Traffic Scotland said some motorists were delayed for up to an hour after the incident involving a car, a caravan and a lorry.
An ambulance was sent to the scene at 1:15pm, according to a spokesman for the Scottish Ambulance Service.
He said: "We were on the scene but the patient refused treatment. A caravan was overturned near the Stoneymollan Roundabout."
A spokeswoman for Police Scotland said officers were also sent to the area at 1:15pm.
She added: "The incident involved a car, a caravan and lorry on A82 Glasgow-bound carriageway. We are not aware of any injuries."