Transportation Deployment Casebook/2025/Busways in Australia

Technology and definition

A busway is a length of roadway that is used exclusively by buses, with general traffic excluded. Emergency service vehicles and busway operations and maintenance vehicles may also use the roadway, but it exists entirely for the purpose of conveying buses.

This is distinct from a bus lane which is a portion of a roadway that is dedicated to buses but is not physically separated from general traffic lanes and often serves a subsidiary purpose such as a turning lane or off-peak parking and loading.

Busways are associated with Bus Rapid Transit (BRT). BRT is the ‘software’, the operational structure of service running in part, or entirely, along a busway (the ‘hardware’). BRT systems have evolved (and in some cases devolved) over the 50 years of their history to the point where a myriad of different services lay claim to the BRT title. These systems range from branded buses operating in mixed traffic, such as the Sydney B-Line, to ‘full BRT’ systems that include off-board fare collection, level platform boarding and full grade separation.

In order to address the problem of defining BRT, the Institute of Transportation and Development Policy developed a ‘BRT Standard’ that scores BRT systems on a wide range of categories to determine one of five classifications: Gold, Silver, Bronze, Basic and Not BRT. The closest antipodean system to a ‘Gold’ BRT is the new Brisbane Metro which features branded buses, level boarding, high frequency service but uses on-board fare collection and includes a small number of at-grade intersections. As this system is new it is not yet rated, however the South-Eastern Busway along which the Brisbane Metro mostly runs is a 'Silver' certified BRT System.

A busway is more readily defined and for that reason this study analyses busway systems across Australia and not the BRT (or ‘Not BRT’) services that operate on them. The essential characteristics of a busway are relatively straightforward for anyone who is familiar with a road. A busway is a sealed road surface, generally either asphalt or concrete, typically of one lane in each direction with indented bus stops at periodic intervals along the route, typically with a wider stop spacing than on-street bus services. A busway is often painted red, if only at the threshold where it intersects with the general road network. There will be signage to indicate that the road is for buses (and certain other exempted vehicles) only and usually some form of enforcement such as cameras or ‘car traps’ that physically block smaller vehicles from entering the busway.

Busway stops are more substantial than a typical suburban bus stop and, at a minimum, provide a shelter, easily memorable stop name and some service information. More well-developed systems include electronic passenger information displays, level boarding and other facilities that one may expect to find at a train station or larger bus interchange.

Busways too can fall upon a spectrum. The M2 bus lanes in Northern Sydney, for example, are excluded as the lanes are mostly not physically separated from general traffic. The Moore Park busway in Eastern Sydney is excluded because it is very short, the stops along it are functionally regular kerbside bus stops and the lack of intersection priority means that it is not materially quicker than buses running in mixed traffic on the adjacent Anzac Parade. Many cities include kerbside, or even centre-running, bus lanes and short sections of bus-only road, but these are not considered busways and will not be considered in this analysis. This study will consider only sections of busway that are at least three kilometres in length and provide most of the trappings of a busway system including being almost entirely physically separated from general traffic, having improved stop infrastructure and a degree of grade separation.

Busways and BRT fall on a spectrum and this study has drawn a line in the sand as must be done, although the exact point as to where this line should be drawn will always have a somewhat arbitrary nature.

Main advantages and main markets

Buses are the most ubiquitous form of public transport across Australia because they are cheap, flexible and, in a world built for cars, readily applicable in almost any urban context. Their limitations are that buses, in mixed traffic, are not usually an attractive or efficient form of transport for moving large volumes of passengers. Cities or suburbs that have outgrown their bus network may seek to develop a fixed route, separated public transport corridor to provide a higher capacity and more reliable service along a key alignment.

This goal can be achieved using a wide variety of different modes including light rail, light rail transit (a sort of light rail/metro hybrid popular in North America), metro or busway. Each of these modes can be modified in different ways to create the enormous diversity of transit systems that exist across the globe. Busway systems stand out as the cheapest form of separated public transport. This is in part because buses are an abundant ‘off the shelf’ vehicle type and road construction and maintenance knowledge and procedure is embedded in every jurisdiction in Australia. It is also because the bus services that use a busway system can also run on regular roadways and in mixed traffic. This allows a system to be developed where the most expensive or technically challenging parts of the network are not built out, with buses instead using public roads through these sections. This is generally not possible with a rail-based system.

