The Minister for Public and Commuter Transport has said he wants to see a "dramatic improvement" in the number of passengers using the Galway-Limerick train service.
Alan Kelly said he was concerned about the volume of business on the line, which reopened in 2010 at a cost of over €100m.
He said the costs associated with the service meant there was a clear need to improve passenger numbers.
Mr Kelly said he was hopeful that a commercial plan being drawn up by Iarnród Éireann would encourage people to use the service.
It is understood this will lead to shorter journey times between the two cities and the introduction of online booking for those wishing to travel on the route.
Campaigners in favour of the line have called for the progression of the next phase of the Western Rail Corridor, from Athenry to Tuam, but the minister said due to the financial situation there would be no announcement in that regard any time soon.
Mr Kelly said that it would not be his choice to close rail lines, but there were concerns about usage of a number of passenger lines on the network.
Minister Kelly announced funding of €3.7m for a number of transport projects in Galway this morning.
These include a redesign of the bus and rail station, extension of bus lanes and funding to examine the viability of a greenway on the banks of the River Corrib for pedestrians and cyclists.