Is the Greater Auckland campaign against the Northland motorway fighting waste — or causing it?
- Grant McLachlan
- Jun 19
- 8 min read
Greater Auckland calls Warkworth to Te Hana the most expensive road the country has ever built. But picking off the single hardest stage of a staged corridor, weeks before a contract is signed, is exactly how you manufacture the incrementalism the group says it opposes.
Greater Auckland has issued what it calls an urgent appeal to every political party: drop the public–private partnership for the Warkworth to Te Hana motorway — the first stage of the planned Northland corridor — before the Government signs a deal it aims to award by the end of July. The group’s spokesman on the project, Connor Sharp, has put a figure on it of up to $12 billion over the life of the contract, and branded it the most expensive road New Zealand has ever built.
The spending deserves scrutiny, and so do the numbers.
But two things sit awkwardly with the framing.
The first is that the man presenting this as cool, independent analysis is an active political campaigner who was not introduced as one.
The second, and the more important, is that the cure Greater Auckland prescribes — stop now, re-scope to “more targeted improvements”, send it back for review — is a textbook case of the stop–start incrementalism the group claims to be fighting.
So the real question is not whether Warkworth to Te Hana is expensive. It plainly is. It is whether killing the single hardest stage of a staged corridor, days before financial close, is scrutiny — or simply the surest way to leave the job half done.
Contents
The most advanced stage, not the cheapest
Start with why this stage is first.
NZTA did not pick Warkworth to Te Hana because it is cheap. It picked it because it is the most advanced section in terms of designation, consents and property acquisition.
The 26-kilometre route is a four-lane highway with an 850-metre twin-bore tunnel under the Dome Valley and three interchanges, and it is stage two of five in a roughly 100-kilometre corridor between Puhoi and Whangarei.
It is also, on the most recent public estimate of $3.5 to $4 billion, likely the dearest road the country has built.
But it is dear precisely because it drives through the worst terrain on the route: the Dome Valley chokepoint, where a tunnel is the only sensible answer.
The next hardest stretch, further north, is the slip-prone Brynderwyn Hills.
The ranking of cost tracks the ranking of difficulty — the toughest geology costs the most to conquer. Those are the “meaty bits” Sharp himself suggested leaving for another day.
A corridor, not a collection of sections
NZTA does not treat the Northland Roads of National Significance as a pick-and-mix.
It has said it will approach them as a single strategic corridor, with Warkworth the first leg of focus. The leg before it, Puhoi to Warkworth, already opened in June 2023.
A motorway delivered in stages is still one motorway. The sensible test is whether the whole corridor stacks up, and then you build it stage by stage as the money allows.
Greater Auckland does the opposite. It isolates the costliest single segment, attaches a worst-case multiplier, and invites the public to judge the entire project by that one number.
That is not assessing a corridor. It is judging a bridge by the price of its centre span — and then arguing the bridge should not be built.
Where the road actually kills people
The hilly, winding sections are not an optional luxury. They are where people die.
NZTA’s own record for the Dome Valley is seven deaths and more than 30 serious injuries in five years, on a road it describes as winding, with poor visibility and steep slopes, where the crashes come from running off the road or crossing the centreline into oncoming traffic. The agency then spent about $80 million on median barriers and shoulder widening there under Road to Zero.
The stretch immediately south, Puhoi to Warkworth, was worse still in its day: nine deaths and 24 serious injuries in five years.
Then the motorway opened.
The Transport Minister noted in June last year that since the new four-lane, median-divided road opened in 2023, no one has died on it.
That is the difference between a band-aid and a road.
The expensive stages are the dangerous ones. That is the argument for building them — not the argument for skipping them.
The incrementalism trap
Pressed on whether his own proposal amounted to the flip-flopping that plagues New Zealand infrastructure, Sharp said no — that sitting the parties down to re-scope would deliver certainty.
He is right that flip-flopping is the disease.
But his remedy is the disease, not the cure: halt at preferred-bidder stage, strip the project back to “more targeted improvements”, and refer it to the Infrastructure Commission.
We have already run that experiment.
“More targeted improvements” is exactly the $80 million of Dome Valley safety works, and the hundreds of millions poured into the Brynderwyns after the hill closed eight times between 2022 and mid-2023 and then again for months in 2024.
The Government itself has conceded Northland needs a more resilient route than the Brynderwyns can provide.
Incrementalism is how you spend a fortune and still end up with a road that keeps falling down. Greater Auckland is recommending more of it.
The $12 billion nobody has costed
The headline figure is Sharp’s own construction.
He takes the $3.5 to $4 billion build estimate and multiplies by three, on the basis that Transmission Gully’s PPP cost about three times its “sticker price”.
The most recent official accounting tells a different story.
In November last year the Transport Minister put Transmission Gully’s total cost to the Crown at about $2.5 billion — roughly twice its $1.25 billion construction cost, not three times. (The build itself rose from $850 million to $1.25 billion after settlements.)
Apply that multiple to Warkworth to Te Hana and the total comes in materially below $12 billion.
It is a curious posture: to demand transparency on cost while anchoring the public debate to a speculative number NZTA has never published — a number Sharp himself concedes is a “maximum”.
