High-Capacity Transport for Growing Cities

As populations in Australian cities continue to grow, mass transit must carry more of the passenger task. Australia’s urban road networks are already experiencing rising congestion and increasing freight movements, limiting their ability to absorb additional private vehicle demand. In addition to supporting growing populations and reducing congestion, investments in public transport projects will support reduced emissions and network efficiency. High capacity public transport modes with competitive journey times can also offer affordable mobility compared to private vehicle trips.

Public transport infrastructure must be sized according to population and travel demand to achieve efficiency, sustainability, and cost-effectiveness. In Australia’s largest cities with high passenger volumes, heavy rail or metro networks are often the most appropriate solution, offering high capacity, speed, and reliability along dense corridors. Smaller cities can benefit from light rail and bus rapid transit systems, which provide flexibility and lower capital costs while enabling urban connectivity. Across all city types, buses play a critical complementary role in ensuring an integrated and accessible network by extending coverage to areas where rail is not feasible, serving as feeder services to major transit hubs and providing first and last mile connectivity.^x

There are multiple benefits of investment in high capacity transport networks in our growing cities. Recent data released by Sydney Metro found public transport usage increased significantly following the opening of Sydney Metro City, with over 17.8 million additional ticketed trips across all public transport modes recorded between August 2024 to July 2025, compared with the year prior.⁸² Following Metro City’s opening, there are 3,200 fewer vehicles travelling southbound over the Sydney Harbour Bridge each day, demonstrating how mass transit projects can reduce congestion and pressure on other infrastructure assets.⁸¹ Similarly, the Australian Capital Territory Government’s Light Rail Benefits Realisation Report 2024 found that the light rail project led to an 18% reduction in motor vehicles at certain intersections compared to 2016, and the project supported 6,100 new dwellings along the light rail corridor over the same period.

Other jurisdictions are also delivering significant high capacity transport projects, such as Victoria’s recently opened Melbourne Metro tunnel, which provides enhanced public transport accessibility and capacity, through new stations, integration with other modes and utilisation of high capacity signalling.⁸³ The European Train Control System (ETCS) is the agreed train signalling system for the National Network for Interoperability (NNI) – a shared technical framework designed to ensure interstate freight and passenger trains can operate seamlessly across jurisdictions. Perth’s METRONET provides approximately 72 km of new passenger rail lines and 23 stations, providing greater high capacity transport access and connectivity across Perth, supporting population and economic growth.⁸⁴

Mass transit projects have broader benefits outside of the transport network and can shape how cities grow, unlocking priority areas for housing and employment. Public transport networks often lag population growth and housing in outer-metropolitan areas, resulting in lower levels of public transport access, entrenched car dependency and growing congestion. Improving access in lower-coverage areas will be important for equity and liveability, connecting new housing to employment and improving travel-time reliability.

Investment in urban roads plays an important role in supporting liveability for new housing and employment growth in surrounding precincts, such as the Western Sydney International Airport. However, road upgrades cannot substitute for expanding public transport coverage and frequency which delivers broader network benefits.

Public transport as a mode share in Australian cities is low compared to international cities where sustainable modes of transport, including public transport, are much higher, such as Paris, Hong Kong, Singapore and London. London has a target of 80% of all trips to be made by foot, cycle or public transport by 2041.⁸⁵ Although Australian cities have different urban forms and lower population densities than other global cities, an ambition for similar levels of public transport connectivity in Australia will support housing and liveability outcomes, including net zero.

Australians living in high-growth areas in middle and outer suburbs are significantly underserved by public transport. Residents more than 10 km away from Australia’s largest city centres often lack convenient, frequent and reliable access to public transport services. Areas in major cities most underserved by public transport have been identified by the Climate Council as:

• Blue Mountains, Penrith and Campbelltown in Sydney
• Cardinia, Mornington Peninsula and Fawkner in Melbourne
• Onkaparinga, Playford and Port Adelaide in Adelaide
• Kwinana, Mandurah and Armadale in Perth
• Hills District, Browns Plains and Beenleigh in Brisbane.⁸⁶

In addition to continued investments in high capacity transport networks, governments should continue to implement initiatives to improve the attractiveness of public transport options. This includes ensuring efficient, frequent services and that bus feeder services and active transport infrastructure adequately support access to mass transit systems. Infrastructure that makes use of high capacity transport networks easy and as friction free as possible, such as smart ticketing systems that operate across modes, should also be considered.

