Several alternative versions for delivering Let's Get Wellington Moving (LGWM) are being planned behind closed doors amid escalating costs.
Last month Treasury warned the $6.4b transport project was expected to cost significantly more than previously estimated.
LGWM is a three-way partnership between Wellington City Council, Greater Wellington Regional Council, and Waka Kotahi NZTA.
The indicative plan was announced more than two years ago and included better walking and cycling, bus priority measures, mass rapid transit from the city to the airport, and a second Mt Victoria tunnel.
Business cases for the two big-ticket items, mass rapid transit and the tunnel, are months behind schedule and yet to be finalised.
Interim work has highlighted emerging affordability challenges and found these packages could be "reshaped" to deliver better outcomes.
So the LGWM partnership board decided to undertake a technical assessment, which included the development of several alternative programmes representing a range of costs and outcomes
The assessment also considered three major strategic shifts which have happened over the life of the plan including climate change commitments, revised population forecasts, and Covid-19.
Ten technical assessment working papers from February have been released under the Official Information Act to Green Party transport spokeswoman Julie Anne Genter.
There are two alternative recommended programmes for investment and seven different approaches for delivery.
They include a range of high cost and medium cost programmes with variations like prioritising mass rapid transit to the southern suburbs and a "long tunnel".
The actual details of each version are redacted for reasons including the need to maintain free and frank expression of opinion and to allow negotiations to continue without prejudice or disadvantage.
LGWM Governance Reference Group chairman Daran Ponter anticipated a smaller number of options would be consulted on with the public than what officials were working on at the beginning of the year.
He said all options were likely to have a new tunnel for Mt Victoria but that it might not cater for all transport modes.
Meanwhile mass rapid transit was being considered from the central railway station out to both the eastern and southern suburbs, Ponter said.
Ponter confirmed the Governance Reference Group has seen figures relating to the escalating cost of LGWM and those would inform decision making on the options for consultation.
He stressed the importance of using the project's objectives as a starting point rather than the "particular desire of politicians involved in the decision making at the time."
"When Let's Get Wellington Moving was announced it had too much of a political hand in it.
"Insufficient time had been given at that point to actually explore the options and what was likely to be the most optimal solutions for Wellington."
The overall aim of LGWM is to move more people with fewer vehicles, but this year objectives were reconfirmed and given weightings.
The issue of climate change is now weighted as a high priority with the programme seeking to reduce carbon emissions and increase mode shift by reducing reliance on private vehicles.
Genter said she was frustrated and hugely disappointed by the delays.
She said years have been wasted on rethinking Wellington transport options with a "four lanes to the planes" approach.
Genter speculated the state highway projects were "massively blowing out in costs and don't deliver the benefits they're meant to".
She acknowledged she was Associate Transport Minister at the time the plan was announced. Differing views were kept behind closed doors, she said.
"From the beginning I've wanted to see the projects decided by an analysis of the most effective way to achieve our objectives not a wish list of projects that poll well."
Transport Minister Michael Wood disagreed the programme was announced with insufficient detail behind it and with too much of a political hand.
He said there had to be agreement across partners and funding allocated before the transport programme could be worked out in detail.
Partners receive advice from officials before deciding on projects, he said.
"I expect given the reconfirmed objectives and financial pressures on LGWM partners, we will be presented with a range of options to take the programme forward.
"I'm not going to predetermine what partners decide on but our intention is to deliver significant transport benefits to Wellington."
Engagement on options for mass rapid transit and highway improvement projects will happen later this year.