Motorists were warned tonight to take extra care over the weekend as temperatures are forecast to plummet to minus 5 degrees.
The Road Safety Authority (RSA) said heavy rain will fall in parts of the north, Connaught and east followed by freezing temperatures and morning fog.
It is feared this combination will lead to icy driving conditions and reduced visibility.
The RSA told motorists to drive slowly, allow extra room between cars and to manoeuvre gently.
Minister for Transport Noel Dempsey also urged all road users to be cautious this weekend.
"I urge everyone to take extra care on our roads over the next few days. Fog and icy roads are potentially very dangerous for motorists, pedestrians and cyclists. If you are driving, keep a safe distrance from the vehicle in front and remember to use dipped headlights where visibility is poor. If you are walking or cycling, remember to wear high visibility clothing and ensure that lights on your bike are working properly."
Cyclists, pedestrians and motorcyclists were also advised to wear high-visibility clothing or carry a torch in fog or darkness.
A guide, Severe Weather Advice For Road Users, is available on the RSA website.
Met Éireann said there will also be overnight frost and fog on Saturday night with temperatures rising to between 4C (39.2F) and 7C (44.6F) on Sunday.
PA