Roads and Maritime Services will close Mount Ousley Road and Picton Road later this month for a range of roadwork activities.
The May 31 closure is the first of three planned closures by RMS - the others will take place on June 14 and June 28.
The closures - from 7pm to 5am - affect the section of Mount Ousley Road in both directions from just north of the Gipps Road overbridge to Bulli Tops.
"The closure is needed to allow Roads and Maritime Services to carry out a number of roadwork activities including road resurfacing, drain maintenance, installation of new road signs, repairs to guardrail and pruning of low-hanging trees," an RMS spokeswoman said.
Picton Road between Wilton and the intersection with Mount Ousley Road will be closed at the same time, as will Old Mount Ousley Road between Gaynor Avenue and Mount Ousley Road.
"The roads will be closed in both directions between 7pm and 5am on all three Saturday nights and detours will be in place for both southbound and northbound motorists," the spokeswoman said.
Southbound and northbound motorists are advised to use Bulli Pass and Memorial Drive.
Drivers of light vehicles travelling to and from the Hume Highway will be detoured via Wilton and Appin roads and Bulli Pass. Heavy vehicle drivers travelling to and from the Hume Highway will be detoured via Narellan Road, Appin Road and Bulli Pass and should allow an additional 40 minutes.