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.
Texas state highway system
In 1992, the of Interstate Highway System in Texas was completed with the opening of a section of I-27. In 1997, the Texas Turnpike Authority was merged with TxDOT and independently, the North Texas Turnpike Authority became responsible for toll projects in Collin, Dallas, Denton, and Tarrant counties.
The Interstate Highway System in Texas covers and consists of ten primary highways, seven auxiliary highways, and the splitting of both Interstate 35 (I-35) and Interstate 69 into multiple letter-suffixed branches. The Interstate Highway with the longest segment in Texas is I-10 at . The shortest in the state is I-110 at .