(The N ran on the IND Queens Boulevard Line until 1987, when the N and R swapped northern terminals in Queens.) The N train was to run between Jamaica Center and Coney Island during weekdays while G trains were to terminate at 71st Avenue. During weekends and evenings the G train was to run between Jamaica Center and Smith–Ninth Streets, while N trains would terminate at 57th Street–Seventh Avenue or 71st Avenue. To serve the Archer Avenue Line during late nights, a G train shuttle would have run between Jamaica Center and Van Wyck Boulevard. Jamaica Line One of the goals of the project was to make Jamaica Avenue service as attractive as possible, and as a result, the NYCTA planned to provide a form of express service. The two options considered to speed up Jamaica Line service were skip-stop service, which would have split Jamaica services into two patterns that served alternate stops, and a zone-express service, which would have split Jamaica services into a short-turn local service and a full-length express services. The zone-express option was dismissed in favor of the skip-stop option because its operation has to be very precisely timed so as to not hinder reliability, because service in the outer zone past the boundary of zone express service at Crescent Street or 111th Street would be too infrequent, and because many stations would lose half their service. Outer-zone expresses after Crescent Street would skip stops on the local track until Eastern Parkway, from where it would run on the express track, stopping at Myrtle Avenue before going straight to Essex Street in Manhattan, skipping Marcy Avenue. Outer-zone expresses and inner-zone locals would have each been limited to frequencies of 10 minutes. The TA decided to implement skip-stop service with two services labeled "J" and "Z", with lightly-used stops designated as "J" or "Z" stops, and those with higher ridership being all-stop stations. In addition, J and Z trains skipped Bowery in Manhattan at all times except evenings, nights and weekends. To further speed up service, J and Z trains would run express between Myrtle and Marcy. Trains on the J/Z ran every five minutes, an improvement over their previous headway of eight minutes. Skip-stop service ran to Manhattan in the morning between 7:15 and 8:15 a.m. and to Jamaica between 4:45 and 5:45 p.m. Midday express service was added with J service continuing to run