The region’s two key roads will be closed on Sunday night.
The M1 Princes Motorway and Picton Road will be closed from 8pm on Sunday until 4am on Monday to allow for maintenance work to be carried out.
The motorway will be closed in both directions between Bulli Tops and Memorial Drive.
All lanes on Picton Road will be closed from the motorway to Wilton Road.
Motorists travelling between Wollongong and Bulli Tops can detour via Memorial Drive and Bulli Pass and should allow 10 minutes extra travel time.
The detour for Picton Road is Memorial Drive, Bulli Pass and Appin Road and drivers should allow up to 40 minutes extra travel time.
Vehicles longer than 19 metres are not permitted to travel on Bulli Pass and should wait until Picton Road and the M1 Princes Motorway reopen at 4am.