For these reasons busways are mainly constructed in:

1. smaller cities
2. cities that lack access to the finance, or that cannot justify the cost, required to build a rail-based system from scratch
3. urban peripheries where the busway connects to a higher capacity or faster rail transit at interchange stations, and
4. cities embarking on construction of their first separated public transport corridor

In Australia we can see examples of the first three of these four typologies:

1. Australia’s first busway was the Adelaide O-Bahn, a guided busway that opened in 1986, in a city with a population of just over one million people.
2. Australia’s busway that best meets the standards of ‘true BRT’, Brisbane Metro, launched in January 2025 along existing busways. Its name, something of a misnomer, is such because it was originally designed as a rubber tyred metro system, similar to the Paris Metropolitain, however due to budget constraints the system was changed to BRT with the ‘metro’ name remaining. A decision that the Chair of Transport at Brisbane City Council has acknowledged as ‘confusing’.
3. The Sydney T-Way network that hubs at Parramatta Station, in Western Sydney, provides separated transit corridors that connect to metro and train services across lower density parts of the city that otherwise lack adequate public transport.
4. No Australian city has ever built a busway as its first form of separated public transport. There are a handful of smaller Australian cities including Darwin, Hobart, the Sunshine Coast and Cairns that do not have any rail based public transport. Should any of these cities seek to invest in a separated public transport corridor, it is likely that busway technology would be investigated as an option. Busways have been touted to improve access to Hobart’s Northern suburbs, notably along a disused rail corridor.

Historical context and invention of the busway

While small lengths of bus only roadway date back to the 1930s, the first busway systems were developed in the late 1960s and early 1970s. Two of the pioneering systems were the Runcorn Busway, built to serve the Runcorn New City on the periphery of Liverpool, England, and the Curitiba Rede Integrada de Transporte that launched in 1974 and remains one of the world’s most significant and well known busway systems.

At this point in time enormous shifts were occurring in urban mobility, following the decline of tram systems across much of the Western world, the rise of automobile ownership, the subsequent spree of motorway building and the changes to land use patterns that were intertwined with this process. Busways were a solution that combined existing technologies in a new way to address the challenges arising from a primarily auto-centric urban transportation system. As cities across the world grappled with the problems of congestion and the reality that non-subsidised mass transit was only viable in rare cases, busways were an affordable and practical solution.

Australia’s first busway is illustrative. The Adelaide O-Bahn is a guided busway in which buses fitted with additional side-facing guide wheels run along a fixed guideway. Some theme park rides are designed in the same manner but the O-Bahn is otherwise unique in Australia. This system allows buses to operate on regular roads and then, upon entering the O-Bahn, be steered by the guidewheels rather than the bus operator. Buses can travel safely in this guideway at up to 100km/h. This system was built at a time when Adelaide had removed all but one of its tram lines and the railway, then as now, was underperforming in terms of patronage and modeshare. Buses were seen as a solution to the city’s transport problems and busway technology allowed the city to develop a separated public transport corridor to the underserved and growing Northeast without investing further in its declining rail transit networks.

Early Market Development

The initial market niche of busways was in cities that wanted a separated public transport line or system but did not want, or were unable, to develop a new (or expand an existing) rail-based transport network. This remains the primary driver of busway systems today.

A well-designed busway can have a theoretical maximum patronage that is competitive with light rail and even smaller metro systems. Factors like the degree of grade separation, vehicle size and manner of operation are a larger determinate of network capacity than whether the vehicle has rubber tyres or metal wheels. Aside from lower cost, the key benefit of a busway is its ability to support and enhances bus services running along public roads.

In many cases a suburban busway system is built from the edge of the Central Business District (CBD) of a city out into the suburbs. As the usage of the system grows, the more costly process of better connecting the busway into the CBD is undertaken. There are several examples of this in Australia.