Tolls, for what it is worth, are real: the proposed $1.50 to $4.50 for light vehicles will offset some of the cost. The $12 billion is not.
Which benefit-cost ratio?
Sharp leans on a benefit-cost ratio of 0.7, which he dates to 2019.
There are other numbers in circulation. The project’s business case and National’s 2023 costing both carried a ratio of 1.40, and the responsible minister says the current figure is above 1.
NZTA has not released it.
Whichever measure properly applies, the lowest one available was the one chosen for broadcast.
And the National Infrastructure Plan that Greater Auckland keeps invoking makes a point worth sitting with. It observes that state highways have historically been built to connect towns and cities rather than to match local population, and that its own forward guidance expects regional highway networks to keep growing regardless of population trends.
A thin local catchment is not, by the Plan’s own logic, the disqualifier it is being made out to be.
The benefit-cost shuffle
Let me be plain: I am no cheerleader for how this motorway was sold.
I have spent years documenting how the numbers on this corridor get built, much of it set out in my book Unleashed.
When NZTA released its 2015 business case for Puhoi to Warkworth, the cheap and obvious fix for Warkworth’s Hill Street intersection — five intersections inside 50 metres that a Board of Inquiry judge called “an amazing clutter of traffic signs and road markings” — was quietly left on the shelf.
The reason was arithmetic.
To reach the ratio the motorway needed, the benefits of upgrading Hill Street and the existing highway were folded into the motorway’s case, alongside conveniently revised-up traffic projections. A parliamentary select committee later asked NZTA why more than $700 million was going to the motorway when Hill Street could be addressed for about $21 million.
The same years produced the Matakana Link Road, a short connector that Auckland Transport’s own analysis showed would draw barely 4 per cent of traffic off Hill Street, yet was fast-tracked a month out from the 2016 local elections so it could open with the motorway.
By 2018, with the figure in the draft regional plan blown out to $89 million, even Greater Auckland called it “stupidly expensive” and observed that much of the traffic it served was holiday traffic to Omaha, not freight bound for Northland.
What Greater Auckland never came back to is what happened next.
The road was not built for $89 million; it was delivered for about $62 million — still a staggering sum for barely 1.3 kilometres, and on a per-kilometre basis much the same as the motorway it joins.
The case that justified it then quietly fell apart: instead of the free-running bypass promised, it opened as a 50km/h four-lane arterial with two new intersections feeding more than 1,200 development lots, which strips out most of the time savings that were the entire point.
None of that earned a follow-up post.
That is the pattern worth watching: seize the alarming top-line figure, then move on before the more awkward delivered reality lands — there is an old habit in big-project budgeting of letting a frightening number circulate and later banking the credit for coming in under it.
A benefit-cost ratio on this road has never been a fact handed down by nature; it is a number assembled by people with a result already in mind.
Expect the same on Warkworth to Te Hana: a $12 billion headline today, in all likelihood a project delivered for a good deal less, and no one on the campaign side ever auditing the gap.
The umpire is wearing a jersey
Greater Auckland describes itself as an independent, evidence-based analysis and advocacy organisation.
It is certainly an advocacy organisation. It began life as a transport blog; its flagship projects are the Congestion Free Network and Regional Rapid Rail — public transport and rail, in and around Auckland.
There is nothing wrong with that.
But it means the group is not a neutral referee on a motorway in the north. It is a participant with a settled view about how transport money should be spent, and where.
The point sharpens with the spokesman.
Connor Sharp stood in last year’s local elections as a City Vision candidate for the Waitemata Local Board.
City Vision is the ticket that brings together Labour, the Greens and aligned independents.
Sharp launched a 2020 petition for a capital gains tax, and worked on Efeso Collins’s mayoral campaign and Chloe Swarbrick’s re-election.
None of this is disqualifying, and none of it is concealed — he has written about it himself.
But none of it was on the table when he was introduced to a radio audience simply as “Connor Sharp from Greater Auckland”.
A listener weighing his verdict is entitled to know they are hearing a transport campaigner and recent council candidate of a particular political stripe, not a disinterested analyst.
The same caveat applies to the organisation: one of its directors and spokespeople, Patrick Reynolds, stood on the same City Vision ticket.
An advocacy group is free to advocate. It is the borrowed authority of the neutral umpire that should be handed back.
The conversation we actually need
The National Infrastructure Plan, broadly welcomed across Parliament, asks for two things in land transport: genuinely independent, transparent scrutiny of major projects, and a durable pipeline that future governments will honour rather than tear up.
Both are good.
Neither is served by killing the most shovel-ready stage of a national corridor in an election year on the strength of a contested ratio and an uncosted headline.
If the corridor’s economics are genuinely weak, then make that case for the whole corridor, in the open, with the figures NZTA is still refusing to release — and let every party commit to the result.
That is scrutiny, and I would back it.
What Greater Auckland is offering instead is a late, well-organised campaign to stop the hard part, dressed up as restraint.
A motorway is not a menu. The tunnels and the hills are not the expensive extras to be sent back to the kitchen — they are the whole reason the road is worth building.
