Authorities will close the road at Giro Hill, about 50km north of Gloucester, to salvage two B-double trucks which were involved in a fatal accident last week. 

A 32-year-old truck driver was killed when his truck careered through a guard rail, before coming to land 50m down an embankment.

A 47-year-old male driver and a 51-year-old woman, following in a second truck, also crashed down the steep embankment and had to be retrieved from the cabin before they were airlifted to Newcastle’s John Hunter Hospital.

Crash investigators are looking at early reports of a brake malfunction which catapulted one of the trucks off the side of the road and down the embankment.

The operation is expected to take up to eight hours.