Major new traffic diversions are to begin in the region of the Red Cow, Ballymount and Palmerstown interchanges on Dublin's M50 from tomorrow morning.
South Dublin County Council and the National Roads Authority said the new diversions represented the "beginning of the end" of phase one of the M50 upgrade.
While the next four weeks are expected to see increased congestion on parts of the motorway, by next week, some permanent "freeflow" routes are to be in place. Extra "freeflow" movements are planned at each junction over coming months, with the N4/Palmerstown junction to be completed early in 2008, up to three months ahead of schedule, according to the council.
Starting tomorrow the changes will see the closure of the southbound exit from the M50 at the Red Cow, for traffic heading west to the N7 road towards Kildare.
This traffic will be diverted further south to the Ballymount interchange from where it will head back along the northbound carriageway to the N7 access ramp.
While this will add congestion to the northbound carriageway, the council said it believed the carriageway had the capacity to carry the additional traffic.
However, further complicating factors will be the Luas route across the off-ramp at the Belgard depot, and traffic lights where the off-ramp joins the N7.
From mid-October traffic heading from the N7 to the M50 southbound will be able to access a permanent "freeflow" loop, giving access from one motorway to the other without traffic lights.
In early November the diversion to Ballymount and the U-turn will end and traffic heading southbound on the M50 will be able to cross the Red Cow interchange once again. The scheduling of other works includes:
• At the N4 Palmerstown junction traffic moving from the N4 westbound to the M50 northbound will have a new "freeflow" loop from next week.
• On the night of October 13th the N4 will be closed between the M50 and the Liffey Valley junction to allow new bridges and sign gantries to be put in place. Diversions will be signposted.
• In mid-October the southbound off-ramp from the M50 at the Palmerstown N4 junction will close. A new temporary route to the N4 westbound will be in place.
• By mid-November new permanent "freeflow" routes from the M50 southbound to the N4 westbound and the N4 eastbound will be in place.
• By mid-December the N4 eastbound to M50 southbound "freeflow" route will be in place.