All the evidence so far shows that "restraint" measures aimed at managing Dublin's traffic problems are working. These include the introduction of bus lanes and quality bus corridors (QBCs), as well as the gradual creation of "environmental traffic cells" to exclude through traffic from large parts of the city centre.
Wheel-clamping has been an unqualified success. Though run at a loss of £500,000 in the first year of operation, its powerful deterrent effect has boosted the corporation's annual revenue from on-street parking by 100 per cent, to around £7 million - and this is ring-fenced for investment in further traffic management measures.
One of the principal benefits of wheelclamping and the imposition of time limits on parking - now being extended to other areas - is that it has freed up numerous spaces in the city centre which were previously hogged by commuters. It is quite easy nowadays to find parking at any time around Merrion Square and St Stephen's Green. Dublin Corporation has been making steady progress on measures to reduce traffic penetration of the city centre. As part of the O'Connell Street area plan, two traffic lanes will be removed from the street to allow the footpaths on both sides to be widened; the ultimate aim is to dedicate the thoroughfare to buses, pedestrians and cyclists.
Mr Christy O'Sullivan, a transport consultant who until recently headed the corporation's environmental traffic division, points to the example of Portobello where "rat-running" by car-commuters has been eliminated by banning right turns at Harold's Cross Bridge. And contrary to expectations, this has not caused a build-up of traffic elsewhere.
"Those who used to rat-run through the area seem to have disappeared," Mr O'Sullivan says. "Just as building a new road creates a certain amount of induced demand, the reverse occurs when you get rid of roads because motorists change their trip patterns fairly widely or find some other way of accessing the city centre."
This has been borne out by a UK study, which found that, on average, 20 per cent of the traffic that used a road seemed to evaporate after it had been closed. In 1994, for example, structural problems forced the closure of Tower Bridge in London. Yet four years after it was reopened, the traffic has still not returned to its original level.
The findings of the study by Prof Phil Goodwin, of University College London, who is the British government's transport policy adviser, cast doubt on traditional assumptions about driver behaviour and earned a provocative headline in New Scientist: "If you want to ease traffic congestion, there's a simple solution: shut a few roads."
An EU-funded research project by the sociology department at Trinity College said Dublin had focused on "putting intelligence into the road network" with computer-controlled traffic lights. Such measures, it found, had increased road capacity, "thus generating more traffic in exactly the same way as would building more roads".
But the creation of environmental traffic cells in the city centre should at least ensure that through traffic is confined to the main corridors, leaving the "rooms" off them relatively traffic-free. As in the Portobello case, the aim is to eliminate traffic with no business being there and give more street space to pedestrians and cyclists.
The corporation is in the process of implementing a traffic management plan for the south city centre retail area east and west of Grafton Street, which should remove 50 per cent of traffic from the area. It is now "only a matter of time", according to Mr O'Sullivan, before the much-used left turn at the end of Dawson Street is banned.
However, since "well over half" the traffic making this turn ends up north of the Royal Canal, relief routes will be required. These are crucially dependent on the installation of new Liffey bridges east and west of the city centre, at Macken Street and Blackhall Place. Both bridges will also accommodate buses and bicycles.
The corporation's traffic department, headed by Mr Owen Keegan - himself a cyclist - is developing an up-to-date traffic simulation tool called Paramix, which physically digitises the city's street network and "drives" individual cars, trucks, buses, bicycles and Luas trams along the various routes, to gauge the effect of making changes.
Even driver behaviour is programmed into it, so that the traffic planners can see how an aggressive driver will behave compared with a tame driver; an estimated 10 per cent of drivers are aggressive and these are responsible for 90 per cent of problems, according to Mr John Henry, director of the Dublin Transportation Office.
Sitting in the corporation's super-cool traffic control centre, with its bank of 40 television screens fed with real-time footage from a network of high-level cameras around the city, one might imagine being in control of the situation. But while the officials manning the centre can and do intervene, the one thing they cannot do is "zap" the cars.