Interstate 26 (I-26) is a main route of the Interstate Highway System in the Southeastern United States. Nominally east–west, as indicated by its even number, I-26 runs from the junction of US Route 11W (US 11W) and US 23 in Kingsport, Tennessee, generally southeastward to US 17 in Charleston, South Carolina. The portion from Mars Hill, North Carolina, east to I-240 in Asheville, North Carolina, has signs indicating FUTURE I-26, because the highway does not yet meet all of the Interstate Highway standards.

U.S. Route 23 or U.S. Highway 23 (US 23) is a major north–south United States Numbered Highway between Jacksonville, Florida, and Mackinaw City, Michigan. It is an original 1926 route which originally reached only as far south as Portsmouth, Ohio, and has since been extended. It was formerly part of the major highway known as the Dixie Highway. The highway's southern terminus is in Jacksonville, Florida, at US 1/US 17. The northern terminus is at Interstate 75 (I-75) in Mackinaw City, Michigan.