The Hudson Line is a commuter rail line owned and operated by the Metro-North Railroad in the U.S. state of New York. It runs north from New York City along the east shore of the Hudson River, terminating at Poughkeepsie. The line was originally the Hudson River Railroad, and eventually became the Hudson Division of the New York Central Railroad. It runs along what was the far southern leg of the Central's famed "Water Level Route" to Chicago.

The West Side Line, also called the West Side Freight Line, is a railroad line on the west side of the New York City borough of Manhattan. North of Penn Station, from 34th Street, the line is used by Amtrak passenger service heading north via Albany to Toronto; Montreal; Niagara Falls and Buffalo, New York; Burlington, Vermont; and Chicago. South of Penn Station, a 1.45-mile (2.33 km) elevated section of the line, abandoned since 1980, has been transformed into an elevated park called the High Line. The south section of the park from Gansevoort Street to 20th Street opened in 2009 and the second section up to 30th Street opened in 2011, while the final section to 34th Street opened in 2014.