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.
U.S. Route 10
U.S. Route 10 or U.S. Highway 10 (US 10) is an east–west United States highway formed in 1926. Though it never became the cross-country highway suggested by the "0" as the last digit of its route number, US 10 was one of the original long-haul highways, running from Detroit, Michigan, to Seattle, Washington, but then losing much of its length when new Interstate Highways were built on top of its right-of-way. In 2010, its length was .