A truckload of cardboard, on the side of the road, caused a traffic tie-up along Interstate 95 Wednesday morning.
State Police say a small fire forced a driver from Pine Tree Waste Management in Hermon to pull over and dump his load.
It happened near the border between Bangor and Orono just after 8 am.
Investigators believe an exhaust issue may have sparked it.
State Police and fire crews responded.
The driver was able to extinguish the flames.
The road was down to one lane while DOT officials worked to clear the scene.