On 14 December 2025, three years later than first promised, the West Gate Tunnel opened to traffic under Melbourne's inner west. A truck driver hauling freight out of the Port of Melbourne could, for the first time, bypass the queue that had backed up along the West Gate Freeway and through residential streets in Yarraville and Spotswood every peak hour for a decade. Ten kilometres north, a commuter in Reservoir no longer waited behind a boom gate that used to drop for minutes at a stretch as Hurstbridge line trains rattled through — the level crossing near her home had been dug out and replaced with a rail bridge years earlier. These are the payoffs Victoria's Big Build was sold on: a fast-growing state that needed a second river crossing, a rail tunnel under its own CBD, and fewer places where a train and a car could meet at speed. All of that has arrived, or is arriving. But the tunnel the truck driver now uses cost close to double what the government first put on the table, and the freeway link still under construction in the city's north-east has grown by tens of billions of dollars before a single lane has opened. The Big Build is both of these things at once — real infrastructure, built at a cost the state's own Auditor-General has spent a decade documenting as consistently, substantially higher than what Victorians were told to expect.
What the government did
Victoria's Big Build is the collective name for the state's transport construction pipeline, launched under the Andrews Labor government from 2014 and continued by Premier Jacinta Allan since September 2023. It now runs to roughly $140 billion (approx.) in projects under way or planned, across more than 100 road and rail jobs (Victorian Government, Big Build program overview, bigbuild.vic.gov.au). In January 2019 the government folded the separate authorities running its biggest projects — the Level Crossing Removal Authority, the North East Link Authority, the West Gate Tunnel Authority, Rail Projects Victoria and Major Road Projects Victoria — into a single Major Transport Infrastructure Authority (MTIA), which itself merged with the Victorian Health Building Authority in April 2024 to form the Victorian Infrastructure Delivery Authority (VIDA), reflecting how much of the state's capital program now runs through one delivery body.
Four projects anchor the program. The Metro Tunnel, a 9-kilometre rail tunnel under central Melbourne with five new underground stations, was budgeted at $10.9 billion in its 2018 business case and opened to passengers on 30 November 2025, with full peak-hour running from February 2026. The West Gate Tunnel, first costed at $5.5 billion when announced in 2015 and valued by the Auditor-General at $6.7 billion in a November 2019 review, opened on 14 December 2025 at a total cost of roughly $10.2 billion (approx.). North East Link, a freeway connecting the Metropolitan Ring Road to the Eastern Freeway, was costed at $15.8 billion in its 2018–19 business case and remains under construction. The Level Crossing Removal Program, which began in 2015 targeting 50 crossings for $5–6 billion, has since been expanded twice, most recently in 2022 to a target of 110 crossings, first due by 2030 and later pushed to 2032 (approx.); as of May 2026 (approx.), 91 had been removed.
The strongest case
A once-in-a-generation rebuild of how Melbourne moves, with a measurable safety dividend
Put at its best, the Big Build is doing something no Victorian government has attempted at this scale: rewiring a city of five million people's road and rail network inside a single, sustained program rather than one project at a time. The safety case for removing level crossings is not a slogan — it is measured. Metro Trains' own network data, cited in the program's safety reporting, shows train-and-vehicle collisions and near-misses across the metropolitan rail network falling from an average of 21 a month in 2017 to five a month in 2023, a drop of nearly three-quarters as boom gates disappeared. Individual removed sites carried real death tolls beforehand: two fatalities and more than 60 near-misses were recorded at the Main Road, St Albans crossing in the decade before its removal in 2016, and Union Road in Surrey Hills recorded two deaths in 2016 alone, shortly before it too was removed (Metro Trains Melbourne / Department of Transport and Planning, level crossing removal safety data, bigbuild.vic.gov.au). A program partly justified on lives saved has produced a network-wide safety trend running the right way.
The city-shaping case is also real. The Metro Tunnel decouples the City Loop's most congested lines, unlocking rail capacity Melbourne's network had effectively exhausted, and opened new underground stations at Arden, Parkville, State Library, Town Hall and Anzac. The West Gate Tunnel's own business case is intended to remove more than 9,000 trucks a day from residential streets in Melbourne's inner west once its truck bans take full effect, addressing decades of freight traffic through suburbs never built for it. North East Link, once open, is intended to complete metropolitan Melbourne's ring road for the first time and is projected by government to cut travel times by up to 30 minutes on the Eastern Freeway–M80 corridor and take 15,000 trucks a day off local roads. And the government's own figures put more than 20,000 people currently working directly on Big Build projects, a workforce it says supports roughly double that number again in flow-on jobs across the wider economy (Victorian Government, Big Build jobs figures, bigbuild.vic.gov.au). For a state absorbing some of the fastest population growth in the country, building the tunnels, rail capacity and safer crossings ahead of that growth, rather than behind it, is a defensible use of the state's balance sheet.
