There are clear indications that at last the Dublin traffic problem is about to be taken seriously. The Dublin Transportation Office has done an extremely thorough job of analysing the city's public transport needs over a 16-year time-scale, and it seems likely that its plans - the cost of which might exceed £500 million a year over that period - will shortly be approved by the Government.
Within the past couple of years there has been a huge revolution in thinking on this issue. When I first examined the problem in 1995-96 I found an absolute reluctance among planners, civil servants and Ministers to face the fact then staring them in the face: that playing around with some quality bus corridors and two tramlines was a totally inadequate and out-of-date approach.
Even as late as 1997 the Luas consultants were still working on 1991 projections of employment and car ownership - despite the fact that I had pointed out to them in 1996 that the actual rate of growth of both of these key indicators had, for the previous five years, been exceeding by a factor of 2.3 times the growth assumptions upon which they were still basing their plans.
The change of government in 1997 led to a new look at the Luas project, in the form of the Atkins Report. This precisely validated the traffic projections I had made several years earlier. But this report failed to draw the logical conclusion from this.
True, it agreed that the demand could not be catered for without a tunnel under the city centre that would make possible the provision of the necessary capacity by eliminating the need for on-street running.
But although the financial issue was not within its terms of reference, it nevertheless perversely declared that we could not afford the tunnel required to provide this capacity, thus flying in the face of the fact that in that year, 1998, our budget, even after financing a £2 billion capital programme, was in surplus to the tune of two-thirds of a billion pounds.
The Government's reaction to this curious report was equally strange. Reportedly under pressure from a Progressive Democrat source, it was decided to build a tunnel - but not the tunnel that the Atkins Report showed was needed - one that would eliminate on-street running and thus make it possible to operate coupled vehicles, which would have involved building a tunnel from Ranelagh through to Broadstone.
Instead, they decided to build a different tunnel - one which the report had recommended against starting until St Stephen's Green.
While such a short tunnel would reduce public transport congestion on city-centre streets, it would not overcome the capacity bottleneck on the route because it would not make possible the operation of coupled vehicles -which alone can increase capacity above the 6,5007,500 peak-hour level.
Frankly, the ultimate lunacy of this half-baked Government decision - building a costly tunnel designed not to solve the capacity problem - made me give up the battle at that stage.
I was unaware that the war was in fact not over. For the Dublin Transportation Office had by then been belatedly authorised to do what should, of course, have been done from the outset - undertake a thorough up-to-date professional review of the entire Dublin traffic problem. And three months ago the Government seems to have given approval in principle for the proposals arising from this review, which belatedly offers a solid basis for a long-term Dublin transportation plan.
The DTO started its work on this plan with a revised long-term forecast of the greater Dublin population. It estimated that, despite efforts at decentralisation, between 1996 and 2016 the population would increase by almost 40 per cent, from 1,350,000 to 1,750,000 - a figure later adjusted to 1,850,000, which may prove a little optimistic for the year 2016, but would be right for around 2020 anyway.
Allowing for a faster growth of employment, peak traffic would double from just under a quarter of a million to almost half a million - and off-peak traffic would rise by over two-thirds.
Now, between 1991 and 1997, the average speed of peak-time Dublin road traffic had fallen from 14 m.p.h. to 8.5 m.p.h., and if nothing was done to improve the situation, this figure would by 2016 have fallen to an estimated 5 m.p.h. In other words, residents of a suburb 12 miles from the centre of Dublin would on average take 2 1/2 hours to commute by road. The target that the DTO has set itself is to get back by 2016 most of the way to the 1991 average speed - to achieve a peak-time average speed of 12.5 m.p.h.
Two significant road improvements designed to shift cross-city traffic onto motorways around the city would make it possible to achieve such an overall peak-time speed in 2016 with roughly the same number of private cars as in 1997. These improvements would be the addition of an extra lane to the M50, and the building of the Eastern Bypass under Sandymount Strand to link up with the already-planned tunnel from the Point Depot to Whitehall. This is a proposal that I had put forward in 1989 to meet the very reasonable objections of Sandymount residents to a motorway being built across their strand, cutting them off from the sea.
The outcome of this set of calculations is set out in the table.
Peak Car Commuters:
1997
180,000
2016
176,000
Peak Public Transport
1997
70,000
2016
312,000
Total Average Peak Commuters
1997
250,000
2016
488,000
Average Road Speed
1997
8.5 mph
2016
12.5 mph
Two things are clear from this table. First, it is clear that in order to return Dublin's car traffic flow to the level of the early 1990s, the volume of traffic on public transport will need to increase 4 1/2 times during the next 16 years - something that cannot conceivably be achieved without a massive investment in commuter rail services.
Second, given people's strong attachment to the car, it is equally clear that without some form of restraint through the application of market forces - some kind of road pricing - the mere provision of public transport services, however high their quality and however excellent their convenience, will not reduce the volume of private car commuting back to its 1997 level from whatever may be the volume to which it rises in the years immediately ahead. To think otherwise would be an absolute delusion.
It may, of course, be possible to argue about some of the details of what appear to me to be well-judged conclusions about future traffic volumes. But it is simply not possible rationally to challenge these two key conclusions.
The DTO now has available to it comprehensive data on the pattern of traffic throughout the Dublin area - including data on how traffic volumes have been developing during the 1990s. The latter data show several important new developments, including growth in orbital traffic demand around the edge of the conurbation, on the Airport/Blanchardstown/Lucan/ Clondalkin/Tallaght axis, which is linked to expansion of business activity in certain key areas such as the airport, Blanchardstown and Tallaght.
Moreover, major developments are now pending in the docklands, the northern fringe, City West (between the Naas dual carriageway and Tallaght, the Sandyford Industrial Estate, Cherrywood near Loughlinstown, and Bray).
On the basis of these data the DTO has been able to construct substantially reliable estimates of the pattern of future traffic flows and, depending on the scale of these flows on each route, it has also been able to calculate what type of public transport mode will be required in each case by 2016.
Thus, buses operating on Quality Bus Corridors can cater for up to 2,700 passengers per peak hour (double-deckers) or 3,600 per peak hour (articulated single-deckers). Next, 40-metre long light-rail vehicles or trams, (much larger than most of those operating in continental cities), operating at intervals of 2.5 minutes, can accommodate a maximum of 7,600 per peak hour.
Eight-car DART electric-powered vehicles, operating at five-minute intervals on track that also has to handle other types of rail services, can carry up to 12,000 per peak hour; and suburban rail services with higher density can carry up to 14,000.
Finally, eight-car metro services operating at two-minute intervals on dedicated track, with no other types of rail vehicles, can handle up to 60,000 people per peak hour.
Tomorrow: the likely shape of Dublin's rail services in the future
