We are or have reached our population limit in Australia - at least on the east coast. From the perspective of air pollution, water resources, energy, housing and traffic congestion.

However, politicians who have only a short term view will try to convince us otherwise. For anyone living in Sydney with the daily smog, heavy traffic, water restrictions, public transport problems etc and the knowledge that every week about 1000 newcomers are moving in, one can only wonder the why we are letting this situation get worse.

The key to Australia's genuine future prosperity are specific water projects aligned with a planned decentralization programme Nationally.

Day by day Governments Federal,State ,Local are notoriously incapable of planning any major infra structure developments. QED

Dear Pericles, the fact sheet at the end of the url indicates that these costs are calculated from a standard 15,000km pa and on the proportion of city KM in passenger car equivalents and the proportion of time spent stopped in traffic. It is not flaky at all as it would include the proportion of vehicle trips taken on toll roads etc.

The fact sheet includes data for Adelaide, Perth and Canberra as well (but not Hobart) and it is the data for Canberra that really underlines the importance of effective decentralisation as the cheapest solution to metropolitan diseconomies.

Canberra's 2015 projected congestion cost per vehicle km is only 5.9 cents/km while Sydney's is 23.2 cents/km and Brisbane's is 53.5 cents. So any metropolis with a projected population growth of a million extra people over, say, 25 years, can make substantial savings for its existing residents by encouraging some of that growth to settle elsewhere.

A new provincial capital of Canberra's current 300,000 people would not happen overnight but a more realistic 100,000 each in three new capitals would buy almost a decade of valuable metropolitan breathing space at a lower cost than Canberra's 1995 estimate of 2.2 cents/km.

The saving for Sydney would be a net 21 cents/total vehicle pcu km x circa 8400km per capita = $1,764 per person x 300,000 = $529 million pa. For Brisbane it would be a net 51 cents/total vehicle pcu km x 8400km per capita = $4,284 per person x 300,000 = $1.285 billion pa.

That leaves an awful lot of change to cover any duplication costs of additional provincial parliaments, dont you think?

What neither the article nor your post illuminates, Perseus, is a) what exactly constitutes a "congestion cost" and b) who pays it, to whom.

I too saw the spreadsheets, and followed the line items' references to the sources, as far as I was able to do so online. There seems to be a disconnect between the base calculation - kms travelled, time spent stationary etc. - with actual, real dollars.

One of the calculations I found when following the trail identified a "cost of a year's life", which was then multiplied by the putative years life lost due to pollution, caused by congestion etc etc. To me, that is a long trail to follow, since you have to agree with every step (life is shortened by pollution, caused by congestion etc.) and on the calculation (one year of life is worth so much) to be able to work out who is losing and who is winning. After all, two years shorter life may be something of a nuisance to the individual, but release two years-worth of nursing costs to the community.

Until and unless there is some more concrete calculation, the entire argument is nebulous and illusory, fuelled only by the emotion of "wouldn't it be nicer if..." Sure, it would be nicer if the air is cleaner, but putting a dollar value on it in this manner is entirely unconvincing. Except to the folk who make money out of dreaming up the figures, of whom I suspect there are many.

I hope you don't fall off your chair, Pericles, when I advise that I actually agree with your wish to see the original work and follow the entire calculation. If you find it post the url for us here, please.

Car usage is a great indicator of several urban-consolidation woes.

The myth that people living in high rise and on transport nodes not needing or having cars is demonstrated (all over Sydney) to be a false, text book wish, all the more cruel due to the failed rail system and over extension of other infrastructure.

The proposal for a congestion tax, like the incredible developer discounts provided by inept public accountability of these modern day bucaneers, will mean nothing to the rich & privilaged - who will reap the benefits of a faster chaffeur driven drive from the Airport to HQ.

Decentralisation in combination with a radical re-assessment of consumerism might have some more real lasting & measurable results!