A short history of the Terrace Tunnel and Mrs Jones stuck in her home
Tuesday, 30 December 2025
The earth moved for Mrs Jones. The first clue was the stuck door.
Beneath her house, a cavity was being excavated through a fault line for what would become the Terrace Tunnel, which opened 47 years ago.
It would become the culmination and less-controversial part of Wellington’s Thorndon motorway – the earlier-built motorway included digging up bodies from Bolton Street Cemetery.
It was not meant to be the end of the project with, even then, a parallel tunnel planned and eventual motorway through to the Mount Victoria tunnel. But money dried up.
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Now the Government is reviving that plan with a second Mount Victoria tunnel and second Terrace tunnel, as well as major changes through downtown and around the Basin Reserve.
In the 1970s, Alex Gray was not long out of university when he was employed as an engineer on the Terrace Tunnel and, in November 1977, wrote a report as it was nearing completion.
He still has a copy of that 56-page typewritten document.
“On a concluding note it is pleasant to record that the expected final cost of the tunnel and associated walls is expected to be $13.3 million which allowing for inflation is below the original estimate,” his conclusion said.
That is $115m in today’s money according to the Reserve Bank Inflation calculator but, in a sign of shifting costs, it equates to $420m in today’s housing or just $49m in clothing.
Included in Gray’s report was a letter written to home owners above the construction from the project manager warning of “ground settlement” with some “sticking doors and windows at three properties and minor cracking of some underground services”.
Gray reckoned he knew almost every resident in the homes above and walked there regularly. He remembers knocking on the door of a house on The Terrace to tell the occupants their lintel had cracked from the work beneath.
And he remembers a call from “Mrs Jones of Dixon St” saying she couldn’t get out her front door. Her house had settled by 25cm and the project team re-piled her home.
“We are keen to remedy as soon as possible any fault that is attributable to our construction work,” the project manager’s letter said.
It has been 50 years since and the only controversy around the project Gray recalls still exists – people perplexed about why the tunnel has just three lanes, two northbound and one south.
The reason is, a second tunnel was meant to start (the footers for its approach can still be seen from the Cable Car) but it never happened.
In contrast, the Thorndon Motorway that preceded it was bogged down in controversy. There was the aforementioned disinterment of graves and reburial in a mass grave.
Hundreds of Thorndon residents were displaced and dozens of homes demolished. Uneasiness was not helped by the fact the government kept the routes secret for five years until 1964, angering many.
“I was pretty upset over it,” John Daniels, who would become the director of the New Zealand Historic Places Trust ‒ now Heritage New Zealand ‒ told The Dominion Post in 2015.
“Like a lot of people, I would have lunch there. There were beautiful large trees that were cut down.”
Fast forward to 2025. No bodies will have to be dug up for the Government’s latest plan but the project was veiled in secrecy. Waka Kotahi NZTA had an investment case, showing the exact routes, done in late June but kept it under wraps until November.
Like the 1960s, opponents are saying their voices are being ignored while supporters say roads are the route out of congestion.
It was previously reported that about 20,000 people drove into the city each day in the early 1960s and the mainly narrow roads were clogged.
The new plans promise up to 10 minutes travel time saved at peak times, a 40% improvement in travel time reliability, and less traffic on local roads. Opponents say new roads mean more people will drive, leading eventually to more congestion.
Recent numbers suggest 80,000 or more cars enter Wellington City each day – four times what it was in 1960. But to attribute that all to a new tunnel or motorway would ignore the many other factors at play. Macrotrends data shows the region’s population was 149,000 in 1960 and 327,000 when the tunnel opened in 1978 to, according to StatsNZ, 520,000 now.
There appears to be a dearth of publicly available reports on the pitfalls and benefits of the Thorndon motorway and Terrace Tunnel but, safe to say, it changed a city.