- Northern terminus: 501 exits I-85 north of Durham, NC to follow North Duke Street, while 15 continues concurrently with I-85 North.
- Southern terminus: 15 and 501 merge onto US 401 just north of Laurinberg, NC; 501 then merges onto I-74 (exit 183) East while 15 continues South on 401.
It also refers to a number of business spurs, usually qualified with "business" or "Boulevard"; the main road is technically a "bypass", but when there are both business and bypass routes, "15-501" by itself is generally understood to mean the bypass.
The entirety of 15-501 is within North Carolina.
- Wikipedia mainly covers 15-501 in its article on U.S. Route 15 in North Carolina