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Project overview

Project introduction

The project is to build a 27km four-lane (two in each direction) median-divided motorway from MacKays to Linden (through Transmission Gully), with interchanges connecting the route to MacKays, SH58, eastern Porirua and Kenepuru.

  • Estimated project cost

    $850 million
  • Project type

    Roads of national significance
  • Project status

    Construction, Design

Purpose

In July 2014, the Transport Agency signed a Public Private Partnership contract with the Wellington Gateway Partnership.  Under the terms of the PPP contract, the Wellington Gateway Partnership will design, construct, finance, operate and maintain the new Transmission Gully motorway for the 25 years that will follow the programmed five-year period to build the motorway. The Wellington Gateway Partnership has indicated that the motorway will be open for traffic by 2020.

Benefits

The proposed highway will assist in remedying the projected capacity problems and current safety/congestion concerns on the existing State Highway 1. It will provide a route that is more resilient to natural disasters (earthquakes, storms, tsunamis etc) than the existing coastal highway. Communities along the existing SH1 will benefit from the reduction of through traffic.

Public-Private Partnership for Transmission Gully

The NZ Transport Agency has, in July 2014, signed a Public Private Partnership (PPP) contract with the Wellington Gateway Partnership.  Under the terms of the PPP contract, the Wellington Gateway Partnership will design, construct, finance, operate and maintain the new Transmission Gully motorway for the 25 years that will follow the expected five-year period to build the motorway. It is aimed to have the motorway open for traffic by 2020.

A Public Private Partnership (PPP) is a long-term contract between the public and private sectors covering the financing, construction and operation of a public infrastructure and services.  Full ownership of the public infrastructure remains with the public sector.

PPPs allow large and complex projects to benefit from private sector innovation and funding which can increase certainty of delivery and drive better value-for-money. There are also savings to be had on all aspects of the project - design, build, maintenance and operational management.

PPPs are typically used for large-scale infrastructure projects where risks can be effectively identified and transferred to the private sector. The NZ Transport Agency aims to use successful ideas and innovations that come out of the Transmission Gully PPP across other highway projects and the wider transport network.

About this project

A Board of Inquiry hearing was held on the request for changes to the Wellington Regional Freshwater Plan in July 2011 and the Board announced its final decision on 10 October 2011. Details of the final decision can be accessed here (external link) .

On 15 August 2011, the Transport Agency lodged the regulatory and resource consent applications for the project with the EPA and detailed information on the applications, process and timeframes can be obtained here (external link) .

The Transmission Gully project is a Public Private Partnership (PPP) project to build a 27-km four-lane (two in each direction) motorway from MacKays to Linden (through Transmission Gully). There will be interchanges connecting the route to MacKays, State Highway 58, eastern Porirua and Kenepuru. The link to eastern Porirua will provide connecting roads to Whitby and Waitangirua. The Porirua City Council will be the authority responsible for those connecting roads.

View our project timeline below

  • 2008

    In 2008, during Phase 1 of the Transmission Gully project, the NZ Transport Agency undertook public consultation on the preferred route through Transmission Gully. The consultation resulted in 88.6% of respondents supporting the preferred route.

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  • 2010

    In 2010, during Phase 2 of the project, engagement on design and environmental matters was undertaken with iwi, community groups, statutory agencies and territorial/local authority stakeholders in preparation for the lodgement of Notice of Requirement (NoR) and resource consent applications with the Environmental Protection Authority (EPA).

    In September 2010, the Transport Agency lodged a request with the Environmental Protection Authority (EPA) seeking changes to the Wellington Regional Freshwater Plan to provide a clearer policy framework within which resource consent applications for activities in and on water bodies can be considered.

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  • 2011

    A Board of Inquiry hearing was held on the request in July 2011 and the Board announced its final decision on 10 October 2011. Details of the final decision can be accessed here (external link)

    (external link) On 15 August 2011, the Transport Agency lodged the applications with the EPA and detailed information on the applications, process and timeframes. 

    On 24 August 2011, the Environmental Protection Authority (EPA) recommended to the Minister for the Environment that the regulatory consent applications lodged for the Transmission Gully project be directed to a Board of Inquiry as a proposal of national significance. 

    On 16 September 2011, the Minister for the Environment directed that the applications be referred to a Board of Inquiry.

    The Minister for the Environment's media statement on the applications referral can be accessed here (external link) .

    The Transport Agency's media statement on the applications referral can be accessed here (external link) .

    The Minister of Transport's media statement on the applications referral can be accessed here (external link) .

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  • 2012

    The Board of Inquiry’s hearing on the Transmission Gully applications was conducted from 13 February 2012 to 15 March 2012.

    The Board of Inquiry’s draft decision was released on 4 May 2012. The draft decision can be viewed here (external link)

    On 22 June 2012, the Board of Inquiry released its final decision on the Transmission Gully applications. The Board’s decision can be accessed here (external link)

    In August 2012, the Minister of Transport directed the Transport Agency to assess the suitability of using a Public-Private Partnership (PPP) procurement model to design and build the highway.

