Light rail stage 2: the cost and the benefit

Most weekday mornings, a Woden public servant boards a rapid bus for the run into Civic and watches construction fencing tighten around London Circuit, on the edge of Lake Burley Griffin. That fencing belongs to Light Rail Stage 2A — a 1.7-kilometre extension to Commonwealth Park — and it will not reach her suburb at all. When it opens, expected in early 2028, she will still change onto a bus, because the section that actually crosses the lake to Woden, Stage 2B, has no public cost estimate, no construction contract and, as of mid-2026, no confirmed completion year. She has watched successive ACT budgets commit billions to a tram line she cannot yet ride, in a city of only around 480,000 people (approx.; ABS, Regional Population, 2024-25), and she is entitled to ask whether the numbers still add up.

What the government did

The Barr Labor–Greens government's light rail program began with Stage 1, a 12-kilometre line from Gungahlin to the city that opened on 20 April 2019 at a capital cost of around $675 million, modestly under its $707 million budget (approx.; ACT Government, Stage 1 project accounts). It runs under a 20-year public-private partnership with Canberra Metro, paid an availability charge regardless of patronage, and carried roughly 4.1 million passenger trips in 2023 (approx.; Transport Canberra annual reporting, 2023).

Stage 2, extending the network to Woden, was split into two projects. Stage 2A runs 1.7 kilometres from Alinga Street to Commonwealth Park along London Circuit; costed at around $268 million in the 2019 business case, it rose to a $577 million major-works contract signed in December 2023 with a CPB Contractors–UGL–Pacific Partnerships joint venture, split roughly evenly between the ACT and Commonwealth governments, and is under construction with completion targeted for early 2028 (ACT/Australian governments, Infrastructure Investment Program, Canberra Light Rail Stage 2A; contract announcements, Dec-2023). Stage 2B, the larger and more contested leg, would run nine kilometres from Commonwealth Park across the lake on a new dedicated bridge, through the National Triangle and the Parliamentary Zone, then along Adelaide Avenue to Woden. In May 2026 the government chose a tunnelled State Circle route over an alternative through Barton, following a draft Environmental Impact Statement exhibited from 7 July to 5 September 2025 (Infrastructure Canberra, Stage 2B EIS and route announcement, 2025-2026). No government-endorsed total cost for Stage 2B has been made public.

The evidence: cost, benefit and the audit trail

None of this needs to be taken on trust: the Auditor-General has twice examined the project's economics. A 2016 performance audit of the Stage 1 business case, under then Auditor-General Maxine Cooper, found the nominal, undiscounted cost could reach roughly $1.78 billion over the 20-year contract life once financing and operating payments were included — far above the headline capital figure — and criticised the government for lacking a plan to track promised benefits once the line opened (approx.; ACT Auditor-General, performance audit of the Capital Metro business case, 2016).

The sharper concerns cluster around Stage 2A. In Report No. 8 of 2021, Canberra Light Rail Stage 2A: Economic Analysis, Auditor-General Michael Harris found the 2019 business case produced a benefit-cost ratio of 0.38 excluding wider economic benefits and 0.56 including them — rounded up by Major Projects Canberra to 0.4 and 0.6 — meaning the project, on its own consultant's modelling, was expected to return well under a dollar of value per dollar spent (ACT Auditor-General, Report No. 8/2021). The audit found around $150 million of claimed benefits depended on the tram catalysing the Acton Waterfront development, with no evidence of how; that the case omitted an estimated 17 per cent uplift in capital costs for retrofitting the fleet with wire-free technology; and that it did not cost construction disruption. Separately, Major Projects Canberra calculated its own "blended" ratio of 1.18–1.20 for 2A and 2B combined — the only figure above 1.0 in the record — but the Auditor-General found no documented methodology behind it and could not verify it independently (ACT Auditor-General, Report No. 8/2021).

The earlier, unified Stage 2 business case (City to Woden) told the same story. Cabinet-in-confidence documents from July 2019, released only after the Assembly compelled disclosure, put the recommended route's cost at around $1.5 billion and its return at roughly 94 cents per dollar spent (approx.; ACT Government, Stage 2 Business Case, Jul-2019, released under Assembly order). A still-earlier January 2018 estimate for a comparable option put the cost at roughly $1.07 billion against $590 million in benefits (approx.; ACT Government, Stage 2 preliminary business case, 2018). Every independently reconstructable figure — 2018, 2019, and the 2021 audit — sits below a benefit-cost ratio of 1; the sole exception is the internal blended figure the Auditor-General could not verify.

