The National Transport Authority has announced plans which could see up to quarter of public transport users facing fare increases from the beginning of next month.
Three quarters of passengers on Luas, Irish Rail, Bus Eireann and Dublin Bus will see no fare hikes, but some will see increases of up to 18% on journeys.
The NTA sets public-transport fares. CEO Anne Graham said only a small number of passengers would see price hikes.
"Three out of four will see no change, and may even see a reduction," she said. "Only a small proportion will actially see a fare increase, and they'll be moderate increases.
The changes wre due to the introduction of a distance-based structure on fares. Operators are permitted to implement the fares changes from December 1.
The NTA published its fares determination reports today. The LEAP card emerged as the best value with savings of more than 20% on single journey tickets.
An estimated 230 million public transport journeys are made in Ireland every year.