Thousands of people are driving home for Christmas this evening, and facing hazardous conditions because of the wintry weather.
Gardaí and the Road Safety Authority are appealing for drivers to slow down, and realise the trip is going to take longer than normal this year.
Brian Farrell from the Road Safety Authority said one of their main concerns is black ice.
All routes out of Dublin are busy with slow moving traffic.
There is black ice and freezing fog in the Midlands , especially around Birr in Co Offaly.
In Donegal and the North West, road conditions are extremely dangerous.
Elsewhere, traffic is heavy in Gorey and Enniscorthy in Wexford, as well as in Limerick City and on the N25 approaching Waterford City.
Compacted snow and black ice are causing the biggest problems for motorists and they are being urged to avoid unnecessary journeys.