A 1948 map has the D and F service switched, with the F going to Second Avenue. But this was afterwards changed back.
On December 11, 1950, trains were extended to 179th Street on evenings, nights, and Sunday mornings. On May 13, 1951, all trains outside of rush hour extended to 179th Street. On October 18, 1951, all trains started to terminate at 179th Street at all times.
On November 26, 1967, the Chrystie Street Connection was completed. D service was rerouted via this connection, over the north side of the Manhattan Bridge, and via the BMT Brighton Line in Brooklyn. F service replaced it on the IND Culver Line. Beginning in July 1968 there was rush hour express service between Jay Street – Borough Hall and Kings Highway. This was discontinued in 1976 due to budget cuts and complaints about reduced Manhattan service by riders at local stations. There has been community support for resuming express service along the Culver Line. The MTA has announced that the elevated Culver Viaduct undergone extensive renovations from 2009 to 2012, after which "There will be no impediment to implementing the F express." The F express service along the Culver Line is still under consideration, as there is some controversy from residents living along the line who fear that they would no longer have a one-seat ride into Manhattan.
On May 24, 1987, N and R services switched terminals in Queens. As part of the reroute plan, F service terminated at 57th Street / Sixth Avenue during late nights.
In December 2000, the F service began to be rerouted via the new 63rd St. connector during nights and weekends. A couple of rush hour specials were soon after scheduled to run through the connector to relieve the 53rd St. tunnel.