Theres not enough leadership or vision from Government to say yes, we do need another tunnel, but future Ministers will blame delays on this project on everybody but the Ministers.Comment & Analysis: Irish Rail has just announced initial public consultation on FourNorth, a project designed to four-track the Northern Line between Connolly Station and Malahide. A rail project thats going in the wrong direction.To be clear: Four tracks, or more importantly, two sets of two tracks, are needed to separate Dart and Intercity services to allow for future growth of the rail system along this important corridor between Dublin, the new outer suburbs around Clongriffin where theres high-density housing, and commuter towns, and Belfast.Its just that a tunnel is a far better idea. While it might not have made the headlines until this week, Irish Rail has been working on Four North since at least 2024, and I want to be clear: Others have suggested a tunnel privately or elsewhere before I am doing so here. Its a suggestion Ive heard repeated by different people who dont always see eye to eye. A large part of the problem is the unwillingness, especially of politicians and the media, to accept the basic fact we need to invest billions in rail projects to catch up with underinvestment since the foundation of the State. In this vein, The Irish Times sends out a poor junior reporter to do vox pops, and the newspaper runs with a headline dismissing the need for the project. This is followed by an endless debate fueled by people (often newspaper columnists) spreading misinformation about public transport. Cheaper, but like BusConnects x100Building FourNorth at ground level, or just below or above it as the line is, would be cheaper than tunnelling. Building extra tracks beside the existing railway is technically possible, but a really bad idea. In some places, theres space that can be used without too much impact. Sadly, that space is not continuous. It should not be any surprise to anybody who knows the Northern Line that this project will require the demolition of a number of houses and 5-6km+ of urban trees and greenery along the tracks within the city alone. People who support the project can make all the arguments in the world about the common good, and Ill agree with them. The problem is that the opposition to this will be like BusConnects on steroids. And BusConnects showed that too many of our politicians are willing not only to represent people, but to make hay of issues.There will be quite a lot of disruption from this project stations will need to be relocated, road bridges will need to be extended, footbridges replaced if possible, and the Dart and Belfast services put off the rails for extended periods of many months.Businesses, parts of school yards, sports pitches, green areas, parts of farms, even playgrounds could be affected. Nothing that cannot be overcome, but BusConnects and other projects show that, along with legitimate concerns, a lot of political hay will be made.Many gardens will be affected, and unlike BusConnects, these will be back gardens which these days are more like extensions of houses. And because of the elevated or trench-like nature of different parts of the line, even the need for temporary possession of some extra lengths of land will eat into gardens quite a lot.Opposition on a project like this can delay it by years or even a decade or more. Adding risk and cost. But this kind of politically fueled indecision and delay is the kind senior politicians often shy away from talking about.MetroLink will involve demolishing a city centre apartment block and other properties, but its not the same thing. The need for a mostly underground metro to be able to build stations in congested areas is more understandable for the general public than four-tracking an existing railway line.The sad fact is that suburban house owners hold more political clout than city centre apartment renters or owners.A key difference is also that the plan for four-tracking in the All-Island Strategic Rail Review plans to have the intercity line divert away from the Northern Line after Clongriffin to link with the airport and bypass the current line this M1-aligned rail corridor is even mentioned in the Four North consultation page. A tunnel would not be a downgrade; itd be an upgrade.IMAGE: Extract from the All-Island Strategic Rail Review.For intercity or other express services to the airport and towards Belfast, a more direct tunnel as in the image below makes more sense. And Im not saying thats the only option that should be looked at this is the perfect time to look at the full Belfast-Dublin-Cork connection. A vision for a connected island. Clearly it still is a big ask to add another mega project, but for the Four North project, were talking about a project which isnt going to see the light of day at least until most of the current Dart+ projects are finished. If were to follow what experts have said, we should have a tunnel project lined up well in advance of MetroLink being finished. This could be it.We need the ability to say that Ireland will need decades to catch up on our public transport infrastructure and to be clear, this would be of regional and national benefit, not just another project for Dublin.The tunnel might cost more, but looking at it as an option now is a far better idea than trying to plough ahead with surface four-tracking only to find out its politically untenable or that the delays are so significant that tunnelling would look better and better as the years drag on.IMAGE: The existing Northern Line in green and the concept of a more direct tunnel in blue.