Iarnród Éireann has confirmed that it will require a further €660 million to upgrade capacity on its mainline routes including commuter and suburban services to and from Dublin.
This is in addition to the €170 million requirement already announced recently for upgrading DART services.
The huge increase over the past decade in the numbers travelling by rail after years of under-investment now means that there are major bottlenecks on parts of the railway system, notably at Heuston and Connolly stations in Dublin.
According to the Strategic Rail Review, published earlier this year, the number of rail passenger journeys could reach between 54 million and 76 million by 2020. Passenger numbers on the DART have risen by 30 per cent over the past 10 years, while outer Dublin suburban services increased by around 25 per cent. Almost two thirds of the 35 million passenger journeys made by rail last year were on Dublin suburban services.
One of Iarnród Éireann's main priorities is to "four-track" the line from Dublin to Hazelhatch in Co Kildare. In effect, this is the equivalent of upgrading a typical national primary route to motorway or dual carriageway standard.
One of the biggest problems at present for trains using Heuston is that the double-track line is getting clogged up. The provision of two additional tracks would enable the separation of fast and slow trains, something that is common in many other countries.
CIÉ is currently currently discussing prioritised investment for the next five years with the Department of Transport. "We are bringing this project to Railway Order stage, and the estimated total cost is €340 million. The Kildare Route Project envisages four-tracking as far as Hazelhatch," confirmed IE spokesman Mr Barry Kenny.
But this is only part of the jig-saw. The section of track from Howth Junction to Dublin Connolly must cater for Belfast-Dublin inter-city services as well as northern suburban line trains from Dundalk and Drogheda, and also DARTs from Malahide and Howth. The estimated cost of four-tracking this is €300 million.
However, the proposed development of a major new station at Spencer Dock, close to the IFSC, is likely to mean that trains from Sligo and Maynooth as well as some northern line suburban services could be re-routed here and this would help to free up capacity at Connolly Station in the short term. It is understood that some Kildare commuter services may travel via the Phoenix Park tunnel to the Spencer Dock station as well.
On the western suburban line, Mr Kenny confirmed IE is "looking at doubling sections between Maynooth and Mullingar" at an estimated cost of €20 million. This could help speed up Sligo services.
Platform 11, the rail lobby group, is fully supportive of plans to increase capacity on the Dublin network. However, it remains critical of several aspects of IE operations, notably the failure to provide a cross-city link using the Phoenix Park tunnel.