New Haven–Springfield Line

The New Haven–Springfield Line is a railroad line owned by Amtrak from New Haven, Connecticut, north to Springfield, Massachusetts, serving the Knowledge Corridor. As a branch of the Northeast Corridor just north of New Haven State Street station, it is served by approximately seven daily Northeast Regional round trips, some continuing from New Haven to Washington, D.C., along the Corridor and others terminating at New Haven as shuttles. On weekends, there is one train daily to Roanoke, Virginia. It is also served by the daily Vermonter, which starts in Washington, D.C., and continues north from Springfield, finally terminating in St. Albans, Vermont. The line is part of the Inland Route connecting Boston and New York via Hartford, Springfield, and Worcester, in contrast to the "Shore Line" along the Connecticut Shore and through Rhode Island.

The line was originally built by the Hartford and New Haven Railroad, and opened to Springfield in 1844. In 2004, Congress added the New Haven–Springfield Line onto the Northern New England Corridor, one of ten federally designated corridors for potential high-speed rail service. Upgrades needed for higher-speed rail, including rebuilding portions of double tracking removed in the 1980s, were performed in preparation for the CT Rail Hartford Line commuter service, which launched on June 16, 2018.