Plans for a high speed rail service that would cut the journey time between Dublin and Belfast to 90 minutes are being drawn up on both sides of the Border.
Keith Moffatt, chief executive of Northern Ireland's transport company, Translink, said it was working with Iarnrod Éireann on an outline "vision 2020" that would provide a non-stop 90-minute service departing at hourly intervals.
The cost of such a service, using 125mph trains and requiring an upgrade of the track, would be around €733 million, he said.
Journey times could be cut to 60 minutes with the use of 140mph tilting trains, Mr Moffatt added, but he expressed doubt that the €2 billion cost would be acceptable to politicians.
Unveiling Translink's vision for the future, he said Northern Ireland Railways and Iarnrod Éireann were working on a scheme to improve the main cross-Border service and that a preliminary report delivered recently confirmed that a high-speed, high-frequency service could be economically viable.
But he said it was all down to a question of money and how much the politicians would provide.
PA