Tunnel Tales (3 of 3) – Rubbery figures: why the West Gate Tunnel doesn’t stack up

The West Gate Tunnel doesn’t stack up and it should never have been approved.
Its economic benefits were overstated in the business case. Rather than $1.30, the project will probably return only $0.60 per dollar invested.
It doesn’t stack up financially either. Transurban needs $2.6 billion from the public purse, plus more toll revenue from CityLink, to make it work.

Tunnel Tales (2 of 3) – transport modelling and the ‘single loop’

Transport modelling for the West Gate Tunnel was not done to prescribed standards.
It contains illogical methodology and errors that probably resulted in significant over-estimates of future traffic on the project.
It also can’t be shown to be mathematically stable, which is a fundamental requirement of such modelling. It therefore shouldn’t have been used for the cost-benefit analysis, nor as a basis for the environment effects statement.
The same is true for East West Link and North East Link, which used the same modelling processes.
Transport modellers must take heed of these issues. Concurrent peer reviews must be compulsory.
It’s time to lift the game and do it properly.

Tunnel Tales (1 of 3)

The Government’s assessment of the West Gate Tunnel contained significant errors in the transport modelling and the cost-benefit analysis that made the project seem a lot better than it was. It should never have been approved, and I predict that when it eventually opens it won’t deliver the claimed benefits.