The National Road Transport Technology Strategy identifies how intelligent transport systems can improve the reliability and attractiveness of mass transit through the use of technology such as signal priority and Mobility as a Service, where a journey across multiple modes and stages can be booked and paid for on a single platform. In addition, AI has potential to contribute to reducing fuel use and emissions by optimising transport infrastructure systems.⁸⁷

Alongside heavy and light rail networks, bus rapid transit and bus priority networks can significantly improve urban mobility. These systems are quicker to implement and come at a lower cost than rail infrastructure and can therefore be used to support rapidly growing areas. Infrastructure Victoria estimates bus rapid transit^xi has the potential to return around $2.20 for every dollar invested, including benefits from public transport user travel time savings and land value uplift around new bus rapid transit stations.⁸⁸

Any investments in public transport systems need to ensure increased resilience is considered in the face of increasing climate risks.⁸⁹ Opportunities provided by new and emerging technologies and mobility models should also be considered to support enhanced service delivery and increase patronage where latent capacity exists.

Recognising the benefits of mass-transit infrastructure, the Australian Government has made significant investments in public transport projects. Examples of major projects with Australian Government funding include METRONET in Perth, Sydney Metro, Suburban Rail Loop East in Melbourne, Melbourne Metro, Gold Coast Light Rail and Canberra Light Rail.

The Australian Government has partnered with Brisbane City Council in collaboration with the Queensland Government to deliver the Brisbane Metro, a high-capacity transit service connecting the Brisbane CBD to key education and health infrastructure and surrounding areas, with further funding provided to explore expansion opportunities. 

The Australian Government has made commitments to planning for the Belconnen Transitway in the Australian Capital Territory, the Adelaide and Regional Rail Network Extension project, South West Sydney Rail Planning and South West Sydney Rail Extension – Bradfield to Leppington and Macarthur Corridor preservation projects and the Next Generation Rapid Transport for Melbourne’s Southeast project.

Investment in high capacity transport infrastructure is needed to service growing populations in Australian cities, support reduced transport emissions and enable economic and housing priorities. This includes continued targeted investment across multiple modes including heavy rail, light rail and bus infrastructure. Road upgrades that support middle and outer suburbs access, new housing growth, bus priority, new employment precincts and regional connectivity remain important to complement major public transport investments.

Expanding high-capacity public transport networks is a national priority. This includes investment in rail and other modes of public transport across Australia’s capitals and other major cities. Rail proposals should consider implementation and application of high capacity signalling to ensure compliance with ETCS standards where metropolitan networks interface with, or provide access to, the NNI. The 2026 Infrastructure Priority List identifies multiple proposals that are priorities for investment over the next 10 years, including:

