Serious concerns about key elements of the Dublin Transportation Office's £8 billion-plus draft plan for the capital - currently under consideration by the Government - have been expressed by Dublin Corporation's director of traffic, Mr Owen Keegan.
He has warned of the "real risk" that the DTO's long-term strategy, by proposing metro-style underground rail links and other "extremely expensive fixed-track options", could divert attention from the "urgent need" to proceed with Luas, suburban rail and bus measures.
In a detailed analysis of the updated DTO strategy, which was presented to a Cabinet subcommittee in April, Mr Keegan said it assumed that funding would not be a constraint - "potentially a very dangerous assumption to make over the medium and longer term".
His critique, seen by The Irish Times, said the strategy "has not been subject to proper evaluation". At the very least, a technical appraisal was required to determine if some of the proposed metro lines were feasible and the length of tunnelling required in each case.
The DTO has proposed a metro to replace the planned Luas light rail line from Sandyford to the city centre, running underground from Ranelagh to Broadstone and on to Dublin Airport. There would also be an underground link between Spencer Dock and Heuston Station.
According to Mr Keegan, the recommended strategy "has been driven largely by the DTO's transport demand forecasts" for 2016, when its computer model shows that the number of peakhour trips throughout the greater Dublin area will nearly double to 488,000.
The DTO then proceeded to develop a strategy on the basis that "these trips are necessary and require to be catered for" (in its own phrase) essentially by ensuring that all growth in travel demand is met by public transport, ignoring the potential contribution of cycling and walking.
As with any long-term predictions, he says there "must be considerable uncertainty" about the DTO's travel demand forecasts for 2016. The 1994 Dublin Transportation Initiative's forecasts turned out to be wrong and the DTO now "runs a high risk of repeating this mistake". In Mr Keegan's view, the DTO has been "reluctant to consider alternatives against which the strategy could be evaluated" and it has also been "reluctant to prioritise projects in terms of their potential return in meeting transportation objectives for the region".
The director of traffic, an economist by training, said a preliminary economic evaluation should have been prepared for each major project in the strategy. Though an overall evaluation of the DTO plan was now being carried out by Goodbody Economic Consultants, his paper suggested that this should have been done before anything was determined "instead of being used to retrospectively justify the selected strategy".
Mr Keegan noted that the public transport improvements envisaged by the DTI in 1994 and the further measures provided for in the National Development Plan would deliver additional capacity to cater for 103,000 extra peak-hour trips for an overall cost of £1.58 billion.
What the DTO was now proposing, based on its forecasts, was that an extra 135,000 peakhour trips would have to be catered for by public transport in 2016. But the additional infrastructure proposed in its updated strategy to meet this demand would cost £4.4 billion.
He said a "fundamental objection" to the approach being followed by the DTO was that "it is not at all clear" that peak-hour travel demand was the appropriate benchmark "and even if it is, it is not clear that we should aim to meet projected peak-hour demand in full".
Aiming for relatively uncongested road and public transport networks at peak times ran a risk that such a strategy would be "economically wasteful" because the infrastructure "would be seriously under-utilised for most of the day and night".
He argued that the current proposal for a Luas line between Sandyford and St Stephen's Green should proceed because it has already been through the planning process, rather than "scrap the project" to begin planning a metro, which would involve "a significant delay".
When contacted yesterday, the director of traffic refused to comment, saying only that his paper had been submitted to the DTO and was not intended for public circulation.
