Last Tuesday in this newspaper, Frank McDonald stated, apparently in all seriousness: "Whether Luas as proposed [viz overground in the city centre] would be physically capable of catering for passenger demand . . . is something of a red herring"!
He went on to justify what seems a remarkably cavalier approach to this most critical issue in the design of an urban transportation system by throwing in an airy suggestion about adding more and longer trams.
He apparently felt no intellectual obligation to address, let alone refute, the detailed reasons I have given in earlier articles for believing that more and larger vehicles would not provide an answer.
It isn't good enough to excuse himself from such serious debate by saying that he doesn't have my "facility with figures". That is a cop-out, especially as he writes as an authority on urban transport. For urban transport is, above all, about numbers.
Thus it is about the number of cars overloading our streets; the number of miles per hour at which traffic flows; the number of traffic lanes available on different streets; the number of passengers a public transport vehicle can carry with varying degrees of comfort; the percentage by which average peak-hour vehicle loads fall short of maximum vehicle capacity; the size of the intervals between trams that will permit a flow of other traffic to cross their track. And so on.
I will repeat briefly the key points of my earlier capacity analysis, which has not yet been challenged, or indeed even seriously addressed, either by Frank McDonald, or CIE, or by the Luas consultants. Of course, the fact that no one has challenged it does not necessarily mean it's right, and I am fully prepared to be shown any errors. But until someone states where and how this analysis is defective, I do not see how the investment of public resources in a Luas operating overground in the city centre can be justified.
I am glad that, in this situation, the new Minister for Public Enterprise, Mary O'Rourke, has resisted bureaucratic pressures in favour of ignoring these issues by deciding on an independent inquiry. But I regret that since I first raised this issue with CIE, two years were allowed to elapse before addressing it seriously and, as a result, the whole scheme has been unnecessarily delayed.
Here is my case:
1, According to the Luas consultants' document, Alternative Options, the maximum line flow with bus feeder services in the year 2001 would be approximately 2,800 passengers per hour, one way, between Ranelagh and St Stephen's Green.
2, But this estimate is based on out-of-date data for population, employment and car-ownership growth in the Dublin area during the current decade. Already, by last year, the growth rate of all three key factors since 1991 had been 2.3 to 2.4 times greater than that upon which the traffic estimates have been based.
As a result, in the cases of all three elements, the 1996 volumes already exceeded the Luas consultants' estimates for the year 2001! (Despite the fact that I pointed this out to the consultants in October last year, these out-of-date estimates were still being used by them last January in a publication justifying the over-ground routing).
3, The economic growth projected by the ESRI for the period 1996-2001 (medium-term review figures, adjusted by quarterly economic commentary data for 1997 and 1998) is the same as that which took place in 1991-1996, viz, 30 per cent. On that basis, an increase in employment and carownership, broadly similar to that of the 1991-1996 period, must be expected. This would bring both of these up to a level 18 per cent higher than that on which the current Luas projections for 2001 are based.
As for population, the growth in the hinterland of the south-eastern Luas between 1991 and 1996 was three times more rapid than in the rest of the Dublin area, and this seems likely to continue.
4, Allowing for the 18 per cent under-estimation of these key factors determining demand, the peak traffic flow with feeder bus services in the year 2001 is likely to be 3,300 rather than 2,800.
5, Economic growth between 2001 and 2011 has been forecast by the ESRI to be one-sixth less than between 1991 and 2001. Assuming very conservatively that growth of employment and car-ownership in Dublin after 2001 will decelerate by twice this amount, viz, by one-third, and allowing also for the reduction in commuter needs that would derive from a limited amount of jobs growth within what is primarily a residential area, it is nevertheless clearly unlikely that by 2011 the peak traffic flow would be less than 3,750-4,000.
6, The Luas consultants have estimated that the planned extension of the line to Cabinteely will increase traffic by two-thirds, which would bring the peak traffic level to about 6,250-6,750 by the year 2011.
7, As all traffic estimates contain a margin of error, usually involving under-estimation, and as it would clearly be absurd to build a transport system incapable of handling traffic growth beyond 14 years hence, the track - but not, of course, the initial vehicle fleet - needs to have a capacity significantly in excess of 7,500 per peak hour.
8, Because of their size, 30metre and 40-metre vehicles can be coupled when operated on completely segregated or underground track, but can be operated on-street only as single vehicles.
9, The consultants state that the standing capacity of the largest, 40-metre long, 60-seat vehicles at the density (four persons per square metre) which they describe as "normal comfort level" is 210, which gives a total capacity of 270. If that "normal comfort level" density were to be increased by as much as one-half, to six persons standing per square metre, the maximum number that could be accommodated would then be 365.
10, In commuter transport the average peak-hour vehicle load is 70-75 per cent of the vehicle maximum which, in the case of a 40metre vehicle loaded 50 per cent above "normal comfort level", gives an average figure of 250275.
11, To carry an eventual 7,500plus passengers at an average peak-hour vehicle load of 250-275 would require about 28-30 services per hour in the peak; viz a two-minute frequency in each direction.
12, Such a frequency would block junctions and cross-streets on average once a minute. In the Dublin case this would almost totally obstruct peak-period bus as well as car traffic operating eastwest across the axis from Harcourt Road North to Parnell Square, and perhaps beyond to Drumcondra, and would similarly obstruct north-south traffic from Westland Row as far as Heuston and, indeed, Inchicore.
On the basis of the above analysis I consider that it would be indefensible to build a system which, within not much more than a decade, would effectively block public as well as private road transport throughout the city at peak periods.
Now, there may, of course, be some flaws in this analysis, which I placed in the public domain a year ago. But, if so, would Frank McDonald or the Luas consultants tell the public what are these flaws?
To persist with a project that could have such negative effects while refusing even to attempt a justification of it is, by any possible standards, quite unacceptable.
Undoubtedly the whole matter has been complicated by the overriding concern of public officials that the EU structural funds be spent on time, and spent, moreover, on the specific projects they may have selected years ago, whether or not these choices have stood the test of time.
The dangers of this approach have been gently but pointedly addressed by Prof Patrick Honohan's ESRI team in the institute's excellent mid-term review of the current round of Structural Funds, a review which was well reviewed in this paper last Wednesday, by Frank McDonald.
I was interested to see in that article a quotation from the review to the effect that additional funding may be necessary for Luas so as to finish it to an adequate standard. By "adequate standard", did the ESRI team perhaps mean putting it underground? I strongly suspect so.
It seems Frank McDonald has a vision of Dublin's centre, from St Stephen's Green north to Parnell Square, being pedestrianised, with only fume-free trams operating along the main corridor through the area.
This is an attractive vision, if, perhaps, one that is difficult to reconcile with Dublin's peculiar geography. But that it is not what those who are planning the Luas project have in mind. Their plan involves fume-creating buses as well as trams in the city centre, with car-traffic also continuing, albeit at a volume to be reduced, not by road pricing, but by squeezing them out physically through the priority to be offered to buses and trams.
Quantitative controls are always crude substitutes for the operation of the market system through pricing, and this engineering approach to Dublin's traffic problem is most unlikely to produce anything like Frank McDonald's dream city.