The Big Stitch

On the Southern Motorway, I saw a sign advising closures on the Newmarket Viaduct this coming weekend.

Big Blue on the Newmarket Viaduct

It's a bit of needlework going on. Almost literally. What NZTA calls The Stitch.
You'll be aware that the roading contractors have fitted the final bit of the new northbound viaduct jigsaw puzzle into place, using Big Blue - the huge lifting gantry that's now an integral part of the Newmarket skyline.
230+ concrete segments, each averaging 70 tonnes, are in position. But now they need to fill the 1.5m-wide gap between the new viaducts to make one complete structure: hence "The Stitch".
The viaducts will be concreted together this weekend over 18hrs, from 6pm Saturday 3rd to midday Sunday 4th.
Obviously it's necessary to close three of the four southbound lanes during this. Diversions for southbound drivers will be in place from the Gillies Avenue offramp to the St Marks Road onramp. Once that's completed, work will continue to prepare the new northbound half of the viaduct for traffic. Switching traffic will happen over Auckland Anniversary Weekend in late January: on that weekend, all three northbound lanes over Newmarket will be closed for 36 hours to link the motorway to the new viaduct.

The coathanger...

+ ...meanwhile the usual summer resurfacing work will continue on the Auckland Harbour Bridge, during the lighter traffic flows of the Christmas/New Year holidays.
The two southbound "clip-ons", as well as Shelly Beach Road off-ramp, will close from 5am Boxing Day-Thurs.6th Jan. Three lanes northbound and three lanes southbound will remain open on the bridge throughout the work. Cook Street southbound off-ramp will also be closed during this period.

(...thanx to AKT)