FIREFIGHTERS took about 40 minutes to extinguish a b-double blaze in the early hours of the morning.
NSW Fire and Rescue Inspector Tony Lenthall said two Fire and Rescue units and a number of Rural Fire Service crews were called to the fire shortly after 2am.
"Both Fire and Rescue and Rural Fire Service worked well to extinguish the fire quickly," Insp Lenthall said.
He said the call was received at 1.49am with the Urunga Fire and Rescue unit arriving at about 2.10am.
Insp Lenthall described the fire as "significant".
"The captain on scene reported the fuel tanks on the truck were involved in fire," he said.
"There was no contamination ... because the fuel was all burned."
Insp Lenthall said the truck was travelling northbound when it crossed the median strip onto the southbound lanes about 4km south of Urunga, between Ballards Rd and the Urunga interchange.
The truck could still be soon smouldering this morning.