I would like to know why they call route 309/Bethlehem Pike the oldest route in North America?

Question

Pennsylvania Route 309/USA, Bethlehem Pike, Minsi, 5 Points Montgomeryville. 2 sources listed it as the oldest route in North America. Living in Pensylvania as it went by, Route 611 goes to city hall in Philadelphia as Broad Street and down the street Minsi is the oldest route in North America and George Washington is in Valley Forge/Norristown and Bethlehem and Nazareth are at the end of Bethlehem Pike that drove the Liberty Bell into existence. What is going on there?

Answer 1

Well, run-on sentences, for one thing.

Answer 2

It may be one of the oldest routes which was designated as a U.S. route, rather than a state route.   I believe that there are separate funding sources and governmental rules about maintenance and availability which distinguish these routes from state routes.