The evidence: what the Auditor-General found
Victoria's Auditor-General (VAGO) has audited this program more than almost any other area of state government, and the pattern across a decade of reports is consistent. In December 2017, VAGO's first audit of the Level Crossing Removal Program found the original 2015 target — 50 crossings for $5–6 billion by 2022 — had already grown to $8.3 billion (approx.) before the first stage was even complete. A 2018 expansion added a further 25 crossings, taking the estimate to $14.8 billion; the 2022 expansion to 110 crossings pushed the target date out to 2030 and then 2032 (approx.), and VAGO's public reporting does not appear to include a single, updated consolidated cost figure for the fully expanded program. That gap is consistent with what VAGO's October 2020 follow-up audit had already flagged: neither the Department of Transport nor MTIA had completed a full business case for the second stage before the government committed to it (VAGO, Follow-up of Managing the Level Crossing Removal Program, 14 October 2020).
The West Gate Tunnel drew an equally pointed finding. VAGO's November 2019 review of market-led proposals — projects offered directly by a private company rather than tendered — found the government approved Transurban's unsolicited West Gate Tunnel proposal without adequate proof it represented value for money, and that Treasury officials failed to warn government that extending Transurban's CityLink tolling to help pay for the project risked handing the company an effective monopoly over the western approach to the city (VAGO, Market-led proposals, November 2019). The project then ran three years late, after a dispute over contaminated soil disposal stalled construction, and by its December 2025 opening cost roughly $10.2 billion (approx.) — close to double its original $5.5 billion estimate.
North East Link shows the same trajectory at greater scale. VAGO's Major Projects Performance Reporting 2023 (approx. November 2023) flagged a possible $6.9 billion (approx.) cost increase before the project's major construction packages were even finalised. Its February 2025 case study within Major Projects Performance Reporting 2024 put the project's total estimated investment at roughly $26 billion (approx.) — an increase of more than $10 billion (approx.) over the 2018–19 business case figure, which Premier Allan has attributed to scope changes, construction-sector cost inflation, supply-chain disruption and the flow-through effects of the pandemic and the war in Ukraine. That same 2024 report, tabled 19 February 2025, found the state's whole major-project portfolio grew by $11.66 billion, or 8.7 per cent of budgeted expenditure, in a single year, and stated that public reporting does not yet let anyone outside government tell whether a given increase reflects an overrun, poor project management, or a genuine change of scope (VAGO, Major Projects Performance Reporting 2024, 19 February 2025). The Metro Tunnel, by contrast, grew from $10.9 billion to an estimated $15.5 billion (approx.) — a smaller proportional increase than the other three, and one government and the Cross Yarra Partnership consortium building it attribute mainly to COVID-era disruption and cost inflation shared between the state and the contractor, rather than the business-case or approval failures VAGO identified on the other projects.
The critique: business cases that don't survive contact with construction
Two failures recur across almost every VAGO report on this program, and neither is really about weather delays or global inflation, even though ministers frequently cite both. The first is business cases that do not survive contact with construction. West Gate Tunnel's approval rested on a Treasury process VAGO found had not tested whether the deal handed Transurban an unwarranted toll monopoly, and North East Link's 2018–19 figure was already showing signs of a $6.9 billion (approx.) hole before the first tunnel-boring machine had turned, according to VAGO's own 2023 tracking. A number that grows by billions before construction even starts is not a project running into unforeseeable headwinds — it is a business case that was too low from the outset, approved on evidence VAGO later found incomplete.
A number that grows by billions before construction even starts was never really the number — it was the opening bid.
The critique: a transparency gap layered on a real achievement
The second failure is disclosure. VAGO's 2024 report on major projects statewide put it plainly: the public cannot currently tell, from what government publishes, whether a given cost increase reflects genuine scope growth the state chose, or a failure of cost control it should answer for. That distinction matters for accountability. When the Level Crossing Removal Program's second stage was added in 2018 without a full business case, per VAGO's 2020 follow-up, Victorians were asked to fund several billion dollars in additional crossing removals without the standard economic test the first stage had been held to — not because the case for safer crossings was weak, but because the government chose not to make that case in the way its own rules required. Genuine achievements — a finished Metro Tunnel, a finished West Gate Tunnel, a rail network measurably safer at former level crossings — do not require inflated original estimates to justify them. The repeated gap between what Victorians were first told and what they were eventually asked to fund is a transparency failure layered on top of a real infrastructure success, not proof the projects themselves were wrong to build.
The blow-outs, project by project
Line up the four flagship projects against their first published figures and the scale of the escalation is easier to see than in any single audit finding:
- Metro Tunnel — $10.9 billion (2018 business case) to roughly $15.5 billion (approx., 2025) — up about 42 per cent (approx.).
- West Gate Tunnel — $5.5 billion (2015 announcement) to roughly $10.2 billion (approx., December 2025 opening cost) — up about 85 per cent (approx.).
- North East Link — $15.8 billion (2018–19 business case) to roughly $26 billion (approx., VAGO's February 2025 estimate) — up about 65 per cent (approx.), still under construction.
- Level Crossing Removal Program — roughly $6 billion (2015 target) to $14.8 billion after the 2018 expansion alone — up about 147 per cent (approx.), before the program's second, 2022 expansion to 110 crossings, for which VAGO's public reporting still does not include an updated consolidated cost figure.
