[4] Walter Burley Griffin's master plan for Canberra proposed the construction of a tram network and a heavy rail line.

Before 1989, the ACT had been directly administered by the Federal Government thus any large public infrastructure expenditure in Canberra was subject to national scrutiny.

[9] The Gungahlin proposal followed a 1991 Murdoch University report, Towards a More Sustainable Canberra, which suggested the city was too car-oriented and should implement a light rail system along the Y-Plan.

[10] In 1993 a report by Maunsell-Denis Johnston and Associates found that a dedicated inter-town busway was a more viable transport option for Canberra than light rail.

[31][32] Expressions of interest were received from the following consortia:[33][34] In March 2015, the government announced that ACTivate and Canberra Metro had been selected to move on to the Request for Proposal stage of the procurement process.

This encompasses the automatic vehicle location, traffic signalling priority, traction power & infrastructure SCADA, CCTV and passenger information systems, amongst others.

[86] The consortia participating in the procurement process for the initial line were asked to develop plans for an expanded route from the City Centre to the Defence headquarters in Russell via London Circuit and Constitution Avenue.

[87][88] The ACT Government decided not to proceed with the expanded route but committed to releasing a plan for a second stage of the light rail network before the October 2016 territory election.

It was considering extending the line not only to Russell but to the broader parliamentary triangle, possibly including Canberra Airport and the Australian National University.

At that stage, the only firm decisions the government had made about the route were that it would run from Alinga Street to the Woden Town Centre and use Commonwealth Avenue Bridge to cross Lake Burley Griffin.

[97] In March 2019, the Commonwealth Government offered its support for the extension to Woden, however, it favoured a different path around Capital Hill, arguing for a route along the State Circle.

[98] A delay in the federal government response meant planning work for the line was postponed, though choosing to not pursue the Barton route could mean a simpler regulatory process.

[98] The ACT Government is now investigating the State Circle route, which involves some technical challenges due to steep gradients for light rail.

[101] In mid-July 2019, the ACT Government submitted a referral for Stage 2A to the Australian Department of Environment and Energy, covering the extension from Civic to Commonwealth Park as well as an expansion of the depot in Mitchell.

[102] In September 2019, the ACT Government approved the business case for Stage 2A, confirming the three new stops on the route and the requirement for London Circuit to be raised at Commonwealth Avenue where the light rail will travel.

[113][114] In mid-July 2019, the ACT Government submitted a referral for Stage 2B to the Australian Department of Environment and Energy, covering the extension from Commonwealth Park to Woden.

[115] In October 2019, the ACT Government released its infrastructure plan which included stage 3 of light rail going from Belconnen to Canberra Airport via Civic, with the Civic–Belconnen section built first.

Instead, they suggested the establishment of dedicated bus lanes along the same corridor, presenting it as a more practical and financially responsible alternative to the proposed rail system.

This proposal aimed to address growing public concerns about the cost, feasibility and long-term implications of the light rail extension, sparking widespread debate about the future of Canberra’s transport infrastructure.

[120][121] The Canberra Liberals argued that dedicated bus lanes would deliver substantial improvements in public transport connectivity and efficiency while avoiding the high upfront costs associated with light rail construction.

Unlike light rail, which requires extensive investment in fixed infrastructure such as tracks, overhead wiring and stations, dedicated bus lanes could be implemented using existing roads with comparatively minor modifications.

Light rail, they contended, has the potential to reshape urban development patterns by encouraging higher-density housing and commercial activity along its corridors.

Proponents also argued that light rail’s fixed infrastructure gives it an edge in attracting investment and instilling confidence in businesses and residents, who view it as a permanent and reliable form of transport.

Supporters of the light rail extension highlighted its potential to reduce Canberra’s overall carbon footprint, contributing to the city’s ambitious climate change goals.

[120][121] In its budget submission, Public Transport Association of Canberra expressed support for expanding the light rail network to include the airport.

The association advocated for extensions as a means to reduce transport emissions and provide a sustainable, efficient travel option for airport passengers.