The Garda is to mount 16 'super-checkpoints' in Dublin over the weekend, targeting drink driving and other road offences.
Motorists have been warned the checkpoints would be "heavily resourced", allowing for large numbers of people to be randomly breath-tested for alcohol.
The October bank holiday weekend enforcement plan will run in the greater Dublin area from this evening until Monday morning. Garda figures show 23 people have been killed on the roads in the region this year.
"While this compares favourably to 30 deaths for the comparable period last year, it still represents unnecessary trauma, heartache and tragedy for dozens of people," a Garda statement said.
"Excessive speed, drink driving and non-wearing of seat belts continue to remain the key contributory factors to death and serious injury on Irish roads.
"This latest Dublin operation aims at tackling all of these activities in an endeavour to encourage a positive change in driver attitude and behaviour."
Other enforcement activities will also take place throughout the region over the weekend.
Thousands of travellers and commuters will be on the move from early this evening to take advantage of the weekend break.
Entertainment lined up for the bank holiday includes a wide variety of music events and a selection of more quirky festival fare, including a pumpkin festival.
The Cork Jazz Festival will be a major draw for the weekend, with a line up headlined by the John McLaughlin five-piece band and including Georgie Fame's Three-line Whip, the Courtney Pine band, Laura Izobor, Honor Heffernan and Acker Bilk and his Paramount Jazz Band.
The fourth Sligo Live festival will also bring the crowds.
This year's line-up includes Tom Baxter, comedian Jason Byrne, Sly & Robbie, Orchestra Baobab, Solas, Cathy Davey, Liz Carroll and John Doyle, Michael McGoldrick and Dezi Donnelly and Le Vent.
In the odder events category, pumpkin growers from around the world will celebrate the second annual Pumpkin Festival today in Virginia, Co Cavan.
The town will be plunged into darkness this evening for the traditional Lighting of the Pumpkins. Fire eaters and exotic dancers will light the place up later during the street carnival.
A spokeswoman for the Halloween event said: "For three days Virginia will be the pumpkin capital of Europe."
"Pumpkin growers from all over Ireland and abroad will unveil their carefully-cultivated prize specimens and the winner of the largest pumpkin will be declared."
The largest pumpkin will receive a €3,000 prize.
Clocks will go back by one hour tomorrow night, adding the all-important extra hour's sleep for anyone enjoying the festivities.
AA Roadwatch warned, however, that the loss of the hour also means daylight hours will be greatly reduced.
AA Roadwatch controller Nicola Hudson said drivers should check all lights are functioning before they set out and drive with dipped headlights at all times.
She also urged all vulnerable road users such as pedestrians and cyclists to make sure they can be seen.
"Cyclists have to remember that if they are not properly lit then they are practically invisible for a car driver, especially in wet conditions."
Stormy weather is forecast for Sunday and motorists should take extra care.
The motoring organisation said cross country routes will carry huge volumes of traffic today and Monday in particular and the most popular destinations are likely to be the Cork Jazz Festival and the west of Ireland.
"Drivers traveling on the N8 should expect delays at Abbeyleix and Durrow but drivers on the N6 have the benefit of the new Moate by-pass that will ease delays," Ms Hudson said.
On Monday, a number of Dublin city centre roads will beclosed to facilitate the Dublin City Marathon, with the main hub of the event focused on the Merrion Square, Fitzwilliam Square and Nassau Street areas.