D (New York City Subway service)

The D 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 D operates 24 hours daily between 205th Street in Norwood, Bronx, and Stillwell Avenue in Coney Island, Brooklyn. Daytime service makes express stops in the Bronx and Manhattan, and in Brooklyn (between Atlantic Avenue and 36th Street) and also bypasses DeKalb Avenue. During rush hours in the peak direction, D service makes express stops between Fordham Road in the Bronx and 145th Street in Manhattan. Overnight service is the same as daytime service, except all trains make all stops in Brooklyn and stops at DeKalb Avenue.

In its early years, the D ran to Chambers Street/Hudson Terminal in Lower Manhattan via the lower IND Eighth Avenue Line south of West 4th Street. From 1954 to 1967, the D ran via the IND Culver Line to Coney Island. With the completion of the Chrystie Street Connection, service was rerouted via the BMT Brighton Line, running there from 1967 to 2001. As part of the multi-year rebuilding of the Manhattan Bridge, a short-lived yellow D service ran via the BMT Broadway Line in Manhattan to the Brighton Line in Brooklyn, while orange D service used the Sixth Avenue, Central Park West, and Concourse Lines in Manhattan and the Bronx.