Dubliners have always looked to other European capitals with envy. For decades, the city’s commuters have made do with with limited bus routes, a badly connected airport and traffic congestion that all seemed hardly befitting for an up-and-coming global city.  

Today, the city has changed. A sparkling new cross-city tram has proved popular, while the government says a systematic reform of bus routes will address long-standing complaints – even if it’s been controversial so far.

Ireland has changed, too, and is now more likely to be found preening itself and strutting on the international stage. Facebook, Google and Twitter have all come to roost in Dublin; and the capital has positioned itself as the technology hub of Europe after Brexit.

Yet beneath this confidence lies an abiding insecurity. It was visible in the hand-wringing over the Apple tax decision in the European Court of Justice and was clear too from the national soul-searching when the conference once known as the Dublin Web Summit decamped to Lisbon, blaming Dublin’s sub-par infrastructure.

The proposed system. Image: National Transport Authority, Ireland.

But most of all, it’s obvious in the city’s love–hate affair with its proposed metro system. Plans were first afoot in the early 2000s for a metro to connect the airport to the city centre – until the 2008 financial crisis got in the way and put a halt to the scheme.

Yet the metro dream is still alive, raising the question: why does the government want another decade of construction and a €3.5bn bill?

The driving motivation, of course, is to connect Dublin Airport – which welcomes 80 perc cent of Ireland’s incoming flights – to the city. There are other considerations too, such as plans to encourage the growth of Fingal, the municipality to Dublin’s north, as a repository of the city’s growing population. Estimates suggest that by 2040 nearly 1.4m people will live in the wider Dublin area.

Dublin isn’t alone when it comes to an obsession with metros: for decades, they’ve been the go-to infrastructure project for aspirational cities. The EU has funded a number of metro developments in Europe and beyond as part of the promotion of sustainable urban development, while in China metros are being built with reckless abandon in cities that arguably don’t need them. In Brisbane a new metro project is just beginning in earnest after years of wrangling.

Even two decades ago, research from the Centre for Transport Studies in University College London was questioning the rationale behind the metro becoming the de facto upgrade of choice for enthusiastic city planners. One article cited a city council leader in an unnamed British city who saw the metro system in Lille and “decided that his city had to have one”.

Yet despite this growing scepticism, city planners are still making the case for metro systems using decades’ old rationales, whether by arguing that metros boost development in peripheral areas, or that they’re better for the environment.

This same logic, often taken at face value, is fuelling the debate in Dublin today. But the city’s population density seems scarcely large enough to economically sustain a metro system, while little time has been spent considering how an upgraded bus network could solve some of the problems at a fraction of the cost. If construction begins as proposed in 2021, it would also immediately follow two significant and disruptive projects – the just completed extension of the tram network and the mooted pedestrianisation of Dublin’s College Green area.

This isn’t to deny that parts of North Dublin, namely the rapidly growing Fingal area, would benefit from a metro, or that the airport requires transport links that don’t grind to a halt in heavy traffic.

But €3.5 billion and several years of disruption seems a high price to pay for a lack of imagination in urban planning. For a country that has learnt the hard way to be wary of infrastructural chimeras, the government still seems to have a one-track mind when it comes to a Dublin metro.