They are increasingly being seen around the world as a way to unstick traffic jams and reduce pollution while providing a revenue stream for transport improvements.
Singapore, London, Milan and Stockholm are among cities that have them. Los Angeles and New York are heading that way.
So-called Low Emission Zones are also common in European cities, which target older, more polluting, vehicles.
Paris is to squeeze more cars away from its famous Champs-Elysees by 2030 with ambitious plans to reduce space for vehicles, creating pedestrian and green areas. Trees will line the avenue.
Dublin is shifting through the same debate here about whether congestion charges are needed as part of a suite of actions to meet climate goals.
Transport Minister Michael Wood has said he is open-minded about a congestion charge in Wellington and hearings have been held in Auckland on charges and tolls.
Getting people to see the collective benefit in something they could well have to cough up money for is, to put it mildly, a challenge.
Fewer cars in city centres would result in quicker bus journeys to and from work, and more room for pedestrians. It could mean a reduced need for parking buildings in city centres, freeing up space for apartments or other uses.
Kiwis tend to see the worth of a development with an expensive price tag once they've viewed it in reality - rather than when they're being sold it beforehand.
After the "feebate", harbour bridge, and road funding decisions, a congestion charge could be taken by many as yet another measure targeting drivers.
There's a wider question of the balance of carrot and stick, incentives and punitive tools, in dealing with these problems.
Authorities might need to focus more on what they can do to encourage the transport behaviours they are seeking - making the use of rail, buses and bikes easier and a commuting advantage - to reduce car use in Auckland.
When London introduced its congestion charge, hundreds of extra buses were added at the same time. It brings in about £150 million net annually.
Traffic fell after congestion charges were introduced in London and Stockholm, although exemptions for taxis, and Uber-style vehicles proved to be a flaw in the British capital's model.
Congestion charges and tolls could allow necessary transport changes to be made at a faster pace and could be a buffer for lower fuel excise in future years as electric vehicles become a bigger slice of the vehicle market.
Any activity that uses fossil fuels will attract more penalties in future, with incentives focused on pushing renewable energy use.
