Engineering works are affecting some rail services today.
A number of Intercity trains will have bus transfers, while the DART will be restricted, however the Cork Commuter line has returned to a normal Sunday schedule.
Irish Rail is advising commuters to check their website for updates.
Irish Rail's Jane Cregan has outlined some of the changes.
"We have engineering works on the north side of Dublin today. There will also be alterations to commuter services from Dundalk and Drogheda."
For further information log onto www.irishrail.ie.