There are branches on both ends of the line. On the south end, the express tracks used by the diverge to Grand Street and the Manhattan Bridge. The local tracks continue through the Rutgers Street Tunnel and to York Street in Brooklyn (used by the ) or via the Chrystie Street Connection and the Williamsburg Bridge to the BMT Jamaica Line in Brooklyn (used by the ). On the north end, north of 47th–50th Streets–Rockefeller Center, the express tracks diverge to Seventh Avenue–53rd Street and the IND Eighth Avenue Line, while a spur used by the continues under Sixth Avenue to 57th Street and the 63rd Street Lines; the local tracks, used by the , merge with the IND Queens Boulevard Line and continue to Queens.