Dublin needs a metro. We need it to help tackle our housing crisis as much as to avoid traffic gridlock. We need to build it quickly because our city is bursting at the seams, but we also need to get it right. The National Transport Authority (NTA) is in a consultation phase on the project at the moment, which it and the Government should use as a genuine period for reflection. There is one significant variation to the current design which I hope in particular they will take on board. They need to switch tracks and run the line to Rathfarnham on the southside.

I am glad the decision was made to connect to the southside in the first construction phase. The metro is due to come up for air near Charlemont station and run from there along the Luas green line to Sandyford. Instead, we should keep the tunnel going for a further 4.5km to the southwest, with stations in Rathmines, Terenure and Rathfarnham.

Such an addition would tackle the worst public transport black spot in our city. Bus passenger numbers on the Rathfarnham quality bus corridor (QBC) have fallen by 20 per cent since 2015 and average bus speeds are half what they are on other routes. The NTA is about to launch a “bus connects” project to upgrade our QBCs. It is just as important a project as the metro and in truth is going to be a lot more difficult to deliver.

The Rathfarnham bus route presents the engineers with their greatest challenge. There is no easy way in which you can fit two bus, cycle and car lanes into such a narrow urban road. We have been looking for easy solutions for 20 years and there is none. Five main roads feed into Terenure village and meet a real impasse. Running a metro to Rathfarnham would tackle this problem in one fell swoop.

Forgotten quarter

With the tunnelling machine and station construction teams already in place, we would get the job done for a fraction of the price it would later cost. Should the budget allow, we could also extend the line to Firhouse or Dundrum. Even if that was not possible, local bus and cycle links would mean everyone in this forgotten quarter would get a fast connection to the rest of the city.

Tunnelling to Rathfarnham would mean the Luas green line would not immediately be upgraded to metro status. This would have its advantages as well as disadvantages. With a resolution in prospect to the use of Na Fianna’s grounds as a metro construction site on the north side, the biggest opposition to the project is now likely to be around issues arising from the Luas line upgrade.

The metro will use faster, higher, heavier and driverless trains, running along a completely segregated line, while the Luas runs at street level with easy pedestrian access from every direction. In Beechwood and at other stops along the green line there is real concern that the metro will divide the local community and that they will lose some of the quiet characteristics which has made Luas such a success.

Building the metro to Rathfarnham would not necessarily mean that the green line stays the same. Even after introducing new longer trams, which will significantly increase carrying capacity in the short term, we are still going to need to provide for increasing passenger demand from new housing developments along the Green line. I believe this can be done by increasing the frequency of the service, while retaining the low-floor, light-rail characteristics of the current system.

Cost saving

In fact, we may see a significant cost saving in not having to revamp each station and close the green line during the major upgrade to metro. Luas passengers could still transfer to the metro at Charlemont street and each line would work better operating to its own original design specification.

The NTA will no doubt have real difficulty with this suggestion. Understandably they will not want to change their plans, for fear it might delay the whole project. To make it happen and to get the necessary planning approval in time we need a strong and clear political direction. With clear leadership from Government I think we can get the public and An Bord Pleanála behind the project and avoid any delays, while getting the best transport solution for the whole city.

The Government has said its national capital plan is an iterative one which is subject to change as new ideas and solutions present themselves. This is a first test of whether it can show such flexibility. There are other changes I would like to make, such as linking to Donabate on the northside and providing for the future Dart interconnector, but for me getting the metro built to Rathfarnham within 10 years should be a priority. I think the public will back the proposal and see the sense in it. It would be a shame if we missed this golden opportunity.

Eamon Ryan TD is leader of the Green Party