Zoom out from those four projects to the whole pipeline and the pattern holds. VAGO's fifth consecutive annual review, Major Projects Performance Reporting 2025, tabled 4 March 2026, tracked 110 major projects across 14 government entities worth $149.33 billion (approx.) in total estimated investment. Measured against the same 89 projects it reviewed a year earlier, the program added a further 67 quarters (approx.) of schedule delay in twelve months, and measured against original timelines, 40 of the 81 longest-running projects have now slipped a combined 369 quarters (approx.), with transport projects alone responsible for roughly 161 of those quarters — about 44 per cent (approx.) — more than any other portfolio VAGO tracks. On cost, those same 89 projects moved only marginally in the year to 2025, but VAGO's lifetime tracking tells a sharper story: transport projects' costs have grown a cumulative $8.0 billion (approx.) since original approval, the largest lifetime increase of any sector. Its core finding has not moved across five years of this review — that budget-paper disclosure still does not let anyone outside government tell whether a given cost or schedule change reflects genuine scope growth or a failure of control (VAGO, Major Projects Performance Reporting 2025, 4 March 2026).
A third driver sits inside who builds these projects and on what terms. In February 2026, barrister Geoffrey Watson KC's 136-page investigation into the Victorian branch of the CFMEU, Rotting from the Top, estimated that criminal and corrupt conduct on union-controlled Big Build sites had inflated project costs by roughly 15 per cent, or about $15 billion (approx.) — a figure the state government disputes — drawing on industry interviews describing site-level cost impacts of 10 to 30 per cent from standover tactics, inflated labour-hire arrangements and enforced go-slows. The federal government placed the CFMEU into administration in August 2024 after related findings of systemic corruption, including collaboration between some union officials and outlaw motorcycle gangs; Victoria Police has since laid more than 90 criminal charges and the state's Labour Hire Authority has cancelled licences for 164 firms. That sits alongside a separate, more contested claim in wider political debate: the federal Coalition's "30 per cent CFMEU tax," drawn from 2024 modelling commissioned by the Master Builders Association in Queensland that put the cost of "maximum application" of union enterprise-agreement clauses at 33 per cent in a worst case, built on confidential assumptions and with no independently verified example of an actual Victorian project incurring that scale of increase — a figure the union itself rejects as describing the gap between its enterprise agreements and the award wage, not real project cost inflation. A national Productivity Commission inquiry into public infrastructure costs, examining 31 enterprise agreements in 2014, reached a narrower but still real conclusion: industrial relations arrangements in general construction were adding measurable cost in some states, sites and unions, without going as far as the premium now in political circulation (Productivity Commission, Public Infrastructure, Inquiry Report No. 71, 14 July 2014).
Every one of these extra billions is borrowed, and the compounding effect is now visible in how the market prices Victorian government debt. S&P stripped Victoria of its AAA credit rating in 2020 and Moody's followed in 2021, leaving Victoria the lowest-rated state government in the country. In August 2025, S&P said it would hold Victoria's AA rating only on the government's assurance that it would control operating costs and slow debt growth, and separately flagged an "elevated risk" that the Suburban Rail Loop — the next project in the same pipeline VAGO has spent a decade auditing — would cost more than forecast and force a downgrade of its own (S&P Global Ratings assessment, reported in MacroBusiness, 4 August 2025). A downgrade is not a symbolic penalty: it raises the interest rate at which Victoria refinances the $165.3 billion (approx.) in net debt already on its books, which is exactly the mechanism turning the cost blow-outs documented above into a permanently higher bill for every Victorian taxpayer, not only the ones waiting on a tunnel or a train.
The risk to the future
A capital program now competing with the debt it created for room to move
Victoria's Big Build has been funded overwhelmingly by borrowing, and the state's own numbers show the consequence. Non-financial public sector net debt rose from $49.7 billion in 2019–20 to an estimated $165.3 billion by 2025–26 — a rise driven by both COVID-era support spending and the capital program described above — and is forecast to keep climbing toward roughly $199 billion (approx.) by 2029–30 (Victorian Budget 2026–27, Budget Paper No. 4, State Capital Program; Victorian Budget 2026–27, debt and interest forecasts). Annual interest costs, already around $6.8 billion, are forecast to reach $11.8 billion (approx.) by 2030 — money that buys no tunnel, no train and no rail bridge, and that must be found from the same Budget that funds hospitals, schools and the next stage of this program.
The risk is not that Victoria stops building — a state still adding population faster than any other needs the capacity North East Link and the Metro Tunnel provide. It is that a Budget already carrying the nation's largest state debt load has less room than any other state to absorb the next VAGO finding of a business case that grows by billions once construction starts. The Suburban Rail Loop, the next headline project in the pipeline, has already had its own cost estimate revised upward before its first stage is finished being built. If the pattern VAGO has documented across the Metro Tunnel, West Gate Tunnel, North East Link and the level crossing program repeats on the next generation of projects, the state will be funding those overruns from an interest bill already consuming a rising share of every dollar it raises.