The Princes Highway is closed in both directions at Falls Creek, south of Nowra, due to multi vehicle crash just south of Jervis Bay Road.
Emergency services, including a medical helicopter are attending the crash site near Willowgreen Road.
Light vehicles can divert in each directions via Jervis Bay Road, Pine Forest Road and Hawken Road.
Heavy vehicles are being parked.
Motorists are advised to allow extra travel time.
For the latest traffic information, download the Live Traffic NSW app, visit www.livetraffic.com or call 132 701.