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Project overview

Project introduction

The Wellington Northern Corridor improvements will ensure the SH1 route between Wellington Airport and north of Levin provides safe, efficient and reliable travel that communities and businesses can rely on to grow and prosper. The improvements are being constructed across eight different sections.

  • Estimated project cost

    $100 million
  • Project type

    Road improvements, Road maintenance, Road management


With a total length of approximately 110km, the Wellington Northern Corridor road of national significance has been identified as having a key role to play in supporting economic transformation by improving the connections that enable the flow of people, goods and services throughout New Zealand.  



  • Support for a growing population: the regional population is expected to increase by 65,000 over the next 20 years, mainly in Wellington City and Kapiti.

  • Support for increasing freight volumes in the region: there will be a 50% increase between 2007 and 2017, with the vast majority of movements by truck.

  • Improved access to Wellington’s port, CBD, airport and hospital.

  • Relief from severe congestion on the state highways and local road networks.

  • Improved safety.

  • Improved journey time reliability.

Key features & benefits

The Wellington Northern Corridor largely follows the current state highway route from the airport to Linden, near Tawa.  From Tawa new roads will progressively be constructed to provide an expressway-style journey to north of Levin.

The corridor is made up of eight different sections and will provide for at least two lanes of traffic in either direction divided by a central barrier. Access to communities along the route will be provided for by a number of different connections, including at grade intersections (ie Wellington’s CBD) to elevated interchanges and overbridges.

Work is being progressed concurrently across the sections in order to complete the project as soon as practicable.  This means that work may be happening in Wellington and the Kapiti Coast at the same time.  Construction is being managed to limit disruption.

All the improvements are designed to help connect people to employment, education, services and recreation and will help people get around, to and through the region, allowing them to spend more time of the things they want to do.


The Wellington Northern Corridor Improvement will, when completed:

  • support Wellington’s growing population: the regional population is expected to increase by 80,000 over the next 20 years, mainly in Wellington City and Kapiti

  • support increased freight volumes in the region: there will be a 50% increase between 2007 and 2017, with the vast majority of movements by truck

  • improve access to Wellington’s port, CBD, airport and hospital

  • reduce severe congestion on state highways and local roads

  • make travel safer

  • make journey times more reliable

  • make the highway more resilient to crashes or natural disasters by providing viable alternative routes and constructing roads that can recover quicker from natural events.

A number of other additional benefits have also been identified. These wider economic benefits include 865 extra permanent jobs in the region and a further 8000 construction jobs created to construct the Wellington Northern Corridor. Businesses will also benefit with outputs and productivity improved as a consequence of businesses being located closely to each other.

Frequently asked questions

  • What is the Wellington Northern Corridor?

    The Wellington Northern Corridor from Levin to Wellington Airport is one of the seven Roads of National Significance.  The Roads of National Significance are essential state highways that the Government has identified because they require upgrading to reduce traffic congestion, improve safety and support economic growth in New Zealand.  The new SH1 route will be a mixture of new divided four-lane highway sections and improvements to the existing network.

  • What are the components of the Wellington Northern Corridor?

    The Wellington Northern Corridor is made up of the following projects (south to north):

    SectionDescriptionCompletion date
    Airport to Mt Victoria Tunnel (2 km) Duplication of the Mt Victoria Tunnel, and widening of Ruahine Street and Wellington Road 2022
    “Tunnel to Tunnel” (3 km) A bridge on the northern side of the Basin Reserve, an underpass for Buckle Street (as part of the National War Memorial Park) and improvements to the existing Inner City Bypass 2017
    Terrace Tunnel improvements (3 km) Includes tunnel duplication 2024
    Aotea Quay to Ngauranga (4 km) Use of existing motorway shoulders as a “fourth lane”, and the implementation of a new traffic management system 2022
    Ngauranga to Linden A link road between Petone (SH2) and Grenada (SH1) may be developed by either the NZTA or local councils if it is determined that it will deliver benefits to the section of SH1 between Ngauranga and Linden and/or to SH2 between Ngauranga and Petone 2023
    Linden to MacKays (Transmission Gully) (27 km) Four-lane expressway standard7 from north Wellington to MacKays Crossing 2020
    MacKays to Peka Peka (16 km) Four-lane expressway standard from MacKays Crossing to Peka Peka 2018
    Peka Peka to Ōtaki (15 km) Four-lane expressway standard from Peka Peka to Ōtaki 2020
    Ōtaki to Levin (approx 30 km) A phased upgrade of the existing SH1 to four-lanes over time. First phase (to be completed 2019 - 2024) includes widening, improved passing opportunities and upgrades to narrow bridges and key intersections. Prior to this phase, minor safety improvements are also being considered 2024
  • What are the benefits of the Wellington Northern Corridor?

