Transmission Gully to open in time for Christmas 2020

Friday, February 14, 2020

The NZ Transport Agency says Wellington’s vital new transport route into and out of the capital is scheduled to open before Christmas 2020.

Transmission Gully will make travel on the route between the city and the lower and central North Island safer and more reliable. It will also provide the region with a key route that will be more resilient to extreme weather and other events, including storms and earthquakes.

To ensure that every chance is given to opening Transmission Gully in time for the very busy 2020 summer holiday season, the NZTA has reached a financial settlement with the joint venture builder (CPB HEB JV).

NZTA interim CEO Mark Ratcliffe says the financial settlement will ensure Transmission Gully is completed to a high standard.

“Transmission Gully is a highly complex project being built on 27km of very difficult terrain. Progress has been slower than anticipated due to a number of issues encountered during construction, including the Kaikoura earthquake in 2016 that diverted resources and materials,” says Ratcliffe.

Construction has been affected by the challenging conditions of the site, and Ratcliffe says the project has required an increased earthworks programme, creating further complexity, disruption and cost to the project through the additional consent requirements.

“These issues, and the impact from several storm events and the Kaikoura earthquake, have meant CPB HEB JV has incurred significant additional costs to construct the project.

“In acknowledgement that these issues were out of the control of CPB HEB JV and not something they could have reasonably anticipated, the agency has provided $190.6m of financial relief to CPB HEB JV.”

The majority of the money will go towards supporting CPB HEB JV, local sub-contractors and employment.

The settlement is conditional on the PPP contractor, Wellington Gateway Partnership, becoming a party to the settlement. The parties are working through satisfying the conditions and obtaining the necessary approvals.  

As part of the settlement, CPB HEB JV’s historic claims against WGP and the NZTA have been resolved without resorting to court action, which would have resulted in further costs and delays to the project.

“As with all projects’ timeframes and expected completion dates, we are always dependent on good weather. CPB HEB JV will be working very hard to complete the motorway by Christmas, subject to good progress through the next six to nine months and to passing a series of standard quality, safety and environmental checks prior to opening.”

Once open, there will be further work required before the project is fully completed, including landscaping and testing and commissioning of new technology systems. These works will most likely be completed by mid-2021.

Ratcliffe says the NZTA, WGP and CPB HEB JV are committed to working together to complete the project and remain excited about the opening of Transmission Gully and the many benefits that it will bring for Wellington and the central and lower North Island.

The money for the settlement has come from the National Land Transport Fund and will not affect any other projects currently being progressed on the state highway network. It is not related to the Government’s $6.8b New Zealand Upgrade Package that was announced on in January.

Transmission Gully key facts

  • Transmission Gully is a four-lane, 27-km motorway running from Mackays Crossing at Paekakariki to Linden.

  • Four interchanges and two link roads will connect the motorway to Mackays Crossing, SH58, eastern Porirua and Kenepuru.

  • It includes more than 10.2 million cubic metres of earth moved, and cuts of up to 70m.

  • There will be 25 structures (bridges and major culverts) equating to a total length of more than one kilometre; the largest structure is the bridge over Cannons Creek – 230m long and 60m high.

  • More than 534ha of ecological mitigation areas and 27km of stream remediation, restoring native landscapes and mitigating the sedimentation effects of the project on waterways.


The photos are a selection of screenshots from an NZTA flyover of Transmission Gully. The full video can be viewed here: https://www.youtube.com/watch?time_continue=32&v=nPBXxNSiLzo&feature=emb_title