    Following an extensive business case analysis (using the Treasury’s better business case framework), the Transport Agency determined that the project meets the Treasury’s criteria for a PPP procurement model.

    In November 2012, the Cabinet gave the Transport Agency approval to finance and build the Transmission Gully highway using a PPP. The Transport Agency was also given approval to borrow up to the estimated costs of traditional procurement as part of the PPP. Final approval of the borrowing limit will be confirmed by the Cabinet before the Transport Agency awards the PPP contract.

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  • 2013

    In January 2013, the Transport Agency called for ‘Expression of Interest’ from consortia (New Zealand and overseas) interested in and capable of delivering the Transmission Gully Public Private Partnership (PPP) project.

    In April 2013, the Transport Agency announced the two consortiums shortlisted to deliver the Transmission Gully Public Private Partnership (PPP) project. These were the Wellington Gateway Partnership and the Positive Connection consortiums.  A request for proposal (RFP) was issued to the consortiums and their proposals underwent a rigorous evaluation process to select the preferred bidder for the project.

    In December 2013, the Transport Agency announced the Wellington Gateway Partnership as the preferred bidder to finance, design, build, operate and maintain the Transmission Gully Public Private Partnership (PPP) motorway.

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  • 2014

    In July 2014, the Transport Agency signed a Public Private Partnership contract with the Wellington Gateway Partnership.  Under the terms of the PPP contract, the Wellington Gateway Partnership will design, construct, finance, operate and maintain the new Transmission Gully motorway for the 25 years that will follow the expected five-year period to build the motorway. It is aimed to have the motorway open for traffic by 2020.

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Community engagement

In August 2008, The NZ Transport Agency (Transport Agency) engaged with the community to receive feedback on the preferred route through Transmission Gully. The consultation period, which officially ended on 20 August 2008, resulted in a total of 2411 responses received with 2137 (88.6%) supporting, 103 (4.3%) didn't mind, and 171 (7.1%) opposing.

Open days/project expo

A series of Open Days and a Project Expo were held in October 2010 to give the public the opportunity to find out more about the Transmission Gully project.

The Open Days and project Expo covered the planning process, noise issues, traffic effects, ecology and water issues and showed what the Transmission Gully route will look like.

FAQs

  • What is a Public Private Partnership (PPP)?

    A Public Private Partnership (PPP) is a long-term contract between the public and private sectors covering the financing, construction and operation of a public infrastructure and services.  Full ownership of the public infrastructure remains with the public sector.

    Close
  • What are the benefits of PPPs?

    PPPs allow large and complex projects to benefit from private sector innovation and funding which can increase certainty of delivery and drive better value-for-money. There are also savings to be had on all aspects of the project - design, build, maintenance and operational management. PPPs are typically used for large-scale infrastructure projects where risks can be effectively identified and transferred to the private sector. The NZ Transport Agency aims to use successful ideas and innovations that come out of the Transmission Gully PPP across other highway projects and the wider transport network.

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  • Why did the NZ Transport Agency choose a PPP procurement model to deliver the Transmission Gully motorway?

    The 27-km Transmission Gully motorway project had the size and complexity which made it a good candidate for a PPP.  The project met the government’s value-for-money criteria, and offered opportunities for private sector innovations in design, construction, maintenance and operation that the NZ Transport Agency can then apply across the wider transport network. Specifically, this project has a significant number of structures and geotechnical challenges where private sector innovation can drive greater value for money than is possible by traditional public sector procurement.  Financing and building Transmission Gullymotorway as a PPP has allowed the NZ Transport Agency to move ahead with certainty to begin construction in 2014 and open the road by 2020, thus delivering the economic, travel and safety benefits to New Zealanders sooner.

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  • Under a PPP, who will own the Transmission Gully motorway?

    Full ownership of the Transmission Gully motorway will remain with the public sector. While a private sector consortium will be responsible for financing, designing, building, maintaining and operating the motorway for up to 25 years, the motorway will remain a public asset – it is never owned by the PPP consortium.

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  • How has value been achieved on the Transmission Gully project?

    The PPP procurement process has seen a competitive tendering process which has resulted in the net present contract price for the Transmission Gully project being less than if the project was procured through conventional means.

    In addition, value for the project has also been achieved in many other ways:

    • The Wellington Gateway Partnership has designed a motorway that is wider, straighter and more resilient than the Transport Agency’s previous scheme. The conditions of the PPP contract has also incentivised the Wellington Gateway Partnership to further minimise safety risks once the Transmission Gully motorway is operational.
    • The Wellington Gateway Partnership is commercially incentivised to deliver consistent outcomes over the 25-year concession period. These include:
      • High and sustained safety
      • Reduced travel time
      • Travel time reliability
      • Route resilience
      • High and sustained customer satisfaction.
    • Transfer of innovative solutions and better ways of working across the wider transport network.

     

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  • Are there any other incentivisation provisions in the PPP contract?

    Yes. Under the PPP contract’s ‘Performance Regime’, the NZ Transport Agency’s quarterly payments to the Wellington Gateway Partnership will be linked to the performance specification criteria which includes:

    • Minimising the time that the Transmission Gully motorway (or specific lanes) is not available, including measures of the free flow of vehicles on the road.

