Iarnród Éireann's radical new timetable will come into effect next Sunday, with a record number of new services, but many of its trains are being slowed by gridlock on the tracks.
Despite record investment in new trains and the upgrading of track, journey times on some of the principal routes are actually slower than they were 20 or 30 years ago.
This is largely because the volume of train services in the greater Dublin region is causing congestion. In effect, trains are queuing to get in and out of the city in certain areas.
However, two major infrastructural projects are expected to ease congestion - and improve speeds - in the next few years.
The Kildare Route Project will see an eight-mile section of track southwest of Heuston being doubled from two to four lines. This will enable fast inter-city trains to pass out slower commuter trains that stop at many stations.
A new signalling system in the Dublin Connolly area - plus the opening of the new Docklands station in March - will allow more train paths on routes radiating out to Maynooth/Sligo, Belfast, Rosslare and on Dart services.
According to the new timetable, the fastest train on the Dublin-Cork route will now take two hours 25 minutes - the same as 20 years ago.
The fastest service between Dublin and Tralee will now take three hours 57 minutes.
Back in 1987 (when Iarnród Éireann was formed) the early morning train from Kerry to the capital completed the journey in three hours 35 minutes.
The bulk of the trains from Belfast to Dublin are timetabled to take two hours 10 minutes, only five minutes less than times of almost 30 years ago.
Most trains on the DublinLimerick route are timetabled to take two hours 20 minutes, but 20 years ago the fastest train was 10 minutes quicker.
Times on the Dublin-Sligo line - one of the most criticised in the past when it had numerous speed restrictions be- fore the laying of new track - are still virtually the same as they were 20 years ago.
Back in 1987, the quickest journey time was three hours 10 minutes. Now it will be just five minutes faster. However, most trains call at more stations.
While the new timetable im- proves times on the Galway route, Mayor of Galway Niall Ó Brolcháin yesterday said in some cases the improvement was as low as two minutes.
Iarnród Éireann spokesman Barry Kenny said there had been a 25 per cent rise in passengers in the past two years "and when you are running more trains there will be more congestion".
The new timetable sees 15 direct services to Cork daily from Dublin Heuston operating on the hour from 0700 until 2100. Frequency will be increased on most routes, and there are new Sunday services on the Kildare commuter line, a new Ballina-Castlebar-Westport service, and additional trains for Gorey and Dundalk.