Kilbirnie to Terrace tunnel: Mayor interested in freed up city streets

Monday, 15 April 2024

Tory Whanau says she is interested at looking at the possible benefits of the tunnel, but would like to better understand the climate change impact.

Mayor Tory Whanau is interested in the opportunities a new mega tunnel could provide for Wellington.

Today the Government announced it had asked NZ Transport Agency Waka Kotahi to prepare advice on a long tunnel that would run from north of the Terrace Tunnel to Wellington Rd, Kilbirnie.

Whanau said she would like to see the climate change impact of the work but she was “interested in looking at the opportunities [the tunnel] would deliver for the city in terms of freeing up surface level road space for housing, walking, cycling and public transport”.

Water reform needed to be a top priority before work on the new tunnel went ahead, Whanau said.

Climate change was already here and the city needed to offer people more low emission ways of getting around and reduce the number of cars on the road.

“We need to offer people more low emission ways of getting around and lessen the number of cars on the road, which reduces congestion and frees up our streets for people.”

Simeon Brown says the long tunnel option would mean less construction disruption for local traffic and would ease traffic congestion in the city.

The option would involve twin two-lane long tunnels, four kilometres in length, that could cut 15 minutes off travel time from Wellington to the airport. If built, it would become New Zealand’s longest road tunnel.

“It solves the entire traffic blocks through Wellington. It solves the Terrace tunnel. It solves Aro Valley. It solves the Basin and it solves Mt Vic Tunnel which are four major areas which need work done into the future and it does it with one major project,” Transport Minister Simeon Brown told RNZ’s Morning Report.

“Instead of a 3-minute travel time benefit, on just doing a second Mt Vic Tunnel, you’d get up to 15 minutes worth of travel time benefits.”

The tunnel would remove traffic travelling through the city centre, allowing for better public transport options, walking and cycling. “We see this as a potential win win,” Brown said.

In the statement Brown said the long tunnel would remove the resilience and safety concerns and provide a connection to the south and the east and in particular to the airport and hospital.

Despite preparations for this new tunnel, planning on the second Mt Victoria Tunnel and Basin Reserve project would continue.

The existing tunnels would be repurposed to provide vital functions in the local transport network to connect the city centre with the highway and outer suburbs.

Details on the plans for a long tunnel are expected to be finalised by the middle of the year.

“The option would also mean less construction disruption for local traffic as the long tunnel option could be built with less disruption to the city centre and less impact on public and private properties required for other options,” Brown’s statement said.

The blue line shows the so-called ‘long tunnel’ route from a previous plan.

“To rebuild our economy and ensure people and freight can get to where they need to go quickly and safely, we need to move at pace to deliver the infrastructure our country needs.”

Improving SH1 from the urban motorway through the city centre to the airport has consistently been part of Wellington’s transport strategies, the statement said.

Four options had been considered: a duplicate Terrace Tunnel, improvements through Te Aro, grade separation at the Basin and a second Mt Victoria Tunnel. The options had been considered as part of the Roads of National Significance policy and also in the Let’s Get Wellington Moving programme business case.

Regional councillor Thomas Nash said it was astonishing that a multi-billion dollar motorway tunnel would be a priority.

“For the cost of what would be New Zealand’s longest road tunnel we could get new inter-islander ferries and terminals, or surface light rail in Auckland, or do most of the upgrades to triple passenger rail in Wellington.

He believed the focus should be on the transport basics – adding more bus priority lanes and increasing rail maintenance on Wellington’s train lines.

The new proposal suggested ministers could see that the second Mt Victoria tunnel “doesn’t actually solve any problems”, Nash said. “It doesn’t help public transport, doesn’t support more housing and makes little or no difference to most drivers.”

A 4km tunnel in Wellington would surpass Auckland’s Waterview Tunnel (pictured) and become the longest road tunnel in New Zealand. (File photo)

“Here we go again,” said city councillor Iona Pannett, describing the mega tunnel as another grandiose plan that was not achievable or affordable.

Similarly to Nash, she did not think the spending on another road was worth it, saying the city needed to focus on improving the transport netowrk Wellington already had.

The cost of a second Mt Victoria tunnel was estimated at $2.2b and Pannett believed a longer tunnel could be double or triple that. “These plans always come unstuck on the money,” she said.

The option was considered in 2021 as part of Let’s Get Wellington Moving. The report on the short-listed options said the long tunnel would bring “urban development benefits to the east and was understood to result in reduced traffic in the city’s streets”.

The tunnel would reduce traffic on streets like Vivian St, the report said – but it would increase traffic across the network as a whole. There were also concerns about how the tunnel entrance and exit would integrate, especially at the Kilbirnie end.

At that point the tunnel was being considered as part of a package including mass rapid transit (either light rail or bus rapid transit) and congestion chargin.

According to the reports traffic specialists viewed the long tunnel as an “innovative solution to the blight that affects the Karo Drive area”.

There were concerns about the noise and vibrations from construction, as the route of the tunnel would be close to buildings.

The next report from Let’s Get Wellington Moving, considering the affordability of the proposed options, outlined a decision not to progress the long tunnel because of the cost.

How expensive are tunnels?

The long tunnel option, at 4km, would become New Zealand’s longest road tunnel, surpassing the Waterview Tunnel (2.4km). Back in 2017 Waterview cost $1.4b to build.

According to Auckland Mayor Wayne Brown, as reported by the NZ Herald, plans for underground light rail were $400m more expensive per kilometre than surface light rail ($750m vs $350m).