The Great Airport Rail Race…

The great infrastructure races of the twentieth century were loud and vertical. Rockets, orbits, flags planted on distant surfaces. Today’s race is less dramatic, running from city centres to airport terminals.

That race may have been quietly triggered in Northern Ireland by Translink’s recent publication of Shaping the Future, which set out the findings of long-awaited rail feasibility studies and, for the first time in years, placed airport rail connectivity firmly back on the policy agenda.

Airport rail connections have become a proxy for how seriously a place takes growth, productivity, and international engagement. They are a simple test of whether a country gets the basics right.

By that measure, Northern Ireland has been getting this wrong for decades. Recent developments suggest it may finally be stepping onto the track – but later, and more cautiously, than its nearest neighbour.

North and South: ambition versus advantage

The contrast between North and South is not simply one of speed or scale. In fact, on paper, Northern Ireland should be starting this race with an advantage.

In the Republic of Ireland, MetroLink is being delivered largely from scratch. The 19-kilometre, mostly underground, driverless metro will tunnel beneath Dublin to link Swords, Dublin Airport, and the city centre. It is complex, disruptive, and expected to exceed €10 billion – yet the Irish Government has accepted those costs as the price of long-term capacity. With planning and legal challenges behind it, the project is expected to be delivered in the mid-2030s.

Northern Ireland, by contrast, is not proposing to bore new tunnels or construct an entirely new railway. The irony is that it begins with rail already at the airport perimeter.

At Belfast International Airport, the Antrim-Lisburn (Knockmore) line already skirts the site. Closed to passengers since 2003, the corridor exists and is protected. Antrim, Crumlin, Glenavy and Ballinderry residents will benefit from the additional services, while Translink’s feasibility work suggests that reopening the line could generate around one million additional passenger journeys per year, serving both passengers and airport staff. Yet despite this inherited infrastructure, delivery is currently framed as a five-to-ten-year prospect, pushing completion into the early to mid-2030s.

The same pattern appears elsewhere. Belfast City Airport already sits beside an active railway line, but is functionally disconnected from it by distance, a shuttle bus, and a non-step-free footbridge. A new station would not create a new route, merely allow an existing one to function properly – yet it remains unfunded and unscheduled.

Further west, a potential halt serving City of Derry Airport would sit on an operational line, subject to journey-time trade-offs rather than fundamental engineering barriers.

Taken together, the contrast is stark. Dublin is tunnelling under a city to reach its airport. Northern Ireland is debating whether to make use of railways that already pass its runways.

Why buses and proximity are not enough

Critics often argue that Belfast International Airport is already served by bus, and therefore rail is unnecessary, but this confuses availability with capacity. The bus service is inherently linear, funnelling passengers into Belfast City Centre and back again, rather than integrating the airport into the wider rail network or reaching a broader population and labour supply. While buses are becoming cleaner, they remain constrained by road capacity, congestion and the reliability of peak-time traffic conditions. Having worked at Belfast International Airport, I know first-hand the limitations of the bus, late-night services dropped me in the city centre, leaving a further 30-minute pilgrimage home, when a train would have taken me within metres of my door on the Lisburn Road.

The same logic applies at Belfast City Airport. While Sydenham Halt exists, it sits roughly one kilometre from the terminal, accessed via a shuttle bus and a footbridge that is not step-free. For passengers with luggage, reduced mobility, or time pressure, this is not a rail-served airport in any meaningful sense. Proximity without accessibility is not connectivity.

Rail does something buses cannot. It multiplies catchment rather than substituting mode. It allows airport workers to commute across regions without driving. It enables passengers to reach flights without routing through the city centre.

Building for future demand, not yesterday’s numbers

One reason airport rail is often deferred is that it is judged against current passenger numbers rather than anticipated demand. That is a category error.

Belfast City Airport’s Master Plan forecasts passenger numbers rising from around three million today to approximately seven million passengers per annum by 2040. Across the region as a whole, air travel from Northern Ireland is estimated to reach around 21 million passenger journeys, a level that would place sustained pressure on surface access if existing travel patterns remain unchanged.

Cleaner aviation strengthens the case

This forward-looking logic also matters for climate and environmental policy. Aviation is often treated as incompatible with decarbonisation, yet the sector itself is changing rapidly.

Airlines including Air Canada have committed to introducing hybrid-electric regional aircraft, with zero-emission short-haul services targeted for operation by 2028. These aircraft are designed for precisely the kinds of regional routes served by Belfast City and City of Derry airports, offering not only lower emissions but also significantly reduced noise levels – an increasingly important consideration for urban airports and residents living under the flight path.

As flying becomes cleaner and quieter at the margins, the case for rail-based airport access becomes more compelling. Mass transit complements lower-carbon aviation, rather than forcing future growth onto congested road networks that are vulnerable to delay and disruption.

Global ambition needs local foundations

This matters well beyond transport policy. The Executive’s ambition to restore direct transatlantic flights from Belfast International Airport – potentially supported by a US pre-clearance facility – is explicitly framed as an economic growth strategy tied to foreign direct investment, tourism and diaspora links.

Yet global ambition sits uneasily atop local constraint. An international airport aspiring to long-haul connectivity, but reliant on car access and limited public transport catchment, is structurally disadvantaged.

Dublin recognised this early. MetroLink is not framed as an airport shuttle, but as nation-building infrastructure that happens to serve the airport. Northern Ireland is only beginning to make the same conceptual shift.

The race is already underway

None of this suggests that Northern Ireland should replicate MetroLink. The scale, density and funding environment are different. But comparison is useful because it exposes mindset.

Dublin treats airport rail as core economic infrastructure. Northern Ireland still treats it as aspirational, vulnerable to budget cycles and political caution – even as feasibility work is completed and future demand is clearly signalled. A cynic might note that the feasibility studies were held back long enough to avoid their inclusion in the draft Budget, sparing the Finance Minister – a party colleague of the Infrastructure Minister – from having to account for their cost.

The Space Race was defined by speed, spectacle and rivalry; airport rail is today’s less glamorous equivalent, and Northern Ireland has finally entered the race, with the question no longer when, but how – perhaps not with a rocket, but with a circle line. For now, the bus remains the default, and it is not taking us to the moon.