Transport Infrastructure Ireland (TII) has submitted a planning application to An Bord Pleanála (ABP) for the MetroLink rail route.
MetroLink is a new railway line, most of which will be underground, between Swords, in north Dublin, and Charlemont, south of Dublin’s city centre.
The Government says that the application, known as a Railway Order, marks a key stage in the development of the project.
The route will serve fast-growing areas such as Swords, Ballymun and Glasnevin, as well as Dublin Airport, the city centre, and major employment, health and education facilities.
Eamon Ryan (Minister for Transport) welcomed the move, adding that he was keen to see construction on the project start as soon as possible.
The Department of Transport says that, depending on the outcome of the planning and procurement processes, construction of MetroLink is set to start 2025, with a view to operation in the early 2030s.