However, Bells Line of Road and Chifley Road remains closed between Kurrajong and Lithgow.

Trains are not running between Katoomba and Lithgow/Bathurst on the Blue Mountains Line either. Buses are replacing trains between Katoomba and Lithgow.

Also in the Blue Mountains/Central West areas:

5.30PM SATURDAY UPDATE: Bathurst and the Central West are again cut off from Sydney this afternoon with the Great Western Highway again closed due to a bushfire.

The latest update from the Traffic Management Centre says the highway is closed in both directions between Hartley and Katoomba.

The Bells Line of Road and Chifley Road also remain closed between Kurrajong and Lithgow, and trains are not running between Katoomba and Lithgow/Bathurst on the Blue Mountains Line.

"This means there is no access between Sydney and the state's West so motorists should delay all travel," the TMC update states.

Also in the Blue Mountains/Central West areas:

For the latest traffic information, visit www.livetraffic.com, download the Live Traffic NSW app or call 132 701.

For the latest public transport information, visit www.transportnsw.info or call 131 500.

7.30AM SATURDAY: The Great Western remains open on Saturday morning but motorists have been asked to reconsider their travel plans today.

A state of emergency remains in place across NSW and with fire conditions expected to worsen throughout the day, police and the RFS have asked people to delay all non-essential travel.

The fire rating for Bathurst and Central Ranges is listed as extreme today with the Greater Sydney, Illawarra/Shoalhaven and Southern Ranges expecting catastrophic ratings.

The Bells Line of Road remains closed while, to the south of Bathurst, the Jenolan Caves Road and Edith Road are closed between Taralga and Duckmaloi Road and Shooters Hill Road.

Trains are not running between Mount Victoria and Lithgow/Bathurst on the Blue Mountains Line and while replacement buses are running, the buses cannot access the Bell and Zig Zag stations.

More road closures are expected throughout the day.

11PM FRIDAY UPDATE: The Great Western Highway is now open in both directions at Marrangaroo, west of Lithgow, after being closed due to a bushfire.

The Traffic Management Centre advises that the speed limit has been reduced to 60 kilometres an hour for eastbound motorists.

The Great Western Highway is also currently open through the Blue Mountains.

Motorists are advised that conditions may change quickly, and roads may close with little or no notice in bushfire-affected areas.

Motorists should exercise caution, follow directions of emergency services, and check the latest traffic conditions at www.livetraffic.com.

4:50PM FRIDAY UPDATE: The Great Western Highway is now closed at Marrangaroo, west of Lithgow.

The Traffic Management Centre said the highway was shut in both directions due to a bushfire.

Motorists are advised to avoid the area.

EARLIER: Bathurst and the Central West will be cut off from Sydney and the Blue Mountains with the closure of the Great Western Highway on Friday evening.

The road will close from 6pm between Blackheath and Little Hartley for a back-burning operation, cutting off the Central West and metropolitan Sydney.

There's no indication of when the road will reopen.

The Bells Line of Road was closed last Monday and remains that way with the Gospers Mountain blaze out of control.

There is no diversion in place for either closed road.

Motorists are advised to delay all travel though the Blue Mountains, with no access in either direction.

Other roads closed in the area due to the fire include The Darling Causeway between Bell and Mount Victoria, Chifley Road between Bell and Lithgow and Bells Road in Lithgow.

Additionally, trains are not running between Mount Victoria and Lithgow due to the bushfire.

Access between Sydney and the south and the north of the state may also be impacted by fires in the next day so motorists heading away should check before leaving home.

Motorists already in bushfire-affected areas should follow the directions of emergency services and traffic crews and keep in mind that conditions can change quickly and roads can close with little notice.

For the latest traffic information, visit www.livetraffic.com, download the Live Traffic NSW app or call 132 701.

For the latest public transport information, visit www.transportnsw.info or call 131 500.