Suppose air transport had just been invented and you were asked to choose a location for Ireland’s main airport, where would you put it? With Dublin by far the biggest urban area, it would need to be somewhere in the vicinity, ideally easy to reach by surface transport from around the city and around the country.

Since the M50 is a C-ring around Dublin and just eight to 10 kilometres from the centre, a location close to one of the interchanges would suit – the C-ring is not just close to the centre, national motorways feed in from all directions. There is strong traffic potential from the Belfast direction, so a junction just to the north of the M50 looks promising.

Aircraft movements

Providence has located Dublin Airport at precisely this spot. It handles 85% of aircraft movements for the Republic and neither of the Belfast airports has a competitive range of flights and frequencies, so it is popular with northerners too. There are no other commercial airports in the province of Leinster and regional competitors in Cork, Shannon and smaller locations struggle to attract and retain airline customers. People vote with their feet and Dublin’s dominance is not a conspiracy to disadvantage the provincial cities, it is a predictable result of economic geography and the commercial decisions of the airlines.

And also a piece of good luck, since it has decent accessibility by public transport, including daily bus services from all 32 counties, and is easily the busiest bus station in Ireland.

Its location is a happy accident – originally a Royal Flying Corps base and re-built as a commercial airport, it opened in 1940 at Collinstown, then on the outskirts of Dublin.

It would be difficult to identify a handier location, close to the centre of what is now a much larger city and convenient for users across the island.

The new runway has just been completed, on time and on budget, at a cost of €320m. This gives the airport twin parallel runways, one each for take-offs and landings, hence a big increase in the airport’s capacity.

Under discussion

There are two important policy initiatives under discussion for Dublin Airport. The first is the attempt by Fingal County Council to cap passenger numbers at 32m despite the new runway, a figure actually exceeded in 2019 before the pandemic.

The second is a proposal, currently with An Bord Pleanala, to spend €10bn on an underground railway from the city centre to the airport and beyond to the outer suburb of Swords. The balance sheet value of the airport (runways, terminals and all other facilities) is roughly €2.5bn, one quarter the latest estimated capital cost of the MetroLink.

Access by surface at Dublin is good and the public transport share is high as at several other European airports that already have rail access, making MetroNorth a solution in search of a problem.

The reasons why surface access is popular include the Port Tunnel, built and paid for, which runs uninterrupted by intermediate stations from the city centre direct to the M1 motorway and the airport entrance.

The tunnel is the preferred route for many of the popular bus services, which offer 23-minute journey times from central Dublin to the terminals.

Frequent bus services

There are also regular and frequent bus services, again direct to the terminals, from all of the main provincial cities and towns.

The choice of a passenger cap by the planners is a curious target.

Passengers do not cause either noise or emissions, they are caused by aircraft movements. Since airline tickets are tax-favoured, the obvious policy to contain volumes is the imposition of VAT on airline tickets, perhaps phased in over a period of years.

Tickets are currently exempt, and there is no excise on jet fuel either. Instead the aviation industry speculates about electric planes and proposes alternative low-carbon fuels, which are decades away.

Some lobbyists for regional airports favour the cap, including green campaigners who seem to expect flights diverted to their favoured local airport to run noiselessly and without burning fuel.

A cap would favour the established airlines which have grandparent rights to scarce slots.

A tighter cap on activity at Dublin would increase their value, delivering returns to Ryanair and Aer Lingus whose managers have campaigned unselfishly against the cap.

It also wastes the €320m spent on the new runway. If there is a noise issue, it should be addressed directly through on-site measurement in the airport’s vicinity.

As for the MetroLink, it never makes sense to commit €10bn to any project unless it addresses a really big problem. Even with some further growth in volumes, there has been no demonstration by the MetroLink promoters that surface access to Dublin Airport ranks as €10bn worth of a national priority.