In conjunction with the construction of the Airport Line, the section of the East Hills Line between Wolli Creek Junction and Kingsgrove was quadruplicated. Once this was opened, the running patterns of the trains on the lines changed. The "flying junctions" interchange near Central Station was altered to give the Airport Line its own platforms (21 & 23) at Central. Local (all stations) trains generally were timetabled to run from East Hills via the airport, peak hour express trains from Campbelltown run along the original route via Sydenham, taking the express tracks between Kingsgrove and Wolli Creek Junction.