https://www.youtube.com/watch?v=NhGNglF7dM8 Amtrak's Keystone Service and Northeast Regional routes are predominantly used as regional commuter trains in the Northeast United States. Both also travel between Philadelphia and New York City -- but that's where the commonalities end. Keystone Service primarily travels east and west, connecting cities in Pennsylvania with New Jersey and New York City. On … Continue reading Keystone Service vs Northeast Regional