The Cabinet has approved Dublins MetroLink project to proceed to the tender stage with a reviewed Detailed Business Case estimating a cost range of 14.44 to 17.49 billion, and a central estimate of 15.75 billion.The review of the business case was undertaken by the Department of Transport and the National Transport Authority and includes contingency and inflation, but excludes VAT.According to a statement by the Department of Transport: The assessed benefits from MetroLink have been shown to exceed the costs, including from faster journey times and reduced traffic congestion. Firm cost ranges for MetroLink will only be known after the market bids are received, next year.The Department expects significant enabling works to start on site in early 2027, followed by heavy tunnelling and station construction.The Government said it will build on the momentum to date to bring MetroLink into construction, including working with the transport agencies to provide a world-class piece of new infrastructure for the country.Todays statement from the Department came with Taoiseach Michel Martin and Tnaiste Simon Harris, Irelands prime minister and deputy prime minister. With a 20,000 passengers per direction per hour capacity, over double that of the Luas Green Line, a lot of the focus in the Government statement was in relation to supporting housing delivery. This is the prime reason cities build metros, although many communities already built have been promised the line for decades. MetroLink is planned to run 19km along a fully segregated and automated route from Estuary at the north of Swords to Charlemont, just south of the city centre.It will be largely underground, using tunnelling south of the M50 at Ballymun, where it will surface and cross the motorway on a bridge before running overground for a short distance before going under the airport. It will surface again north of the airport, then run in cut-and-cover tunnels around Swords before surfacing again, while remaining highly segregated around its park-and-ride location at Estuary.While Dublin Airport is often excessively focused on, there will be 15 other stations, including serving areas of Swords, Ballymun, the area around Dublin City University, the Mater Hospital and the north city centre around it, and St Stephens Green.There have also been claims the project will not integrate with other public transport, but every stop will have at least bus connections close by, and the project is planned to have stations within a short walk or directly to the two Luas tram lines and the citys planned expanded Dart suburban rail network. There will be an interchange with Luas at Charlemont; buses and Luas close by at St Stephens Green; and Dart and buses at Tara Street; and Luas and buses on OConnell Street.A new Metro and Dart Glasnevin station is to be built beside the Royal Canal Greenway beside Harts Corner. It will have underground platforms for Metro and semi-underground platforms for the two planned western Dart+ routes, one to Maynooth and the other to Hazelhatch & Celbridge. It will also connect to bus services to Finglas and other parts of Glasnevin. Taoiseach Michel Martin said: Todays approval reflects the Governments commitment to investing in new infrastructure. MetroLink will help make our capital city a better, more sustainable place in which to live, travel, socialise and work. I am delighted that the Government has moved MetroLink into the detailed procurement phase for multi-billion-euro construction and operation contracts, and we will continue to support it into construction.Tnaiste Simon Harris said: Todays decision is an important milestone in the delivery of a major public transport project that will connect our capital city to national transport networks and strengthen our economy as well as our competitiveness as a country.By providing a fast, frequent, and reliable public transport service, MetroLink will improve access to education and health facilities, to jobs, and to sports clubs, parks, and playgrounds. Projects like this are central to building the country our growing population now requires by helping to connect communities and unlock new housing, said Harris.Minister for Transport Darragh OBrien said: I welcome todays important step forward for MetroLink, a vital transport project that will help reduce traffic congestion, improve access to Dublin Airport and unlock much-needed new housing development at scale.MetroLink will support the delivery of approximately 77,000 new homes along its route and, through its integration with other public transport services, up to 200,000 new homes across the Greater Dublin Area.This is a game-changer for Dublin and the wider region as we work to deliver more homes for a growing population. MetroLink will not only transform connectivity and access but also strengthen our economic competitiveness, support sustainable growth and unlock the development potential of communities across the Greater Dublin Area, the transport minister said.