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 Highways in Alaska
The Interstate Highways in Alaska are all owned and maintained by the U.S. state of Alaska. The Alaska Department of Transportation & Public Facilities (DOT&PF) is responsible for the maintenance and operations of the Interstate Highways. The Interstate Highway System in Alaska comprises four highways that cover . The longest of these is A-1, at long, while the shortest route is A-3, at long. All Interstates in Alaska are unsigned and are not generally referred to by their highway numbers.