List of Interstate Highways
There are 70 primary Interstate Highways in the Interstate Highway System, a network of controlled-access freeways in the United States. They are assigned one- or two-digit route numbers, whereas their associated "auxiliary" Interstate Highways receive three-digit route numbers. Typically, odd-numbered Interstates run south-north, with lower numbers in the west and higher numbers in the east; even-numbered Interstates run west-east, with lower numbers in the south and higher numbers in the north. Highways whose route numbers are divisible by "5" usually represent major coast-to-coast or border-to-border routes (ex. I-10 travels from Santa Monica, California, to Jacksonville, Florida, traveling from the Pacific to Atlantic oceans). Additionally, auxiliary highways have their numbering system where a different number prefixes the number of its parent highway.
Interstate 74 in North Carolina
The Intermodal Surface Transportation and Efficiency Act (ISTEA) of 1991 initially authorized the new high priority transportation corridor 5, tentatively known as Interstate 73, to travel from Michigan to South Carolina. Because of several disputes to the routing, a compromise was reached in 1995, by Senator John Warner and Senator Lauch Faircloth, that extended Interstate 74 from its then current eastern terminus of Cincinnati, Ohio to overlap Interstate 73. In Virginia, I-74 would follow I-77 into North Carolina, while I-73 would go east to Roanoke then south along US 220 towards Greensboro. However, when I-73 crossed a border between two states, the federal law authorizing the road required that the two states agree that their sections meet. Originally, both Carolinas selected a route running south from Rockingham, North Carolina. North Carolina had more money to spend on roads, though, and on May 10, 1995, the U.S. Senate Environment and Public Works Committee approved North Carolina's plan for I-73 to run eastward to the coast and enter South Carolina at North Myrtle Beach. Another compromise, between Senator Lauch Faircloth and Senator Strom Thurmond, agreed to have both interstates enter South Carolina: I-73 south of Rockingham and I-74 south of Wilmington. After later amendments and the Transportation Equity Act for the 21st Century of 1996 (TEA-21), on July 25, 1996, AASHTO accepted Interstates 73/74 into the Interstate Highway System within the states of South Carolina, North Carolina, and Virginia.
The portion from south of Steeds north to south of Ulah was completed August 27, 1996, and was the first road marked as I-74 (and I-73). Future signage was also installed north to the Greensboro area. The remainder of of existing and new freeway between Ulah and Candor was also signed as I-73/I-74 along US 220. In 1998, NC 752, a freeway spur of I-77 was renumbered as the segment of completed I-74, from I-77 to US 601. On June 30, 1999, the freeway was extended an additional to US 52, south of Mount Airy. In April 2001, I-74 was overlapped with I-77 from the Virginia state line to exit 101.