Some 200,000 people are expected to take to the roads this weekend to attend matches at Croke Park and the Madonna gig at Slane.
Over 60,000 football supporters are likely to travel to the Fermanagh versus Mayo All Ireland football semi-final replay tomorrow, and similar numbers are expected to attend the Kerry-Derry All Ireland football semi-final on Sunday.
Elsewhere, some 80,000 music fans are expected to attend the Madonna concert, according to a spokesman for MCD Music Promotions.
For tomorrow's Fermanagh/Mayo game, motorists are advised to use supervised car parking facilties near Croke Park at Clonliffe College, Clonliffe Road (access via Lower Drumcondra Road), and O'Connell's school, North Richmond Street, (access via North Circular Road).
Only residents, residents' families or those with business or legitimate reasons are allowed through the Garda cordon. Illegally parked vehicles may be impounded or clamped and their drivers fined.
The gardaí have prepared a route to assist vehicles to depart both car parks as quickly as possible after the games. The route will divert official car park traffic away from the Port Tunnel area, returning to the junction of the M50 and M1 motorway on the northern side of the Port Tunnel.
Motorists will have the option of taking the M1 motorway or travelling on the M50 to the N2, N3,N4 or N7. Gardaí say the route will be signposted.
Supporters travelling from Derry on Sunday are advised to allow sufficient time to arrive in Dublin as delays are expected due to the Madonna concert in Slane. Gates open at 4 p.m., with Madonna scheduled to take the stage at 8.30 p.m.
Gardaí advise football supporters travelling from the North to Croke Park to be aware that the N2 Derry/Dublin Road at Slane will be closed to traffic from 8 p.m. tomorrow until 3 a.m. on Monday due to the Slane concert.
Motorists are advised to travel to Dublin on the N3 via Cavan/Kells/Navan and into Dublin city or at Ardee to travel towards the Drogheda by-pass and onto the N1 or M1 towards Dublin.
The weekend will also see some 250,000 people attend this year's Fleadh Cheoil na hEireann which kicks off in Clonmel, Co Tipperary, this evening.
The Minister for Community, Rural and Gaeltacht Affairs, Mr Eamon O'Cuiv, will officially open the festival, which attracts thousand of musicians from the United States, Britain and Ireland each year.
Hundred of All Ireland music championship events will be held today and tomorrow in venues throughout the town. The programme includes open-air concerts and late night ceilís each day. The crowds are to be accommodated in two large domes and a tented village erected for the weekend festival.
The Fleadh ends on Sunday night with the All Ireland Senior Ceile Band Competition - a highlight of the weekend of activities.