The O-Bahn Busway is a

guided bus Guided buses are buses capable of being steered by external means, usually on a dedicated track or roll way that excludes other traffic, permitting the maintenance of schedules even during rush hours. Unlike trolleybuses or rubber-tired trams ...

way that is part of the

bus rapid transit Bus rapid transit (BRT), also called a busway or transitway, is a bus-based public transport system designed to have much more capacity, reliability and other quality features than a conventional bus system. Typically, a BRT system includes ...

system servicing the northeastern suburbs of

Adelaide Adelaide ( ) is the capital city of South Australia, the state's largest city and the fifth-most populous city in Australia. "Adelaide" may refer to either Greater Adelaide (including the Adelaide Hills) or the Adelaide city centre. The dem ...

South Australia South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...

. The O-Bahn system was conceived by

Daimler-Benz The Mercedes-Benz Group AG (previously named Daimler-Benz, DaimlerChrysler and Daimler) is a German multinational automotive corporation headquartered in Stuttgart, Baden-Württemberg, Germany. It is one of the world's leading car manufacture ...

to enable buses to avoid traffic congestion by sharing

tram A tram (called a streetcar or trolley in North America) is a rail vehicle that travels on tramway tracks on public urban streets; some include segments on segregated right-of-way. The tramlines or networks operated as public transport are ...

tunnels in the German city of

Essen Essen (; Latin: ''Assindia'') is the central and, after Dortmund, second-largest city of the Ruhr, the largest urban area in Germany. Its population of makes it the fourth-largest city of North Rhine-Westphalia after Cologne, Düsseldorf and Dor ...

. Adelaide's O-Bahn was introduced in 1986 to service the city's rapidly expanding north-eastern suburbs, replacing an earlier plan for a tramway extension. The O-Bahn provides specially built track, combining elements of both bus and rail systems. Adelaide's track is long and includes three interchanges at Klemzig,

Paradise In religion, paradise is a place of exceptional happiness and delight. Paradisiacal notions are often laden with pastoral imagery, and may be cosmogonical or eschatological or both, often compared to the miseries of human civilization: in paradis ...

and Tea Tree Plaza. Interchanges allow buses to enter and exit the busway and to continue on suburban routes, avoiding the need for passengers to transfer to another bus to continue their journey. Buses can travel at a maximum speed of , but are now restricted to 85 km/h (53 mph). , the busway carried approximately 31,000 people per weekday. An additional section including a tunnel opened in 2017 at the city end to reduce the number of congested intersections buses must traverse to enter the Adelaide city centre. The development of the O-Bahn busway led to the development of the

Torrens Linear Park The Torrens Linear Park was completed in 1997 as the first of its kind developed in Australia where it is the largest hills-to-coast park. It began as a flood mitigation scheme along the River Torrens running westward from the Adelaide Hills, ...

from a run-down urban drain into an attractive public open space. It has also triggered urban development around the north-eastern terminus at

Modbury Modbury is a large village, ecclesiastical parish, civil parish and former manor situated in the South Hams district of the county of Devon in England. Today due to its large size it is generally referred to as a "town" although the parish c ...

Track

The O-Bahn track is made of concrete; it is elevated from the ground because of the poor quality of

alluvial soil Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluv ...

s along the

River Torrens The River Torrens , (Karrawirra Parri / Karrawirraparri) is the most significant river of the Adelaide Plains. It was one of the main reasons for the siting of the city of Adelaide, capital of South Australia. It flows from its source in the ...

, which frequently move due to their high level of

plasticity Plasticity may refer to: Science * Plasticity (physics), in engineering and physics, the propensity of a solid material to undergo permanent deformation under load * Neuroplasticity, in neuroscience, how entire brain structures, and the brain it ...

