A truck's trailer unit has been destroyed in a fire on State Highway 2, between Papamoa and Te Puke.
Constable Kurt Waugh said the fire appeared to have been started in the back tyre of the truck.
He said the trailer unit was full of tissue paper which also caught alight.
The truck driver didn't notice the fire until he was waved down by a member of the public.
Traffic is backed up in both directions and the road is down to one lane. Motorists are being warned to expect delays until the road is cleared.