The start of the next phase of the upgrade of Dublin's M50 motorway - the rebuilding of junctions to freeflow status at the Lucan, Ballymount and Red Cow interchanges - is to be officially announced by South Dublin County Council and the National Roads Authority (NRA) today.
The work, which follows on from the current road widening scheme on the M50, will involve major detours for traffic at each of the junctions, beginning with the N4 Lucan interchange after Christmas.
However, on a number of routes, traffic lights will be removed allowing freeflow movements across the interchanges, which should improve journey times for motorists.
The council and the NRA are to launch a publicity campaign to inform motorists of the new routes which can become quite complex.
A spokesman for the NRA described the task, which will see traffic continue to use all junctions, as similar to "performing open heart surgery on a person while they are on their way to work".
According to advance copies of the publicity campaign seen by Motors the freeflow system at the N4 interchange will open first. The slip road leading from the N4 eastbound, that is from Leixlip and the west, will allow motorists to turn left to go northbound on to the M50 and the toll bridge without going through a traffic light.
After Christmas the traffic lights for traffic travelling eastbound through the N4 junction will be removed, offering unimpeded access to the eastern side of the junction; that is traffic coming from Leixlip/the west which is destined for the city.
Traffic travelling north on the M50, which currently turns right for the city, will instead turn left and use the Liffey Valley junction to turn back for the city.
By Easter 2007 work will be completed on the M50 median and main M50 traffic will be routed there to allow work on the verges of the motorway get underway.
At the same time a second bridge at the Ballymount junction will be in place and freeflow routes will be in place at the southeast and southwest sides of the junction.
The bad news for motorists is that the NRA has confirmed road works on the upgrade will continue until 2010, although the majority will be completed by 2008.
One of the last junctions to be rebuilt is to be the airport/ M50 interchange which also handles traffic to and from the Dublin Port Tunnel.
Work is expected to get underway there before mid-2008 - a little more that a year after the tunnel opens.
The NRA has reiterated that by 2010 the M50 will have freeflow or near freeflow junctions at all interchanges from the M1 to Sandyford.
There will be three lanes in each direction between those points with a fourth 'drop off' lane linking junctions. Barrier-free tolling will replace the West-Link plaza.
Traffic management details will be available from the project website, www.m50.ie, from today.