Auckland Council has long wanted toll roads, but the Government hasn't been so keen -- until now.
On Tuesday the pair released the second of three reports on the joint Auckland Transport Alignment Project, which concluded "road pricing -- or directly charging for road use -- will also be part of the toolkit", in the words of Transport Minister Simon Bridges.
"There comes a point where we can't keep building lanes on motorways," he told Paul Henry on Wednesday.
"There just comes a point when you've done all you can do, to use the economic term the supply side -- you've built all the roads -- and you need to find new tools to move people around. That's what this is about."
But he denies it's a cash-grab, either by the Government or the council.
"Petrol taxes and road user charges would progressively come down, and you'd move the network pricing up."
Instead, "to an extent" it's a stick to stop so many people using the roads, so more don't need to be built, that will complement the "carrot" of extra investment in public transport and eventually greater uptake of self-driving cars and ridesharing.
"When you've built the network, you've done better public transport but you've still got growth in a city like Auckland... you need to change behaviours and you need to manage the demand better," says Mr Bridges.
The cost of implementing a road toll system hasn't been worked out yet, and there's no hurry -- Mr Bridges says any changes to how Auckland's transport infrastructure is funded are years away.
"The final report will give us much more of a sense of the kind of implementation of this over the years and we'll just have to work our way through it. It will require law changes and a variety of measures."
The National Party hasn't always been opposed to toll roads in Auckland. In 2008 before becoming Prime Minister, John Key suggested $2 tolls could apply to fund new roads, while his then-transport spokesperson Maurice Williamson suggested $5.