Auckland harbour crossing: Planners want $5b rail tunnel a decade before any new road link

Tuesday, 3 November 2020

Transport officials want a $5 billion rail tunnel under the Auckland harbour a decade before any additional road link, according to new council documents.

And that’s just the start of big costs relating to a wide range of improvements to rail, road and busways for New Zealand’s biggest city – which in total could go as high as $18 billion over the next 27 years.

The huge sums and first details of the new business case have emerged in an agenda for an upcoming meeting of Auckland Council’s planning committee.

The business case has been worked on by staff from Auckland Council, the New Zealand Transport Agency and Auckland Transport.

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It recommends an urgent upgrade to the Northern Busway followed by an additional rapid transit connection for the North Shore, including across the harbour to the CBD.

Planners estimate the busway upgrades will cost between $500m and $600m.

Linking Takapuna and the central city with a tunnel, at least 6km long, will cost $5 billion.

An additional $3 billion would be required to extend it further north to Albany, according to the business case.

It estimates the cost of an in-line road bridge expanding the capacity of the existing bridge at $1-$2 billion.

That figure balloons to $10 billion if a road tunnel is built instead, linking the city centre and Esmonde Rd with additional motorway lanes to Constellation Dr.

All up, the business case found the capital cost range of its recommended program would be between $6 billion and $18 billion between 2024 and 2047.

Operating and maintaining the new connections would cost $100-$130 million each year, mostly spent on managing the tunnels.

A 2011 business case prepared by the NZ Institute of Economic Research and PricewaterhouseCoopers estimated the total capital cost of a tunnel to be $7.9 billion, compared to $6 billion for a new bridge.

A summary of the business case provided in the agenda shows officials estimated an additional rail link would take 15 years to complete and is needed by the mid to late 2030s due to population growth.

The business case does not specify whether the new rapid transit connection will be light-rail, light-metro or heavy rail.

It also found the rail connection would not fully address traffic congestion on the Auckland Harbour Bridge.

“Modelling undertaken for the project comes to similar findings as previous work has; that constructing additional lanes across the Waitematā Harbour will not eliminate congestion and only minimally improve travel times, due to the saturation of the overall road network,” the agenda states.

However, increasing traffic volumes across the harbour would likely feed more traffic into the city centre and surrounding roads, the business case found.

As a result, it recommended other options, including enhancing the busway, applying new road pricing and the new rail connection be considered before construction any additional new road connection.

The business case did not identify a need for a new road connection before the mid to late 2040s.

Who will pay for it?

The Auckland Harbour Bridge is part of State Highway 1, meaning its operation and maintenance is the responsibility of central government via the NZ Transport Agency.

However, a comment towards the end of the Auckland Council agenda shows the question of exactly how it will be funded remains up in the air.

“As a project of national significance, it is expected that most, if not all, of the future stages of the project would be funded by central government; however, this is not guaranteed,” the agenda states.

Auckland Mayor Phil Goff said the expected “eye-watering” cost of the project would be largely met by central government.

In any case, there was no way local government could come up with that kind of cash, he said.

Goff said the business case was not fast-tracked because of the recent prolonged closure of several harbour bridge lanes due to a truck crash.

He would not be drawn on his preference for the best type of rapid transit for the any new tunnel.

A new road crossing built sooner than the 2040s would not solve congestion issues, as much of the traffic build up was on roads either side of the bridge, rather than on the crossing itself, he said.

More bridge closures expected as structure ages

Concerns about the city’s reliance on the Auckland Harbour Bridge came to the fore after a truck was blown into a steel support truss, forcing urgent repairs and closing several lanes for a prolonged period. Traffic chaos ensued across the city's road networks.

The council agenda notes there is a “very high and growing' dependency on the bridge, exacerbating the effect of any lane closures.

It opened in 1959 and clip-on lanes were added a decade later.

A comment in the agenda hints that further lane closures are likely as the ageing structure starts to demand more and more maintenance.

“While the harbour bridge is in good condition, it is an ageing structure with growing maintenance needs and will require increasing traffic management restrictions to protect its ongoing structural integrity.”

Incoming Transport Minister, Mt Roskill MP Michael Wood, said he had not yet been briefed or spoken to officials about the new crossing.

“I think the crash a month or so ago certainly highlighted to everyone the importance of having a resilient way of getting across the harbour,” Wood said.

He was unable to say whether the truck crash and lane closures had fast-tracked the business case.

“At this point the process is proceeding along, we’ll be receiving the report shortly then considering the next steps.”