Motorists taking the road from Raphoe to Convoy are being urged to take extreme care this morning.
The road surface at the bends is reported to be very slippery. It is not known if there is oil or another material causing issues.
A Donegal Daily reader said they had a frightening experience earlier:
“My car slid everywhere and I ended up on the other side,” they said.
“It’s a very busy road and I’m very lucky that nothing was coming the other way when I ended up on the wrong side.”
Gardaí have been made aware of the problem.