hours only, with the using the express tracks to relay when it terminated at West 4th Street at other times. Service on the Culver Line to Coney Island was replaced by extended F service. On July 1, 1968, it would become the full-time Sixth Avenue Express when non-rush hours service and new KK service was extended to the new 57th Street–Sixth Avenue station. On August 19, 1968, to reduce conflicts at the Brighton Beach terminal, D service was truncated to Brighton Beach when it ran express on the BMT Brighton Line (morning rush hours through early evenings, and QB (rush-hour peak direction only) and QJ (morning rush hours through early evenings) were extended from Brighton Beach to Coney Island–Stillwell Avenue. In addition, the span of Manhattan-bound D express service was increased by two hours, with the last express leaving Brighton Beach at 7:37 p.m. Effective January 2, 1973, the daytime QJ was truncated to Broad Street as the J, and the M was extended beyond Broad Street during the day along the QJ's former route to Coney Island–Stillwell Avenue, via the Montague Street Tunnel and Brighton Line local tracks. Also, changes were made to D and M service on the Brighton Line. Northbound weekday M train service originating at Kings Highway would begin at 5:46 a.m., while northbound service from Coney Island would begin at 6:34 a.m. From 5:40 to 6:34 a.m. northbound D trains would run local from Brighton Beach to Kings Highway, and then run express to Prospect Park. Late morning and early afternoon D trains would from then on run express from Brighton Beach to Kings Highway. The span of D express service to Brighton Beach was extended by 45 minutes to 9:05 p.m. from Prospect Park, and the span of M service from Broad Street to Coney Island was extended by 45 minutes over the span of QJ service to cover local stops. Rehabilitation work D service was divided and ran in two sections when the north tracks of the Manhattan Bridge closed on April 26, 1986, due to construction, with regular service expected to resume on October 26, 1986. The northern section ran between Norwood–205th Street in the Bronx and 34th Street–Herald Square (the orange D) while the southern section ran from 57th Street–Seventh Avenue on the BMT Broadway Line, then express along the Broadway Line to Canal Street, then over the south tracks of