Back in 1997, I wrote about Luas in this column on several occasions, arguing that because of the volume of traffic that would be generated by the proposed rail line from Stillorgan (and eventually from Bray) to Stephen's Green, and onwards towards the airport, it should be designed and built as a full-fledged metro rail system, rather than as a Luas tram.
I based this argument on official traffic projections made in the early 1990s, modified to allow for the Celtic Tiger.
In early 1997, I met the consultants working on the scheme, whose team, most unfortunately, included no economist. To my absolute astonishment I found that they had taken no account whatever of the Celtic Tiger, but were still publishing - and also using for their own planning purposes - traffic estimates based on totally out-of-date data that had been prepared back in 1991, on the basis, as I recall, of the second-last census of population!
They were quite unaware of the fact that the growth rates both of employment and of cars in Dublin since 1991 had been 2.3 times greater than the increases projected six years earlier.
Taking that into account, any attempt to cater for eventual demand on this route with trams, even operating at very high frequencies, was clearly going to fail. And in continuing it on street to O'Connell Street would so congest the difficult Dawson Street/Nassau Street corner, as well as the narrow street between Trinity College and the Bank of Ireland - the only south/north street between Westland Row and Christ Church Cathedral. Dublin Bus tell me that two-thirds of all their buses run through College Green, and they are greatly concerned at the likely impact of Luas on the great bulk of their city services.
In 1997, there was immediate strong opposition to my suggestion that the Luas project should be reviewed in the light of these facts.
But, after that year's election the PDs, returning to government after five years, grasped the half of my argument about congestion in the city centre - but apparently not the other, even more crucial, element of my case about traffic volumes.
As a result the new Government was persuaded to adopt a short-sighted half-measure - stopping the Luas tram at Stephen's Green, instead of converting it into a metro running in a tunnel from just south of Ranelagh and onwards through the city centre.
As I predicted, Luas traffic volumes have already been much higher than planned. Indeed, despite the termination of the tram service at Stephen's Green, there have from the outset been problems of capacity shortage at peak hours, both between Heuston and Connolly Stations on the Red Line, and between Dundrum and Stephen's Green on the Green Line.
At this stage, and because the line has been stopped at Stephen's Green, this capacity problem has been met by adding a new short-distance tram on the Red Line, one that operates only between the two railway stations, and by also adding an extra peak-hour service on the Green Line, with more to follow.
But given the huge volume of residential building currently under way and planned for the foothills of the Dublin Mountains above Stillorgan, the Luas tram, even with much increased frequencies, will not prove capable of coping indefinitely with the traffic volume on this route - especially after it is linked at Stephen's Green to a metro running through the city centre to the airport and beyond.
A firm decision has recently been announced to build a metro now from Swords and the airport to Stephen's Green - stopping, however, at that point, instead of continuing as had originally been intended, along the present Luas Green Line to Stillorgan and beyond. Halting it at Stephen's Green means that for years ahead passengers between south Dublin and the airport will have to change and lug their bags between two different levels at Stephen's Green station - and Henry Street shoppers will have to do the same with their purchases!
Instead of taking the opportunity to create now a through-service metro between south Dublin, O'Connell Street and the airport, current plans involve spending money on the construction of two almost parallel Luas and metro lines between Stephen's Green and O'Connell Street. But duplicating the new metro between Stephen's Green and O'Connell Street, by extending the over-ground Luas even further into the city, will disrupt the whole south city centre for several years and, when completed, will slow the passage of two-thirds of our city bus services.
Is this a wise decision? And has it been independently evaluated, taking full account of the negative traffic effects of extending Luas through our most congested streets?
Such a crucial decision should clearly be taken in the context of the long-term commitment the Government has made to extend the new metro from Stephen's Green through a tunnel to just south of Ranelagh, whence it would continue over ground along the present Luas track to Stillorgan and Cherrywood, and eventually to Bray.
Instead, it is my understanding that the financial valuation of the currently proposed Luas extension, which is to parallel the new metro from Stephen's Green to O'Connell Street, has been based on a view of the situation limited to a period of only 10 years - a quite extraordinarily short time-scale for the evaluation of a major infrastructural project. Such a short-term evaluation could not adequately assess the economic relationship of this Luas extension to the parallel metro, which on present plans would not be developed until after 2016.
In the long-term, the key issue must be what impact this parallel Luas project would have on the much larger metro project that is to run eventually from Swords and the airport to Bray, rather than the other way around. Instead, the matter is being approached in an upside-down way, by a Rail Procurement Agency which currently seems very strongly Luas-oriented - because at present Luas is all they have to run.
It seems to me that a reassessment of this project by an independent body is needed - one that will not allow the Luas tail to wag the metro dog, and that will take full financial account of the social cost of disrupting our city centre traffic by running a Luas through the south city centre in parallel with the new metro.
Such a re-evaluation might lead to a conclusion that, rather than spending money now on two parallel rail routes between O'Connell Street and Stephen's Green, it might make better sense to bring forward the plan to convert the Luas Green Line into a metro. The metro tunnelling machine could be allowed to continue beyond Stephen's Green for the further mile and a half to a point south of Ranelagh - instead of letting it, as has been suggested, moulder away under Stephen's Green for more than decade.
Due to a technical error only part of this article was published last Saturday