Airport rail study was doctored to ensure Sunshine ‘won’ shortlist of routes, commission told

The allegation is that the airport rail study did not compare routes fairly. A secret working group was allegedly directed to build evidence supporting Sunshine before the 2018 election. Its work was kept from colleagues, and meetings were not diarised.

The key mechanism was an alleged increase in Maribyrnong’s tunnelling requirements. Experts who reviewed the route calculated that 3.5 unnecessary kilometres of tunnel added between $3.8 billion and $4.6 billion to its estimated cost. The resulting estimate was $20 billion to $25 billion, compared with $8 billion to $13 billion for Sunshine.

That comparison made Sunshine appear clearly cheaper and easier to justify. The Victorian government endorsed Sunshine in August 2018, followed by the federal government in November. Jacinta Allan denies the allegations and is expected to give evidence. The claims now put the project’s business case and funding commitment under scrutiny.

The Melbourne Airport Rail Link, or MARL, is a proposed rail project intended to connect Melbourne Airport with the city. The article describes it as a priority project backed by a $12 billion joint state and federal funding commitment, although the route and business case are now being challenged.

Sunshine would take the airport line through Melbourne’s western suburbs and was the route ultimately endorsed by both governments. Maribyrnong was described as a more direct route to the city. It would have passed beneath Highpoint shopping centre and opened disused defence land for residential development.

The routes also differed sharply in their published cost estimates. Sunshine was estimated at $8 billion to $13 billion, while Maribyrnong was put at $20 billion to $25 billion. A group of experts later calculated that Maribyrnong’s average cost could have been $16.5 billion in 2018 dollars, suggesting the comparison may have been distorted.

The study gave Sunshine an estimated cost of $8 billion to $13 billion. Maribyrnong was priced at $20 billion to $25 billion. On those published ranges, Maribyrnong appeared between $7 billion and $17 billion more expensive, depending on which ends of the ranges are compared.

The most striking alleged distortion was the tunnelling allowance. The planning expert and former colleagues calculated that 3.5 kilometres of unnecessary tunnel had been included in the Maribyrnong estimate. They said this added between $3.8 billion and $4.6 billion in 2018 dollars.

Their alternative calculation produced an average Maribyrnong cost of $16.5 billion in 2018 dollars. That would still make Maribyrnong more expensive than the published Sunshine range, but not by the dramatic margin shown in the strategic appraisal. The estimates were later built into the 2021 business case, making the disputed figures consequential for the project’s justification.

A multibillion-dollar cost gap can dominate a route comparison. The strategic appraisal priced Maribyrnong at $20 billion to $25 billion, versus $8 billion to $13 billion for Sunshine. The article says this comparative cost was a critical factor in tipping the decision towards Sunshine.

The earlier 2012 study ranked the direct-tunnel Maribyrnong option first among 22 routes, with Sunshine a close second. The article also describes Maribyrnong’s potential to open disused defence land for housing. However, it does not provide separate scores for passenger benefits, business benefits or inner-north-west development.

The alleged mechanism was therefore simple: inflate a major cost category, then use the resulting total to make the preferred alternative appear better value. The estimate was published in 2018 and carried into the 2021 business case. If the allegations are substantiated, the route decision and the $12 billion funding commitment could face renewed scrutiny.

The article identifies Jacinta Allan, then public transport minister, as the politician alleged to have directed the secret working group. Ben Carroll is identified as the premier’s priority project, while Daniel Andrews was premier during the 2018 route debate. Malcolm Turnbull was prime minister when the federal government announced funding.

The working group allegedly included Transport Department public servants and outside consultants. They were reportedly told not to discuss their work with colleagues or direct reports and not to diarise meetings. The planning expert who raised the allegations worked with former rail engineering and major-project costing colleagues.

The Victorian government endorsed Sunshine in August 2018, and the federal government followed three months later. Turnbull had earlier announced $5 billion in federal funding and preferred Maribyrnong. Together, the state and federal governments later committed $12 billion. Allan denies the allegations and is expected to be called before the royal commission.

In 2012, a study commissioned by the former Liberal state government ranked Maribyrnong, then called the direct-tunnel option, first among 22 possible routes. Sunshine was a close second. This established Maribyrnong as a strong alternative before the later political decision.

The contest changed in April 2018, when Prime Minister Malcolm Turnbull came to Melbourne and announced $5 billion in federal funding. Maribyrnong was the federal government’s preferred route. Daniel Andrews did not appear at the announcement, and the article says he was focused on unveiling the Suburban Rail Loop as an election promise.

A strategic appraisal published in July 2018 gave Maribyrnong a much higher estimated cost than Sunshine. Victoria formally endorsed Sunshine in August. The federal government followed in November. The article alleges that a secret working group helped produce evidence for that outcome, while Allan denies the claims.

A public infrastructure business case sets out why a project should proceed. It normally compares options, estimates construction and operating costs, assesses expected benefits and identifies major risks. For a multibillion-dollar rail project, it should let governments and the public see how the preferred option was selected.

Cost estimates must use consistent assumptions across routes. Benefits should be measured in comparable ways, including transport outcomes and broader development effects. Independent reviewers should test tunnel lengths, engineering choices, demand forecasts and cost ranges. Records of meetings and instructions also matter because they help show whether analysis was impartial.

The article illustrates why these safeguards matter. Maribyrnong’s estimate allegedly included 3.5 unnecessary kilometres of tunnelling, adding $3.8 billion to $4.6 billion. Those figures entered the 2021 business case and influenced the route decision. The royal commission’s examination could affect confidence in the business case and the $12 billion funding commitment.