Auckland roads will remain free to drive on for at least five years after the latest work by officials on congestion pricing.
Three years after the Government and Auckland Council agreed to investigate congestion pricing in response to rapid population growth and traffic chaos on the city's roads, officials are suggesting weekday tolls of $1.50 to $3.50 from 2025.
Tolls would be rolled out over the following 10 years once the city has much better public transport.
Lobby groups said they were cautiously open to the idea of congestion charges as a means to control Auckland's winding traffic jams.
However, they warned authorities that the congestion charge should only be implemented as a way to ease congestion and should not be seen as a cash grab for the council.
Officials from six government agencies, Auckland Council and Auckland Transport have been working on a project called The Congestion Question (TCQ) to identify how to get people moving more efficiently in Auckland.
A technical report looked at 26 options and found congestion pricing would bring significant benefits for all Aucklanders, including more reliable journey times across the city, increased business productivity, improved air quality and lower vehicle emissions.
The report found that having an access charge for private vehicles to enter key areas of the city during peak times from Monday to Friday would have the most impact and be fair for all.
Priority-based and distance-based charges were considered but using access charges means travellers who live in outer suburbs without access to public transport are not faced with higher costs for longer trips.
The suggested charges would improve the performance of motorways and main roads by 8 to 12 per cent and have about the same impact on overall road efficiency as seen during school holidays.
"While congestion charging is just one tool in a larger toolbox, it's still important for creating an efficient and integrated transport system," said AT board chairwoman Adrienne Young-Cooper.
The findings in TQC follow years of data-based research to help start real conversations, and now it's time to set up a process to engage with Aucklanders and stakeholders to find a solution that works for all, she said.
The benefit of congestion pricing over current road pricing methods is that it would incentivise Aucklanders in private vehicles and who have a choice to travel outside of times where congestion charges apply, or walk, use public transport or bicycles, or other low impact modes.
AT chief executive Shane Ellison said before congestion charges are introduced, the city needs better public transport.
"People need choices and that means the City Rail Link and other fast and frequent public transport options need to be up and running," he said.
Ellison said cities like Stockholm and London - which have far superior public transport to Auckland - have congestion charges to improve the efficiency of the roads.
"The Auckland Ratepayers' Alliance, meanwhile, "warned" Auckland mayor Phil Goff to take heed of "the most important recommendation" in the report.
"The primary objective of congestion pricing is to improve network performance, not to raise additional revenue from road users," the Alliance said.
That meant it was "disturbing to see Phil Goff already quoted saying he'll need to persuade Aucklanders it's a good way of building revenue," Alliance spokeswoman Monique Poirier said.
"Many ratepayers will be open to the idea of using prices to reduce peak-hour traffic, but they won't want to give Auckland Council yet another stream of hard-earned money to be blown on pet projects," she said.
She said revenue brought in by a congestion charge should then be used to reduce or abolish the council's regional fuel tax.
"Any surplus revenue beyond that should be taken off general rates," she said.
David Aitken, chief executive of trucking lobby National Road Carriers, also cautiously welcomed the charge provide it was effective reducing congestion.
"While on first blush we support the principle of congestion charging, we would need to see more details and be assured that forecast productivity and efficiencies gains can be secured," he said.
"Additionally, the price per freight vehicle for accessing the central city or arterials routes would need to be right."
He said traffic congestion was costing Auckland more than $1 billion annually and urged authorities to act quickly.
"This is not the first time we have seen a report on congestion price. The technology for congestion charges is well-proven," he said.
"There have been enough reports. It is now time to trial a congestion charge scheme and see if it actually works."
Young-Cooper said comprehensive public and stakeholder engagement needs to take place to make sure Aucklanders support a scheme that prices congestion and its benefits and have a big say on how any such scheme would work.
"Additionally, the Government should make sure that the system does not unfairly penalise low income earners. There should be a discount scheme that reduces costs for those on low incomes."