So this was a quick couple of hours of thoughts... Feedback to NZTA is due by Sunday 14 December if you are interested.
Background information is here (PDF)
A video flythrough is here
Apologies, I've been following this whole segment of road for far too long, from growing up being driven through Mt Victoria Tunnel, to some work on the Inner City Bypass 20 odd years ago to living near the tunnel today.
....
The Government’s proposal for a 2nd Mt Victoria Tunnel, 2nd Terrace Tunnel, reconfiguration of the roads around the Basin Reserve and widening of Vivian St is the latest set of proposals to fix the unfinished business of the Wellington Urban Motorway. We will see whether all, some or any of it proceeds, but for the sake of Wellington at least some of it should (specifically the tunnels), because the status quo, notwithstanding the largely evidence free claims of Green Party politicians, is an absurd waste of time and energy in a city of this size.
History
It wouldn’t be hard to write a book about the history behind all of this, which started with then US consultancy firm De Leuw Cather, preparing a “transportation master plan” for Wellington. It considered the option of a waterfront motorway (see Seattle and San Francisco for now demolished versions of this), but preferred what was known as the Foothills Motorway. It follows the existing motorway, with two instead of one Terrace Tunnel (3 lanes each way), with 2 lanes continuing on a motorway going under and over various streets and, initially, demolishing the Basin Reserve for a motorway interchange, before finishing up at a second Mt Victoria Tunnel (2 lanes each way using the existing tunnel). De Leuw Cather also proposed placing the Wellington commuter rail service underground to Courtenay Place, through the reclamation land. Of course that latter proposal wasn’t going anywhere, but the motorway started from Ngauranga (not connected to Ngauranga Gorge, but rather as just an extension of the Hutt Road from the Hutt). In the 1960s and early 1970s, the motorway cut a swathe through Thorndon and Kelburn, with much of a cemetery dug up and interred in a mass grave (don’t think that this was an era of much consecration to Christian religious values). However, the 1974 oil crisis (entirely stemming from the Yom Kippur War) saw a slowing down of the project, with the Muldoon Government ultimately deciding that it (and multiple other road projects) would be terminated at Willis Street, with the segment from Bowen Street south halved in scope. One Terrace Tunnel, one lane southbound, two lanes northbound.
At the time, with the motorway only being SH2 (SH1 still being the Hutt Road from Ngauranga to Aotea Quay, and continuing along the waterfront to the termination point of Jervois Quay and Taranaki Street), this made some sense. It was never congested, and the scale of traffic through Te Aro was easily handled by the Vivian St/Ghuznee Street one way pair.
In 1983 the Ngauranga Interchange changed all that, by around doubling traffic on the motorway, the end of the motorway became a bottleneck, exacerbated by the single lane in the tunnel. Further bottlenecks existed with Ghuznee Street and Buckle Street, with the dog leg route from the Basin Reserve to the motorway being utterly unsuitable for the traffic volumes going through it. This situation persisted for 12 years.
Meanwhile, a scaled back proposal to ease the traffic pressure came from the then National Roads Board. A motorway extension designed as an arterial highway with 70km/h speed standards. The original plan to destroy the Basin Reserve for a motorway interchange (which had been shelved some years previously) was replaced with a highway bridge across the northern boundary of the park. The Terrace and Mt Victoria Tunnels would be linked by a fully grade separated highway going under Willis and Victoria Streets, severing Cuba Street (except for a pedestrian bridge), passing over Taranaki Street before darting under Tory and Sussex Streets. One lane would extend from Mt Victoria Tunnel under Sussex Street to join a second lane from the south. Whereas one lane would exit at the Basin to Cambridge Terrace and Dufferin St, with one lane extending to Mt Victoria Tunnel.
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| 1980 scaled down motorway extension proposal before it got dropped in a trench in 1991 |
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| Fully trenched but not covered in this brutalist image that looks like it was designed to kill it |
The next decade or so would see the project rise up the regional priority rating, as other projects were built: Upper Hutt Bypass, Mungavin Interchange, Silverstream-Manor Park 4-laning etc, but then the funding system for roads was reformed. The Ministry of Works was abolished, and shortly thereafter, Ruth Richardson slashed funding for roads. At the time, funding was mostly allocated based on a cost/benefit analysis, with 25 year return periods. For around two years funding was not even sufficient to keep up with maintenance, and as the 90s progressed, the Wellington Urban Motorway arterial extension went up in cost and was always borderline for funding. However, it always had a BCR of over 2 when the threshold for funding was 5 or 4.