• Melbourne Suburban Rail Loop East – the first stage of the Suburban Rail Loop (SRL) is identified as an immediate priority for delivery investment to support a rail connection between Cheltenham and Box Hill. This will reduce travel times, facilitate new housing and connect major employment, health, education and retail areas in Melbourne’s east and southeastern suburbs.
• Melbourne Suburban Rail Loop – Future stages – includes SRL North and SRL West, which incorporates the Melbourne Airport Rail proposal (see Ports Capacity and Connectivity section). The proposal for future stages of SRL is a future investment opportunity in the 5-10 year pipeline that would provide improved connectivity to Melbourne Airport and support housing and employment centre development across the middle and outer suburbs of Melbourne.
• Sydney rail connections from Bradfield to Leppington and Macarthur – includes connections between the Sydney Metro Western Sydney Airport line and existing rail links in South West Sydney. The proposal is a priority for future investment in the 2-4 year pipeline to provide high-capacity public transport services connecting to the Western Sydney Airport and Aerotropolis, guiding land-use planning within key corridors. The Australian Government has committed $1 billion towards securing rail corridors for this proposal.
• Sydney rail connection between Tallawong and St Marys – identified as a future investment opportunity in the 2-4 year pipeline to provide a high-capacity rail connection between the Sydney Metro Western Sydney Airport line and the Sydney Metro North West line, via Schofields and Marsden Park. The New South Wales Government protected a preferred corridor from Tallawong through to Marsden Park for future transport infrastructure, which may support a staged approach to the proposal.
• Perth rail network planning (East Wanneroo Rail Link, Perth metropolitan orbital rail route) –identified as a priority for future investment in the 5-10 year pipeline to investigate the expansion of the heavy rail network to support projected population growth.
• The Wave (Sunshine Coast mass transit) – provides a new passenger rail line between Beerwah and Birtinya, and a proposed future bus rapid transit route connecting the new rail line with the Sunshine Coast Airport. This proposal is identified as an immediate priority for delivery investment to provide high-capacity public transport services within fast-growing suburbs on the Sunshine Coast. The Wave, together with upgrades to Mooloolah River Interchange – considered an enabler of the bus rapid transit connection – will reduce congestion, improve network efficiency and support continued housing development. The proposal will also support delivery of the Brisbane 2032 Olympic and Paralympic Games.
• Ipswich to Springfield transport capacity (South East Queensland) – identified as a future investment opportunity in the 5-10 year pipeline to deliver a new high-capacity transport service between Ipswich and Springfield, which would create a connection between existing rail lines. This connection would improve access to public transport, reduce travel times and support continued housing development and economic growth within South East Queensland.
• Salisbury to Beaudesert rail connection (South East Queensland) – identified as a priority for future investment in the 2-4 year pipeline to progress planning undertaken by the Australian and Queensland governments for a new rail corridor between Salisbury and Beaudesert. Services within this corridor would support rapid population growth in outer urban areas with limited public transport access and provide connections to the Brisbane passenger rail network and interstate rail services. The proposal also provides an opportunity to improve freight rail connections.
• Brisbane Metro expansions – extensions to Brisbane Metro services, including connections to Brisbane Airport, will increase access to public transport and ease congestion, while also supporting housing development and preparation for the Brisbane 2032 Olympic and Paralympic Games. The proposal is identified as a priority for future investment in the 2-4 year pipeline, with the Australian Government previously committing $50 million to the development of a business case and some early and enabling works. Proposal planning will be led by the Brisbane City Council in partnership with the Queensland and Australian governments.
• Gold Coast public transport capacity and access – public transport improvements to north-south and east-west travel on the Gold Coast as part of a broader integrated transport strategy. This proposal is a priority for future investment in the 2-4 year pipeline to provide capacity to meet high growth in forecast demand, which is being driven by rapid population growth within Australia’s sixth largest city. Improved access to public transport will increase liveability and reduce reliance on private vehicles.
• Adelaide public transport improvements – seeks to expand and electrify major passenger rail lines, including rail extensions to key growth areas in the north, northwest, and south of Adelaide. The proposal also includes electrification of the Outer Habor and Belair rail lines and upgrades to address capacity constraints within the Adelaide CBD, particularly around Adelaide Railway Station. This proposal is identified as a future investment opportunity in the 2-4 year pipeline to facilitate a shift to public transport and support increased housing density.
• Canberra public transport improvements – new public transport corridors across Canberra, including future light rail routes, are identified as a future investment opportunity in the 2-4 year pipeline. The proposal will support improved access to public transport and connections to heavy rail and Canberra Airport. New corridors will also provide capacity to meet forecast population growth in identified growth areas, while also supporting increased urban in-fill and new housing development.

