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.
Pacific Highway (United States)
Good roads advocate and road-building pioneer Sam Hill was perhaps the main motivating force behind building the original Pacific Highway as a "national auto trail"; from Blaine, Washington, on the Canada–US border, where he would build his Peace Arch, through Oregon to the Siskiyou Mountains of northwestern California. The road was built in the early 20th century—long before the U.S. Highway System was established. In 1923, its of pavement made it the longest continuous stretch of paved road in the world at the time. The Pacific Highway later extended north to Vancouver, British Columbia, and south through San Francisco to San Diego in Southern California.