The Eighth Avenue Line is a public transit line in Manhattan, New York City, running mostly along Eighth Avenue from Lower Manhattan to Harlem. Originally a streetcar line, it is now the M10 bus route and the M20 bus route, operated by the New York City Transit Authority. The M10 bus now only runs north of 57th Street (near Columbus Circle), and the M20 runs south of 66th Street. The whole line was a single route, the M10, until 2000 when the M20 was created.