There will be changes to rail services on the weekend of January 13-14 as essential trackwork is undertaken, impacting Coasties travelling to Sydney.
Buses will replace all trains between Strathfield and Central from 11pm on Saturday, January 13, until 5am on Sunday, January 14.
From 10.30pm Friday and all weekend, buses will replace trains between North Sydney and Wynyard on the T1 North Shore Line.
Passengers should also be aware that on January 13 and 14 City Circle trains will run in one direction only, from Central with the first stop being Town Hall.
As an alternative travel option passengers can use the light rail which runs in both directions between Circular Quay and Central.
Sydney Trains will have around 801 workers undertaking a significant amount of work to remove around 66 high-priority defects.
Some trains may run to changed stopping pattern and timetable.
Passengers may need to change trains and are encouraged to allow extra travel time and plan ahead by visiting transportnsw.info or using trip planning apps.