Trains are about to be banished underground through the heart of New Lynn, meaning the removal of two difficult road level crossings.
Passengers will from Monday catch trains rolling along a single set of tracks from a temporary station erected inside a $160 million railway trench, giving road traffic a freer run above.
Transport Minister Steven Joyce will join Waitakere Mayor Bob Harvey and a full deck of officials before 6am on the first passenger train to arrive at New Lynn from Henderson through the trench.
A permanent station and above-ground bus interchange are expected to open in September, after KiwiRail lays duplicate tracks in June through the 800m trench between Portage Rd and the western end of New Lynn.
That will mark the completion of the entire western line track duplication project between Newmarket and Swanson.
The busy four-way intersection of Clark St and Rankin Ave will remain controlled by traffic lights, but drivers will after the weekend no longer face frequent added delays from level-crossing barrier arms.
They will also have free passage to and from the eastern end of the LynnMall shopping centre, between Ward St and Veronica St, as that route will lose its level crossing as well.
The Clark-Rankin intersection previously featured a roundabout which became notorious for the railway line which ran through it.
Although the Treasury initially opposed the rail trench, a sceptical Labour Finance Minister at the time, Michael Cullen, was persuaded to commit $120 million of Government funds to the project after Mr Harvey and New Lynn MP David Cunliffe led him to the roundabout in rush-hour traffic.
Mr Harvey said the demise of the level crossing would help to pave the way for the redevelopment of New Lynn as a 21st century growth centre.
He recalled warning Dr Cullen that without the trench, worsening road congestion from traffic heading to or from the new Mt Roskill motorway extension would "stop the West" and he praised National for continuing with the project.
His city council has also contributed $20 million to the trench, and more than $50 million for associated civic developments, and the Government's liability rose to $140 million in 2008 after a late design change to cope with wet ground conditions.
That delayed a start to the project by six months, although it took only that long for 89,000 cubic metres to be dug for the trench, after nine months of elaborate enabling works including moving water mains and other underground service lines.
A level crossing in Portage Rd near the eastern entrance to the trench will remain closed until the end of March to allow major surface alterations, but new road bridges built for Waitakere City over the railway tracks as extensions of Memorial Drive and Hetana St will open in coming months.
KiwiRail says building the extra track capacity through New Lynn "positions public transport well for post-economic recovery because the global recovery is likely to push fuel prices up".
The recent opening of a supermarket on "the wrong side of the tracks" from New Lynn's town centre is seen as an early vote of confidence in the project.
FINAL LINK IN THE CHAIN
* From Monday trains will roll along a single set of tracks from a temporary station inside the new $160 million railway trench.
* KiwiRail will lay duplicate tracks in June through the 800m trench between Portage Rd and the western end of New Lynn.
* A new permanent station and above-ground bus interchange are expected to open in September.
* This will complete the entire western line track duplication project between Newmarket and Swanson.