The main road into Carrigaline from Cork, the N28, is closed.
A truck overturned at the Shannon Park Roundabout - north of the town - and traffic was reduced to one lane each way.
A crane will be used to upright the truck, which is lying on its side.
The roundabout will be completely closed during this operation, and debris from the incident will needed to be cleaned away.
No one was injured in the accident.
Motorists are asked to completely avoid the area as delays are expected.
