Gardaí in Killarney are appealing to motorists not to use side roads to avoid the N72 between the Lissivigeen roundabout and Barraduff village.
That section of the N72 is currently closed.
A portion of the Killarney - Rathmore road is closed between the Lissivigeen roundabout and Barraduff village to facilitate the removal of a fallen crane, using two additional cranes.
Diversions are in place, and Gardaí are advising drivers to travel via Glenflesk instead.
They say some motorists are attempting to use narrow side roads and are being forced to turn back, causing further congestion.
The road is expected to remain closed for several hours while the recovery operation continues.