Road conditions are very hazardous across the country following heavy overnight snowfall and freezing temperatures.
Air temperatures are below freezing in many parts of the country with compacted snow and ice reported on many non-national routes.
AA Ireland is advising drivers to allow additional time for their journey and to maintain a safe distance from the vehicle in front.
Heavy fog has also been reported in Co Kildare. A number of routes on higher ground are impassable including The Sally Gap and the Wicklow Gap are impassable.
Met Éireann said temperatures today were between minus 2 degrees and 3 degrees and also warned of patches of freezing fog.
It said further showers of hail, sleet and snow would affect counties in Ulster and coastal counties along the east, south and northwest coasts this evening.
It said there would be a widespread severe frost this evening with temperatures dropping to minus 6 degrees, with lows of minus 10 degrees possible.
At a briefing in Dublin today the Government’s Taskforce on Emergency Planning warned motorists that roads are expected to be extremely ice tomorrow morning with traffic moving much more slowly than usual.
Of the State’s 90,000 kilometres or roads just 16,000 kilometres, the main roads are due to be gritted.
The National Roads Authority has said supplies of salt for gritting roads are 30 percent above normal stock levels and local authorities are gritting key national and regional routes.
The taskforce has also advised people to help clear ice and show from outside their homes, to avoid unnecessary journeys and to use public transport where journeys are unavoidable.
The cold snap has also impacted on public transport.
Dublin Bus said driving conditions were extremely difficult and that many routes are curtailed or subject to diversions. It is providing a full list of affected routes on its website and is updating this list every hour.
“Buses have been leaving garages this morning but there is likely to be significant curtailments and diversions to some services today,” said a spokeswoman.
Bus Éireann said while the majority of its services are operating as normal, there were delays and disruptions on some routes, particularly across the east of the country. It is providing details of disruptions to its services on its website.
Mainline train and Dart services are reported to be running as normal. However, the bad weather means there are Luas Red Line services into or out of Connolly Station.
Dublin airport is open but there are reports of some delays and passengers are advised to check with their airlines for details.
Minister for Transport Noel Dempsey yesterday revealed the country’s transport agencies would ensure commuters face the least disruption possible during the cold snap.
He also stressed the National Roads Authority had sourced 80,000 tonnes of salt supplies for the road network in the event of prolonged severe weather.
“Local authorities are already treating roads during this cold period and they are prioritising critical access routes to the main national road network,” Mr Dempsey said.