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 91
Interstate 91 (I-91) is an Interstate Highway in the New England region of the United States. It provides the primary north–south thoroughfare in the western part of the region. The Interstate's southern end is in New Haven, Connecticut, at Interstate 95 and its northern end is at Derby Line, Vermont, a village in the town of Derby at the Canadian border, where it continues past the Derby Line-Rock Island Border Crossing as Autoroute 55. I-91 is the longest of three Interstate highways whose entire route is located within the New England states (the other two highways being I-89 and I-93) and is also the only primary (two-digit) Interstate Highway in New England to intersect all five of the others that run through the region. The largest cities along its route are New Haven, Connecticut, Hartford, Connecticut, Springfield, Massachusetts, Brattleboro, Vermont, White River Junction, Vermont, and St. Johnsbury, Vermont in order from south to north.