Proposals for a new underground DART line connecting Heuston Station to Christ Church, St Stephen's Green, Pearse St and the Docklands area were launched today.
The high-capacity DART Interconnector service would cost €1.3bn to build, although DART officials admit that price tag could go up.
The plans currently under consideration would link DART passengers to the current LUAS and future Metro North lines.
Subject to approval from An Bord Pleanála, work on the project would begin in 2010 with a completion target of 2015.
Iarnród Éireann also wants to extend the DART to Maynooth in Co Kildare and Dunboyne in Co Meath - and create direct routes for Balbriggan/Howth to Hazelhatch and Maynooth/Dunboyne to Bray/Greystones.
Speaking on RTÉ's Morning Ireland, Iarnród Éireann spokesman Barry Kenny said the proposals were part of the Government's Transport 21 programme.
The proposals are available on the Iarnród Éireann website and will be on display to the public next Tuesday and Wednesday.