. On top of the pylons are

concrete sleeper A concrete sleeper (British English) or concrete tie (American English) is a type of railway sleeper or railroad tie made out of steel reinforced concrete. History In 1877, Joseph Monier, a French gardener, suggested that concrete reinforced ...

s on which the track rests. 5,600 pylons were drilled in place to support 5,600 sleepers and 4,200 prefabricated L-shaped track pieces, sited at intervals. Concrete

pylons Pylon may refer to: Structures and boundaries * Pylon (architecture), the gateway to the inner part of an Ancient Egyptian temple or Christian cathedral * Pylon, a support tower structure for suspension bridges or highways * Pylon, an orange mar ...

were cast into the ground to ensure stability, to a depth of up to . The width of both tracks, sitting on the sleepers, is .Northeast Busway Project (Brochure). South Australian Department of Transport (1983).Busway Information, Paper Two: O-Bahn Guided Bus Concept. South Australian Department of Transport (1983). The O-Bahn's concrete tracks were narrower and lighter than those of the initially proposed light rail development, and put less stress on the land. The concrete components were precast and then laid onto piers. At the city end, the O-Bahn begins at

East Terrace __NOTOC__ East Terrace marks the eastern edge of the Adelaide city centre. It is one of the main north–south thoroughfares through the east side of the city. Although the terrace essentially runs north–south between North Terrace and South ...

, as an extension eastwards from

Grenfell Street Grenfell Street () is a major street in the north-east quarter of the Adelaide city centre, South Australia. The street runs west-east from King William Street to East Terrace. On the other side of King William Street, it continues as Currie S ...

into the parklands. The O-Bahn enters an tunnel, completed in December 2017, which curves from east to north, emerging onto bus lanes in the middle of Hackney Road just north of the intersection with Botanic Road and North Terrace. The bus lane continues north to the Torrens River and into the original entrance of the O-Bahn on Hackney Road, opposite the East Parklands, where it enters a tunnel at a speed limited to , due to the tight initial corner, ensuring that the rear tyres (especially trailer tyres of

articulated buses An articulated bus, also referred to as a banana bus, bendy bus, tandem bus, vestibule bus, wiggle wagon, stretch bus, or an accordion bus, (either a motor bus or trolleybus) is an articulated vehicle used in public transportation. It is usua ...

) do not 'scrub' against the track. Speed is gradually increased to for most of the trip to

Klemzig Interchange Klemzig Interchange (previously known as Klemzig station) is a bus interchange operated by Adelaide Metro in Klemzig, South Australia as part of the O-Bahn Busway. History Klemzig Interchange was built as part of Stage 1 of the O-Bahn Busway t ...

. Once en route to

Paradise Interchange Paradise Interchange is a bus interchange operated by Adelaide Metro in Paradise, South Australia as part of the O-Bahn Busway. History Paradise Interchange was built as the terminating station of Stage 1 of the O-Bahn Busway. It was officiall ...

, the speed limit was up to , but has been limited to since late 2012. On some sections was achieved in tests. The average service speed including stops is about . On entering interchanges the O-Bahn ends and the speed limit is . In the interchange area, the speed limit is . The O-Bahn is officially considered a road, due to a court ruling in the early years of the system's operation. This ruling permits the

South Australia Police South Australia Police (SAPOL) is the police force of the Australian state of South Australia. SAPOL is an independent statutory agency of the Government of South Australia directed by the Commissioner of Police, who reports to the Minister for ...

to install

speed camera In everyday use and in kinematics, the speed (commonly referred to as ''v'') of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a scalar quantity. ...

s and fine speeding drivers. Cars entering the O-Bahn are deterred by a large number of signs at entrance points and a sump buster device that rips out a car's

sump A sump is a low space that collects often undesirable liquids such as water or chemicals. A sump can also be an infiltration basin used to manage surface runoff water and recharge underground aquifers. Sump can also refer to an area in a cave ...

(oil pan) if it gets onto the track. An average of four cars per year enter the O-Bahn and must be removed by crane. Linear Park

Buses

The first buses to enter service on the O-Bahn were 41 rigid and 51

articulated An articulated vehicle is a vehicle which has a permanent or semi-permanent pivot joint in its construction, allowing it to turn more sharply. There are many kinds, from heavy equipment to buses, trams and trains. Steam locomotives were somet ...

Mercedes-Benz O305 The Mercedes-Benz O305 was a single deck, double deck and articulated bus manufactured by Mercedes-Benz in Mannheim, West Germany from 1968 until 1988. It was built as either a complete bus or a bus chassis and was the Mercedes-Benz adaptati ...

s. These were modified for O-Bahn use by

Mitsubishi Motors is a Japanese multinational automobile manufacturer headquartered in Minato, Tokyo, Japan.Clovelly Park plant before being bodied by

Pressed Metal Corporation South Australia Pressed Metal Corporation South Australia (PMCSA) was an Australian bus bodybuilder based in Royal Park, Adelaide. History The business originally formed as Freighter-Lawton Industries being rebranded Freighter Industries in 1963.

