Residents and motorists are advised of upcoming closures of Moss Vale Road along Cambewarra and Barrengarry mountains for essential maintenance work.
A Roads and Maritime Services spokesperson said the work would include stabilising the slope on Cambewarra Mountain as well as road shoulder repairs and drain and gutter clearing at Barrengarry.
"Crews will use special tensioned rock fall mesh and bolts to secure the slope with the aim of reducing the severity of any future rock falls and improving safety for all motorists," the spokesperson said.
Moss Vale Road at Barrengarry will be closed between 8pm and 4am on July 30 and 31 between Bunkers Hill and Myra Vale Roads, weather permitting.
Moss Vale Road at Cambewarra Mountain will be closed at nights from Sunday to Thursday for six weeks from August 4 between Tourist and Kangaroo Valley roads at Cambewarra, weather permitting.
Night work will be carried out from 7pm to 5am until September 15, weather permitting.
During the night closures, light vehicles can detour via Kangaroo Valley Road and Tourist Road, adding 15 minutes to travel times.
Vehicles over 7.5 metres or 12 tonnes will need to detour via the Illawarra Highway and Princes Highway, adding 90 minutes to a trip between Kangaroo Valley and Nowra.
Daytime lane closures will be in place during this work between 5am and 7pm from Monday to Thursday and motorists should allow an additional 15 minutes travel time.
Detours for all vehicles will be in place during the closures, with motorists travelling between Kangaroo Valley and the Southern Highlands diverted via the Princes and Illawarra highways and Macquarie Pass, adding up to 90 minutes to travel times.
There will be no closures on weekends, public holidays or school holidays.
Access to properties will be maintained under the guidance of traffic control and every effort will be made to minimise noise associated with the work.
Motorists are advised to plan their journey, drive to the conditions and follow the direction of signs and traffic control.
For more information including detour maps, please visit rms.work/srrc.