GAA fans, festival enthusiasts and holidaymakers are among the hundreds of thousands of people who are expected to take to the country's road and rail networks during the bank holiday weekend.
As the holiday exodus began yesterday evening, AA Roadwatch reported that traffic in Dublin was quiet throughout yesterday evening.
However, there were some delays around the N11 southbound through Arklow due to roadworks, which had eased by 7pm. Delays in Galway were also expected as the Galway Races finished for the night.
With GAA All-Ireland football and hurling championship matches due to take place at Dublin's Croke Park today and tomorrow, and with both the Galway Races and Waterford's Spraoi festival continuing until tomorrow, authorities have advised prospective travellers to plan well ahead for any journey.
Other events taking place this weekend include a George Michael concert at the Odyssey Arena in Belfast tonight, the Bray Summerfest which concludes on Monday, the Greystones Arts Festival, and the opening of the World Fleadh in Portlaoise on Monday.
Dublin airport also expects to see the number of people travelling through its doors increase by 10 per cent - to some 350,000 - when compared to last year's August bank holiday weekend.
By yesterday afternoon, the airport was reporting average waiting times at security channels of between 10 and 13 minutes.
A spokeswoman said it was providing extra customer service staff to minimise any delays.
Meanwhile, Iarnród Éireann yesterday reminded passengers that Dart services will be suspended between Connolly and Sydney Parade stations until Tuesday, although a shuttle bus service will operate between Connolly and Booterstown stations.
The suspension of service is to allow for work to take place on Lansdowne Road stadium, due to the demolition of the West Stand.
While a full northern and Maynooth line commuter service will operate to and from Connolly Station, Rosslare to Dublin and Gorey/Arklow to Dublin services will operate with bus transfers between Greystones and Dublin.
AA Roadwatch's Nicola Hudson advised those planning to travel by road over the weekend to bear in mind that the GAA matches on Saturday will bring traffic from all over the country to Dublin.
However, Sunday's matches will focus all traffic on to routes from the south, particularly the N8 from Cork and the N9 from Waterford and Kilkenny.
The N7 Naas Road will carry heavy volumes of traffic into Dublin throughout the day from 10.30am onwards and unnecessary journeys should be avoided, Ms Hudson said.
A spokesman for the Garda press office said five people died on Irish roads this time last year. Garda authorities will be deploying significant additional resources throughout the State to monitor and enforce road traffic laws, he said.
This will see priority given to ensuring adherence to the speed limits, while ongoing anti-drink driving measures will also be prioritised, he said.