A stock truck driver appears to have misjudged the height of their trailer and crashed into a railway overbridge near Balclutha.
A police spokeswoman said it was called to the single vehicle crash at 11.20am.
The truck was stuck under the overbridge, closing both lanes and traffic management had been called in.
The council had been contacted.
There were no reports of injuries.
A firefighter at the scene of an earlier crash on the outskirts of Balclutha, which involved three cars and a truck, said a stock truck carrying cows had crashed into the overbridge.
A reporter at the scene said by just before 1pm the stock trailer had been removed from under the overbridge, but ad hoc repairs were being carried out on the trailer before it could be towed away.