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 state highways in Utah
The longest contiguous highway signed as a Utah State Route is State Route 24 at . However, State Route 30 is longer at when the unsigned concurrencies with I-84, I-15, and US-89 are included. The longest highway of any type in Utah is U.S. Route 89 at . The shortest state route is State Route 231, a connector route in Fairview, though this route is unsigned. The shortest signed route is State Route 103 at long, connecting Hill Air Force Base to I-15 and SR-126.