. The cost was included in the original $98 million budget. Modified

MAN A man is an adult male human. Prior to adulthood, a male human is referred to as a boy (a male child or adolescent). Like most other male mammals, a man's genome usually inherits an X chromosome from the mother and a Y chromo ...

SG280s and SL202s were later purchased. With the Mercedes-Benz O305s approaching their 25-year age limit, tenders were called in 2007 for replacements. The new buses were

Scania K230UB The Scania K series is a series of chassis in Scania's city bus and coach range with longitudinally, straight-up mounted engine at the rear, replacing the K- ( K94, K114, K124) and L-type ( L94) chassis of the 4 series. The K series was fir ...

rigid and Scania K320UA articulated buses bodied by

Custom Coaches Custom Bus (previously Custom Coaches) is an Australian bus body builder in St Marys, New South Wales. History Cycle Components Manufacturing Company In 1935 Stanley Hillsdon founded Cycle Components Manufacturing Company (CCMC) in Guildford, ...

. , these, along with rigid Scania K280UB/K320UB buses, articulated Scania K360UA buses, one diesel/electric hybrid Scania K320UB, and one

Mercedes-Benz O405NH The Mercedes-Benz O405 was a single-decker bus manufactured by Mercedes-Benz from the mid-1980s to the early 2000s as either an integral bus or a bus chassis and was the last VöV SL-II standard bus in production. It was the replacement for th ...

make up the fleet. In the case of breakdowns, a specially designed vehicle nicknamed 'Dumbo' is used to tow buses from the O-Bahn. In the early stages of design it was intended that all buses would have towing ability; however, this was soundly rejected by the drivers' union and 'Dumbo' was purchased. If a tyre blows during a trip the guide-wheel prevents the bus from erratic movement, and a smaller aluminium inner tyre allows the bus to be driven to the nearest station at . The guide-wheel, which protrudes just ahead of the front wheels, is the most important part of the bus when travelling on the O-Bahn. It is connected directly to the steering mechanism, and steers the bus by running along the raised edge of the track. While it is not strictly necessary for drivers to hold the

steering wheel A steering wheel (also called a driving wheel (UK), a hand wheel, or simply wheel) is a type of steering control in vehicles. Steering wheels are used in most modern land vehicles, including all mass-production automobiles, buses, light and ...

when travelling on the O-Bahn because of the guide-wheel, safety procedures require the driver to be alert to their circumstances at all times. A

rumble strip Rumble strips (also known as sleeper lines or alert strips) are a road safety feature to alert inattentive drivers of potential danger, by causing a tactile vibration and audible rumbling transmitted through the wheels into the vehicle interior. ...

before stations is a reminder that they need to resume control. The guide-wheel is the most delicate part of the system and is designed to snap off upon sharp impact; before the O-Bahn was in place, a number of buses were fitted with guide-wheels for their ordinary routes to test their durability. Drivers were forced to be more cautious on their normal trips after numerous guide-wheel-to-kerb impacts. Since June 2018, services are operated by

Torrens Transit Torrens Transit is an Australian bus service operator in Adelaide. It operates some services as part of the Adelaide Metro network under contract to the Government of South Australia. It is a subsidiary of Transit Systems, which is a part of the ...

under contract to

Adelaide Metro Adelaide Metro is the public transport system of Adelaide, the capital city of South Australia. It is an intermodal system offering an integrated network of bus, tram, and train service throughout the metropolitan area. The network has an ann ...

. , the busway carries approximately 31,000 people per weekday.

Interchanges

Adelaide O-Bahn, Modbury Interchange (overpass-northeast)

is the first station, three kilometres (1.8 mi) from the city centre in the suburb of Klemzig. It was built as a connector to the city loop 'Circle Line' bus service, which followed the Adelaide outer ring route. Many bus services bypass Klemzig and the station has limited capacity. It contains a

park & ride A park and ride, also known as incentive parking or a commuter lot, is a parking lot with public transport connections that allows commuters and other people heading to city centres to leave their vehicles and transfer to a bus, rail system (rap ...

carpark with 450 spaces.

is the second station, six kilometres (3.7 mi) from the city centre, in the suburb of

. The terminus before the completion of Stage 2, it is now served by buses from suburban streets, and has a total of 875 car parking spaces in two areas.

