IND Sixth Avenue Line. The two-track IND Queens Boulevard Line, also in 53rd Street, curves south into a lower level of the 50th Street station, and merges to the south, taking E trains onto the local tracks. An unused southbound-only lower level at 42nd Street–Port Authority Bus Terminal was formerly accessed only from the southbound track from the Queens Boulevard Line. Plans for the 7 Subway Extension required partially demolishing the lower level to make room for the new IRT Flushing Line tracks. The four-track line continues south under Eighth Avenue to 14th Street, where it turns southeast under Greenwich Avenue and south under Sixth Avenue, above the four-track IND Sixth Avenue Line. The two-level West Fourth Street–Washington Square station allows easy transfers between the two lines. Just to the south are track connections between the local tracks of each line, not used by current normal service patterns. The Sixth Avenue Line turns east into Houston Street after passing the connections. Canal Street, under Sixth Avenue, is the last normal four-track station on the line. Crossovers in each direction, beyond the station, take C and late night A trains between the local tracks to the north and the express tracks to the south. As the subway turns from Sixth Avenue into Church Street, the southbound local track passes under the express tracks, bringing E trains to the east. At this point, a bellmouth originally intended for the never-built IND Worth Street Line is present on the east side of the tunnel. It has been proposed to use this to bring Long Island Rail Road Atlantic Branch trains to Lower Manhattan as part of the Lower Manhattan-Jamaica/JFK Transportation Project. The four tracks continue south under Church Street, with two separate but connected stations at World Trade Center at the end of the local tracks and Chambers Street on the express tracks. The two express tracks turn east under Fulton Street, crossing the East River through the Cranberry Street Tunnel into Cranberry Street in Brooklyn. Cranberry Street leads to High Street, from which the line turns south into Jay Street, straddled by the two-track IND Sixth Avenue Line from the Rutgers Street Tunnel. The Eighth and Sixth Avenue Lines end, becoming the IND Fulton Street Line and IND Culver Line, at crossovers (currently unused) allowing trains to switch between the two, located between High Street and Jay Street–MetroTech. Both the A and