Operators of most public transport services are operating a new schedule of services on a phased basis from Monday.
The National Transport Authority (NTA) says revised timetables are now in place for Iarnród Éireann.
While those for Dublin Bus, Go-Ahead Ireland and Bus Éireann will come into effect from Wednesday April 1st.
This means services will run at approximately 80% of their current levels.
The NTA has requested operators to monitor passenger loadings on services across the network.
This was taken into account when putting together the new timetables.
While passenger numbers on public transport services are down by about 80%, there are some services that continue to have heavier loading, leading to concerns around social distancing.
With some fleet and driver resources being freed up under the new schedules, additional vehicles are to be given to services where there is greater demand.
NTA and the transport operators say they are "confident that the capacity of customers and staff to observe social distancing requirements will be maintained under the new timetables."
Under the new schedules, demands on public transport fleet will be reduced.
The NTA says the move will enable the public transport operators, particularly Iarnrod Éireann, to conserve maintenance materials and components.
"This will ensure that fleet is more likely to remain available for service on a longer term basis", it says.
It also means the operators will be in a stronger position to ensure ongoing continuity of services in the context of increasing rates of COVID-19 in Ireland.
All areas that currently have a public transport service will continue to have one.
Operators under the new timetables are moving to a ‘Saturday Plus’ schedule, which will be based on the current Saturday schedule - with additional services, particularly in the early morning.
Go-Ahead Ireland will be operating services at approximately 94% of current levels, with Dublin Bus and Bus Éireann both operating services at over 80% of current levels.
Dublin Bus Nitelink services were also suspended last week "until further notice."
While there will be some reductions in peak and off-peak services, the NTA says on-bus journey times are faster as a result of a dramatic reduction in traffic in built-up areas.
Full details are available on individual operator's websites.
However Luas services are not changing at this time.
The tram system will manage the service daily by extending the tram headways if this is required.
Anne Graham, NTA chief executive officer, says: "NTA would like to thank everybody involved in the public transport sector for the effort they are putting in to make sure that vital services can be kept going.
"The revised schedules we are announcing today will ensure that those who need to, can continue to get around, on services that remain frequent and reliable, now and in the weeks ahead."