A schematic map showing existing and proposed rail lines in the Greater Dublin Area, such as the Circle Line (in black) now being studied by CIE consultants. This would include a £500 million underground link in the city centre between Spencer Dock, Pearse and Heuston stations.

With a reopening of passenger services on the largely disused track through the Phoenix Park tunnel, the route would function as an orbital rail link, picking up most other public transport services from outer suburban areas to the city centre, including Luas and the various bus corridors (not shown).

The map also shows both a DART-type heavy rail line and a Luas light rail line to Dublin Airport. The former would branch off the Mullingar/Sligo line at Broombridge, near Cabra, running via Finglas to the airport; the latter would be an extension of the Ballymun line to the airport and Swords.

Other proposals being seriously considered by CIE's consultants, Ove Arup and Partners, and the Dublin Transportation Office include reopening a rail service between Dublin and Navan. Luas extensions from Sandyford to Cherrywood and from Connolly station to the Docklands (not shown) are also planned.