Last December, the Government rejected the term "Growth Centre" in favour of "Growth Gateway" at the launch of the £41 billion National Development Plan (NDP).

The obvious need was to avoid political fall-out as a result of favouring one location over another, while the term "gateway" implies a wider spread of the current prosperity. But call it what you will, the Department of the Environment has been asked to prepare a spatial development plan targeting particular towns and cities outside Dublin for major growth over the next seven years.

And while the most likely locations of those centres - or gateways - is officially unknown, the NDP itself contains some pretty blatant clues.

The first is that whatever happens, the locations will have to be served by significant motorway links. And the plan has usefully, told us exactly where those roads are to be.

They are the M1 to Belfast serving the Dublin to Belfast economic corridor, which was to have been expected; the N4/N6 Dublin to Galway road; the N7 Dublin to Limerick road; and the N9 Dublin to Waterford road, which the NDP describes as being developed to motorway/ improved dual carriageway. Even a cursory examination of the roads to the west, the N4 and the N6, reveals a number of likely contenders for growth, which include Athlone, Tullamore, Mullingar and Athenry.

As for the road to Waterford, the N9 strategic corridor, the National Roads Authority recently indicated its preference for the "Central Corridor" route for the new highway. This route follows the existing N9, although the final decision on by-passing Carlow town to the east or the west has not yet been taken.