In our MetroLink Explainer on upgrading the Green Line we found that these slow speeds and shared running in the city centre significantly limit the capacity on the Luas Green Line. The trams go slow to avoid collisions with pedestrians and other motor traffic in the city centre. Transport Infrastructure Ireland are predicting the Luas Green Line will run out of capacity in 2027 without further upgrades. The only option left to upgrade the Green Line is moving the Luas underground in the city centre. The MetroLink scheme does just that.

However, this raises interesting questions. The Luas Green Line first opened on 30th June 2004. It has been upgraded a multiple times since then. There are now more, longer trams operating on the line than when it first opened. It will run out of capacity again in 2027, that's only 23 years after opening.

Why didn't Ireland build a higher capacity Luas system in the first place? Why wasn't the Luas underground in the city centre from the start? We're going to explore the history of the Luas Green Line starting in 1994, ten years before it opened.

The origins of the Luas system in Dublin

The original idea for a tram system in Dublin was first suggested in 1994, by the Dublin Transportation Initiative (DTI). This report was an integrated transport strategy for Dublin that aimed to tackle the city's congestion by convincing more people to take public transport, cycle or walk, instead of using the private car. This report led to the creation of the Dublin Transportation Office (the predecessor of the National Transport Authority). The report recommended the creation of Quality Bus Corridors (bus lanes), an upgrade to the DART service and the creation of two light-rail tram lines in Dublin.

The findings of the DTI report around the Luas network were controversial at the time. Many politicians and business leaders in the city didn't think the Luas would solve the growing congestion in Dublin city. There was much speculation that no one would use the new Luas service. The whole project was declared a 'white elephant' by some. It retrospect these claims seem ludicrous. Both the Red and Green Luas lines have both been huge successes and are quiet popular with the public. However, at the time these were serious concerns.

The Stephen's Green Luas stop under construction.

Indecision, compromise, change of government and public inquiries

There were many changes to the Luas plans from when they were first conceived before construction in 1994. The original plans included a Luas line from Ballymum to Dundrum and from Tallaght to O'Connell Street. The Ballymum to Stephen's Green line was dropped in 1994.

In 1996, former Taoiseach Dr. Garret FitzGerald, argued that running the Luas overground north of Ranelagh would be a tragic mistake as it would severely limit the capacity of Luas Line B (the Green Line) and cause traffic congestion in the city centre.

Through the late 90s the project was spearheaded by then-Minister for Transport, Michael Lowry. However, in June 1997 the Fine Gael, Labour, Democratic Left coalition government led by John Burton collapsed. A Fianna Fail, government led by Bertie Ahern takes power. This meant some decisions on the Luas project were revisited.

Two major public inquiries, necessary to build the two proposed Luas Lines, were launched. The inquiries will make a report to the Minister on whether the lines should be built.

In May 1998, the cabinet agrees to put Luas Line B underground in the city centre. However, the underground section of the Luas cannot legally be examined by the two already launched public inquiries. This leads to the situation where both Luas lines are separate projects that don't connect in the city centre.

In early 1999, Minister for Public Enterprise, Ms O'Rourke, receives the report of the public inquiry recommending the construction of the Red Line from Tallaght to Abbey Street, and the Green Line from Sandyford to Stephen's Green. Another public inquiry is launched to extend the Red Line from Abbey Street to Connolly station.

In February 2000, Minister O'Rouke receives the report on the geotechnical survey in the city centre for the underground Luas line. This section of the line would cost €300M, and would run from Stephen's Green to Broadstone, where the Luas Cross-City is now. This project never advanced much further, leaving Dublin with two unconnected Luas lines until the Luas Cross City opened in December 2017.

In 2003 after construction had started, Dr. Garret FitzGerald argues that the whole Luas project has gone off the rails in an Irish Times opinion piece:

The stated intention to convert some years hence the Stillorgan-St Stephen's Green Luas into a metro means that the stretch of overground tram route now being completed between Ranelagh as far as St Stephen's Green will have to be abandoned within a few years of its expensive construction, and the rail service may have to be closed down for quite a long period in order to permit a new tunnel entrance to be constructed somewhere south of Ranelagh.


Multiple changes in leadership of the project, cost cutting, and indecisiveness lead to the Luas project not completing it's original objectives from the DTI report, finishing late and way over budget.

Many commentators at the time pointed out that the Luas Green Line would be under capacity and should run underground. The MetroLink project will rectify these mistakes by under-grounding the Luas Green Line from South Dublin in the city centre section as it should have done from the start.