At the same time the nascent Green Party campaigned vehemently against it. To try to address concerns the project was first redesigned to be trenched the whole way across Te Aro, then put in a cut-and-cover tunnel to the bridge on the north of Basin (called Tunnellink). However, it was clear by the mid 1990s that funding wasn’t likely for over a decade. So a three stage project was advanced. First a simple one-way pairing of Buckle and Vivian Street, followed by what is now known as Karo Drive. Karo Drive literally took around 12 years from its inception to opening, largely because of the opposition to it by the Green Party spreading vast amounts of misinformation. Then Green MP Sue Kedgley always called it a “motorway extension”, and eventually when it got funded by Transfund, and all legal avenues under the RMA to stop it were exhausted, it got built. It was only meant to be a ten year stopgap until the Tunnellink could be built.
However, by then Transit NZ (later to be merged with Transfund and the Land Transport Safety Authority) had largely given up on the idea of a cut and cover tunnel. So the next step was to fix the Basin Reserve, and plus ça change it was stopped by an organised campaign of the Greens and Mt Victoria NIMBYs. This was for a two-lane 50km/h one lane bridge clear of the Basin Reserve, westbound.
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| 2001 - preferred Basin grade separation without Tunnellink |
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| 2008 - one of the options for the Basin Bridge |
At the tail end of the Key/English Government there was a commitment to a second Mt Victoria Tunnel, but of course that all was stopped under the Ardern Government, as the Greens made sure that the Let’s Get Wellington Moving project would prioritise emission reductions, and put little value on reducing general traffic congestion.
The Ardern/Hipkins Government did support a second tunnel, but it was to close the existing tunnel to motor vehicle traffic, and build a new one with four-lanes, two for buses. In short, no relief for general traffic.
What’s been proposed?
So here we are today with essentially five main elements to upgrading SH1 through Wellington. Once again the Greens are talking about “building a motorway through Wellington” which it absolutely does not do. It doesn’t build one metre more of motorway, but it does widen one section along an existing motorway corridor. The five elements are:
- Second Terrace Tunnel
- Upgrading SH1’s one-way pair through Te Aro
- Basin Reserve reconfiguration
- Second Mt Victoria Tunnel
- Widening eastern approach roads to Mt Victoria Tunnels.
Second Terrace Tunnel: This is sensible, because it will the single biggest measure to remove 20% of traffic from the waterfront route. It is on a smaller scale than the original proposal (will be two-lanes not three southbound and the existing tunnel will only be two-lanes northbound), but should not be controversial. What will constrain it is…
Upgrading SH1 through Te Aro: Reversing forty years of planning, Te Aro will still be blighted by heavy highway traffic pushing through it, by widening Vivian Street (which has been designated on the Wellington District Plan for many years) to three lanes one way. As a stopgap this is satisfactory from a traffic flow point of view. but is hardly a long-term solution. It should have a cut-and-cover tunnel along the line of Karo Drive, which would be expensive and disruptive, but would be transformational for Te Aro. A proper bypass would make a huge difference, but for now with the two tunnels being the major bottlenecks, that idea isn’t progressing. In short, this will be the new bottleneck, exposing the greatest number of pedestrians (and traffic) to delays and emissions. It’s the cheap part of the package, and it will need to be addressed at a later date.
What’s disconcerting is that there is little future proofing to enable a solution to his, especially with this proposal…
Basin Reserve reconfiguration: There is no shortage of options designed to fix this problem, which is essentially the need to separate east-west traffic from north-south traffic, while also allowing it to interchange. The latest proposal partially separates traffic, but it means the same number of traffic light controlled intersections westbound and eastbound on SH1. See below:
No doubt clearing Mt Victoria Tunnel congestion will improve eastbound flows, but it is far from clear that retaining a network of pedestrian controlled traffic lights and keeping SH1 at ground level in front of the Basin Reserve will not create new bottlenecks, and worsen the concentration of traffic/emissions across the northern side of the Basin. The Rugby/Dufferin Street sections outside the schools will be quieter, but be a ratrun for traffic from the city to SH1 west, and from Newtown to SH1 east. The big winner is north-south traffic to and from Newtown towards the city.
No doubt there will be a net improvement, but it is clear from the proportion of benefits of the total package that this is where not much will be gained. What’s particularly concerning is that it doesn’t look like it provides for future proofing building a parallel eastbound pair of lanes to take traffic from Vivian Street and over to the second Mt Victoria Tunnel. I understand the reluctance to elevate SH1 near the Basin, but it could be done by elevating Sussex Street over SH1 and building an artificial hill to carry the road with significant mitigation of the visual and noise impacts of a bridge. This is a mess. The new Green Link looks like it is preserving an option, or maybe it is preventing it.
Second Mt Victoria Tunnel: This is like past proposals and is entirely suitable as a solution to this problem. It is a shame that westbound its capacity will be constrained by unnecessary intersections at the Basin.