Tea Tree Plaza Interchange Tea Tree Plaza Interchange (previously known as Modbury Interchange) is a bus interchange operated by Adelaide Metro in Modbury, South Australia as part of the O-Bahn Busway. It is a central public transport hub for the north eastern suburbs of ...

is the terminus, from the city centre, in

. Adjacent to the Westfield Tea Tree Plaza, it is the largest O-Bahn station. Bus services from this interchange connect to areas as far away as Elizabeth and service the Golden Grove area. It has 700 car parking spaces, after a multiple level carpark was built during a redevelopment in 2013.

Route

Outbound O-Bahn bus routes travel through the

Adelaide city centre Adelaide city centre (Kaurna language, Kaurna: Tarndanya) is the inner city locality of Adelaide, Greater Adelaide, the capital city of South Australia. It is known by locals simply as "the City" or "Town" to distinguish it from Greater Adelaid ...

along

, and enter the O-Bahn via the tunnel (opened on 10 December 2017) through the

Adelaide Park Lands The Adelaide Park Lands are the figure-eight of land spanning both banks of the River Torrens between Hackney and Thebarton and separating the City of Adelaide area (which includes both Adelaide city centre and North Adelaide) from the surro ...

Rymill Park Rymill Park / Murlawirrapurka (previously spelt Mullawirraburka), and numbered as Park 14, is a recreation park located in the East Park Lands of the South Australian capital of Adelaide. There is an artificial lake with rowboats for hire, a c ...

. They then exit the tunnel on Hackney Road, north of the intersection with Dequetteville Terrace, and then proceed northwards along the road in designated bus lanes. Along this stretch the

Adelaide Botanic Garden The Adelaide Botanic Garden is a public garden at the north-east corner of the Adelaide city centre, in the Adelaide Park Lands. It encompasses a fenced garden on North Terrace (between Lot Fourteen, the site of the old Royal Adelaide Hospital ...

is on the left, followed by

Botanic Park Botanic is an adjective related to botany, the study of plants. Botanic may also refer to: * Botanic (District Electoral Area), an electoral ward of Belfast, Northern Ireland, named after Belfast's Botanic Gardens ** Botanic railway station, se ...

. Hackney Road—along with the designated O-Bahn bus lanes—crosses a bridge over the

, with the bus lanes veering easterly, to the northbound entrance of the guided O-Bahn busway. The busway dips below the surface road (Park Road) to join the inbound (southbound) track, both heading northeast. The busway follows roughly the Torrens River valley, but with smoother curves. This means that it crosses the river quite often, with either a park or a few houses on a point surrounded by the river and busway. This occurs a total of eight times before the busway reaches

on the north side of the river. The busway crosses the river again soon after Klemzig and passes Lochiel Park and part of the suburbs of Campbelltown and

to its north between the busway and the river before reaching

. After Paradise Interchange, the busway passes under Darley Road, then over the Torrens for the last time. The terrain becomes steeper as the busway proceeds up along the outflow creek and past the northwestern side of the Hope Valley Reservoir. It proceeds north under

Grand Junction Road Grand Junction Road is the longest east–west thoroughfare in the Adelaide metropolitan area, traversing through Adelaide's northern suburbs approximately 8 kilometres north of the Adelaide city centre. Route Travelling from the Port Adelaide r ...

, then swings east and north again to enter the eastern side of the Westfield Tea Tree Plaza shopping centre precinct, where the guided busway ends at

. Most buses continue on normal roads to service suburbs further afield. All listed routes connect Adelaide City Centre to the named endpoint, but service different suburbs between the O-Bahn interchange and that endpoint.

