The CBG failed to confront this, saying it was not part of its remit, but did admit in the opening paragraphs of the final report, released on Monday, that "even with a significant increase in investment, the forecast performance of key parts of the transport system will be worse from 2031 than it is today".
A confession that even if their proposals for extracting an extra $12 billion out of Aucklanders are accepted, things will be worse than now. Its draft report, released in late March, was even more candid, admitting that "even with the fully funded programme, road congestion levels will deteriorate with volume/capacity ratios exceeding 100 per cent on most of our arterial road network by 2041 and emission levels exceeding current levels".
In other words, it's a plan that if successfully completed is doomed to fail.
It's a fatal flaw picked up by mayoral hopeful John Palino. In a statement that has the fingerprints of his campaign boss and former National Party president, John Slater, all over it, Mr Palino says the CBG "should have investigated ... why the mayor's programme costs so much and yet delivers more congestion".
He says the CBG "should have been given the opportunity to consider how we can get better value out of our motorway and public transport systems to make travelling either cheaper or faster - not slower and more expensive".
With excellent timing, the well-informed enthusiasts at the Auckland Transport Blog recently produced an alternative 2013-2030 transport plan, costed at $34.4 billion. Their congestion-free network is centred on a "world class public transport network" and would be fully operative in 17 years.
The network would be built on the existing public transport skeleton, and proposes "right of ways" involving trains, buses, ferries and, in places like Dominion Rd, light rail. "The key point is that by growing this network Aucklanders will have the option to move across the whole city at speed completely avoiding road traffic."
The backbone of the system will be "rights of way" not just for rail as at present but buses also, providing high-frequency services, every 10 minutes or better.
With such an efficient network, Aucklanders will have a true alternative to using their cars. More than two-thirds of the Transport Blog's proposed $34.4 billion will still go towards state highways and local roads, but it argues that with its $10 billion public transport network up and running - at an estimated cost of about $10 billion - many of the more expensive and invasive road projects won't be needed.
The $5 billion-plus new harbour crossing already has a big question mark over it. A Beca Infrastructure report to the Transport Agency in 2011 noted a decline in both traffic loadings and volume on the existing Auckland Harbour Bridge since 2005, reversing a history of steady growth dating back to 1960. Part of this was no doubt connected to the 81 per cent increase in bus traffic from North Shore to the central city between 2001 and 2011, which was more than double the 36 per cent predicted in 2004 by the agency.
Matt Lowrie, writing on Auckland Transport Blog, adds that the number of commuters "crossing the bridge by bus increased from 18 per cent in 2004 to 41 per cent in 2011 and we expect we will see similar results from investment in other high-quality alternatives. What's more, it would be cheaper than what is currently planned".
If there is a new harbour crossing, they're proposing a rail-only - possibly light rail - link.
It's the sort of radical thinking that Mayor Len Brown and his transport planners should be engaged in. Producing a plan that isn't programmed to fail.