New Zealand announces plans for Auckland Harbor Tunnels

The New Zealand government has picked an ambitious plan for two three-lane tunnels as an alternate for the Waitematā Harbor crossing. The New Zealand Herald reported that the two three-lane tunnels (one in each direction) will be for cars and trucks in between the central Auckland motorway junction and Akoranga on the North Shore. The tunnels would be 5-6 km (3-4 mile) long, at least twice as long as the Waterview Tunnel. The goal is to start construction by 2029 and could cost about US$27 billion.

Prime Minister Chris Hipkins and Transport Minister David Parker released the chosen option in Auckland after Waka Kotahi NZ Transport Agency consulted on five options for another crossing which were a mix of bridges and tunnels.

Hipkins said he was “ambitious for Auckland” even after a lot of negativity he’d witnessed with respect to another harbor crossing.

He referenced the weather events that often limited use of the current Harbour Bridge, and how it would require maintenance which would mean further closures.

 “There is no question that additional connectivity across the harbour is required,” he said.

He didn’t rule out using a toll to pay for some of the project, saying the current Harbour Bridge was formerly tolled.

“All options in how we fund this are still on the table,” Hipkins said when asked whether public-private partnerships or further borrowing could be used to fund the project.

A 21km light rail tunnel would stretch from Albany to the Wynyard Quarter, passing through Takapuna and Belmont. It would be a separate project from the two roading tunnels, and be built in stages after at least the first of the road tunnels was completed.

As the tunnels were built, the use of the existing Harbour Bridge would change: two lanes would be turned into dedicated bus lanes to extend the Northern Busway to the CBD, and some clip-on lanes would become cycling and walkways. Waka Kotahi was also looking into building an elevated walkway above the cycle lanes to separate pedestrians.

The remaining four lanes would be for general traffic.

Steps would also be taken to rebuild SH1 north of the bridge to raise it up and reduce the risk of flooding.

The indicative costings for the full plan total $35 billion to $44.5 billion, but the tunnels would be built in stages to spread it out. The Government had asked Waka Kotahi to look at funding options and said it was open to considering different options.

The roughly NZ$35-45 billion price tag would be paid for over many years in keeping with other significant roading projects, Hipkins said.

More detailed work on how it can be delivered will be done between now and Christmas. Cabinet would consider it early next year.

Construction on the road tunnels was expected to start by 2029 and Waka Kotahi was considering whether to build them one by one or both at once.

However, details are still tentative on how much it would cost and how it would be paid for.

Waka Kotahi’s indicative costings total $35 to $44.5 billion. Of that, the two road tunnels are expected to cost $12-15 billion and the light rail tunnel would cost up to $11 billion from Takapuna to the CBD, and up to $16 billion from Takapuna to Albany.

Parker said it was the most ambitious of the options Waka Kotahi consulted on, but could be done in parts.

The proposed routes would also leave options open for the wider Auckland roading and public transport networks, including links to the north west and along the proposed light rail route to the airport. It would deliver benefits, whether or not those programs went ahead.

He has also hinted that the Northwestern Busway would get the go-ahead when the Government sets out its Government Policy Statement for transport in the near future, describing it as “much-needed”.