The Northeast Corridor Line is a commuter rail operation run by New Jersey Transit along Amtrak's Northeast Corridor. It is the successor to Pennsylvania Railroad trains between Trenton Transit Center and New York Penn Station. After arrival at New York Penn Station, some trains load passengers and return to New Jersey, while others continue east to Sunnyside Yard for storage. Most servicing is done at the Morrisville Yard, at the west end of the line.