The truck’s cab caught fire on the Peka Peka Expressway northbound lane just south of the Ōtaki River around 5am Wednesday.
At its peak there were 19 fire trucks, tankers and specialist vehicles at the scene, Fire and Emergency NZ said.
Police said there were no reports of injuries.
In an update just before 7am, Assistant National Commander Bruce Stubbs said the fire had been contained to the cab and vehicle tractor. The fuel it was carrying did not catch on fire.
“It’s a really good save by our crews,” he said. Firefighters remain at the scene to dampen down the area.
New Zealand Transport Agency Waka Kotahi said the road was now back open in both directions.