The changes were announced on the Transport NSW site this morning (January 2), where it said that it was ongoing for "some NSW TrainLink Intercity train services".

It outlined that trains on the Southern Highlands Line from Campbelltown to Moss Vale in both directions are going to be impacted.

"Sydney Trains, NSW TrainLink Intercity and Regional train timetables across the state will be adjusted from Monday 10 January, to help provide reliability and continuity of services while patronage levels are down due to COVID-19," the announcement read.

"Transport for NSW will return to a dynamic timetable similar to what was run during the peak of the Delta outbreak in August.

"While patronage remains low across the network, services will be adjusted to an enhanced weekend timetable."

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Routes on the Blue Mountains Line, Hunter Line, Central Coast and Newcastle Line and South Coast Line are also going to be affected.

Intercity trains are currently running at a 75 per cent capacity.

Passengers must wear masks on all modes of public transport including taxis and rideshare services.

They are encouraged to plan trips in advance by checking timetables for updates, and make adjustments such as travelling outside of peak times, walk, drive or cycle where possible.

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