The next phase in the reopening of the rail line from Dublin to Navan would cost €578 million, was "not financially viable" and "would require the full capital costs to be borne by the Government," councillors in Meath were told by Iarnród Éireann yesterday.
The reopening of the line is part of the Government's Transport 21 infrastructure programme and the first phase of the line, from Clonsilla to an interchange with the M3 at Pace near Dunboyne, is scheduled to open by 2010.
However, the study on the viability of continuing the line to Navan found that it was costly, and if the final route took in Dunshaughlin the cost would jump by another €55 million.
The report, drawn up by consultants Roughan & O'Donovan - Faber Maunsell revealed the emerging preferred route would use two-thirds of the pre-existing line, with an extension to create a station at Navan North to link in with an existing but disused line to Kingscourt.
Including construction, stock, land and property, the cost of the line is estimated at €455 million in 2007 terms.
However, with construction anticipated to take place between 2010 to 2012, that cost would rise to €578 million, with annual operating costs of €6.8 million in today's terms. The presentation to Meath County Council also heard the service could be operational by 2013 - two years ahead of the target date in Transport 21.
The journey time to Dublin from Navan would be approximately one hour, with trains every 15 minutes at peak times, and there would be stations at Pace, Drumree, Kilmessan, Navan Central and Navan North.
With a projected 5,300 trips each way from Dublin to Navan, it would have an anticipated financial return of 4.6 per cent, and therefore just meets the Department of Finance's threshold of 4 per cent.
Tom Finn from Iarnród Éireann told councillors that 85 per cent of the projected population growth would be needed to justify the development and "even the slightest drop in population could have a very significant impact on the rate of return." He acknowledged that "financially, you would not touch it with a barge pole because of the costs".
The scoping study ruled out spurs on the line to Ratoath, Ashbourne and Dunshaughlin, but the emerging preferred route does includes going close to Dunshaughlin.
It also said up to 25 per cent of the funding could be raised through development levies, with the balance sought from the exchequer. The report will now go to the Department of Finance.