The accident happened about 8 a.m. near the Hogan Road exit.
Police said a truck flipped on its side and lost some of the asphalt it was carrying.
"It would appear there was an incident with merging. The truck ended up hitting a guardrail and going into the median," said Trooper Bryan Creamer of the Maine State Police.
The Maine Department of Environmental Protection was called to the scene because of the spilled asphalt.
Police said no one was injured in the accident.