Commuters were tonight urged to take extreme care after Met Éireann issued a severe weather warning with high winds, snow and wintry storms.
Driving conditions are expected to be treacherous with icy roads, gales up to 130kmph and showers of snow, hail and sleet during the next two or three days.
Ulster and Connacht are expected to be hit hardest with the strongest winds.
The Road Safety Authority (RSA) urged drivers to be extra vigilant if they are caught in the winter weather.
“Vulnerable road users such as pedestrians, cyclists and motorcyclists are advised to be seen, wear bright clothing with reflective armbands, or a reflective belt or carry a torch,” a spokesman said.
The RSA issued other advice:
Watch out for falling/fallen debris on the road and vehicles veering across the road,
Cross winds may affect control of vehicles with high sided vehicles and motorcyclists particularly vulnerable,
Don’t tailgate and give motorbikes and cyclists extra room, and
Always used dipped headlights in poor visibility.
Met Éireann forecast cold conditions to sweep across the country tomorrow wintry showers of hail, sleet and snow and icy roads.
Thunderstorms are also expected with rain and sleet turning to snow and heavy and significant falls in places.
The wintry weather is expected to last until Saturday when conditions will ease.
Forecasters said Ulster, Connacht and West Munster is most at risk but some snow is likely in other areas on Thursday night and Friday, with a risk of icy roads.
The northwest, north and northeast are likely to experience the greatest snowfalls.
The RSA said if drivers are travelling in stormy conditions drivers should check tyre treads for depth of 1.6mm and pressure and allow for extra stopping distance.
Experts added that higher gears will help avoid wheel spin and skidding and urged motorists to avoid harsh braking and acceleration.
The RSA said to brake on ice or snow without locking wheels, get into a low gear, allow speed to fall and use the brakes gently.
In the event of a minor skid the RSA advised releasing the brakes and turning the steering wheel in the same direction as the skid but try to avoid over-correction.