Major red flags continue to be raised by transport experts over the Basin Reserve flyover, which could see the project sent back to the drawing board.
Arguably the most serious matter is the "inconsistent" way the NZ Transport Agency used cost to justify the flyover instead of a tunnel, or improvements to the existing Basin roundabout.
Transport consultant Abley raised the concern in November after it was asked to peer-review NZTA's case for a highway flyover, 20 metres north of the cricket ground. More information has since been provided by the agency. But in a report out last week, Abley consultants said they still had three significant concerns with the $90 million project. Crucially, they still believe the method used to discount alternatives to the flyover was "inconsistent" and lacked transparency.
The agency will attempt to convince an independent board of inquiry otherwise when an eight-week resource consent hearing for the flyover begins on February 3. If the board decides the agency has not done a good enough job of considering other options, it could reject its application.
Abley's concerns stem from when the agency first sought to find a solution to the Basin's congestion woes in 2009. It decided to separate state highway traffic from local traffic via a flyover rather than reconfigure the existing road, even though the latter option - costing as little as $40m - made better economic sense.
The reason was that a flyover provided much better transport benefits, such as faster journey times, which made its extra cost negligible. But when a tunnel was considered later in the process, the agency dismissed it as being unaffordable, even though it had all the same benefits as a flyover, with the addition of being less of an eyesore and more environmentally friendly.
As Abley pointed out in its latest report, that decision appeared to contradict the transport agency's statement that its preferred option would have the least social, community and environmental impact. "The apparent inconsistency and lack of transparency in the underlying process . . . is a significant concern of the reviewers," it said.
The Abley report also criticised the way the agency dismissed the flyover's slightly worse benefit-cost ratio (BCR) the first time around. "Small differences in BCR for projects costing tens or hundreds of millions of dollars can result in multimillion-dollar differences in return on investment."
The Abley report did note, however, that the flyover proposal was likely to satisfy the problems it was intended to solve, either in whole or in part.
NZTA declined to comment to The Dominion Post yesterday, but flyover project manager Selwyn Blackmore addressed Abley's concerns in documents given to the board before the hearing, which were put online this week.
He defended the agency's selection process as robust, and said Abley's peer reviews were based on a handful of documents that did not tell the full story.
- The Dominion Post
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