The main Opposition party is betting that any shift in public attitudes is minor. National leader Judith Collins says the Government's "fixation on walking, cycling, and forcing people out of their cars is out of touch with modern New Zealand".
Plenty of people would see the solution to Auckland's congestion as more road routes for vehicles. With the city's building boom, tradies' vans are ubiquitous. Electric vehicles are still a small fraction of cars on the streets.
The $685 million structure, next to the Harbour Bridge and to be completed in about five years, would be considered by some to be unrealistic and expensive.
Turning a bridge lane over to cyclists and walkers has been suggested as an alternative. Transport Minister Michael Wood said that could be a temporary option.
The announcement of an additional route over the Waitematā Harbour flags that the Rubicon has been crossed and policy makers now have to consider the climate consequences of decisions. Wood said a future tunnel crossing would mostly likely involve public transport.
Speaking more generally about infrastructure upgrade plans, Wood said more than 47 per cent of the country's greenhouse gas emissions came from transport.
Wood said the Climate Commission's report, whose final recommendations are to be unveiled this week, necessitated a rethink.
"Recognising the need to decarbonise our transport system, we're rebalancing the package to increase investment in rail, public transport and walking and cycling."
Current economic and social trends could be more influential in five years. For instance, automotive companies are in fierce competition to produce hybrids and EVs, and greater take-up of remote working and less business travel would mean fewer unnecessary trips. More cycle pathways could increase demand.
The bridge itself would be a valuable tourism asset for New Zealand's biggest city. An attractive, standalone purpose-built bridge would be a more appealing experience for users than a transformed lane.
Anyone who has ever wished they could stop and admire the view as they motor across the existing bridge would be able to do so on two wheels or feet. It would enhance any Viaduct visit and bring more foot traffic to businesses there.
The move shows some boldness and vision on the Government's part, being a break from past attempts to get to grip with gridlock. It also shows Labour's habitual caution and method of using outside advice and reports to bolster its actions.
Other governments were far quicker to realise that pandemic recovery spending needed to also be strongly green-focused. The EU came up with a €750 billion climate plan a year ago.
The Government will have to weather criticism now, but its bet could pay off in the long term. Getting the majority of people to gradually move with the times will require constant explaining, cajoling, incentives and investments.