A new phase of traffic diversions begins on Dublin's M50 this morning, in preparation for the rebuilding of the Ballymount, Red Cow (N7) and Lucan (N4) interchanges.
The diversions begin at 6.00am with westbound traffic on the Red Cow being routed through the Luas park-and-ride depot at Belgard.
Diversions will continue on a phased basis until mid-2008, when freeflow or near-freeflow traffic movements are achieved on all three interchanges.
The National Roads Authority said yesterday the diversions were necessary to allow for the building of additional bridges and expanded junctions.
The works will include the building of a new, segregated Luas route through the Red Cow interchange. The interchange will ultimately have three levels instead of the current two.
Following 2008 the work will move to two other sections of the M50, between Blanchardstown and Dublin airport and between Sandyford and Ballymount.
The last piece of the M50 to be improved is to be from the West-Link bridge to the Blanchardstown section.
Speaking at a press briefing on the changes yesterday, South Dublin County Council's director of transportation, Frank Coffey, said next month would also see changes to traffic on the "mainline" section of the M50.
This would involve traffic moving to new lanes in the central area of the motorway while construction gets under way on the building of a third lane on the extreme left-hand sides of the carriageways. A fourth "auxiliary lane" and a hard shoulder will also be built.
As part of the work on the Red Cow interchange the Luas Line B will move and the bridge that it currently uses will be incorporated into the design of the new interchange.
The new Luas route across the interchange will be completely segregated from other traffic. It is not envisaged there will be any disturbance to Luas traffic during construction work.
Over the coming months as traffic diversions are introduced at all three junctions, motorists are to be asked to slow down and follow local diversion signs. "We are asking motorists to slow down and follow the new road layout and remember the speed limit of 60km/h," said Mr Coffey.
Two Garda speed cameras have already been erected on the M50, but the Garda said yesterday these will be augmented by mobile "Gatso vans" and mobile patrols.
The NRA also revealed that since the speed cameras were put in place last week, several hundred speeding vehicles a day have been detected. Many of these were at night.
When the works are complete, scheduled for 2010, the M50 will have three main lanes in each direction, with a fourth lane linking junctions. Each side of the motorway will also have a hard shoulder. Single point, barrier-free tolling is being installed from next year, in a move which will see the scrapping of West-Link toll booths.
The cost of the upgrade would be €1 billion, the National Roads Authority's Hugh Creegan said yesterday.
