B (New York City Subway service)

The B Sixth Avenue Express is a rapid transit service in the B Division of the New York City Subway. Its route emblem, or "bullet", is colored orange, since it uses the IND Sixth Avenue Line in Manhattan.

The B operates only on weekdays between Brighton Beach in Brooklyn and 145th Street in Harlem, Manhattan, making express stops in Brooklyn along the BMT Brighton Line and in Manhattan along Sixth Avenue, and making local stops along Central Park West. During rush hours, the B is extended beyond 145th Street to and from Bedford Park Boulevard in the Bronx, making local stops along Grand Concourse.

Prior to November 1967 (1967-11) the B ran almost exclusively in Manhattan, as the BB, from 168th Street in Washington Heights during rush hours to 34th Street–Herald Square in Midtown Manhattan. Upon the opening of the Chrystie Street Connection, the B started running via the BMT West End Line (local) and BMT Fourth Avenue Line (express) in Brooklyn. A short-lived B service marked with a yellow bullet ran via the BMT Broadway Line in Manhattan and the BMT West End Line in Brooklyn from 1986 to 1988 due to Manhattan Bridge renovation, while orange B service traveled the pre-1967 route between 168th and 34th Streets. After 1989, the B north of 47th–50th Streets–Rockefeller Center used the IND Eighth Avenue Line to 168th Street on weekdays, and the IND 63rd Street Line on evenings and weekends. Late night service ran as a shuttle on the West End Line. Weekday service was rerouted to the Concourse Line in 1998, while off-peak service along 63rd Street ceased in 2000. The B started using the Brighton Line in 2004 after work on the north side of the Manhattan Bridge was completed.