Better utilisation of existing public transport networks is a key opportunity for managing growth and improving efficiency. As outlined in our 2024 Annual Budget Statement, optimising current assets and networks can be a more cost-effective method of meeting current and future needs than constructing new assets that increase pressure on the market’s capacity to deliver and add to the growing whole-of-life costs of asset portfolios.

Optimising existing assets and networks can include signalling upgrades, new rolling stock, and bus rapid transit lanes, through to system changes such as improved ticketing or timetable changes. Ease of optimisation can also depend on the mode. For example, buses can be more flexible in their ability to respond to increased demand through increased service frequencies or bus-priority infrastructure.

In addition to being more flexible, bus infrastructure can be a lower cost option to other public transport modes – both in terms of cost of infrastructure and operation. However, when sharing the road network with private vehicles, buses can be susceptible to delays from congestion, impacting their reliability and attractiveness to commuters. Prioritisation of road space for high capacity transport such as rapid transit lanes, priority signalling and interchange infrastructure supports timely, consistent bus services.

Public transport will also play a critical role in supporting Australia’s net zero targets. Passenger cars and light commercial vehicles are the single largest source of transport emissions, comprising 59%⁹⁰ and accounting for more than 10% of total emissions.⁹¹

Shifting car use to public transport ridership is a meaningful strategy to reduce greenhouse gas emissions in the transport sector. Further discussion and analysis on the potential of zero emissions buses is outlined in the Delivering Net Zero and a Clean Energy Economy section.

Current planning and reform activity

Several jurisdictions have undertaken significant reviews into bus networks and infrastructure. One of the recommendations of the Bus Industry Taskforce Second Report in New South Wales was the development of a State-wide Medium Term Bus Plan, which is being developed by Transport for New South Wales with a focus on 10 high-quality rapid routes, 27 frequent routes and other improvements to local services.

In Queensland, the 100 Day Review of Brisbane 2032 Olympic and Paralympic Games Infrastructure identified that upgrades to Brisbane public transport are required to support successful delivery of the Games. This includes improvements to the Eastern and Northern corridors and Brisbane High Frequency Bus Network as well as investigating connections to the airport. The review also recommended improvements to the East-West bus priority corridor and High Frequency Bus Network in the Gold Coast, the Sunshine Coast High Frequency Bus Network and depot upgrades in South East Queensland.

The Victorian Government released Victoria’s Bus Plan in 2021 with six priority actions to make the bus system more attractive and useful for residents. The Northern Territory Government has committed to a review of bus network infrastructure as part of their Bus Safety Reform Strategy and recognised bus and rapid transit corridors as a key infrastructure priority over a 5 year horizon through the Northern Territory Infrastructure Audit 2023.⁹²

Infrastructure Australia supports strategic, long-term planning to identify prioritised programs of work to improve bus infrastructure networks and encourages consideration of identified proposals for investment.

Legacy public transport that is unable to integrate with technological advancements will reduce efficiencies, network utilisation and capacity. Coordinated upgrades of legacy assets alongside the adoption of new technologies is needed to ensure the interoperability of future public transport system that can support the transition to net zero. Upgrades to rolling stock, signalling and train control can require necessary upgrades to rail corridors, stations and platforms. For example, more than one third of Victoria’s regional train station platforms are too short for the six-carriage V/line VLocity trains– the fastest train in V/line’s fleet – preventing higher capacity services to run on these train lines.⁹³

Where appropriate, High Capacity Signalling (HCS) systems should be standardised nationally to support interoperability and skills transfer for businesses and employees in the industry. Current investments in signalling upgrades include automated train protection signals upgrades on the Seaford Line in South Australia, and HCS on METRONET in Western Australia.

Investments in projects providing upgrades to existing infrastructure include extensions to train platforms and future electrification of the Melton Line and upgrades from South Geelong to Waurn Ponds in Victoria, and the relocation of Loganlea Station in Queensland. Continued targeted investment in the renewal and upgrades of existing public transport infrastructure networks is likely to be required to support efficient operation and support emission reduction initiatives.

