8.28pm: Macquarie Pass reopens after truck carrying a load of hay is pulled back onto the road.
5.30pm: The Illawarra Highway is now shut in both directions on Macquarie Pass.
5.20pm: The truck accident has closed the highway eastbound.
Eastbound light vehicles can use Jamberoo Mountain Road, while heavy vehicles should use Picton Road as an alternative route.
There is traffic control on site and westbound traffic is getting past the accident scene.
4.30pm: A truck with a trailer hanging off the side of Macquarie Pass is affecting traffic in both directions on Thursday afternoon.
The accident happened on the Illawarra Highway, near the Calderwood Trail, shortly after 4pm.
Initial reports suggest the incident involves a semi-trailer, which is carting a load of hay.
It is understood the truck's trailer is hanging off the edge of the road. The driver has not been injured.
Contra-flow traffic conditions are expected to be put in place.
Motorists have been advised to exercise caution in the area and allow extra travel time.
Police, NSW Rural Fire Service (RFS) volunteers, Fire and Rescue NSW crews are on the scene, as well as Roads and Maritime Services representatives.
More to come.