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 77 in Iowa
US 77 has never been a long route in Iowa. When it was extended into the state in 1929, it only traveled in Sioux City before crossing the Big Sioux River into South Dakota. After I-29 was built in Sioux City during the late 1950s, US 77 was moved onto the new Interstate Highway. At both historic ends of the highway in Iowa, bridge failures have caused US 77 to be detoured around Sioux City. In the mid-1980s, the national end of the highway was moved to the interchange with I-29.
This is not the shortest highway in the USA. Pretty certain the Old Edgerton Highway in Alaska is the shortest at less than 12 miles long.