Better utilisation of existing public transport networks is needed given increasing pressure on current capacity from population growth and long lead times for delivering new infrastructure. Technological advancements are providing new opportunities to maximise the performance and utilisation of existing networks.

Future investment in HCS will support increased efficiency and reliability of public transport networks in major cities. Replacing existing assets, signalling, and train control systems with modern technologies will optimise passenger rail networks by enabling more frequent train services, reducing crowding, and shortening travel times on public transport. 

The 2026 Infrastructure Priority List includes the following priorities: 

• High Capacity Signalling – Perth (METRONET) – this proposal is identified as a priority for future investment in the 2-4 year pipeline to support the implementation of a HCS system (Communication Based Train Control) on Perth’s urban passenger network. This will support optimisation of the network and align with significant Australian Government investment in METRONET projects. Any future signalling upgrades on the NNI (including for Westport) will include ETCS technology. The Australian Government has previously committed $300 million to delivery of program components, including a purpose-built Public Transport Operations Control Centre.
• High Capacity Signalling – Sydney (Digital Systems Program) – this proposal is identified as a priority for future investment in the 2-4 year pipeline to support implementation of ETCS across additional sections of the Sydney network, including the City Circle and Central to Redfern. This includes implementation of a Traffic Management System to support recovery from disruptions and improve the overall resilience and efficiency of the network. Planning for wider HCS implementation should consider how this system will integrate with ETCS on the NNI within Sydney.
• High Capacity Signalling – South East Queensland (ETCS) – this proposal is identified as a priority for future investment in the 2-4 year pipeline to support ETCS implementation across additional sections of the South East Queensland rail network. These sections will support integration with other major projects that incorporate ETCS upgrades, in particular Logan and Gold Coast Faster Rail and The Wave. Installing ETCS across the network will provide capacity to meet future demand forecast for the Brisbane 2032 Olympic and Paralympic Games and beyond. Planning for wider HCS implementation should consider how this system will integrate with ETCS on the NNI within South East Queensland.
• High Capacity Signalling – Melbourne – this proposal is identified as a priority for future investment in the 2-4 year pipeline to support implementation of HCS systems across the Melbourne network. A Communication Based Train Control system has been implemented across sections of the Cranbourne, Pakenham and Sunbury lines as part of the Metro Tunnel project. Planning for wider HCS implementation should consider how this system will integrate with ETCS on the NNI within Melbourne.

In addition to signalling infrastructure, investment is also needed in stations and rail lines to increase the capacity of networks. The 2026 Infrastructure Priority List includes Perth rail lines capacity (also referred to as the Platform and Signalling Upgrade Program), as a future investment opportunity in the 2-4 year pipeline. Lengthening of platforms on Perth’s heritage lines (Armadale, Midland and Fremantle) will enable the use of new higher capacity rolling stock. The signalling upgrades included as part of this program are required to replace assets reaching end-of-life ahead of implementation of the High Capacity Signalling program.

The 2026 Infrastructure Priority List also includes the Melbourne rail upgrade program – North and Melbourne rail upgrade program – West proposals as priorities for future investment in the 2-4 year pipeline. These programs include line upgrades and electrification, as well as station delivery and upgrades across the northern and western sections of the Melbourne passenger rail network.

In addition to optimising rail infrastructure, investment is also required for wider improvements to public transport networks to support integration of modes and improved access to public transport. The 2026 Infrastructure Priority List identifies the Hobart transport network improvements proposal as an opportunity for future investment in the 2-4 year pipeline. This proposal involves implementation of a program of works incorporating upgrades to multiple transport modes (including active transport) and optimisation of freight movements through Hobart.

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x    First and last mile refers to the initial and final segments of a trip. First mile is the segment from the place of trip origin to a public transport hub, such as a train station or bus stop. Last mile is the segment from the public transport hub to the destination. 

xi     Includes rapid transit lanes but not signals or bus jumps.