John FitzGerald: As a child I dreamt of a Dublin metro. But is it feasible?
Cost benefits of proposed Metrolink look impressive on paper but caveats apply
The Luas line on O’ Connell Street. The green line of the service would face significant disruption if Metrolink goes ahead. Photograph: Cyril Byrne
When I was 10, pretty bored recovering from chicken pox, my father gave me the London underground map and suggested I design a metro for Dublin. He persuaded me that this was a fun thing to do and I fell for it. Ever since I have hankered after travelling on a Dublin metro.
To date, I have had to make do with a Luas, but there is now a possibility that my childhood dreams will be realised, even if my economic training suggests caution.
In 2006, the ESRI was asked to advise on priorities for investment in the forthcoming National Plan. Two of the key projects in the draft plan were the Dart Underground and a metro to the airport. When the ESRI sought the research underpinning these proposals from the Department of Transport, there was considerable reluctance to provide the documentation.
Serious pressure from the Department of Finance was needed to obtain the papers, even on a confidential basis.
Apart from the lack of transparency, the studies for those two projects were undertaken separately because two different companies were involved and, as a result, they did not factor in the network benefits that would arise from building the two lines. They also underestimated the costs.
However, the great recession intervened and these projects were not proceeded with.
Last month, a new set of studies was published underpinning a proposed metro (Metrolink) from Swords, through the airport and the city centre, linking in to the southern Luas green line, to be completed by 2027.
This time a more transparent process has been adopted. The National Transport Authority, which has overall responsibility in this area, is co-ordinating how the system is planned, rather than competing companies being involved. A detailed set of documentation is available on the Metrolink web site, including a cost-benefit study and a series of documents explaining why the preferred route has been chosen.
This cost-benefit study suggests that the long-term benefits of the scheme of nearly €7 billion will be more than double the envisaged costs. On this basis, the project looks like value for money. However, a number of caveats apply.
While the studies factor in contingency amounts for unexpected additions to costs, experience worldwide suggests that such projects nearly always prove more expensive than expected, even after the extra margin built-in.
Going on experience of the original Luas project, the biggest risk of cost overruns may come from design changes after the project is commenced. Legal challenges could also ramp up costs.
The cost-benefit study does not take account of the costs of disruption during the construction phase. While this disruption will only be temporary, it can be significant, as we have seen with Luas works over the years.
In particular, the planned routing for the new line will result in the closure of the existing Luas green line from Beechwood to St Stephen’s Green for around a year. In the end, existing Luas users will have a much better service into the city. However, the heavy passenger numbers currently using the Green line suggest that temporary closure will add considerable costs in terms of lost revenue, extra congestion, and the value of people’s time in slower journeys.
Reshaping the city
As against this, the studies’ estimation of the benefits of the new metro does not take account of the possible effects it may have in reshaping the city through denser development along the line. Already along the Luas Green line, the density of both housing and office development has increased significantly, particularly in the Sandyford area. If the Dublin planning authorities were to require much denser development along the line, this could enhance the benefits of the project for the city and the wider environment.
Proximity to the Luas Green line adds up to 10 per cent to the value of property. So denser development along the Metro will also realise higher property tax receipts from both increases in the volume and the value of developments.
The value of lower carbon dioxide emissions from fewer car journeys is an appropriate inclusion in the Metro cost-benefit study. While only a small share of the overall benefits, it is important to factor in such environmental costs, at an appropriate price, in any economic assessments of public investment.
As consultations and investigations continue on final route selection, it is important to factor in full costs. Once the route is finalised, further changes could be exceptionally expensive.
My childhood dream of a Dublin Metro has a while to go before being realised.