Motorists are advised to avoid travel in southern and western areas of NSW on Saturday January 4, especially in the South Coast and Snowy Mountains regions of the state.
A spokesperson from Transport for NSW said widespread extreme fire danger is forecast for these regions, so motorists and tourists should stay away from the South Coast of NSW.
"Major roads may close with little to no notice due to fires, including the Snowy Mountains Highway, Monaro Highway, Hume Motorway, M1 Princes Motorway and the Great Western Highway," the spokesperson said.
"The Princes Highway may close again between Falls Creek and Milton, and may remain closed between Batemans Bay and Moruya and between Narrabarba and Cann River in Victoria."
The Kings Highway also remains closed between Braidwood and Nelligen.
A number of local roads are already closed in the South Coast and Snowy Mountains areas, and many roads crossing the NSW - Victorian border are also closed.
Transport for NSW Coordinator General Marg Prendergast said Transport's key focus was supporting the NSW Police, the Rural Fire Service and other agencies in getting people out of bushfire impacted areas ahead of worsening conditions on Saturday.
"With extremely dangerous fire conditions expected to hit parts of NSW on Saturday, it's not a day to be on the roads, especially in the south of the state," Ms Prendergast said.
"The conditions on Saturday are expected to be worse than New Year's Eve so do not travel to the South Coast or Snowy Mountains Region.
"We ask that motorists remain patient and calm while driving away from bushfire impacted areas as we know traffic will be heavy and journey times longer than usual."
Motorists should also avoid travel between Sydney and west of the state as the predicted conditions may close the Great Western Highway in sections between Penrith and Bathurst.
Anyone who cannot delay their trip should continually check the latest conditions - real-time road and traffic alerts are published on the LiveTraffic website and app - and be prepared for road closures.
Motorists should exercise extreme caution and follow the directions of emergency services and traffic crews, while keeping in mind that conditions can, and do change very quickly, especially in these forecast conditions.
"Make sure you have adequate fuel, a fully-charged mobile phone and plenty of water and snacks if you have to be on the roads," Ms Prendergast said.
"Thick smoke may affect visibility on roads that are open and restricted speed limits may be in place so motorists need to drive safely to the conditions."
Once a road closes, it cannot reopen until it is safe to do so. The road surface needs to be checked, arborists need to ensure trees are not at risk of falling, and infrastructure such as power poles, signs and guard rails need to be made safe.
For the latest traffic information, visit www.livetraffic.com, download the Live Traffic NSW app or call 132 701.