The DTO's solution for Dublin's traffic requirements 16 years hence combines an expansion of Quality Bus Corridors; a new DART service replacing the Kildare and Maynooth suburban rail services; two new linked metro services; and a major expansion of the Luas light-rail system, construction of which has already started.
On its own, this proposed £810 billion investment will not resolve Dublin's traffic problems. For by 2016 the number of cars in use in the Dublin region will have doubled since 1996.
Already, between 1991 and 1998, the car numbers in the Dublin area rose from 248 per 1,000 people to 382 per 1,000, and the DTO is assuming that by 2016 it will be at 480 per 1000, which would be one-fifth lower than the present "saturation" US ratio. This means the DTO is assuming that the rate of growth of Dublin's car/people ratio will fall sharply in the years ahead, from almost 6 per cent a year to less than 1.5 per cent.
Allowing for the projected Dublin area population increase of almost 40 per cent during the 20-year period from 1996 to 2016, this, possibly conservative, calculation would suggest that between 1998 and 2016 the number of cars in the Dublin area will have doubled, from about 450,000 to 900,000.
In the light of those figures it is obvious that, even with a first-class public transport system, there is no way in which, without some financial constraint on car use, the volume of car traffic in 2016 could be held to its 1997 level. A car-pricing system is thus inevitable, and Dublin, with its double set of river and canal bridges on both side of the city, is well suited to the introduction of such a system.
This will require cars to be fitted with electronic devices that will be triggered by their entry to the city centre. The rates to be charged will vary depending on the time of day, with much higher rates at peak periods. There will probably also be variations in charges depending on the length of time a car spends in the city.
These charges will be designed to equate the demand for access-road usage at different times of day with the capacity of the road network and also to equate the demand for car spaces within the city with the capacity to accommodate vehicles.
However unpopular all this may prove with motorists in the short run, some such system is now inevitable - for the sake of the motorists themselves as well as of the majority who, within a decade, will be travelling by public transport.
What about the rail system which the DTO has devised as a counterpart to these "road-calming" measures?
First, the existing DART system will have to be further developed, lengthening platforms to take eight-car trains. The Kildare and Maynooth suburban services will be electrified and converted to DART standards, which will mean installing additional track along the main lines which they use: two more tracks to Kildare and either one or two to Maynooth.
Moreover, to make this new DART really useful for commuters, it will have to be extended from their present termini into the city centre. The Maynooth line is to be diverted to the new Spencer Dock station, east of the Financial Services Centre, and will then run underground to Pearse Station and onwards via Stephen's Green and the Liberties to Heuston Station, where it will surface and continue on to Kildare.
Because these DART services will be operating along mainline track, like the existing DART services they will use traditional Irish 5.3" gauge stock. However, it is proposed that the new metro and Luas service operate on the Continental gauge of 4.8". This is a point about which some rail experts may have queries to raise.
The proposed Luas light rail service from Stillorgan to the city is to become a metro service, operating in a tunnel between Ranelagh and Broadstone. This will enable coupled vehicles to be used to provide the necessary capacity - which Luas would be incapable of doing.
This metro will intersect with the underground section of the new Maynooth-Kildare DART at St Stephen's Green. However, instead of going straight from there to Broadstone, as had earlier been envisaged, it is now intended that it curve to the east so as to intersect with the existing DART line at Tara Street, with intermediate underground stations at Nassau Street and the Rotunda.
This metro line will then run on from Broadstone, through a tunnel for part of the way from Liffey Junction to Finglas, and thence to Dublin Airport and Swords. This line will also be extended southwards from its earlier proposed Stillorgan terminus along the old Harcourt Street line to Shanganagh Junction, where the old line used to join what is now the DART line to Bray and Greystones.
A new proposal is for a second, orbital metro using the north-south DART tunnel from near Ranelagh to Broadstone and on to Finglas, but branching off from the airport line at Finglas and then circling round via Blanchardstown, Palmerstown and Clondalkin, to Tallaght. From there, it is to run back to the city via Kimmage, going underground from that point to Rathmines and rejoining the north-south metro tunnel between Ranelagh and the Grand Canal.
To these two DART and two metro lines, a series of on-street Luas light rail or tram-lines will provide services on some routes where the volume of traffic is likely to be less dense.
Most of the Luas line from Tallaght via the Naas Road, Rialto, Heuston Station, Abbey Street, Connolly Station, Spencer Dock, and eventually to the Point Depot is already in preparation. But a new Luas line is to be built from Lucan via Ballyfermot to join the Tallaght Luas line at Bluebell, near Inchicore.
Moreover, the Rialto to Spencer Dock section of the Tallaght-Point Depot line is eventually to be duplicated by an alternative route running from Rialto along the South Circular Road and Adelaide Road to Leeson Street Bridge, and then down the Canal to the new Barrow Street Station, and across a new bridge to rejoin the main Tallaght-Point Depot line at Spencer Dock.
Finally, a new north-south Luas is also proposed, to run from Dun drum via Churchtown, Rathfarnham, Terenure, Harold's Cross, Christ Church to Broadstone. Given that the original proposal for a Luas line via Whitehall to Ballyfermot is now to be converted into a metro line running via Finglas to the airport, this new Luas line from Dundrum via Rathfarnham is now to be routed from Broadstone along Dorset Street to Whitehall, and thence to Ballyfermot, joining the new airport metro line at Sillogue.
A new branch off this line is to be constructed from Whitehall across the north-west city to Howth Junction, where it will intersect with the DART lines to Howth and Malahide.
These three rail concerns - DART, metro and Luas - are to be operated by different companies, under the auspices, one presumes, of an overall Dublin Transportation Authority. And this remarkably dense commuter rail system is, of course, to be backed by bus services, which will also be planned by this authority and then bid for competitively both by reconstituted Bus Eireann and Dublin Bus companies and also by private bus concerns - a process due to be completed within the next 4 1/2 years.
For all this to be implemented efficiently, we need transport and roads to be controlled by a single Government department - and we also need a Dublin regional authority capable of getting this huge commuter traffic and transport system into operation. At present, the competing ideas and local interests of the seven local authorities in the region inevitably slow planning and implementation. That bottleneck has to be eliminated.
Queries will be raised about aspects of this overall plan. Whatever about Luas, should the metro not run on the same gauge as DART? No doubt there are short-term savings in terms of cheaper rolling stock using the standard 4.8" European gauge, but in the longer term, the gauge difference between the metro and the Iarnrod Eireann and DART lines is bound to cause problems - inability to link the airport with the Belfast line eventually.
And should the metro not be extend from Shanganagh Junction to Bray, and the Luas line from Broadstone to Sillogue not be extended the short distance to the airport in parallel with the metro?
A more urgent question, upon which the Government is reported to be divided, is whether it is worthwhile investing a lot of money in building a temporary on-street Luas line from the Grand Canal to St Stephen's Green to be used only during the couple of years that this section of the Ranelagh-Broadstone tunnel is being built.
More important than questions like these, however, is that of the feasibility of catching up with very many years of neglect by completing all of this huge infrastructural project within the relatively short space of 16 years - given the doubts that already exist about the feasibility of our medium-term National Development Plan to 2006.
Is it going to be physically possible to get all this work done within a 16-year period?
The important thing, however, is that at last we have a serious proposal for Dublin's long-term traffic and transport needs. We can now see the shape of Dublin's future.