Endpoints of
US Route 17-1

US 17-1 was among the original routes of 1926 (the following image is from AASHO's April 1927 route log).  Claim to fame: US 17-1 was the only major US highway that was ever assigned a hyphenated route number.  I suspect its strange number was intended to convey the fact that it ran between US 17 in Wilmington and US 1 at Petersburg (photos and more info on those pages).