There is one very serious problem with this sort of approach. It is a tax on the functioning of a state capital and will, therefore, be incorporated into the cost of delivering government. And this cost will then be spread to all citizens of the state, including those who live in regional towns who can walk to work or drive to work in 5 minutes.

It also does nothing to address the root cause of the congestion which is the continual concentration of the 15% of state GDP in the one capital city. With the exception of Hobart, Canberra and Darwin, our capitals have all grown beyond the point where they create an economic momentum of their own. But they continue to extract GDP from the regions as well and this produces compound growth pressure to the point where serious diseconomies of scale are the norm.

An example of these diseconomies is the new Ipswich Bypass which will cost $2.3 billion to provide 9km of road for a population of less than 400,000. The rest of Brisbane, the SE corner and the rest of the state, will rarely use it.

But if those 400,000 people were spread evenly over the rest of the state under an effective decentralisation policy there will be no need for a new road. An extra 4000 people in each of 100 towns could have their extra 9km of road for less than $500,000 each or a total outlay of only $50 million. In many places the road is already there and underutilised.

That is what effective decentralisation can deliver. A tax on the users of this $2.3 billion road, on the other hand, will only increase the cost further and incorporate those costs into the cost of delivering government, even to the folks in the country towns who will never use it.

A couple of weeks ago I was at Flinders Street Station in Melbourne racing down the pedestrian walkway at Elizabeth St. It was really congested full of people travelling at different speeds and in both directions. I remember 35 years ago when Melbourne's population was half its present size and pedestrian traffic flowed fast through that tunnel, towards the city in the morning and towards the river at night. Today the tunnel is split in 2 so the railway users can't mingle with the Southbank promenaders until their tickets are checked. I realised just how much more pressured we are with half the space of yesteryear and double the population with a severe reduction in customer service.

Christian's plan sounds really complex, not another bureaucratic nightmare, it has to be simple! Ration petrol and raise its price, if every driver gets the same petrol ration then gas guzzlers will be swapped for economic runabouts.

Now how to stop city traffic congestion - improve frequency of public transport, increase car parking at railway stations, have a flat price transport ticket irrespective of distance travelled i.e. all of melbourne metro out to geelong, tralagon ballarat and bendigo is zone 1. At the moment, if you live in outer suburbs and work in CBD the cost of driving and parking is just a little more than the train trip and driving is much faster. Run public transport after dark and on weekends - surprising how many outer suburbs have no bus service. Don't let the ticket inspectors treat public transport users like criminal second class citizens and losers or when they can they will flee to sanctuary of their cars.

There will still be casual workers who will have to drive to work if they are rung up at the start of shift and they have to get to work fast, but to resolve that problem make it illegal and socially unacceptable for employers to rely on that type of staffing practice.

Not sure how to combat kids being dropped at creche, day care or school without punishing the parents.

I don't often agree with Christian, but this makes sense in principle. In practice it may be hard and intrusive to police – the authorities will have to keep track of where all vehicles are, all the time. Also, there needs to be a time of day element in pricing - travelling on an empty freeway at 2am causes no congestion, six hours later the story is very different.

Christian, you’ve presented some good ideas here, but with respect you miss half the picture:

Even if we are highly successful at implementing these things and reducing the average amount of driving and consequent greenhouse gas emissions, we are not likely to reduce, or to keep down, the overall production of greenhouse gases, or traffic congestion…..for as long as the population continues to rapidly increase.

You really do need to tackle this issue head-on if you are serious about achieving the goals that you espouse to.

You talk about capping the number of kilometers per person and setting up a market to trade kilometers, along the same lines and carbon credits. Well, surely a cap in the overall number of consumers is vastly more important. And of course a population cap and hence a limit to the overall impact on our environment and resource base is of vital importance to many other aspects of our environmental and societal wellbeing, and for sustainability.

If a trade was set up in kilometers, it would be pretty meaningless if the overall number of kilometers continued to increase, that is if everyone had the same base-level allocation year after year while the population steadily increased. If the overall level remained constant, then everyone’s share would be steadily declining due to this population growth. So curtailing the continuous growth factor must be a fundamental part of the plan.

Perseus makes a good point. A scheme such as this will result in increased taxes on us all, as well as the obvious increased restrictions on our freedom of movement.

The increased taxes would result from a necessary increase in policing and administration. If such a system is to work and to be anywhere near fair, then the administration regimes would need to be strong…. and that would mean considerably increased bureaucracy, and taxes.

Incidentally Perseus, we have an unfinished discussion on this whole decentralisation business at http://forum.onlineopinion.com.au/thread.asp?article=5523#72603

I have a novel idea...how about building a public transport system that WORKS? I'm so tired of the big stick approach in this country. Yes London has a CBD entry charge, but London also has a subway system that means you don't have to use a car.

This is what Australian planners seem to forget. They want to use all the sticks but offer no carrots. I lived in Japan for 10 years and used a fabulous, clean subway everyday that ran every three minutes - on time, every time. It was a dream and a joy to use. Australia's city buses however are a joke - they're always late, old, overcrowded and infuriating and outside peak hours hardly run at all.

This article is so typical of the money-grubbing Australian approach: price something sky-high so only the wealthy can afford it and then squeeze the masses onto rundown public facilities. Just get a life and build a proper public transport system. If you can't imagine where to start just go to Japan and learn how it's done properly. The lack of public spirit in this country is amazing.

Every time I hear the phrase "road-pricing" my blood boils - JUST BUILD A PROPER PUBLIC TRANSPORT SYSTEM AND YOU WON'T NEED IT.