This is to raise $12 billion over the next 30 years to fund the shortfall in the mayor's favoured Auckland Plan Transport Network - the gold-plated transport plan designed to put a grin on the face of cyclists, truck drivers, motorists and public transport enthusiasts alike.
For a politician, it's a canny tactic. Everyone gets something, and Mr Brown won't be around in 30 years to explain to the next generation of congestion-bound Aucklanders what went wrong. Or to point out to them the small print snuck into the reports released a year ago and say I told you so.
For the fact is, he and his advisers know it's not a solution.
In July last year, the experts conceded that even with the extra $12 billion, "the forecast performance of key parts of the transport system will be worse from 2031 than it is today".
An earlier draft of this report 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".
This week's report avoided such awkward confessions, concentrating instead on raising the $12 billion.
The mayor and advisory board chairman Stewart Milne referred darkly to the city "grinding to a halt" otherwise.
Mr Brown claimed "independent experts" had shown that adopting his plan "would improve congestion by 20 per cent over the next 10 years ..."
But a graph released at the same time suggests that there's not much change in any of the indicators over the next 20 years, whether you have access to the extra $12 billion or not.
For instance, it's not until 2036 that morning peak congestion rates start to get much worse if we stick to the "basic" plan rather than the gold-plated version.
As Auckland intensifies and its population grows, more roads and more cars seem to be the last thing to encourage. More obvious would be a transport plan centred on a "world class public transport network". One, for example, along the lines proposed a year ago by the enthusiasts at The Auckland Transport Blog.
It's the revolution in thinking that the mayor and his council should be embracing, or at least contemplating.
Auckland Council should also be demanding the proposed Central Rail Link and other major public transport projects be fully funded by the New Zealand Transport Agency (NZTA). Every other rail tunnel in New Zealand was funded centrally; why are Aucklanders expected to pay 50 per cent for this one out of rates?
It is just as much a transport corridor as the $1.4 billion Waterview road tunnel, which is fully funded by the government agency. That is because Waterview is part of the state highway network, with the other great motorways criss-crossing the Auckland isthmus. But they're predominantly a part of the local road network, and vast numbers of Aucklanders commute back and forth along them every day.
The same happens in Wellington. Take for example, the government-funded $120 million tunnel/war memorial park now being built. Throughout the country, locals use government-financed highways as local roads. The NZTA tries to restrict the number of on- and off-ramps to deter such use.
The proposed central rail link is as much a national highway as the Northwestern Motorway which is being upgraded at great expense to the NZTA.
The motorway requires expansion not because of growing intercity "national" traffic, but because of a population explosion on the Te Atatu Peninsula and further west. The rail tunnel is required for similar reasons, yet Aucklanders must share the cost.
If we want to spend part of Auckland's share of NZTA cash on a rail tunnel instead of more roads, why shouldn't we?