The critique: a business case that keeps failing its own test

Three independent readings of this project's economics — the 2018 preliminary estimate, the 2019 business case and the Auditor-General's 2021 review — all land below a benefit-cost ratio of 1. The one figure that clears that bar, the 1.18–1.20 "blended" ratio, was produced outside the consultant's process and could not be checked against any documented model. A capital city audit office does not use language like "insufficient attention" lightly; those findings describe a government that built its most expensive infrastructure project of the decade on an economic case its own auditor could not verify, then leaned on the one unverifiable number to justify proceeding.

The escalation compounds the problem. Stage 2A — a modest 1.7-kilometre extension — was costed at roughly $268 million in 2019 and contracted at $577 million in December 2023, more than double in four years, before a single tram has run on it. The Canberra Liberals' calculation that Stage 2A's full 16-year cost, including maintenance, operations, new vehicles and the wire-free retrofit the Auditor-General flagged as missing, reaches around $1.46 billion was built from the Chief Minister's own answers to the Assembly's Budget Review Committee (reported Canberra Times/Canberra Daily, 2024). The government disputes the framing but has published no competing lifecycle figure for Stage 2A, and none at all for the larger Stage 2B — despite a March 2025 Assembly motion giving it 30 days to disclose a current estimate, which it met by declining to release a number it deemed commercially sensitive (Legislative Assembly of the ACT, motion and government response, Mar-2025).

Every independently checkable calculation of this project's return puts it below a dollar for a dollar. The only figure above that line is the one the government's own Auditor-General could not verify.

That transparency gap matters most for Stage 2B, where the real money and complications sit. It runs nine kilometres against Stage 2A's 1.7, needs a new bridge across the lake, and — unlike anything the ACT has built before — crosses the Parliamentary Zone and National Triangle, land governed by the Commonwealth's National Capital Plan rather than ACT planning law. Works within the Parliamentary Zone require approval from both Houses of the Commonwealth Parliament under the Parliament Act 1974, on top of National Capital Authority sign-off for anything touching the heritage-listed vistas and Commonwealth Avenue Bridge approaches that define the national capital's design (National Capital Authority; Parliament Act 1974 (Cth), Parliamentary Zone provisions). That is a second, federal veto point layered on the ACT's own budget process. A government asking Canberrans to accept a sub-1.0 ratio for the easy 1.7-kilometre stage has, for the harder nine-kilometre stage, not yet told them the cost at all.

Heritage, the parliamentary zone and the transparency problem

The May 2026 route decision — a tunnelled State Circle approach over the Barton alternative — followed a draft Environmental Impact Statement exhibited for 45 business days from July to September 2025, required because the project sits inside one of the country's most heritage-sensitive landscapes. The National Triangle and the Commonwealth Avenue Bridge approaches were designed as part of Walter Burley Griffin's original plan for the national capital and carry statutory protection the Assembly cannot amend on its own. A dedicated light rail bridge threaded between the existing road bridges, and a tunnel cut into State Circle near the Parliamentary Triangle, are the direct, costly consequence of routing a modern transit system through a precinct built to a 1920s ceremonial design — and a large part of why Stage 2B's per-kilometre cost is expected to run well above Stage 1's. None of that is a reason the crossing cannot be built. It is a reason the government's refusal to publish a current cost estimate is harder to justify than commercial-in-confidence caution suggests: it has known since at least 2018 that this route would cross a heritage lake and need a vote of both Houses of Parliament, so the constraint is not new information a contractor could exploit. Assembly members voting on future appropriations, and the taxpayers funding them, are entitled to a current order-of-magnitude figure before contracts are signed, not only after.

What the government got right — and what it still needs to show

Stage 1 opened close to budget, patronage has grown, and Gungahlin's corridor has seen real development. Splitting Stage 2 into a cheaper 2A and a harder 2B is a defensible sequencing choice, letting the network build patronage while the far more complex Commonwealth approvals proceed in parallel — and continuing to fund an Auditor-General willing to scrutinise the government's own flagship project deserves credit too. But the core test any multi-billion-dollar commitment in a city of under half a million people should clear is a credible, current, independently verifiable case that benefits exceed costs. On the government's own numbers, reviewed by its own Auditor-General, that case has not been made for the network as built, and has not been made at all for Stage 2B. Until a real cost is published and audited, the honest summary is city-shaping infrastructure resting on a business case that, every time it has been independently checked, has come back below break-even.