History

Planning

Adelaide O-Bahn guided busway -- schematic diagram

The greater Adelaide area experienced significant growth during and after World War II. Between 1944 and 1965, the area's population doubled, and the number of private motor vehicle registrations increased 43-fold. In 1955, the state government under Premier Sir Thomas Playford established a Town Planning Committee and commissioned a coordinated plan to guide the future development of Adelaide. The resulting 300-page study, "Report on the Metropolitan Area of Adelaide 1962", laid out a 30-year development plan, including a proposed of improved roadways. Shortly before leaving office in 1965, Playford commissioned a detailed study focusing on the recommended transportation improvements. In 1968, the government received the

Metropolitan Adelaide Transport Study The Metropolitan Adelaide Transport Study, or "MATS Plan" as it became known, was a comprehensive transport plan released in 1968 proposing a number of road and rail transport projects for the metropolitan area of Adelaide, South Australia. It ...

(MATS) that envisaged a network of 10 freeways crossing the metropolitan area, a rapid rail network, and an underground city loop railway. MATS drew massive public opposition, as it called for the acquisition of thousands of properties and would effectively supplant a number of suburbs that were to become the sites of interchanges. Arguments broke out in Parliament, and widespread images of

gridlock Gridlock is a form of traffic congestion where "continuous queues of vehicles block an entire network of intersecting streets, bringing traffic in all directions to a complete standstill". The term originates from a situation possible in a grid ...

in overseas freeway networks contributed to the furore. Nonetheless, in early 1969 Premier

Steele Hall Raymond Steele Hall (born 30 November 1928) is a former Australian politician who served as the 36th Premier of South Australia from 1968 to 1970. He also served in the federal Parliament as a senator for South Australia from 1974 to 1977 and ...

approved implementation of the plan in a modified format, and the government began to purchase property along the proposed corridors. In mid-1969, faced with ongoing opposition, the state abandoned plans for 2 of the 10 proposed freeways. Hall was voted out of office in 1970, and the new government under Premier

Don Dunstan Donald Allan Dunstan (21 September 1926 – 6 February 1999) was an Australian politician who served as the 35th premier of South Australia from 1967 to 1968, and again from 1970 to 1979. He was a member of the House of Assembly (MHA) for th ...

passed a 10-year moratorium on freeway development, effectively shelving MATS. The already-acquired corridors were retained for potential future use. By the mid-1970s, transportation had become a problem in the north-east suburbs. The population of the Tea Tree Gully region had increased from 2,500 in 1954 to 35,000 by 1971. A corridor of land along the

from Adelaide to

, originally purchased for the Modbury Freeway proposed under the MATS plan, was the subject of a new proposal in 1973 when the State Director-General of Transport suggested building a heavy rail line that would connect the suburb to the Adelaide railway system. A subsequent study, the "North East Adelaide Public Transport Review" (NEAPTR), considered heavy rail, light rail, busways, and freeways, ultimately concluding that a light rail line or busway would be most viable. The state government decided on a light rail proposal to extend the historic

Glenelg tram line The Glenelg tram line is a tram/ light rail line in Adelaide. Apart from a short street-running section in Glenelg, the line has its own reservation, with minimal interference from road traffic. The service is free in the city centre and a ...

. The new route was to continue along King William Street beyond what was then the terminus in Victoria Square and weave through the

to the Modbury corridor.Wilson, Tom. Items of Interest for Planning of Luton Dunstable Translink, Appendix A: Report on Adelaide O-Bahn. (Tom Wilson was the Principal Consultant Service Development & Busway Operations Manager 1981–1989.)Busway Information, Paper One: Background History of the Northeast Corridor Transportation Proposals. South Australian Department of Transport (1983). The light rail system would connect with feeder buses at stations along the length of the corridor to transfer passengers to suburban routes. New light rail vehicles were to be bought to replace the ageing 1929 H type trams. Public opposition to the project was broad. The

Adelaide City Council The City of Adelaide, also known as the Corporation of the City of Adelaide and Adelaide City Council is a local government area in the metropolitan area of greater Adelaide, South Australia and is legally defined as the capital city of South ...

objected to the plan on the basis that it would interfere with the well-designed layout of the city proper. In response, the government altered the plan to redirect the line underneath the city, at a considerable increase in cost. Residents in inner-city suburbs such as St Peters were concerned about the noise of the light rail vehicles, and protested against any disruption of the Torrens Gorge in the Modbury corridor. Test drilling commenced for the tunnel, but the entire light rail project was halted in 1980 after Premier

David Tonkin David Oliver Tonkin AO (20 July 1929 – 2 October 2000) was an Australian politician who served as the 38th Premier of South Australia from 18 September 1979 to 10 November 1982. He was elected to the House of Assembly seat of Bragg at the 1 ...

appointed Michael Wilson, an opponent of the plan, as Transport Minister.

