The "biggest-ever" funding plan to fix Auckland's transport network will be unveiled by the Government and Auckland Council on Thursday.
It'll include funding for two major roading projects - Mill Rd in the south and Penlink in the north - as well as boosts to public transport.
"We've had a decade or longer of underinvestment," Auckland Mayor Phil Goff told The AM Show.
"You can't keep growing your population at a rate faster than almost any other developed city in the world, then not put the money into infrastructure to make sure people can get around it. That's been the problem."
Auckland is the country's fastest-growing region, and has some of the worst traffic in the world.
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Recent improvements to public transport such as the electrification of the rail system have only helped so much.
"You've got to run really fast to stand still, because we're growing by 45,000 people a year," said Mr Goff. "But the package we announced today is... the biggest-ever funding package for Auckland."
National's 10-year plan for Auckland was estimated to cost around $26.9 billion over 10 years. It's predicted the new plan will cost as much as $30 billion - the extra funding coming from the upcoming regional fuel tax, which National refused to let the council implement.
Mr Goff has long argued for an extra tax to help Auckland pay for its much-needed transport improvements. The election of the Labour-NZ First coalition Government last year made that possible.
"Nobody likes paying any extra for anything, but Aucklanders are realistic. We know people in Invercargill won't pay for our transport system. We've got to pay our fair share, Government's got to do their fair share, and we've got to get on and do the damn job."
A congestion tax is still at least five years away, Mr Goff said.
"The problem with a congestion tax is when you tax people to change behaviour, you've got to have different modes for them to change to. So if you put a really big toll on the motorway but you didn't have an alternative public transport system, that could cope, people would regard that as being unfair."
Public transport advocates argue that new roads - such as Penlink - encourage more people to drive, making congestion worse. Thursday's announcement is expected to reveal funding boosts for public transport, cycle and walkways and light rail, but Mr Goff says that won't be at the expense of good old-fashioned roads.
"That doesn't meant to say you don't do projects like Mill Rd or Penlink, or you don't deal with some of the major arterial routes that are absolutely clogged."
Under the original 30-year Auckland Transport Alignment Project (ATAP), Penlink was scheduled for construction in the second decade. It was brought forward in August to the first decade, and Transport Minister Phil Twyford has now told NZME $200 million will be allocated to get it done - likely as a public-private partnership, likely making it a toll road.
Mill Rd in Drury was also pencilled in for the second decade, but has been brought forward. Around $500 million is expected to be spent on that road, which Mr Twyford called a "vital artery" for south Auckland.
Other details of the new ATAP will be revealed at midday Thursday by Mr Goff and Mr Twyford at Newmarket Train Station.
'We can't solve congestion completely'
Matt Lowrie of Greater Auckland, who blogs about transport, says Aucklanders have voted with their wallets in favour of more bus and train services.
"[Patronage has] grown 10 or 20 percent a year over the last few years... They will use it, if we provide it. Aucklanders have shown that - we just need more of it now."
He's hoping today's announcement will include funding for the Skypath - a pedestrian/cycling add-on for the Harbour Bridge - and more bus lanes in new motorways.
"I am optimistic. The noises that we've heard from Phil Twyford and others over the last few months have been really positive."
Public transport needs to be a priority, he says, because no amount of new roading will fix traffic.
"We can't solve congestion completely - there's always going to be some congestion somewhere. What we need to do is provide alternatives so not everybody is stuck in it."