Train and bus services will be scaled back from next week due to the COVID-19 crisis.
The National Transport Authority says Irish Rail, Dublin Bus, Go-Ahead Ireland and Bus Éireann services will be running on revised schedules.
There will be no changes to Luas services for now.
Transport authorities say passenger numbers on public transport are generally down around 80%, but there are concerns about social distancing on some busier services.
They say the new timetable will free up resources so extra vehicles can be set aside for services where there is greater demand.
The new Irish Rail timetables come into effect from Monday, while the changes to bus services will be in place from Wednesday.
Go Ahead services will operate at 94% of current levels, while Dublin Bus and Bus Éireann will be operating at over 80% of current levels.
Intercity and commuter train services will run at 45-55% of normal levels.
Meanwhile, DART services will run every 15 minutes at peak and every 30 minutes at other times.
The NTA said that the changes are designed to ensure public transport services “remain frequent and reliable” during the weeks ahead.
All details will be available on the websites of the individual operators.