AN BORD PLEANÁLA has granted planning permission for the Metro North project, the largest rail construction project in the history of the state.

The multi-billion-euro project was approved by the planning authority in a 1,700-page ruling issued this morning, and will now be returned to the government for final approval based on a cost-benefit analysis, according to RTÉ News.

The Railway Procurement Agency believes the 15.7km line will carry up to 20,000 passengers an hour, offering a rail link from Dublin Airport to the city centre for the first time – and leaving the two just 20 minutes apart.

Among the elements approved by the board is an underground track from the St Stephen’s Green terminus to the north side of Ballymun, where the track will then cross the M50 on a newly-built flyover.

The route continuing northbound will include Dublin Airport, which will have an underground stop, and terminate at Swords. Some of the line between the terminus and the airport will be on stilts.

The ruling did not, however, permit the construction of two stops at Belinstown and Seatown, as had been planned. The latter station was dropped because the stops at Fosterstown, Swords and Estuary would already provide adequate service to the area.

The former stop, meanwhile, is removed because of a risk of flooding to the area. A park-and-ride facility planned for the stop is to be relocated.

Elsewhere in the conditions attached to the approval was the demand that the main ‘south box’ of the O’Connell St stop be redesigned “in the interest of pedestrian safety and free-flow at this important transport node.”

The project – originally estimated at €5bn, though it has now been decreased to €3bn on the basis of reduced construction costs – has been criticised for its expense, with some – including Labour leader Eamon Gilmore – arguing that the project should be postponed until the state is in a better position to afford it.

The Railway Procurement Agency, however, says it will likely begin work on the construction in April.

The RPA last week announced its intention to apply for a railway order for the companion line of Metro West, running from Dardistown (south of Dublin Airport) to the Old Blessington Road in Tallaght.