As someone notes in the responses:
"Congestion pricing is such a good idea everywhere there is rock solid public transit alternatives. Where there’s not, it just becomes a tax on the poor."
If most of the poorer and working class road users cannot shift their transport times (and typically they can't) and then you don't have good and affordable public transport options for them to take instead then it effectively becomes a charge that the people who can't avoid it pay so that those with flexible lives can enjoy a smoother commute.
Which is to say that it might well reduce congestion but the cost of doing so is lumped on those that can least afford it, rather than those that can. As with most things its a choice of who pays for what to reach the aim. I would prefer that we increase taxes on wealthier people and fund expanded and free(er) public transport with a huge increase in safe cycling routes.
I think it could be argued that Auckland and Wellington have decent public transport options, and they would be the most likely place to implement congestion charges.
I wonder if you could reduce the cost of public transport using the funds raised, as an attempt to balance it.
Free public transport would be great, better if they removed the requirement to outsource and let councils or some new government entity control it.
I've not used Auckland PT, but Wellington's is definitely decent, probably depending on where you live. I think the trains would work better if they were faster, and thus more frequent - its probably difficult to make them much bigger given the platform lengths.
Some areas the bus services are a bit borderline, but would work better with less private vehicles to contend with. And to make PT even better some smaller busses with dynamic routing (like is trialled in Heretaunga-Hawkes Bay) could be the missing link that makes cross network travel much better.
The only thing is the routing algorithm would need work because up here what's tended to happen is that they've kinda just become large subsidised taxis for individual or groups going point to point rather than a vehicle travelling across the network picking up & dropping off along the way.
Auckland's PT is excellent getting in and out of and through the CDB, which is where the the congestion charges would apply.
Reducing congestion makes everyone who actually needs to drive a vehicle to/from/for work lives' easier.
It's still regressive, like any flat tax, in that the charge will impact lower incomes more. That can be alleviated by moving marginal tax rates to compensate.
