Iarnród Éireann has today announced its largest order of new trains, with 120 railcar carriages planned for the Intercity services.
The Minister for Transport, Mr Cullen, revealed the investment today at Heuston Station in Dublin.
Funded under the National Development Plan, the new carriages will cost €262 million and will begin entering service from 2007 to allow Iarnród Éireann to increase frequency on Intercity routes.
The modern carriages will have improved accessibility for mobility-impaired customers, internal CCTV systems and will also contribute to faster journey times.
CIÉ and Iarnród Éireann chairman Dr John Lynch said: "With these new trains, offering faster, more comfortable and more frequent services across our network, we can continue to grow dramatically our record number of customers."
Iarnród Éireann also plans to introduce 67 new carriages for the Cork/Dublin route later this year and 36 new carriages planned for commuter services.
The Government has come under fire for failing to provide Dublin Bus with sufficient resources to buy 150 extra vehicles, however.
Labour Party Councillor for Rathmines, Mr Oisin Quinn, described the Government as "short-sighted".
"Last November, I wrote to Transport Minister Martin Cullen, appealing to him to meet the commitment given by the Government in the National Development Plan to provide 150 extra buses to Dublin Bus.
"I merely received an acknowledgement from the Minister, with no commitment given to live up to this promise," Mr Quinn said.