The Princes Highway is closed in both directions at Brogo, north of Bega, due to a truck crash.
The highway is closed at the Brogo River near Blanchards Lane.
Light vehicles are being diverted southbound from Cobargo via Cobargo-Bermagui Road and northbound via Carp Street at Bega.
These diversions are not suitable for heavy vehicles, which are being parked up.
Emergency services and transport crews are on site.
There is currently no forecast on when the highway will reopen.
For the latest traffic information, download the Live Traffic NSW app, visit www.livetraffic.com or call 132 701.