Two major roads in the region will be closed on Sunday night.
The M1 Princes Motorway between Bulli Tops and Memorial Drive, and Picton Road between the M1 and Wilton will close in both directions from 8pm and 4am.
Picton Road eastbound will close from 7.30pm.
The closure will allow road crews to carry out maintenance along both routes.
Detours will be in place for both routes.
Motorists travelling between Wollongong and Bulli Tops will detour via Memorial Drive and Bulli Pass, which will add as much as 10 minutes travel time.
Those travelling between Wollongong and the Hume Motorway will be detoured via Memorial Drive, Bulli Pass and Appin Road, and should allow up to 40 minutes additional travel time.
Light vehicles can also use Broughton Pass between Appin Road and Picton Road.
Motorists travelling to the Hume Motorway will also be able to detour via Macquarie Pass.