Thanks for making the effort in putting this case, which clearly raises questions which need to be answered. Most of the time the public simply has to accept the PR the government feeds it.

A decent commuter train service would prove far more cost effective, get traffic off the road, thereby allowing commuters to use their commute time much more productively, and arrive far less stressed.

As usual, the Conservatives are trying to look after their mates; and their privatization plans?

If we could just point to one example where privatization has resulted in lower fees and charges, they could make a case for some of it?

Instead, the usual experience is higher fees and charges, and therefore, money being necessarily diverted from essential discretionary spending! Which invariably results in further economic contraction!

And an inter city very rapid rail service, could be paid for with the later resale of newly resumed and rezoned land, adjacent to the new lines.

New urban development replete with brand new CBD's and industrial estates, will also mitigate against inner city over development and gridlock!

Moreover, we remain one of the few countries to use thirty year self terminating bonds, to get some income earning infrastructure built!

And madness that flies in the face of a national super fund bigger than our economy!

One is reminded of the old joke that goes; a baby sardine swimming alongside its mum, looked up and saw the gold Coast.
Whereupon, he remarked, look mum, tinned people!

Everything the author points up against the economics of the projects
completely misses the parameter that will crash the traffic numbers.
The cost of fuel will force most commuter traffic off these roads.
By the end of this decade world oil production will have started down
very significantly and the cost will be unsustainable for long drives
to work plus tolls five days a week.

I suggest you read the articles on the motorway economics on Matt Mushalik's
web site crudeoilpeak.info
He has analysed all the Australian motorways and their financial failures.
The upshot is the motorways are destined for failure as their finance
program requires heavy traffic number for the next thirty years.
There is no guarantee of cheap fuel for anything like that period