    The Wellington Northern Corridor will provide the following benefits:

    • Support Wellington’s growth strategy by making it easier for people, goods and service to flow to and through the city.

    • Improve access in and out of the capital, and to key destinations such as the hospital, port, airport, CBD and ferry terminal

    • Unlock Wellington’s economic growth and productivity potential by making travel for people and freight more efficient.

    • Make the transport network more resilient to disruptions like severe weather storms, crashes and earthquakes by construction a more robust and safer road between Wellington and central North Island.

  • What strategies and plans support the Wellington Northern Corridor?

    There are a number of strategies that support and/or complement the Wellington Northern Corridor.  These include the Regional Transport Committee’s Western Corridor Plan and Ngauranga to Airport Corridor Plan, Regional Transport Plan and a raft of strategic studies prepared by the NZ Transport Agency for the different sections. 

  • What opportunities have people had to comment and provide feedback on the Wellington Northern Corridor sections?

    Communities, road users and stakeholders have had an opportunity to provide comments and feedback on the different sections for a number of years. Consultation programmes are ongoing for some sections where consent has not been sought or granted.

    There will be active engagement with construction teams and their surrounding local communities.  This will include regular information on progress, advice on activities that may affect travel or create noise and opportunities to learn more about the project, including public events.

  • What other opportunities will there be for people to provide comment and feedback on Wellington Northern Corridor proposals?

    Many sections of the Wellington Northern Corridor still have to complete their investigation, design and consent processes before they can be constructed. The community will be fully consulted as the project develops.

    In parallel with these investigations, the Transport Agency will be consulting landowners, iwi, stakeholders and other affected parties to ensure they fully understand any issues that could affect the highway’s design. This will include developing further mitigation details including ecological restoration, traffic noise mitigation, erosion and sediment control, landscape design and protocols in case of accidental archaeological discovery. The consultation process will include a combination of site visits, individual meetings, Public Information Days and surveys. For further information on the Resource Management Act see (external link) .

    Active engagement with construction teams for different sections where work has begun will allow communities to maintain a regular dialogue with the people constructing new or improved sections of road.  This dialogue will ensure that people who may be affected by work can talk to the team and have their concerns heard about how to manage or mitigate the effects of any construction activities.

  • How will environmental effects be managed?

    The NZ Transport Agency is committed to appropriately protecting and enhancing the environment.  To develop each section of the Wellington Northern Corridor an iterative approach to project development and design is used.  This approach means that project options and the design of a preferred option happens in a way that responds to a continually growing understanding of environmental effects.  This approach imbeds environmental considerations into our project designs, while still being mindful of our objectives of delivering transport outcomes in a financially responsible manner.

    By taking this approach, we identify and understand the potential effects of our proposals and use this knowledge to inform both mitigation measures and our RMA consent applications. Mitigation measures form an integral part of our consent conditions and become an enshrined part of the project’s eventual construction when consents are granted.

    Below are some particular environmental issues and how we would manage them on the basis of current guidelines or policies.  Full details of agreed mitigation measures are available for the sections where consent has been granted (ie Transmission Gully).

    Noise control

    Noise levels will comply with NZ Transport Agency Guidelines and the New Zealand construction standard limits. Measures used will include:

    • Monitoring of noise during construction and advance notification of any unavoidably noisy construction activity.

    • Haul routes for moving materials will be away from main roads and sensitive residential areas wherever practicable.

    • Landscaped buffer zones and noise barriers.

    Visual impact, landscaping and environmental measures

    Careful consideration will be given to native wildlife and habitats, in order to minimise impact and disruption. Landscaping and planting will be used to mitigate the visual impacts of the new road and create a pleasant environment for both road users and others. Culverts will be used and plans developed to manage natural water flows and drainage.

    Significant sites - Cultural, historic and environmental

    A range of measures are in place to protect cultural, historic and environmental sites.
    Liaison will take place with local groups and on site archaeological controls will be in place to ensure that processes are followed.