An artist impression of mass rapid transit at Post Office Square as part of Let's Get Wellington Moving. Image / Supplied
The big reveal for Wellington's transport plan has been delayed, pending a Cabinet decision, and might not give a conclusive answer to one of the city's biggest questions: light rail or bus rapid transit?
In the coming weeks, Let's Get Wellington Moving (LGWM) is due to make a decision on what the blueprint for the city's future transport network will be after four transport "options" for the plan were presented last year.
All four options included a form of Mass Rapid Transit (MRT), but they differ on what route it would take and whether the mode would be light rail, which has higher capacity but is more costly, or bus rapid transit, which is cheaper but has less capacity.
Wellington City councillors were scheduled to formally approve the final option at a full council meeting on June 30, it's understood.
But they were recently advised by LGWM partnership board chairman Dave Brash he now expected a ministerial announcement to be made about the project at the end of this month.
"This will provide clarity on next steps for our partners, the programme and, importantly, the wider community - and help your decision-making."
A full council meeting has since been scheduled for July 6, during what's usually a winter recess period for councillors.
Transport Minister Michael Wood said work on developing an MRT solution was continuing to progress well and in line with previously indicated timelines.
"Cabinet are yet to consider the next stage of the project, and any announcement on the next stage of the process would be made once those decisions have been taken."
Recently, however, there was internal uncertainty within LGWM over whether the selection of an "option" would conclusively resolve the question of mode.
Key partners in LGWM had raised concerns about whether uncertain housing development forecasts could be relied on to justify light rail.
LGWM governance reference group and regional council chairman Daran Ponter wrote to Wellington's mayor in December seeking clarification between the projections of LGWM and the city council.
Ponter said LGWM suggested light rail could enable 21,000 dwellings within 10 minutes' walk of MRT, but the council's spatial plan only estimated about 14,000 new dwellings for the central city and inner suburbs.
"The housing intensification estimate that you agree on will have implications for the viability of the MRT option that we select," he told Foster.
Ponter wrote another letter at the end of April this year to LGWM partners acknowledging the "public's cry" for the transport plan to move faster.
But he said decisions must be able to withstand scrutiny in the future.
"We are of the view that robust information underpinning the indicative business case is critically more important than simply getting a decision over the line before the local government elections."
Ponter urged them to consider making a separate decision on the mode of MRT later this year, rather than as part of the preferred option to be announced shortly.
"Because to poke several billions of dollars at an MRT system is not something you do on a lazy Sunday afternoon based on some crude figures in front of you," he told the Herald.
Both letters Ponter wrote were proactively released by the regional council.
The Herald understands LGWM's board is leaning towards selecting "option one", although a formal decision has yet to be made.
Option one as it was originally announced included light rail through the city to the south coast, redevelopment of transport around the Basin Reserve, and a new tunnel through Mt Victoria with dedicated public transport lanes.
However, following the concerns regarding the urban development forecasts, this option is likely to include an "off-ramp".
This would mean the light rail at the heart of the scheme could be converted to cheaper bus rapid transit if the dwellings along the route and Wellington's growing population failed to justify a more costly, but more efficient, light rail.
LGWM programme director Sarah Gardner said an announcement on the preferred option for delivering MRT will be made in the near future, but did not say whether that will include the mode.
"These are significant decisions that will change the way we move and live in Wellington and we are committed to working with our partners as part of this decision-making process."
Wellington mayor Andy Foster said there were reasons for the difference between the council's urban development projections and LGWM's.
These included the number of dwellings enabled versus how many they actually expected to build, that the spatial plan is yet to factor in densification triggered by MRT stations, and new planning rules allowing three homes of up to three stories spreading development rather than centralising it.
Irrespective of these particular numbers, Foster shared Ponter's concerns about the certainty of future population and dwelling projections and whether they could be relied on for decision-making.
"The problem is you need to be reasonably certain you're going to get enough people within the MRT catchment to make either form of MRT financially viable. Obviously, LRT (light rail) can take more people and also costs more so needs those extra people."