An eye-watering $31 billion is the price tag National has put on the infrastructure upgrade required to fix the country's transport network and Auckland and upper North Island's congestion crisis.

In her first big policy announcement today, new National leader Judith Collins delivered the opposition's infrastructure plan - a policy former leader Todd Muller was meant to make before quitting on Tuesday.

Collins has also announced a National government would repeal the Resource Management Act completely, and replace it with two new pieces of law.

More than half of the money announced by Collins today ($17b) would be invested in the upper north, which Collins says is home to half of all New Zealanders.

To fix the congestion issues Collins has announced "National would go ahead with everything Labour has said it will do in transport" - with the exception of Transport Minister Phil Twyford's "light-rail Ghost Trains, and the probable exception of the $360 million Skypath 2".

She said National would also go much further, with some work beginning immediately and the larger projects rolled out over the next decade.

One of the most ambitious projects announced is four-lane expressways - including tunnels under the Brynderwyn and Kaimai mountain ranges - to connect Whangarei, Auckland, Hamilton and Tauranga.

"National's vision is to transform the four cities to be one economic powerhouse, unlocking their potential so the upper North Island becomes Australasia's most dynamic region,'' Collins said.

Also part of the announcement is Auckland's rapid transit network, including rail to the airport and new busways.

"One rough definition of a city is that it is a place you can get from one side to the other in an hour, or a place that the average time to get to work is 30 minutes. National will measure our progress against the goals of 30 minutes to get to work and one hour to get across the city,'' Collins said.

An additional harbour crossing has also been announced - Collins said planning work would begin immediately with spades in the ground by 2028.

"National's Plan is that the crossing should be a tunnel or tunnels, and be for both road and rail, and new public transport technologies that come on line,'' she said.

Other plans included expanding the ferry network in Auckland and new walking and cycling links as well as expanded park-and-ride facilities.

In addition to the larger long-term projects, $300 million worth of "digger-ready" projects across the country in 2021 would fix potholes, roundabouts and crash corners.

Collins said the $17b for Auckland and the upper North Island, and the $14b for "soon-to-be-announced projects in the southern half of the country" would be paid for out of the current government's Covid fund.

At this year's Budget Finance Minister Grant Robertson set aside $20b of untagged funding for Covid-related recovery projects.

"NZTA will also be allowed to better leverage its balance sheet by borrowing up to $1 billion a year, and there will be tolls on the new Brynderwyn, Waitemata and Kaimai tunnels,'' Collins said.

Transport spokesperson Chris Bishop said Aucklanders would also benefit from National's repealing of the Auckland Regional Fuel Tax within its first 100 days in office.

That would put $150m in savings per year into Aucklanders' back pockets.

"We will not increase fuel tax or road user charges in our first term,'' he said.

RMA repeal

Collins said previous governments have tinkered with the RMA with amendments, and that is a "mistake''.

She plans not to reform it, but repeal it altogether.

"We will replace it with two new pieces of law: an Environment Standards Act, setting our environmental bottom lines; and an Urban Planning and Development Act, giving clarity and consistency. We will begin this work in our first 100 days.

"We will introduce new legislation by the end of next year,'' she said.

That process will however be too slow for the projects she's announced in her infrastructure policy today.

The RMA fast-track legislation passed in response to Covid-19 provides a useful interim framework, but is too limited, she said.

"National will make far more extensive use of the fast-track Act.

"New Zealand is facing an extraordinary jobs and economic crisis; and it demands a proportional response.

"We simply cannot let the RMA stand in the way of urgently needed infrastructure development,'' she said.