Dublin has "simply exploded", as the economist Colm McCarthy puts it. Driven out by the extravagantly high cost of housing in and around the capital, people are buying cheaper houses far beyond the Greater Dublin Area.
This trend has been facilitated by major road improvements, including new stretches of motorway on national routes.
As Brendan Williams and Patrick Shiels of the DIT in Bolton Street have noted, housing development is "leap-frogging" established dormitory areas such as Leixlip-Maynooth or Bray-Greystones in exchange for locations much more distant from Dublin, such as Gorey, Co Wexford, Rochfortbridge, Co Westmeath, and Virginia, Co Cavan.
Such is the magnetic pull of Dublin that towns of 1,5003,000 within the extended commuter belt grew more than 10 times faster between 1991 and 1996 than towns outside the capital's sphere of influence.
Next April's census, the results of which are eagerly awaited by planners, is expected to confirm that this trend has intensified since 1996. Colm McCarthy anticipates that the eastern parts of Westmeath, Offaly and Laois, as well as the southern part of Louth, will show big population increases. Between 1994 and 1999 new house production increased by 163 per cent in the outer Leinster counties, 3.5 times faster than in the Greater Dublin Area (GDA). Another indicator is that the number of planning permissions for new housing rose by 40 per cent in outer Leinster between 1997 and 1999, compared to just over 12 per cent in the GDA.
Figures for individual counties are startling. Between 1994 and 1999 new housing provision and planning permissions for houses went up by 280 per cent in Westmeath. And while new house completions in Louth rose by a more modest 134 per cent in the same period, the level of planning permissions increased by a staggering 572 per cent.
Between 1995 and 1999 new house completions went up by 52 per cent in Offaly, 91 per cent in Laois, 127 per cent in Carlow, 182 per cent in Wexford and 131 per cent in Cavan, which isn't even in Leinster. Within the GDA, Wicklow's figure rose by only 26 per cent, while completions actually fell in Dublin city and Dun Laoghaire-Rathdown.
Although rapid growth in new housing is taking place in larger towns such as Arklow, Navan, Kells, Kinnegad and Drogheda, another strong trend also documented by Williams and Shiels is the development of large housing schemes in villages throughout the extended Dublin commuter belt. Last November, for example, An Bord Pleanala approved plans for a suburban estate of 270 houses near Dunleer, Co Louth.
The decision meant that a village dating back to early Christian times would be "overwhelmed by development" before it even had a chance to complete work on an action plan, according to one community leader.
The appeals board has, however, turned down similar plans for other villages such as Vicarstown, Co Laois. There, local objectors won an appeal against a 26-house scheme which they believed would destroy its canal-side environment.
Residents of Termonfeckin, Co Louth, are filled with dread that it, too, will be swamped by housing. And though An Bord Pleanala eventually turned down one scheme of 147 houses, the same developer is now seeking approval for an even more ambitious 252-house scheme on the same unzoned site.
Co Longford, way beyond Dublin's 90km commuter belt, is also experiencing an explosion of housing development, much of it targeted at those commuting to the capital.
The real lure is that house-buyers can write off half the cost of relatively cheap new homes against tax under the Upper Shannon Rural Renewal Scheme.
The number of planning applications for individual houses in the countryside has also risen dramatically, according to Longford's senior planner, Donal Mac An Bheatha. "Many existing urban dwellers are using the tax incentives to leave the urban area and build their dream home in rural areas," he said.
And they include people from Dublin. One senior civil servant who recently passed through Rochfortbridge, Co Westmeath, was quite taken aback by the spread of suburban housing there, saying: "You'd think you were in Dundrum". It would not be so much of a problem if the new residents were working in, say, Mullingar. But most of them are commuting to Dublin.
The dispersal of Dublin's population is also evidenced by a 164 per cent increase in new car registrations in the outer Leinster counties between 1994 and 1999, compared to an overall 114 per cent for Dublin, Meath, Kildare and Wicklow.
Commuting by car from many outer Leinster towns is now "as attractive and as quick as a cross-city commute" from Foxrock to Dublin Airport, which "can take up to 90 minutes on a bad day", according to Colm McCarthy. And commuting times from relatively remote towns will fall, at least in the short term, as more roads are upgraded.
However, it is clear to Williams and Shiels, and most other observers, that reducing the level of car dependency in the commuter hinterland of Dublin "must form a key element of future transport strategy". That's why they advocate that the GDA Strategic Planning Guidelines (SPGs) be extended to outer Leinster "to reflect the new reality".
One of the key issues is the extent to which the population growth which the SPGs expected to cater for in the Greater Dublin Area is now being absorbed by "leap-frog" development outside its boundaries. At present nobody knows, not even the planners themselves. For them, outer Leinster doesn't exist; it is "here be dragons" territory.
But the situation on the ground, as Colm McCarthy has pointed out, is that the process of urban sprawl around Dublin has already spread throughout north and mid-Leinster, far beyond even the large area covered by the SPGs, and this "suburbanisation of the countryside", if it goes unchecked, will only intensify car reliance.
"The next decade will see the greatest house-building programme in Ireland's history. If present trends continue, we risk the creation of suburban sprawl that will colonise most of the province of Leinster," Mr McCarthy warned. And in his view, this process is being encouraged by the narrow focus of the SPGs.
The present trend of uncoordinated peripheral expansion and resulting sprawl represents "the least sustainable option", according to Williams and Shiels. And though the benefits of a more integrated approach have been "clearly demonstrated internationally", they doubt the collective political will exists to deliver the alternatives to sprawl.