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.
List of Interstate Highways in Illinois
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. The Illinois Department of Transportation (IDOT) is responsible for maintaining these highways in Illinois. The Interstate Highway System in Illinois consists of 13 primary highways and 11 auxiliary highways which cover . The Interstate Highway with the longest section in Illinois is Interstate 57 at ; the shortest is Interstate 41 at .