An alcohol ban is to come into effect on four Iarnród Éireann services from Heuston Station from next Friday, 12 October.
The transport company said the unprecedented restriction follows "persistent complaints" from passengers about anti-social behaviour on board certain services from the capital on Fridays.
The 11.25am, 1.25pm and 5.35pm services from Dublin's Heuston Station to Galway will now be alcohol free on Fridays from next week.
A ban will also come into effect for the 2.45pm service to Westport every Friday.
Iarnród Éireann says any passengers boarding these services with alcohol will have it confiscated, and no alcoholic beverages will be sold on board.
A spokesperson told RTE News that while the vast majority of passengers who drink on board do not impact their fellow passengers, "there is a minority who overindulge."
The spokesperson said the complaints centered around people travelling in large groups.
RTÉ's This Week reported in June that anti-social behaviour on rail services jumped by 43% in a two-year period.
Iarnród Éireann has already banned drinking on a number of other services.
These are the 1.15pm and 3.10pm services to Waterford from Heuston on Fridays, the 1pm service from Galway to Heuston on Sundays, and the 12.40pm, 3.10pm and 6.05pm services from Waterford to Heuston on Sundays.
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