Transport Minister Michael Wood has revealed five options for an additional Auckland harbour crossing, with the final design to be confirmed in June.
The timeline for construction has also been brought forward with work to begin in 2029, earlier than expected.
Wood said the additional connection or connections, depending on which scenario is chosen, will allow people to cross the harbour by car, bus, light rail, walking, cycling, or truck.
"Each scenario includes a new walking and cycling link across Te Waitematā, a new light rail link that will connect to Auckland Light Rail in the City Centre, and will build generations of resilience into State Highway One for private vehicles and freight," Wood said.
He said the new rapid transit connection the city centre to the North Shore will fully integrate with other projects, like Light Rail and rapid transit to the Northwest.
"Through the Government's investment we a building a linked-up rapid transit network across the city, to provide faster, safer, low-carbon travel. This connection, with Light Rail at its heart, is key to delivering this vision."
The preferred option for the crossing will be confirmed in June 2023 after feedback is collated. A detailed business case and engagement with communities is then expected for 2024, before consenting, detailed designs and further engagement in 2026.
The five options:
Scenario one: A new light rail tunnel running eastwards from Wynyard to Smales Farm via Belmont and Takapuna. There would also be a road tunnel directly between the central motorway junction and Akoranga Dr. Current road space would be reallocated on the existing Auckland Harbour Bridge for walking, cycling and buses with good, services, freight and traffic able to use the tunnel.
This is the costliest of the options, would result in high emissions during construction and would have one of the longest construction durations. Walking and cycling would only be available once the tunnel is completed and lanes on the current bridge can be reallocated.
However, it would provide alternative transport corridors for all modes of transport to cross the harbour, creating a resilient network. Light rail would connect the Devonport community to opportunities in Takapuna, and the tunnels mean less impact on land around the harbour and there's no need for structures on the seabed.
Scenario two: A new bridge next to the existing Auckland Harbour Bridge for light rail, walking, cycling and three new general traffic lanes. This would provide five general traffic lanes in each direction at all times. The Light Rail would be connected from Wynard to Takapuna via the Akoranga Station. The bridge would be of a similar gradient and height to the existing bridge.
This is the least expensive to construct and operate, would result in the lowest carbon emissions to construct, and be the quickest to construct. Walking and cycling would also open at the same time as other modes of transport.
However, it has the least resilience as it relies on a single corridor, would have a significant impact on the harbour, headlands and the seabed, cause significant disruption to State Highway 1 between Akoranga Dr and Onewa Rd to address impacts of sea level rise and have a significant impact on Westhave and St Mary's Bay.
Scenario three: A new light rail tunnel running westwards from Wynyard to Takapuna via Birkenhead, Northcote and the Akoranga Station. A new bridge for State Highway 1 traffic directly between the central motorway junction and Sulphur Beach. Walking and cycling would be provided for on the new bridge, while the existing bridge would be retained for local traffic and buses.
The benefits of this option are that walking and cycling would open when the new bridge is completed and there would be more direct walking and cycling to the city centre. The light rail would connect the Birkenhead and Northcote communities to Takapuna. There would be some improved resilience due to the separation of the light rail and road systems.
But it's expensive to construct and operate, would result in high carbon emissions during construction and take one of the longest durations. There are also significant impacts on the harbour, the headlands, the seabed, Wynyard Quarter, Westhaven, and St Mary's Bay.
Scenario four: A new bridge beside the existing Auckland Harbour Bridge for light rail, as well as walking and cycling landing at Sulphur Beach. The light rail would go from Wynyard to Takapuna via Akoranga Station. It would be of a similar gradient and height to the existing bridge. Meanwhile, a tunnel would be created between central motorway junction and Akoranga Dr for road use.
The benefits include reduced disruption for movement across the harbour as maintenance requirements increase for the existing bridge. There would be alternative options for all modes, creating a more resilient network. Walking and cycling would open the new bridge completion.
However, it's expensive, would result in high emissions during construction of the tunnel, and have significant impacts on the harbour, surrounding headlands and on the seabed. But the extent of reclamation would be less compared to other bridge options.
Scenario five: A new bridge for light rail and walking and cycling from Wynyard Point to Sulphur Beach, with the light rail carrying on to Takapuna via Akoranga Station. A new tunnel would connect the central motorway junction and Akoranga Dr.
This has similar benefits and challenges to the option above. There would also be an impact on vessels navigating Westhaven Marina from the east. There would be significant engineering and staging complexity due to road and light rail crossing at Akoranga Dr.
