The economic case for building two metro lines in Dublin "has not been proven" and it is "probable" that Dublin's future public transport needs could be met by bus, Luas and suburban rail services, according to one of Ireland's leading transport experts.
In the first independent analysis of the Government's €34.4 billion transport investment programme, Prof Austin Smyth said it is clear that the decision to invest in metro "will involve substantially higher costs than equivalent Luas schemes".
His analysis, prepared for the Chartered Institute of Logistics and Transport, said one of the key questions is why Iarnród Éireann's proposal for a spur off the Dublin-Belfast line was "not appraised as an alternative to metro" in serving Dublin Airport.
The estimated cost for such an airport link would be in the region of €350 to €400 million. Increasing the capacity of the railway line between Clontarf Road and Howth Junction by adding a third track to speed up Belfast trains would cost a further €400 million.
By comparison, Prof Smyth told The Irish Times yesterday, the planned metro line between St Stephen's Green and Dublin airport would cost "billions", as would the proposed orbital metro line in Transport 21 running from Tallaght to Ballymun.
"The cost of the two existing Luas lines more than doubled, so whatever figure they put forward for metro now is likely to be an underestimate," he said. However, no information had been made available on the economic case for the two metro lines.
"Last autumn's announcement of Transport 21 represents a massive expansion in spending on transport by the Government. The key question is - assuming the measures are delivered - will this represent good value for use of taxpayers' money?"
Prof Smyth added: "In most societies when such programmes are unveiled, it is possible to come to some sort of conclusion on the efficacy of the expenditure informed by the supporting documentation that typically goes hand-in-hand with such announcements.
"When Transport 21 was announced, the surprise was that it was accompanied by little on either costs or economic case and financial appraisal of the proposals it contained. This in turn has raised concerns in many quarters about the robustness of the case."
In the light of substantial cost overruns on recent transport projects, he said it was "only reasonable and in line with practice elsewhere" for the economic case for Transport 21 to be presented "with accurate statements of costs and full quantification of benefits".
Given the scale of the investment programme and the fact that politicians liked to be seen opening "big ticket projects", Prof Smyth said Transport 21 needed to be subjected to independent scrutiny, particularly in the run-up to next year's general election.
His analysis of the programme concluded that plans for the expansion of Luas are likely to deliver "substantial economic benefits", but emphasised that Dublin's bus and rail network "should be planned together with a clear strategy for interchange". However, instead of adding an entirely new element (metro) to the mix of public transport services, he suggested that Dublin should develop an integrated suburban rail network similar to Schnellbahn (S-bahn) in German cities like Berlin and Munich.
The "jewel in the crown" of such a network would be the proposed €1.3 billion rail tunnel between Heuston Station and Spencer Dock, with new underground stations in the High Street area, St Stephen's Green and Pearse Station (Westland Row).
As Prof Smyth's analysis noted, this rail interconnector would link the Dart with other commuter rail services, including the Kildare line, the Maynooth line and northern and southern suburban lines. He also concluded that the benefits would include - large journey time savings for transport users, support for major new development, promotion of sustainable transport modes, improved reliability by relieving bottlenecks, and relief of road congestion and reduction in emissions.
However, under the timetable in Transport 21, the crucial rail link would be one of the last elements to be completed - in 2015. This was symptomatic of the "general inconsistency" in the Government's programme, according to Prof Smyth.
"Several cities in Europe have developed fully interconnected suburban rail networks with high-frequency cross-city trains . . . Generally, these depend on a city centre connecting tunnel and the availability of radiating suburban rail lines.
"This opportunity now exists in Dublin where the interconnector project, together with the proven role of Dart, can easily form the basis of a fast, electrified, high-frequency suburban network for the city region . . ."
