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Last updated: 7 April 2025.
There is a long history of planning work for improvements to cross-harbour transport connections, with at least ten major studies conducted over the past 30 years.
At a regional level, the growth of Auckland’s North Shore and the wider region is placing increasing pressure on the transport system. In addition, SH1 is a nationally strategic corridor and a key route for the nation’s freight, goods, and services.
The current Auckland Harbour Bridge structure is coming under increasing operational pressure, affecting the resilience of the bridge and the wider network, and these pressures are forecast to increase further as population, employment and freight needs continues to grow. Ongoing regular maintenance is needed on the bridge structure, and unexpected incidents such as crashes and high wind events mean the bridge and wider network are increasingly compromised, causing widespread disruption to the transport system.
There are ongoing environmental and climate related considerations that this project will tackle when investigating options for new connections, especially relating to rising sea levels affecting the section of Northern Motorway from Esmonde Road to the Auckland Harbour Bridge.
The Auckland Harbour Bridge carries most major services and utilities, such as power, telecommunications and water and we will look at how we integrate these services into any new or existing infrastructure to continue to support these essential connections.
We know that the aging Auckland Harbour Bridge is vulnerable to delays caused by crashes and extreme weather events, causing partial or full closures. This creates travel disruption and delays, as well as economic impacts for the movement of goods, freight and services. The bridge will soon need intensive, more frequent maintenance to keep it operational, which will mean more closures. Beyond the Auckland Harbour Bridge, parts of both the Northern Motorway and Northern Busway are susceptible to flooding, extreme weather events and ongoing sea level rise.
Resilience of Auckland’s transport network is a key objective of this project.
In addition, the section of State Highway 1 between the Auckland Harbour Bridge and Akoranga Drive needs to be raised to help protect against sea level rise.
The project will deliver on the Government Policy Statement on Land Transport (GPS) 2024 by creating an efficient and resilient transport system supporting economic growth and productivity. Progressing an additional Waitematā Harbour crossing is a priority for the Government.
Waitematā Harbour Connections will provide for a well-connected and efficient transport system, providing greater long-term resilience for the wider transport network and reducing the current pressures on the aging Auckland Harbour Bridge.
The current phase builds on the 2018-2020 business case.
Previous work in this phase included assessing a range of options for cross harbour connections. This included:
NZTA will progress geotechnical, environmental, and utilities investigations to gain a comprehensive understanding of ground and seabed conditions. During this period, NZTA will refine the scope of the crossing and develop a more detailed understanding of the costs, risks, trade-offs, and assumptions, as well as undertaking market testing for the tunnel and an equivalent bridge option, prior to seeking a decision on which option to progress.
Land based investigations started late last year and geotechnical drilling in Waitematā Harbour started mid-March. The Auckland Harbour Bridge will need major upgrades in the coming decades, and it is critical that an alternative crossing is available to ensure the resilience of Auckland’s most significant roading connection, as well continuing to enable growth along the Northern Busway corridor.
The current phase will look at investigations required to provide confidence to decision makers in recommending an additional harbour crossing. Work planned for this phase includes:
During this current phase of work NZ Transport Agency Waka Kotahi is working with our Ngā Iwi o Tāmaki Makaurau partners and our Alliance professional services providers to continue to progress options for this nationally significant project.
This programme of work is expected to take 12-18 months. The detailed programme and scope will be submitted to the NZTA Board, prior to seeking an investment decision mid-2026.
The potential cost of a future programme of work will be established during the current phase.
Addressing the medium to long term resilience and efficiency challenges will require various funding and financing investment methods for a single infrastructure programme in NZ. The project has unique characteristics that enable some funding for the investment to be secured from alternative financing sources.
Alternative funding and financing approaches will be considered for both the bridge and tunnel option. Work to date has shown there are several approaches that can be considered for the project in addition to traditional Crown and NLTF funding.
Incremental interventions have upheld the productivity of the corridor over many years, with different studies looking at the short, medium and long term needs of this corridor.
Time of use pricing is the last optimisation intervention left to improve efficiency or resilience on this critical corridor and investigations have confirmed that a ‘do nothing’ approach is not a viable option for this critical corridor, even with time of use pricing.
As the corridor has long been congested for general traffic at peak times, growth in traffic flow has been accommodated through a lengthening of the traditional ‘peaks’, a process that is forecast to continue across much of Auckland’s motorway system in the future.
Without alternative routes across the Waitematā Harbour, all day congestion of this corridor is expected and would have widespread effects at a local, regional and national level. The corridor is a key part of New Zealand’s freight network, and further delays and poor reliability will have wider impacts on overall economic productivity and prosperity.
Numerous upgrades, additions and restrictions on heavy traffic and during high winds along with rigorous monitoring and repairs to the bridge continue to ensure it remains resilient and productive, given its importance in Auckland’s transport system and the wider state highway network.
In the coming decade, the bridge will require more significant rehabilitations for it to continue to operate and increasing restrictions on use of the bridge may occur, with multiple lanes likely to be closed for significant periods of time to complete resilience works. An additional crossing would ease pressure on the aging Auckland Harbour Bridge, assist with enabling maintenance of the existing structure to occur without widespread disruption, and providing a level of improved resilience.