The process of designing an underground Dart link through Dublin's city centre has begun, Iarnród Éireann announced today.
The interconnector is due to link Hueston Station with the Docklands with construction due to start in 2009 with a 2015 completion date.
"The Interconnector rail line, from Docklands to Heuston Station, will complete the quadrupling of the Greater Dublin area's rail service capacity from 25 million passenger journeys annually now, to 100 million passenger journeys," Iarnród Éireann said.
The line will extend the rail link for commuters using the Kildare and Maynooth lines to the city centre and beyond. Users of the Northern line into Connolly Station will benefit from the link to Hueston which services routes to the South and West.
The extension of the DART network to Maynooth, Hazelhatch and Balbriggan also forms part of the plan. The company today announced it had advertised for specialists to assist in progressing the plans.
The interconnector, which is part of the Government's Transport 21 ten-year investment plan, also links all rail modes in the city - the Commuter and Intercity services, along with Luas and the proposed Metro.
The 5.2 km underground line links with the Northern line Dart branching off at Clontarf Road and going underground at the proposed Docklands Station where the line will connect with the Red Luas.
It continues to Pearse, connecting with the proposed Maynooth to Greystones Dart line; and on to St Stephen's Green, connecting with the Green Luas and the Metro to Dublin Airport.
It then continues to High Street at Christchurch, linking with the Red Luas at Hueston as well as the Intercity and Commuter services before merging above ground on upgraded lines to Hazelhatch.
Iarnród Éireann says the line will also enhance the city's limited suburb-to-suburb travel with as new links between Balbriggan and Hazelhatch; and Maynooth and Greystones come into operation.
The company is already in discussion with the Rail Procurement Agency to develop plans for key interchanges such as St Stephen's Green, where Luas and Metro services will be accessible.
The company says the plans will also create the capacity to allow the Clonsilla to Navan line to be constructed in two phases. Work on the Clonsilla to Dunboyne/M3 Park-and-Ride is due to begin in 2009, continuing to Navan by 2015.
A series of new stations are planned along the Kildare Route which will include the four-tracking of the line between Cherry Orchard and Hazelhatch beginning 2010.
The new stations are due to be located at Adamstown, Kishogue, ParkWest, Fonthill Road, Grange Road, Pelletstown, Hansfield, Dunboyne, Pace M3 Park 'n' Ride and Phoenix Park.