The weekend will see tens of thousands traversing the country's travel networks to and from sporting events and festivals at home and abroad.
This morning saw the beginning of the world-renowned Killorglin Puck Fair, Co Kerry, and record numbers of over 100,000 are expected at the event, which was first granted licence in 1603 by King James I.
A packed schedule will see a parade and the coronation of King Puck in the town today, and road users are warned to expect delays in Killorglin and on all approaches until 6.30 pm at the earliest.
A Horse Fair is also taking place just outside Killorglin at Dromavalla, off the N70 (Tralee Road).
The N70 between Tralee and Killorglin and the N72 between Killarney and Killorglin will carry extra traffic throughout the weekend until the end of the festival on Sunday, when King Puck will be released back into the wild.
Kilkenny's annual Arts Festival begins today and continues until Sunday week, August 19th. The festival will attract thousands of visitors and is expected to lead to heavier-than-usual volumes of traffic in and around Kilkenny City.
There may be traffic delays due to a free outdoor performance at Cillín Hill on the Dublin/Carlow Road in Kilkenny on Sunday.
In Co Laois, Portlaoise Main Street will be closed to facilitate the World Fleadh international music festival. Road users will have to take an alternative route.
Elsewhere, Dublin will again host tens of thousands of GAA faithful who will flock to the capital for the much-anticipated All Ireland Football quarter final between Dublin and Derry.
The usual restrictions will apply around Croke Park for this fixture and Sunday's All Ireland hurling semi final between Waterford and Limerick and the All Ireland football quarter final between Kerry and Monaghan.
Various spots around the country will suffer delays due to roadworks. AA Roadwatch is warning that the road from Naas to Caragh between Halverstown Cross and Caragh Village will close until August 14th due to essential repairs on the Liffey Bridge. Diversions will be in place.
In Cork, the to the westbound carriageway (Midleton - Cork) will have roadworks on the N25 at Ballyadam, Carrigtohill, and traffic from Midleton to Cork will be reduced to one lane daily until Tuesday.
Dublin airport will, as is usual for this time of year, be very busy with departing and returning holidaymakers. They will be supplemented this weekend by rugby supporters travelling to Murrayfield for Ireland's pre-world cup friendly with our Scottish cousins.
Predictably enough, the resumption of the Premiership this Saturday will see many thousands of soccer fans depart on pilgrimage, by air and by sea, to pay homage to their favourite English team.