The gardaí have issued an urgent appeal to motorists to slow down and drive more carefully because of icy road conditions.
Inspector John Ferris of the Garda press office said today there was evidence from stations all over the country that some people were driving too fast and too close to cars in front of them.
At a briefing of the Severe Weather Coordination Group, Mr Ferris said the gardaí were urgently appealing to all drivers to reduce their speeds and allow plenty of space between cars.
He said people should plan their car journeys carefully and, if possible, make trips during daytime. Mr Ferris also appealed to pedestrians to take extra care.
The warnings by the Garda follow three deaths on the roads at the weekend. Early yesterday morning a male pedestrian was fatally injured in an incident on the N11 at the White's Cross junction near Blackrock. A 35-year-old woman and her 10-year-old son were killed yesterday following a single vehicle crash on the old M1 south of Castlebellingham in Co Louth.
At the briefing, Joan Blackburn of Met Éireann warned the freezing weather would stay until Christmas Eve. She forecast daytime temperatures would at best reach 0 degrees, preventing any significant thaw. Night-time temperatures would fall to between minus 5 degrees and minus 10 degrees. She said a lot of places would enjoy dry weather but there would be snow showers in places.
She said a thaw should set in on Christmas day when a belt of rain would cross over the country. She this could fall as slow at first.
The freezing weather is posing a problem for local authorities in the worst affected counties and the National Roads Authority due to dwindling salt and grit supplies.
There is currently a national stock of 10,000 tonnes of salt, which is being used at a rate of about 2,000 tonnes per day, according to Sean O'Neill of the National Roads Authority.
He said salt supplies are currently being re-distributed from the least affected counties to hotspots Donegal, Roscommon, Monaghan, Galway, Cavan, Kerry and Cork.
"We are taking from Peter to give to Paul," he said.
He said two new shipments of salt are expected to arrive on Wednesday or Thursday to alleviate the salt shortage. He said a logistics plan was already in place with some 130 trucks ready to distribute the salt when it arrives at Cork harbour.
Asked about current salt shortages in particular counties, Mr O'Neill said the framework policy document drawn up last year on salt supplies did not preclude any local authorities from purchasing salt themselves. He said he couldn't say whether any local authorities had purchased salt.