    • Service performance outcomes such as safe travel, the performance of key interchanges, environmental performance and customer satisfaction.

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  • Are there any benefits from the Transmission Gully PPP project that can be applied to the wider NZ Transport Agency or local authorities’ roading network?

    There are expected to be benefits to the wider transport network from sharing innovations applied on the Transmission Gully motorway.  Examples of these include:

    • New approaches to overall design and construction to optimise capital and operating costs, and incentives to incorporate ‘best practice’ throughout the life of the project.

    • Developing a better understanding of whole-of-life risks, and appropriate allocation and management of these risks.

    • Adoption of technology solutions such as the proposed speed telemetry system that uses radar incident detection and seismic monitoring.  This application of technology is expected to set a new benchmark in monitoring state highways of strategic importance.

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  • Will the Transmission Gully Motorway be tolled?

    The potential for tolling the Transmission Gully motorway to offset some of the cost of the project has previously been signalled. However this is being treated as separate to the PPP project and no decision has yet been made in this regard.

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  • Will PPPs be used to deliver other key NZ Transport Agency projects?

    The NZ Transport Agency will consider PPPs for other projects that have characteristics such as large scale and complexity that will permit superior value-for-money to be achieved by using a PPP approach.  The Puhoi to Warkworth project in Auckland is currently being procured through a PPP process.

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  • How will stakeholder interests be catered for under a PPP procurement model?

    The NZTA remains committed to the effective management of its relationships with stakeholders of the Transmission Gully project.  That commitment will not change under a PPP and the NZ Transport Agency will be taking an active role in ensuring that the PPP consortium effectively manages stakeholder relationships during the duration of the PPP contract.

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  • What is the Transmission Gully project?

    The Transmission Gully project is a project to build a 27-km four-lane (two in each direction) motorway from MacKays Crossing to Linden (through Transmission Gully). There will be interchanges connecting the route to State Highway 58 and Kenepuru with a connection to Porirua CBD. In addition, there will be two link roads from the eastern Porirua suburbs of Whitby and Waitangirua to the route. The Porirua City Council will be the authority responsible for the Whitby and Waitangirua link roads. The project entails extensive protection or relocation of utilities including the complete removal of transmission towers by Transpower from the northern section.

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  • Why build the Transmission Gully motorway?

    The Transmission Gully project will provide:

    • A safer road and a four-lane route with central median barrier and additional crawler lanes on the steeper sections.
    • Reduced likelihood of landslides, floods and damage to the highway from a major storm or earthquake.
    • Quicker reinstatement than the existing State Highway 1 in the event of a major earthquake.
    • Peak period travel time savings estimated at around 10 minutes per vehicle for Kapiti to/from Wellington, 15 minutes Kapiti to/from the Hutt Valley, five to seven minutes Porirua to/from the Hutt Valley.
    • Easier access from State Highway 1 to Porirua and the Hutt Valley with shorter and more efficient freight movements to and from Seaview/Gracefield, Wingate and the Wairarapa.
    • Important arterial connections for residential and light commercial areas in eastern Porirua to the State Highway network
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  • How will the Wellington region benefit?

    The Transmission Gully route will:

    • Provide an alternative strategic link for the Wellington region which will improve regional road network security.

    • Assist in remedying the safety concerns and projected capacity problems on the existing State Highway 1 by providing a safe and reliable route between MacKays Crossing and Linden in an environmentally responsive manner.

    • Assist in enabling wider economic development by providing a cost-optimised route that better provides for the through-movement of freight and people.

    • Assist in the integration of New Zealand's land transport system by enabling the existing State Highway 1 route to be developed into a safe multi-functional alternative to the Transmission Gully motorway.

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  • What has been the background to the Transmission Gully project?

    The chronological history of the Transmission Gully project has been as follows:

    • There has been documented public interest in a state highway route through Transmission Gully going back as far as 1919.  However it has only been in the last decade that public views have been canvassed formally.

    • Two major public consultations were undertaken to ascertain the views of residents of the greater Wellington region whether a route through Transmission Gully should be progressed with.  Both public consultations showed overwhelming support for a motorway through the Gully.

    • In June 2012, regulatory consent applications for the project were heard and approved by an independent Board of Inquiry.

    • In November 2012, the Cabinet gave the NZ Transport Agency approval to finance and build the Transmission Gully motorway through a Public Private Partnership.

    • In April 2013, the NZ Transport Agency short-listed two consortia to each prepare a proposal for the design, construction, financing, maintenance and operation of the Transmission Gully motorway for 25 years.

    • These proposals were received in October 2013 and underwent an evaluation process which saw the announcement in December 2013 of the Wellington Gateway Partnership as the consortium that the NZTA will enter into Preferred Bidder negotiations with.

    • Successful completion of contract negotiations between the NZ Transport Agency and the Wellington Gateway Partnership led to the signing of the PPP contract for the Transmission Gully project in July 2014.

    • Construction is now underway.

    • The Wellington Gateway Partnership has indicated that the Transmission Gully motorway will be open for traffic in 2020.

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