* Metro North will carry 35m people a year along an 18km track. It is estimated to cost €3.5-€4bn.
* There will be 17 stops with nine underground. They will be at St Stephen's Green, O'Connell St, Parnell Square, Mater Hospital, Drumcondra, Griffith Avenue, DCU, Ballymun, Northwood, Dardistown, Dublin Airport, Fosterstown, Swords, Seatown and Belinstown, plus two provisional stops at Estuary and Lissenhall, north of Swords.
* Journey time from Belinstown to the city centre will be 30 minutes, while the airport to city centre trip will take 20 minutes.
* Trains can run every two minutes, but it will initially operate every four minutes.
* 4,000 construction jobs will be created, with another 3,000 in ancillary services.
* It will take five years to build, and 350 staff will be employed to run the service.