The Government's $6 billion light rail programme for Auckland is making slow progress as bureaucrats grapple with one of the biggest projects in New Zealand's history.
Light rail, or modern-day trams, are promised by Labour to run from the CBD to the airport and from the CBD to the West Auckland within 10 years. Prime Minister Jacinda Ardern promised to build light rail to Mt Roskill within four years.
Official papers and a statement from the NZ Transport Agency show the task is more difficult than the Labour politicians envisage with a business case for the CBD to airport line still being worked on months after it was due in December last year.
It is particularly complex, given it requires extensive works along some of the city's main traffic arteries
Investigations for the CBD to West Auckland line "are at a very early stage", NZTA told the Herald.
This will be frustrating the New Zealand Superannuation Fund, which is chomping at the bit to open its $40 billion wallet to fund, build and operate light rail in Auckland with the help of a Canadian pension fund.
Last month, the Herald reported the Super Fund is working with international and local experts on its own plan for light rail with a focus on "fresh thinking".
A political source said the country's pension fund was looking at tunnelling below Queen St to provide a faster and safer route through the city centre.
Light rail is on the radar at Treasury with the head of the national infrastructure unit, David Taylor, calling for careful planning.
Light rail is not only one of the biggest projects ever undertaken in New Zealand, Taylor told Twyford and Finance Minister Grant Robertson in June last year, "but it is particularly complex, given it requires extensive works along some of the city's main traffic arteries".
Taylor's comments are included in documents released by Treasury under the Official Information Act to the Herald.
The documents show early drafts of the business case have been shared with Treasury and Ministry of Transport (MOT) for feedback.
Treasury and MOT are also assessing the proposal from the Super Fund and providing advice to Government ministers on alternative funding, delivery and operating models.
Last November, the NZTA board approved $30 million for further investigation and design work for the CBD to airport route.
No date has given for the public release of the business case or the route and stations from the CBD to the airport. Last year it was renamed the CBD to Mangere route to play down light rail as the main public transport route for airport commuters.
"It's not about getting people to catch the planes," Twyford told the Herald in October last year.
The business case for the CBD to West Auckland line will identify a preferred route and potential stations and stops. The original plan to end light rail at Westgate has been extended to Kumeu.
In a statement today, Twyford said ministers have received advice from Treasury and MOT and are considering it.
"I'd always like critical projects like light rail to progress faster, but it's important to take the time to get them right. Light rail will transform Auckland," said Twyford.
Auckland councillor Chris Darby has written to Twyford, saying councillors expect to have early and meaningful engagement with ministers over what is happening with light rail, given the impact and disruption it will have on Aucklanders.