Northbound and southbound motorists on the highway are taking turns using this lane under alternating traffic conditions while an operation continues to salvage the truck.

Motorists are advised to expect delays, allow extra travel time and exercise caution through the area.

EARLIER:

The truck fire blocked the highway at Rollands Plains Road, north of Port Macquarie, about 4am.

When Fire and Rescue NSW firefighters from Port Macquarie and Kempsey, along with NSW Rural Fire Service volunteer firies from Telegraph Point, responded they were confronted by a B-double trailer well alight with the mixed load of aerosol cans, batteries and mechanical spare parts exploding and producing an intense heat. 

Specialist HAZMAT crews work to protect the surrounding area from the toxic run-off. 

The truck driver suffered minor injuries and his quick actions in separating the prime mover from the trailer are being praised for preventing a bad situation from becoming worse. 

The Pacific Highway was closed in both directions for several hours while firefighters contained the blaze and protected the scene by applying large quantities of sand and holding the toxic run-off. 

The fire was extinguished before 7am and diverted traffic on the highway allowed to pass the scene. 

It is understood the driver was treated for smoke inhalation.

These alternating conditions are expected to remain in place throughout the day as the salvage operation continues.