
|---|---|
Standard Illinois Interstate Highway markers | |
 Interstate Highway system in Illinois | |
| System information | |
| Maintained by IDOT, ISTHA, and SCC | |
| Length | 2,248.93 mi[2] (3,619.30 km) |
| Formed | June 29, 1956[1] |
| Highway names | |
| Interstates | Interstate X (I-X) |
| US Highways | U.S. Route X (US X) |
| State | Illinois Route X (IL X) |
| System links | |
The Interstate Highways in Illinois are all segments of the Interstate Highway System that are owned and maintained by the U.S. state of Illinois.[3] The Illinois Department of Transportation (IDOT), Illinois State Toll Highway Authority (ISTHA), and Skyway Concession Company (SCC) are responsible for maintaining these highways in Illinois. The Interstate Highway System in Illinois consists of 13 primary highways and 11 auxiliary highways which cover 2,248.93 miles (3,619.30 km).[2] The Interstate Highway with the longest section in Illinois is Interstate 57 at 358.57 miles (577.06 km); the shortest is Interstate 41 at 0.90 miles (1.45 km).
- ^ McNichol, Dan (2006). The Roads that Built America. New York: Sterling. p. 106. ISBN 1-4027-3468-9.
- ^ a b Adderly, Kevin (January 15, 2014). "Table 3: Interstate Routes in Each of the 50 States, District of Columbia, and Puerto Rico". Route Log and Finder List. Federal Highway Administration. Retrieved April 7, 2015.
- ^ Staff. "Interstate Frequently Asked Questions". Federal Highway Administration. Retrieved February 25, 2008.