The Adelaide O-Bahn was built out in the 1980s and then was expanded with a short tunnel in the 2010s to improve access into the CBD. Similarly, the Brisbane South-Eastern Busway initially ran from the southern edge of the CBD out into suburban Brisbane. Over time the network was expanded in inner ring neighbourhoods. In 2025 a tunnel under the CBD linking the Northern and Southern CBD termini of the network was completed, which allows through running of the busway system. As the cheaper parts of these networks were built out, the demand they generated created the political will to undertake construction of more costly sections of the network.

Another development in the process of busway delivery has been the pairing of busway expansion projects with urban motorway and highway expansion. In Sydney, much of the Northwest T-Way parallels Windsor Road and was built at the same time as a significant duplication of that road. In Brisbane, most of the South-Eastern Busway has developed in tandem with the construction and expansion of the M1 motorway it parallels.

This suggests a symbiotic relationship between highway building and busway construction that does not exist with rail projects that instead typically compete for funding with autocentric transport projects like highway and motorway expansions. The currently under construction Eastern Busway in Melbourne is the city’s first busway and demonstrates both of these trends. It will run from suburban Melbourne to the CBD fringe where buses will continue in mixed traffic and is being delivered as part of a widening of the Eastern Freeway that it will parallel.

The Role of Policy

The policy environment that most aligns with the growth of busway systems in Australia has been the acknowledgement from a government perspective that motorway development and auto-centric planning cannot scale and provide the same benefits relative to their cost of public transport projects. This is a geometric problem. It is simply more expensive to move people at high volumes that are spread out in private vehicles than to move people in modes of transport that do so at a higher density.

Stagnation in the expansion of public transport networks befell all Australian cities between the post World War II years when cities dismantled their tram networks until a public transport network renaissance began from the 1990s. The exception were small rail network improvements to facilitate access to the Central Business Districts in Sydney and Melbourne which commanded a much higher rate of public transport modeshare than other parts of those cities, even through periods of lower public transport investment.

Growth Phase

The growth phase of Australia’s busways occurred from 2000 to 2012 (see Figure 1). Over this 13-year period 84 kilometres of busway opened across two Australian cities, representing 74% of all busways that have been built (or are currently under construction) in Australia.

While Australia’s first busway was a guided busway, there has been no adoption of this technology since then. The two systems that developed in the growth phase are in Brisbane and Western Sydney and are traditional busways that use no technology beyond that which can be found in regular roadways. This includes road surface and construction technologies, traffic signal technologies (including in some instances bus priority) and enforcement technologies such as cameras.

Brisbane has favoured grade separated busways, whereas in Western Sydney there are many intersections where the busway interfaces with general traffic. Brisbane is home to Australia’s most significant busway system and the introduction of bi-articulated buses, an Australia first, alongside the rebranding of their busway system as ‘Brisbane Metro’ continues to place the system at the forefront of busway development in Australia. Brisbane is the only city in Australia that has a sustained plan for future busway growth.

The Western Sydney T-Ways have not expanded since they were first built in 2002 and 2007. These systems are generally considered to have underperformed, failing to reach patronage targets or stimulate transport-oriented development along their length. Since this time Sydney has focused public transport investment in rail based modes; expanding the heavy and light rail networks, building a new metro system and improving the functioning of the on-street bus system. This included the roll-out of the ‘BRT light’ B-Line service in 2017, which provides high frequency service on high capacity, branded buses but operates almost entirely in mixed traffic.

Maturation

Maturity in Australia’s busways set in after 2012. Since then, there have been minor expansions to the O-Bahn with a short CBD tunnel, several minor expansions in Brisbane, two of which are still under construction, and a forthcoming new busway in Melbourne, the city’s first, expected to open in 2028.

The O-Bahn tunnel and Brisbane Metro are upgrades to increase reliability for buses using the busways rather than expanding into new markets. The expansion of Brisbane South-Eastern Busway and Melbourne’s new Eastern Busway and both occurring in tandem with motorway widening projects.

