The newest section of the M1 was formally unveiled today, making the road the longest motorway in the State.
Opened by the Taoiseach, Mr Ahern, with the Minister for Transport, Mr Brennan, and the chairman of Fingal County Council, Mr Michael Kennedy TD, it will be available for use for rush hour today when it open for traffic at 5 p.m.
It is estimated the now 72-kilometre stretch of road will take 3,000 trucks and 30,000 other vehicles per day off the N1 and local roads and cut the travel time to Dundalk by an hour at peak times.
Traffic volumes on the N1, from Balbriggan to the M1/M50 motorways, and at Dublin Airport roundabout are expected to fall by 60 per cent.
The section from Dublin Airport to Balbriggan is 16.3 kilometres long and cost €230 million to build.
The Taoiseach said the road "clearly demonstrates the Government's commitment to the delivery of Ireland's new motorway network as set out in the National Development Plan".
Mr Brennan said he was "particularly pleased" the road had been delivered ahead of ahead of schedule.
The motorway is a four-lane dual carriageway, with provision for widening to three lanes in each direction. There are ten bridges and three interchanges. The interchanges are at Dublin Airport, Lissenhall and Rowan's Road, joining the motorway to Balbriggan Bypass.
Over €700 million has been invested to date in the upgrading of the M1 to motorway standard with €270 million coming from the European Regional Development Fund and the Cohesion Fund.