The crucial calculation that could kill Wellington tunnels plan
Thursday, 9 July 2026
Wellington’s tunnel dreams are on shaky ground, with Government documents showing the project could be ranked near the bottom of a $49 billion list of unfunded transport spending.
Ministry of Transport advice to Transport Minister Chris Bishop, released under the Official Information Act (OIA), says New Zealand’s roads of national significance (RoNS) would be prioritised based on their benefit-cost-ratio but adjusted for any “major delivery risks and strategic fit”.
Of the country’s 18 listed RoNS, the $2.9b to $3.8b Wellington tunnels and Basin Reserve upgrade has the lowest benefit-to-cost ratio and is expected to cost more than the benefits it delivers. It nudges into positive territory once wider benefits are included, but still ranks as the lowest of the non- redacted RoNS.
Listed benefits include faster and more-consistent travel times and more walking and cycling, but also more pollution and worse safety.
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The capital’s other big project - the $2.1b to 2.7b Petone to Grenada Link Road and Cross Valley Link - was near the bottom.
“Recent reviews of large transport capital investment projects … have highlighted the tendency for large capital transport projects to consistently result in lower benefits and higher costs than the business cases forecast,” an August report from the ministry to Bishop noted.
Bishop this week confirmed, with the Budget “been and gone” for the year, the Wellington projects were not ready for construction funding ahead of the November general election.
“The current focus is on finalising design work and the assessments of effects needed to support lodgement of the [fast-tracked] application, which is expected in the coming months,” he said.
Bishop had promised spades in the ground for a second Mount Victoria tunnel this term, but in February said it could be delayed until after congestion charging showed if the project was needed. The second Mount Victoria tunnel, with a second Terrace tunnel and Basin Reserve changes make up most of the planned central Wellington changes.
The RoNS are set to cost $56b, with $49b of that yet to be funded, the documents show.
Green Transport spokesperson and Rongotai MP Julia Anne Genter said the Government had to come clean and tell people they couldn’t pay for the “vast majority” of RoNS.
“The Wellington tunnels appear unlikely to ever be built, but NZTA’s already blown over $25 million on consultants and contractors alone - and that’s just for one of the many projects they don’t have funding for.
“National Party ministers are telling Wellingtonians that they’ve got shovels in the ground when it’s abundantly clear they don’t. To be honest, they appear to be building ghost roads with ghost shovels.”
Connor Sharp, campaign director for advocacy group Greater Auckland, obtained the OIA and said it showed Wellington’s low benefit-cost ratio meant the project was unlikely to ever be built.
“If you had $3.7b there are much better things to do with that money. You could fix the entire train network, plus roll out the cycleway network, plus fix buses plus fix local roads,” he said.
A separate OIA release shows that, in a draft July 2025 ministry document, it was noted that even with increases to fuel excise duty and road user charges there was only RoNS funding to deliver phase 1 of the Northland Expressway - the Warkworth to Te Hana road.
A Wellington City Council statement said the council was working with Waka Kotahi/NZTA on the project’s design, but it was not aware of any funding committed beyond what had been announced so far.