Options for funding Auckland transport and easing road congestion need to be part of a consistent framework that can be applied in other parts of the country, says the NZ Institute of Economic Research.
Congestion pricing will be necessary to help drive greater use of public transport and cycling, the institute says.
But it will also be a necessary source of funding as the take-up of electric vehicles reduces the fuel taxes available for roading and other transport, says institute principal economist Chris Nixon. Additional funds will also be needed for the public transport and cycleways required.
"There is a tendency to think that Auckland traffic and road development funding is the problem that needs to be 'fixed'," Nixon says in a discussion document on road pricing. "Our view is that fixing Auckland's problems may be part of the solution but what needs to be done in Auckland needs to be consistent with the rest of New Zealand.
"Until drivers are incentivised to stop and think about how and when they use selected roads, congestion will remain a problem.
"Now is the time to start thinking about how to reduce congestion in a way that is fair to all Kiwis."
In 2013, the NZ Transport Agency estimated the cost of traffic congestion at about $1.25 billion a year. By 2017, NZIER estimated the value of de-congesting Auckland alone at $900 million to $1.3b a year.
The NZIER has been looking at the issue since 1993. Its latest paper — What price to relieve the gridlock? — says the time for congestion pricing has "undoubtedly" come.
The problems are only becoming more pressing and user-friendly technology, such as number plate recognition software, GPS, and open road tolling devices is increasingly available, it says.
But the institute warns that public support for the change will be key.
Price signals must be clear in advance and people need choices.
The NZIER says road pricing schemes will also tend to place more burden on the poor, unless there is ample public transport or other support for low-income workers.