When Melbourne Airport Rail opens, and even if air travel resumes its pre-COVID growth, the trains could be less than half-full at the busiest time of day.
SkyBus and airport trains together could take one-third of journeys to and from the airport. This is a high mode share by Australian standards, but continued growth means that traffic queues on the Tullamarine Freeway will not disappear.
There are of course many uncertainties that could affect these predictions; air travel might not recover to pre-COVID levels, especially if we get our act together on emissions reduction.
INDUCED travel due to changes in the transport network is a well-known phenomenon. For many years, it was ignored in transport modelling, by accounting only for re-routeing of trips rather than mode shifts or origin and/or destination changes. Nowadays, most modelling includes it, thus producing variable trip matrices between scenarios rather than fixed ones. AContinue reading “Induced travel: how quickly do people adapt?”
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.
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.
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.