Taxis will not be allowed into the traffic exclusion zone in Dublin for the mass by Pope Francis in the Phoenix Park on Sunday 26 August, the National Transport Authority has confirmed.
The "controlled access area" will be in force from 6am to 11pm that day from O'Connell Bridge West along the South Quays.
At the Phoenix Park it will widen to the north of the city nearly as far as the N2.
To the south, the zone will extend to the Grand Canal.
However the NTA said all taxi ranks will be operational with the exception of Aston Quay and Heuston Station.
There will also be accommodation for taxis at Dublin Industrial Estate in Glasnevin.
Pope Francis is visiting Ireland on Saturday 25 and Sunday 26 August.
More than 600,000 people are expected to attend the mass in the Phoenix Park on 26 August.
People planning to do so are being urged to use public transport and not to drive to the venue.
A number of park-and-ride hubs are being set up to facilitate the crowds.
These are at the UCD campus in Belfield, Leopardstown Racecourse in south Dublin, Fairyhouse Racecourse in Co Meath and Maynooth University in Co Kildare.
Public transport journeys in Dublin on Sunday 26 August will be free for people who have tickets for the Phoenix Park mass, to encourage people to avail of these options.
Bus Éireann will operate a normal weekday service nationwide to bring people to the capital, while Dublin Bus has created seven dedicated 'Papal transport hubs' near the gates of the Phoenix Park.
Luas services will also operate on a six-ten minute frequency on the day.
No formal permits will be issued for local residents and members of the workforce who will need to enter and exit the zones.
Gardaí will aim for minimum disruption in how they permit access, in the same way that they did during the centenary commemorations of the 1916 Rising.