List of Interstate Highways in Utah
The Interstate Highways in Utah are maintained by the Utah Department of Transportation (UDOT). The Interstate Highway System is a nationwide system with only a small portion of these routes entering Utah. Originally, the State Road Commission of Utah, created on March 23, 1909 was responsible for maintenance, but these duties were rolled into the new UDOT in 1975. There are of Interstates within the state. The longest is Interstate 15 (I-15) at and the shortest is I-215 at . One unique former route is Interstate 415, which was never signed as such, and was only used as a temporary designation for the eastern portion of what is now the Interstate 215 belt loop around Salt Lake City.
Interstate 57
In the state of Illinois, Interstate 57 runs from the bridge over the Mississippi River north to Chicago. I-57 is the longest Interstate Highway in Illinois. Its route follows essentially the earlier route of US 51 in southernmost Illinois (US 51 has been diverted to I-57 where I-57 has always been close to old US 51 between Future City and Dongola) before taking a northeastward diagonal to Illinois 37, which remains intact as a town-to-town through route, past its interchange with Interstate 24 (the northwestern terminus of Interstate 24) near Pulleys Mill and a short duplex with Interstate 64 near Mount Vernon north to Effingham, where it has a short concurrence with Interstate 70. It then follows US 45 bypassing cities of Champaign and Urbana (where it meets Interstates 72 and 74), and heads north to Onarga whereafter it follows the formerly duplex path of US 45 and (now decommissioned in most of Illinois) old US 54 to Kankakee. At Kankakee it heads northward largely parallel to the now decommissioned route of old US 54 (since renumbered largely as Illinois 50) into the Chicago area, meeting Interstate 80 in Hazel Crest, Interstate 294 in Blue Island, and feeding Interstate 94 on Chicago's South Side.