U.S. Route 15 or U.S. Highway 15 (US 15) is a 791.71-mile-long (1,274.13 km) United States Numbered Highway, serving the states of South Carolina, North Carolina, Virginia, Maryland, Pennsylvania, and New York. The route is signed north–south, from US 17 Alternate in Walterboro, South Carolina, north to Interstate 86 (I-86)/New York State Route 17 (NY 17) in Corning, New York.
James Taylor Bridge, Chapel Hill, North Carolina, part of the US 15/US 501 route
View north along US 15 north of SR 230 in Madison Mills, Virginia
"Future I-99 Corridor" sign on US 15 southbound north of Williamsport, Pennsylvania
Authentic US 15 shield at the former northern terminus in Rochester, New York
United States Numbered Highway System
The United States Numbered Highway System is an integrated network of roads and highways numbered within a nationwide grid in the contiguous United States. As the designation and numbering of these highways were coordinated among the states, they are sometimes called Federal Highways, but the roadways were built and have always been maintained by state or local governments since their initial designation in 1926.
The "final" U.S. Highway plan as approved November 11, 1926
This sign, photographed in 1941 on US 99 between Seattle, Washington, and Portland, Oregon, illustrates one rationale for a federal highway system: national defense.