More commuters are opting to take the train, according to figures released by Iarnród Éireann on Monday.
Rail passenger journeys on Intercity, Dart and commuter trains were up by 650,000 in the first six months of this year.
Iarnród Éireann has said the increase in journeys is due to a number of factors including Leap Card initiatives, online sales promotions, and economic growth and stabilisation.
The preliminary figures show that about 19 million people took a trip on one of Iarnród Éireann’s trains between January and June in 2015, which is a 3.5 per cent increase on the same period last year.
Over 8 million passengers took the Dart, which is up almost 6 per cent on last year.
The Intercity services saw an increase of 1.5 per cent, while commuter journeys were also up by 2.1 per cent.
The railway operators also believe the increase is due to the growth in the number of employers participating in the Taxsaver scheme, which gives full tax relief on annual and monthly train ticket costs for commuters.
Iarnród Éireann has said it plans to release a new timetable in early 2016 to keep up with the increased demand, with a public consultation to be held in autumn regarding changes to services.