Motorists could be driving through tunnels under Auckland's Waitemata Harbour within 20 years after the Government gave the go-ahead to a new harbour crossing.
The twin tunnels capable for both road and rail are the biggest news in a $10 billion bundle of Auckland transport projects the Government committed itself to on Friday.
The idea of a new harbour crossing linking the central city to the North Shore has been parked for several years while the Auckland Council settled on its preferred option - twin tunnels carrying three lanes of traffic each way, and capable of carrying trains in a lower level.
Prime Minister John Key told a business audience in Auckland on Friday that the Government will build that option.
The existing Auckland Harbour Bridge is 54 years old, and despite strengthening, the outer clip-on sections might not be able to carry trucks within a decade. The tunnels will cost between $4 billion to $5 billion and should be finished in 12 to 17 years' time.
Mr Key said funding is not yet clear for the tunnels or another $5 billion committed to Auckland transport projects.
There are also less detailed commitments to other projects around Auckland. The Government will share with the council the cost of a $600 million east-west link highway to help large numbers of trucks cross the southern industrial area.
Future stages of the AMETI highway and public transport route to the east might also be accelerated and sections of motorway, including the road to the airport, upgraded.
The Prime Minister said these projects were scheduled to start in about 10 years, but wants them to start sooner and funding has still to be identified.
Toll roads not ruled out
The Prime Minister said it is too soon to say how a tunnel under Auckland harbour may be funded, but can't rule out toll roads.
John Key told Radio New Zealand's Checkpoint programme on Friday that the New Zealand Transport Agency (NZTA) and Auckland Transport would assess the projects and report back on what the funding options should be.
Mr Key said the Government has pretty much ruled out tolls to pay for the projects, but can't say that won't be how the Auckland Council pays for its share.
"There'll be a sequence of events for all of these things. Go out there and basically get NZTA and Auckland Transport to go and look at the designations, look at the costings, firm that sort of stuff up, give us a sense of where we might go and our funding mix option."
Mr Key said the Government is currently spending $1 billion a year on road and transport in Auckland, so there is a lot of cash available for new initiatives.
$1b for rail link
John Key also confirmed a start of 2020 for the downtown rail tunnel and the Government would contribute about $1 billion of the $2.8 billion cost.
Mr Key has set targets for any earlier start. Employment in the central business district will need to grow by 25% and annual rail patronage double to 20 million trips a year.
Auckland mayor Len Brown wants to negotiate an earlier start, but on Friday said he was comfortable with the targets the Government has set.
"You cannot be dissatisfied with what has been announced today. This is the biggest commitment by a government in this city in at least the last 10 years, so it's been a very, very strong commitment and backs up the Auckland plan completely."
Mr Brown said Friday's announcements represent a big step forward for the city and for the country as a whole. He said he is pleased that the Government appears to be listening to Auckland.
Auckland Chamber of Commerce chief executive Michael Barnett has been pushing for urgent action on transport projects around the city and wants the timing of major projects brought forward.
"I think it's up to Auckland and Auckland leadership now to try and accelerate some of these delivery dates, because we have a history of delaying making decisions and a history of not doing stuff fast enough."
The general manager of logistics for Mainfreight says traffic has only been getting worse in Auckland and the problem needed to be addressed. Craig Evans said he hoped the new developments would have the same success as the Victoria Park Tunnel has had in easing traffic to and from the Harbour Bridge.
The New Zealand Transport Agency (NZTA) will spend the rest of this year securing the rail route and start formal planning for the tunnels, which will be New Zealand's most expensive road project.