The public is being asked for their input on the plans
A route has been unveiled for the proposed MetroLink project in Dublin.
The emerging route - which has not been finalised - is to run between Swords and Sandyford, connecting key destinations including Dublin Airport and the city centre along a 26km route.
A large proportion of the route will be underground, including where it passes under the city centre area and the airport.
The underground section will terminate close to the Charlemont Luas stop.
Under the plans, the Luas Green Line will be upgraded to metro standard.
MetroLink will have a total of 25 stations, including 15 new stations, 3,000 additional Park and Ride spaces, and a journey time of approximately 50 minutes from Swords to Sandyford.
MetroLink scheduled to operate from 2027.
It will have the capacity for 30 trains per hour in each direction, with 4,000 jobs set to be created during construction.
The National Transport Authority (NTA) and Transport Infrastructure Ireland (TII) say public consultation will begin next week - with a series of information events for communities along the route.
There are information evenings organised for areas such as Swords, Ballymun, Dublin City, Glasnevin, Ranelagh and Leopardstown.
A Transport Strategy for the Greater Dublin Area (2016-2035) propsoed a rail link from the south city centre to Swords.
It also envisaged the upgrading of Luas Green Line to metro standard, which would link up to the metro services running north to the airport and beyond.
Under the National Development Plan, Metro North and Metro South will now become one project - known as MetroLink.
National Transport Authority CEO Anne Graham said: "There are very significant benefits associated with MetroLink, particularly in terms of the integrated transport system that it will bring about for Dublin.
"For example, thanks to MetroLink, there will finally be a rail link to Dublin Airport, and with easy interchange with other modes including bus, DART and commuter rail, MetroLink will make it easier than ever to move into and around the capital."
Transport Infrastructure Ireland CEO Michael Nolan added: "Really what today is all about is the launch of the consultation process for MetroLink, because we want to make sure that people at local level have a say.
"What we are publishing here is the ‘Emerging Preferred Route’ (EPR), rather than the final route.
"Having examined in detail the various alignments and options, the EPR is the one that we feel is the best fit for the project.
"But we remain open to looking at other proposals, and if people or communities feel there are better ways of doing it, we will of course be happy to consider any alternatives put forward."
The preliminary estimated cost, in current year values, of the MetroLink is approximately €3bn.
The NTA says its anticipated timeline is as follows:
• 2018 – Consultation on emerging preferred route
• 2019 - Application for a railway order
• 2020 – Granting of railway order
• 2021 – Construction commences
• 2027 – MetroLink becomes operable