A digger caught fire on SH5 about 200m from the roundabout near Ngongotahā this afternoon.
A Fire and Emergency NZ spokesman said they were alerted to the incident at 12.35pm and the digger was "well alight" when they arrived.
Two appliances from Ngongotahā and one from Rotorua attended the fire which had now been put out, he said.
One lane was blocked off but the berm on the other side was being used to allow traffic to continue flowing.
He said it was not yet known how the fire started.