All road users are being urged to take extra care this morning after icy conditions overnight.
Temperatures plunged to as low as -4°C in parts of the country with Met Éireann's yellow snow and ice warning still in place.
The lowest temperature recorded by Met Éireann at 6am this morning was at Dublin Airport where it was -5.8°C.
It was followed by Mullingar at -4.8°C, Mount Dillon -4°C and Oak Park -3.7°C.
Most motorways and main routes have been gritted, but local authorities are advising that not all secondary and minor roads have been treated.
More wintry showers are expected today, especially on higher ground.
"Road conditions are wet this morning in parts of Munster, particularly around Cork City, Waterford City and Tralee while icy conditions have been reported around Thurles and Letterkenny this morning," said Elaine O'Sullivan from AA Roadwatch.
"In Wicklow, the Old Military Road remains closed between Glencree and Sally Gap following icy conditions yesterday.
"Gardaí are also advising motorists to avoid the Sally Gap Road but Wicklow Gap is open this morning."
Motorists are reminded that it does take 10 times longer to stop on icy roads so it is important to slow down and take manoeuvres gently.
