Under current lockdown measures, only essential travel is permitted and from today, public transport will operate at 80pc capacity.
Transport for Ireland has urged the public not to travel unless "absolutely essential".
"While public transport is still operating, we would ask everyone not to travel unless absolutely essential.
"If you do have to travel, remember to give yourself and other passengers a little more space to maintain physical distancing."
These restrictions will kick in from today - here’s all you need to know.
Revised timetables for Iarnród Éireann across all routes will come into effect from today, seeing revised and reduced schedules in operation on all routes, including Intercity, DART and Commuter. Passengers are advised to check times using the Irish Rail journey planner.
Services will not operate on the following routes from Monday 30th March until further notice: Waterford to Limerick Junction, Limerick to Ballybrophy (via Nenagh) and M3 Parkway to Clonsilla services will not operate on Saturdays and Sundays.
Unallocated seating policy has also been suspended.
On Mondays to Fridays, Bus Éireann and Expressway services will operate to a Saturday timetable, some exceptions. These include city and town services in Cork, Galway, Limerick, Navan, Sligo and Waterford as well as eastern, southern and western commuter, local and rural services.
Expressway services will also be affected, with many routes to Dublin Airport cancelled.
Passengers are also advised to avoid using cash.
Nitelink and Airlink services will not operate until further notice.
The Dublin Bus head office, including public sales and information office and also lost property offices are also closed until Sunday 12 April.
New timetables will come into effect from Wednesday April 1, which will move to an enhanced Saturday schedule, augmented by additional services, especially in the early morning.
Passengers are advised to check their routes on Dublinbus.ie prior to travelling.
Luas trams are all operating at normal schedules. However, physical distancing is being implemented on board trams, with some sections of carriages sealed off and increased Luas personell on board.
Timetables will switch to the new Saturday Plus timetables which will be in place until further notice. The schedule change will apply to Outer Dublin Metropolitan Area and Dublin Commuter services.
On weekends and public holidays, the normal Saturday or Sunday timetable will be in use.