Kia ora and welcome to the October/November 2020 update from the Transmission Gully team.

Kia ora

Spring has well and truly arrived – with its usual fickle weather conditions, but when it rewarded us with a fine day we grabbed the go pro and the drone and went for a drive. With the road opening in less than twelve months, we thought you might like to join us for a tour along the alignment. Check out the video below.

Our construction update and aerial photos give you a closer look at the latest progress – especially paving preparations – along the 27 kilometre alignment.

We have two traffic switches coming up to be aware of. The first at Linden, the other at Paekākāriki. Keep reading for more information on what they will mean for your journey.

We continue to remind all members of the public to stay safe and not enter the project site at any time. Work is underway in multiple areas and it remains a high hazard area.

If you have any questions please contact us at info@tg.co.nz. If you have an urgent matter, please call the 24-hour project hotline on 0800 TGINFO. If we are working outside of our normal work hours and you’re one of our neighbours, we’ll be in touch with you directly as usual.

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Sneak peek at Transmission Gully

Take a look at progress around the interchanges and check out the sights with John and Natasha.

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Construction update

Paving works

Paving works have recommenced on Transmission Gully. It’s an exciting time, with most of the major earthworks complete. A bit like building a house, once you’ve done the hard work getting solid foundations down, there’s lots of visible progress.

Unpaved road meets paved bridge.

Bridge 20 with southbound lanes paved, and earthworks and stabilisation continuing at pace on the large cut on the north side of the bridge.

In order to pave the road we need to source the aggregate (which we’re doing from the nearby Willowbank Quarry) and store it close to where we need it. You can learn more about the temporary asphalt plant at Mackays Crossing further on in the newsletter. We also have a pug mill, used for mixing cement into the raw aggregate materials, and temporary aggregate storage at various spots along the alignment as well as at our Paekākāriki Hill Road compound.

Transmission Gully motorway between two hills.

Paving is imminent on the stretch adjoining Duck Creek. In the foreground is a diversion of Duck Creek running under Bridge 19 which will include a public access track.

Piles of raw aggregate alongside motorway.

A pug mill used for mixing cement into raw aggregate used for building pavement layers in the South zone.

Aerial view of storage yard.

Our storage yard off Paekākāriki Hill Road is being rapidly filled with stockpiles of paving aggregate. In the foreground, the earthworks to replace the hill in front of the new road is visible. This will shield residents from the motorway.

Link roads

As well as constructing the motorway, our construction team are also building two link roads for Porirua City Council. These links roads will provide the communities of Whitby and Waitangirua safe access to and from the new motorway. Work is continuing to build momentum in this part of the alignment.

Whitby Link Road on the left with Tranmission Gully motorway on the right.

West of the Transmission Gully motorway, work advancing on the Whitby Link Road connecting to James Cook Drive.

Motorway flyover with two roundabouts, one on either side.

Interchange for the Waitangirua and Whitby links. Stockpiles of road aggregate are visible north of the flyover.

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Upcoming traffic changes


At Linden we are constructing six lanes where Transmission Gully connects with the existing State Highway 1. Four lanes are currently used for SH1 traffic. We will be swapping northbound traffic from the middle two lanes into the outside lanes, so we can finish work in the median. It’s the last stage before we lay the final road surface and open all six lanes next year.

The recent wet weather has delayed work for this change. At this stage it is likely to occur late in the week commencing 9 November. There will be signage on the State Highway and advice on the Waka Kotahi Wellington Facebook page closer to the time.

Paekākāriki to Mackays Crossing

SH1 traffic will be shifted onto a 1.3 kilometre portion of Transmission Gully motorway at Paekākāriki in late November. This is to allow work to be completed on local road connections to the coastal route (the current SH1).

You may notice roadworks and temporary traffic management over the next four weeks.

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Asphalt plant and proposed CVSC site

Switching SH1 traffic onto the section of Transmission Gully between Mackays Crossing and Paekākāriki, will also support the safe operation of a temporary asphalt plant supplying asphalt to the paving crews working in the north of the project.

With a very busy six months ahead in our paving season, there will be a lot of trucks travelling to and from the asphalt plant. We’ve got a plan to keep these trucks separate from vehicles travelling on the state highway. The graphics below illustrate how we’re proposing trucks will travel between the asphalt plant and Transmission Gully; and show public vehicle access to and from SH1.

Site access Mackays crossing map

Site access Mackays crossing map

Upcoming traffic changes – November 2020 to September 2021 [PDF, 615 KB]

Proposed CVSC site

Once we’ve finished paving, the temporary asphalt plant will be removed, and closer to opening, the Mackays site will no longer be required for the project.

This Mackays Crossing site is now being proposed as the future location for a Commercial Vehicle Safety Centre (CVSC) – previously known as weigh stations.

Once Transmission Gully opens, a new CVSC is required to serve the greater Wellington region.

Waka Kotahi is currently consulting with the community on a proposed CVSC at Mackays Crossing.

The CVSC will use roadside technology and intelligent software to screen heavy vehicles and direct potentially overweight vehicles to the site for further inspection.

Targeting potentially overweight non-compliant vehicles can enable compliant heavy vehicles to continue their journey without interruption and makes for a better use of resources and time.

The Mackays Crossing site, known locally as ‘the sand pit’ has been proposed because of its safety and environmental factors, solid ground conditions, and ease of access.

Mackays Crossing CVSC and proposal feedback information

An overview of how the interchanges at Paekākāriki and Mackays Crossing will work once the Transmission Gully motorway is opened is shown in the link below:

Upcoming traffic changes – November 2020 to September 2021 [PDF, 615 KB]

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Art wall

Vertical slats with panels of stylised cut-outs.

Artist’s impression of completed Ngāti Toa art wall near Linden.

From the middle of November you may also see some activity alongside the southbound lanes of SH1 in the Linden area. This is the installation of panels covering two shotcrete retaining walls.

The panels have been designed by Ngāti Toa artists, and include a representation of Ka Mate, the haka composed by Ngāti Toa chief Te Rauparaha. They’re made of corten weathering steel and will look impressive once they’re all up. We expect the art wall to be complete by Christmas.

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Keeping you up to date

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We hope you enjoy reading these updates, and we’d love to hear from you. If you have any questions, comments or story suggestions, you can email them to info@tg.co.nz

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