Widening eastern approach roads: Four-laning Ruahine St and Wellington Rd (six lanes at points) has long been the right approach, but the design of intersections seems bizarre indeed. Grade separating at Hataitai Park (to a new road where houses currently exist) seems over the top. The removal of Taurima St access to Mt Victoria Tunnel needs a solution, as does access to Hataitai Park, but why is this intersection getting such lavish treatment, but Wellington Rd/Ruahine St (which enables access from Newtown to the airport, from Hataitai to Newtown, and for access to southern Newtown to and from SH1 bypassing the bottleneck in front of the Hospital) is curtailed to simple slip lanes in one direction only? The latter should be a full scale intersection. Previous plans simply had an elaborate intersection at Goa Street, although there is some merit in having grade separation, it seems odd that a low traffic intersection gets it, but not the much heavier traffic ones at Kilbirnie Crescent and Evans Bay Parade (although imagine the outcry if that were proposed).
There are lots of minor details in this section which make access between Kilbirnie, SH1 and Hataitai worse, presumably to save money from more comprehensive wider intersections. Much of this looks worse for residents. In particular, anyone driving from Newtown to the airport will weirdly have to drive through Kilbirnie’s CBD (but not in the other direction). Anyone driving from Hataitai to Newtown will either have to go through Mt Victoria Tunnel to ratrun past the stands at the Basin Reserve, or go into Kilbirnie and ratrun up Duncan Tce. (a narrow street with poor visibility at the top).
This is all details though in intersection design, which I expect locals to have their views on. The Greens are claiming a big increase in traffic in Moxham Avenue will occur, but that’s mostly a shift from Taurima Street and the existing intersection on Ruahine Street.
Thinking more widely
There is talk of tolling the route, although no details have been presented, it is difficult to envisage it not simply being at the tunnels. On its own this would have merit if the whole proposal enabled free flow traffic all the way. It doesn’t. Paying a toll to drive through the Terrace Tunnel to end up at Vivian Street isn’t a compelling proposition, and would divert local traffic from the tunnel to The Terrace. Likewise paying to use Mt Victoria Tunnel to reach a pair of traffic light controlled junctions by the Basin Reserve. A full scale freeflow bypass would be another proposition, offering a high value fast trip, but that isn’t what is proposed.
On the other hand, a central Wellington congestion pricing scheme within the boundaries of SH1, which helps pay for this, would have much more merit as it would reduce traffic towards the city at peak times, and enable better flow of traffic around it. An AM peak inbound, PM peak outbound price for driving in and out of Wellington on weekdays would have some merit.
Much has been raised about the BCRs of the project, but although I put some value on economic analysis, when it comes to tunnels, the return period for them is much longer than any conventional highway or bridge. Tunnels last almost forever once dug, and only need moderate upgrades throughout their existence. So I treat the two tunnels as very long term investments in addressing the resilience of the city’s transport network, and enabling a future full scale bypass of the city.
Claims from the likes of the Greens that “car tunnels” (a deliberate misinformation campaign to diminish the role of freight and buses) will just induce more traffic are largely nonsense, especially if congestion pricing is introduced in parallel. There is no more capacity that will be build north of Ngauranga Interchange, so more traffic cannot be attracted from that direction, and with much of the traffic on the route bypassing the city, little of that is going to be attracted from public transport to driving. Modern cities have good bypasses, Wellington has lacked it for decades.
So I’m in favour of the tunnels, in favour of the widening east of Mt Victoria Tunnel (with some caveats), but the upgrade through Te Aro is cheap and nasty, and needs to make provision for something better once the two tunnels are built. It will be obvious the city needs a proper bypass. The Basin Reserve proposal is messy and poor value. It’s unclear why north-south traffic going in a four-lane trench is better than being on a four-lane bridge over the east-west traffic, and why so many light controlled intersections should be kept. It should be reconsidered.
- It aims to “fix” traffic congestion by building a bigger road in the centre. Never, not ever, has this worked.
- If you look at the numbers for how LGWM’s package was going to “fix traffic”, it wasn’t the very expensive road-building that was going to do the heavy lifting: it was congestion charging (digital infrastructure and some gantries) and the second spine for public transport (paint, signage, timetabling). And the costs for civil construction (which this expansion project is all about) have rocketed since then.
- There are lots of flaws with the logic: smooth, faster-flowing traffic through the city centre while also somehow not worsening severance in Te Aro, and while also allowing lots of cars to turn on and off it…
- Its Cost-Benefit Ratio is already low (even with the extra-low discount rate now allowed to be used) and the Inner City Bypass was found to have been probably not worth the money spent on it (we lose more than we gain from having it) so it’s highly likely this will be worse given its far greater costs. The opportunity cost of this public money is dismaying.

















