Severe ground frost and black ice have hit motorists around the country today, as a number of minor crashes were reported on national roads.
The midlands have been particularly badly hit; drivers in Kildare, Carlow and Laois have been urged to drive very carefully.
AA Roadwatch issued a warning to motorists, saying they should begin to give themselves more time in the mornings from now on as winter sets in.
Spokeswoman Nicola Hudson said: "You should begin to give yourself additional time in the mornings, allow the car to warm up and windscreens defrost. This will also give you the chance to reduce your speeds on the way to work, without worrying about being late."