These two different types of growth are indicative of the maturity of the busway market in Australia. There appears to be little appetite for significant expansion unless funded alongside road construction. In future years it is likely that Brisbane will expand its busways further, possibly tunnelling under sections of the network where buses currently operate on surface roads, and by expanding further along each existing route alignment.

Future opportunity exists to enhance Australian busways to more closely approach the level of service and ride quality of rail-based transport modes. Further grade separation or using electronic solutions to the problem of intersections by providing ‘guaranteed green’ lights to vehicles using the busway could help make these systems more desirable. In particular, Sydney’s T-Ways have failed to provide the time savings expected because of the number of intersections and the lack of bus priority at them. Upgrading stop infrastructure to better reflect what is generally found at rail stations, including level platform boarding and consistently working electronic next service displays, will improve the customer experience of busways.

As we move into a future marked by higher density urban forms, rail-based transit will continue to be more desirable for its high capacity, strong public perception and consistent ability to stimulate transport-oriented development. Perhaps financial constraints leading from lower economic growth and ever-increasing infrastructure costs will lead to a renaissance of the simple busway in Australia in years to come.

Quantitative Analysis

S(t) = S_max/[1+exp(-b(t-t_i)] where:

• S(t) is the total length of busways in Australia in kilometres
• t is time in years between 1986 and 2028
• t_i is the inflection time which occurs in 2006
• S_max is saturation status level, the expected maximum network extent to best fit the data which is calculated at 116 kilometres.
• b is a coefficient equal to 0.142346825

Figure 1 - Total Kilometres of Busways in Australia as observed and predicted by the described S-curve

Table 1 – Busways in Australia in kilometres as observed and predicted. Data was sourced by using aerial imagery (Google Maps) to measure busway length.

Year	Observed Busways (kilometres)	Predicted Busways (kilometres)
1986	6	6
1987	6	6
1988	6	7
1989	12	8
1990	12	10
1991	12	11
1992	12	12
1993	12	14
1994	12	16
1995	12	18
1996	12	20
1997	12	23
1998	12	26
1999	12	28
2000	15	32
2001	28	35
2002	28	39
2003	59	42
2004	62	46
2005	62	50
2006	62	54
2007	86	58
2008	88	63
2009	93	67
2010	93	71
2011	94	75
2012	96	78
2013	96	82
2014	96	85
2015	96	88
2016	96	91
2017	97	94
2018	97	96
2019	97	98
2020	97	100
2021	97	102
2022	97	104
2023	97	105
2024	97	107
2025	102	108
2026	102	109
2027	102	110
2028	113	111

The maximum system length recorded is in 2028 at 113km when the Eastern Busway that is currently being constructed in Melbourne is due to be completed. Given there is still an upwards trajectory to the data, the predicted line of best fit required the determination of a maximum assumed network extent. The best fit which resulted in the highest RSQ value of 0.89462 assumed a maximum network size of 116km with an inflection point where growth began to slow in 2006 which is at the midpoint of the 13 year growth stage identified between 2000 and 2012.

The stages of busway development in Australia can be defined as:

Period	Years
Birthing Phase	1986 – 1999
Growth Phase	2000 – 2012
Maturity Phase	2013 – circa 2040 or beyond
Decline Phase	Not able to be determined based on existing data

The model provides a strong correlation to the data as an S-curve is an appropriate fit for this dataset. Busway length in Australia has never declined, although conversion of busways into rail-based transit, general traffic roadway or total closure is possible and may occur in the future. What the model struggles to account for is the extreme growth that occurred in the 13 years from 2000 when 74% of the busways network was built out. Because of the long plateau from 2012 onwards, the model of best fit assumed a maximum network length of 116km. This seems unlikely as busways are a well-established form of transportation in Brisbane in particular and that city has plans to further expand the network in years to come. It also seems possible that as Western Sydney sprawls, busways may be used again to fill gaps in the heavy rail network and that Melbourne may expand their first busway further along the Eastern freeway corridor. For these reasons, and that a busway in Australia has never declined in length, it can be expected that the maturation phase will continue well into the future and ongoing, if slower, growth of busways will occur than what was predicted by the model.