Travellers between New York and Philadelphia could purchase a ticket from New York to one of the branch line stations on the Harrisburg branch of the Northeast Corridor, and disembark in Philadelphia leaving the feeder portion of the ticket unused.
Passengers traveling between New York and Philadelphia could buy a ticket from New York to one of the branch line stations on the Harrisburg branch of the Northeast Corridor, and get off in Philadelphia by discarding the unused part of the ticket.