[Update 2.41pm]: Traffic is flowing normally again on the Pacific Highway south of Grafton after a head-on truck-and-car accident overnight at Dirty Creek and a truck fire in the northbound lane near Bonville.
The Traffic Management Centre reports that further closures at Dirty Creek to allow for salvage of vehicles is now complete.
At Bonville, the on-ramp remained closed at 2.30pm.
[Original report]: The southern section of the Pacific Highway is closed to traffic after two major traffic incidents south of Grafton overnight.
A b-double truck collided head-on with an oncoming car around 4am, causing the highway to be closed in both directions.
A short time later a second b-double collided with the first, further complicating the crash.
The 31-year-old driver of the car has been airlifted to hospital with life-threatening head injuries.
All vehicles except b-doubles can use the Orara Way as an alternative route to Coffs Harbour.
The highway is expected to be closed for most of Friday morning.
Further delays to northbound traffic can be expected south of Coffs Harbour after a truck caught on fire earlier this morning.