The Northeast Corridor (NEC) is an electrified railroad line in the Northeast megalopolis of the United States. Owned primarily by Amtrak, it runs from Boston in the north to Washington, D.C. in the south, with major stops in Providence, New Haven, Stamford, New York City, Newark, Trenton, Philadelphia, Wilmington, and Baltimore. The NEC closely parallels Interstate 95 for most of its length. Carrying more than 2,200 trains a day, it is the busiest passenger rail line in the United States by ridership and by service frequency.