There are delays on the Hume Highway on Wednesday afternoon following a two-vehicle accident.
The accident involving a truck and car occurred north of the Menangle Road turnoff at about 12.30pm.
As a result, the highway is closed in the southbound direction.
There are heavy traffic conditions in the area.
Transport Management Centre spokeswoman Bronwyn Martin said emergency services were working to free a person trapped in one of the vehicles.
Ms Martin said motorists were advised to avoid the area.
All southbound lanes of the hwy are now closed. Use Narellan Rd instead. https://t.co/hnxto6QVCt— Live Traffic Sydney (@LiveTrafficSyd) September 13, 2017
Diversions are currently in place for light vehicles via Narellan Road, Appin Road, Wilton Road and Picton Road.
Diversions are in place for heavy vehicles via Narellan Road, Camden Bypass, Old Hume Highway and Picton Road.
More to come.