Motorists face a diversion between St Monans and Pittenweem because of subsidence on the A917.
The road is closed and repairs are being carried out after part of the carriageway collapsed.
The road may be closed for three weeks.
Diversions are in place via Abercrombie on the B941 and B942.
Local MSP Roderick Campbell commended Fife Council and the police for the prompt action in setting up the diversions.