The proposed metro line linking Swords and Dublin airport with St Stephen's Green is now likely to run via Ballymun and Glasnevin rather than taking a route to the east or west of this central alignment, writes Frank McDonald, Environment Editor
There is now a strong preference within the Railway Procurement Agency for the central route after positive feedback about it from the public during a round of consultations that started in February.
However, the RPA will be reviewing proposals to run the line on an elevated structure in the middle of Ballymun Road after this emerged as the most contentious issue with the public.
The RPA distributed 100,000 flyers to people in the potential catchment areas, held six "open days" on the three principal route options and received more than 1,000 written submissions from members of the public. An RPA spokesman said all of these responses will be assessed before a final decision is made on the route in July by the project team, after which there will be another round of public consultations on its detailed design.
However, not even ballpark estimates of the cost of Metro North are being released. The RPA's revised "business case" for the line was submitted to Minister for Transport Martin Cullen last year, but it is being kept strictly confidential.
"The Minister is not giving out information, so we can't either," RPA project leader Rory O'Connor said. This includes a cost-benefit analysis which was audited by Goodbody Consultants for the Department of Finance.
Mr O'Connor said there was "massive support" for the metro and "most people see it as the beginning of a commuter network linking up with other services".
However, although the metro line would cross two existing railway lines at the southern end of Glasnevin, he conceded that there would be no direct connection between them - unless the east route, via Drumcondra, was chosen.
The proposed Botanic station on the central alignment would be located at the Smurfit site on Botanic Road. This would be at least 400m from a new Prospect station planned by Iarnród Éireann on the Maynooth commuter line.
Dublin City University would be served by Metro North, with a station south of Collins Avenue. But there is a very long gap - 1.8km - between it and Botanic station. This is more than three times longer than the optimum distance of 500m.
The west route, via Liffey Junction and Broadstone, is likely to be ruled out because it would be 5km longer. However, it would serve the proposed Dublin Institute of Technology's new campus at Broadstone, where there is major development potential.
The most likely location for the airport metro station would be close to the existing main terminal, Mr O'Connor said. An alternative option of locating it at the Great Southern Hotel - remote from the terminal - was put forward to save money. "The Great Southern option avoids having to go underground. It would also be closer to the centre of gravity of where people work at the airport, which we estimate would account for half of the people using the airport metro station."
Metro North's capacity to carry is critically dependent on a huge increase in the density of development along the route it will serve, especially north of the airport.Studies by Fingal County Council suggest the population of Swords could grow from 34,000 to 120,000 over 10 years, developing along the metro corridor.
Mr O'Connor said Metro North will have the same gauge as Luas, although its vehicles would be wider-bodied - 2.65m, as against 2.4m. It would also be "much more like light rail than heavy rail", such as Dart and most metro systems elsewhere.
The big difference is that it would run on segregated track, without crossing road junctions. For example, assuming the central alignment is chosen, it would run either over or under the busy junction of Ballymun Road and Collins Avenue.
Mr O'Connor conceded that Ballymun Road is wide enough to accommodate Metro North on the surface, running along the middle of it. However, it is likely to run on an elevated structure along the main street of Ballymun, now being intensively developed.
The RPA is working closely with Iarnród Éireann on the design of St Stephen's Green underground metro station, to ensure there is no clash with the proposed €1.2 billion rail interconnector between Heuston Station and Spencer Dock.
The centre of Upper O'Connell Street would have to be excavated to create an underground metro station, which would have entrances near the Spire and the Parnell monument.