Government, health and transport authorities have issued appeals to motorists to drive with particular care over the Bank Holiday weekend.
Sporting events and festivals are expected to draw thousands more people out on the roads with the increased likelihood of accidents.
Gardaí are deploying significant resources to monitor roads over the long weekend, which is traditionally the busiest of the year.
Their campaign to crackdown on motoring offences will target speeding and drink driving. Nearly 2,500 people were caught speeding and 330 drink driving arrests were made over the same holiday period last year. Five people died.
The National Ambulance Service said careful driving this weekend would save lives.
The Minister for Transport, Noel Dempsey, has called on motorists to avoid taking any chances with innocent lives on the roads.
He urged people to be especially vigilant this weekend and to travel safely.
Declan Naughton of the Road Safety Authority asked motorists to think of the consequences of speeding or carelessness.
AA Roadwatch says that the Galway Races, Waterford Spraoi, World Fleadh in Portlaoise and the All-Ireland championship matches in Croke Park will attract thousands of visitors making tailbacks inevitable.
Any GAA supporters who would traditionally drive up the N11 and avail of DART services from Bray and Greystones are reminded that rail services will operate only to Sydney Parade because of the redevelopment of Lansdowne Road Stadium.
Met Éireann has issued a severe weather warning of heavy rainfall for the weekend.
Totals of 30 to 35 mm of rain are expected over much of the country leading to some flooding.
Rainfall in excess of 50 mm is possible, especially in parts of Munster and Leinster.
Such conditions will result in reduced visibility, flooding and slippery road surfaces making driving particularly hazardous.
For their own safety and the safety of other road users drivers should adjust their driving behaviour to suit these changing conditions.
