The first train in a new €400 million Irish Rail intercity fleet went into service yesterday on the Sligo-Dublin line.
A total of 183 new carriages will be rolled out this year by Iarnród Éireann under the project, which promises to transform the "quality, comfort and frequency" of rail services in the State.
Rebecca Stevens, chief executive of Sligo Chamber of Commerce, welcomed the new train, describing yesterday as a "brilliant day for Sligo.
"We are delighted to have this infrastructure here. We have campaigned long and hard for it and the increase to eight trains will open up the tourist and corporate market.
"Before, we only had three trains a day and that was very restrictive. So this is a wonderful achievement."
The first of the new trains - funded under the Transport 21 initiative and the European Regional Development Fund - entered service on both the Sligo-Dublin and Limerick-Dublin lines.
The Sligo-Dublin line is the national network's fastest growing route and had more than 1.25 million passenger journeys in 2007 - an increase of more than 30 per cent in two years.
Since 1999, more than €150 million has been invested in Sligo services including the renewal of track, resignalling, level crossings, platform lengthening and other safety investment.
Iarnród Éireann spokesman Barry Kenny said Sligo-Dublin passengers had already benefited from a big increase in frequency, with the service increasing from five trains each way to eight trains each way daily.
The company said its new trains represented the most eco-friendly diesel fleet in Europe.
Rail fares went up by 5 per cent this year, but the firm said that capital investment in the new carriages would not affect day-to-day fares. It said the new additions were vastly different from older carriages in their performance, reliability, design/appearance and the interior features such as audio-visual displays, mobility measures and air-conditioning were also much improved.
Other routes set to benefit from new trains are the Rosslare/Dublin, Waterford/ Dublin, Westport/Dublin, Tralee/Dublin, Tralee/Cork, Galway/Dublin, Limerick/Dublin lines, along with Carlow, Athlone, and Portlaoise commuter lines.
Frequency improvements will be delivered across all routes, when all trains are in service by the end of this year, said Mr Kenny.
The fleet was ordered from Mitsui of Japan, in partnership with Rotem of the Republic of Korea (where the fleet was built) and Tokyu Car Corporation of Japan.