A salvage operation is underway on the Hume Highway south of Goulburn following a truck crash.
Emergency services were called to reports a B-double had rolled in the highway's northbound lane, near Lerida Road South, north of Gunning at 5.40am.
The vehicle, carrying milk and diesel in tanks, left the road and rolled down an embankment, Southern Tablelands RFS operational officer, Mitchell Butler said.
On arrival, a Gunning-Fish River RFS found the driver out of the vehicle and walking around.
Crews tried to disconnect the truck's battery, which was wedged between the vehicle and trees.
Mr Butler said about 50,000 litres of milk product spilt from the vehicle but the diesel tanks were not ruptured.
Police, Fire and Rescue NSW and RMS are on scene and the northbound lane remains closed. Another Fire and Rescue NSW crew is en route from the Shoalhaven.
A heavy tow from Wagga Wagga has also arrived.
Motorists are advised to slow down in the area.
The rollover is one of a series of truck crashes in the area over the past week. On Thursday, a man was flown to Canberra Hospital after his semi-trailer, carrying an empty shipping container, rolled down an embankment at Tirrannaville, some five kilometres south-east of Goulburn.