Development

In search of a replacement for the light rail project, the new Government sent experts to examine an innovative guided bus system being developed in West Germany by

. From the

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

''Omnibus'' (bus) and ''Bahn'' (path or way, as in Autobahn for automobiles and Eisenbahn or just Bahn for railway, e.g.

S-Bahn The S-Bahn is the name of hybrid urban-suburban rail systems serving a metropolitan region in German-speaking countries. Some of the larger S-Bahn systems provide service similar to rapid transit systems, while smaller ones often resemble com ...

and

U-Bahn Rapid transit in Germany consists of four U-Bahn systems and fourteen S-Bahn systems. The U-Bahn commonly understood to stand for Untergrundbahn (''underground railway'') are conventional rapid transit systems that run mostly underground, while ...

), the O-Bahn system was developed for use in tram tunnels in

. After extensive consultations with German authorities, State Transport Authority engineers decided the O-Bahn could be used. The system was seen as far superior to previous proposals; it used less land, made less noise, was faster and cost less. In addition, its unique feature of a non-transfer service direct from suburban streets to the city centre made it more attractive. Plans were drawn up for a length of : initially only were to be constructed as O-Bahn, with the rest being conventional busway. However, safety concerns and public opposition led to O-Bahn being used for the entire length. Construction began in 1983 for the first section to

. Another change of Government in 1982 resulted in uncertainty over the future of the project. The

John Bannon John Charles Bannon (7 May 1943 – 13 December 2015) was an Australian politician and academic. He was the 39th Premier of South Australia, leading the South Australian Branch of the Australian Labor Party from a single term in opposition ba ...

Government, after consultations, decided to continue with Stage 1 (City to Paradise) and in 1986 proceeded with Stage 2 (Paradise to Tea Tree Plaza).Northeast Busway (Brochure). State (South Australia) Transport Authority (1990).O-Bahn Busway Information (Brochure). South Australian Department of Transport (1987). The cost of the project was A$98 million, including the buses.Busway Information, Paper Four: Environment. South Australian Department of Transport (1983). Stage 1 opened on 9 March 1986. Stage 2 opened on 20 August 1989. The O-Bahn had more than 4 million passenger trips in the year after completion of Stage 1 in 1986, with a 30% increase the following year. When the completed O-Bahn was opened on 20 August 1989, passenger numbers rose another 17%. The Adelaide public transport system was privatised in the 1990s and overall patronage across all systems (bus, rail and tram) dropped 25%. The exception to this was the O-Bahn with no decrease, and there were 19,500 passenger trips daily in 1996 (7.13 million a year). , the busway carries approximately 31,000 people per weekday.

Expansion proposals

There have been a number of proposals to extend the O-Bahn to Golden Grove or build other routes, but none have progressed beyond consultation. An extension to Golden Grove would require the acquisition of extensive tracts of private property, due to the absence of an available corridor. Population increase in the area is negligible, although sprawl continues from

for another eight kilometres to the Adelaide Hills. The current route was built with an allowance for a station at

but it has not been built.Busway Information, Paper Three: Operational Strategy. South Australian Department of Transport (1983). A southern O-Bahn proposal attracted the most attention and has been the subject of various studies and Parliamentary Committees as to its viability since 1996. The rail route through Adelaide's far south is off-centre, without the large catchment area of a more central transport route. An O-Bahn running direct through the region would be able to take advantage of an already large population and the continuing growth in the area. One suggested route for an O-Bahn was for an alignment adjacent to the Noarlunga Centre railway line from the city to the Tonsley line. The O-Bahn would end there, with buses continuing on the Southern Expressway through the far south. Construction of this O-Bahn would require moving the railway track slightly to fit the O-Bahn alongside. In addition,

Emerson Crossing ''Emerson Crossing'', the 'South Road Overpass' or simply 'the Overpass' are the informal names given to the intersection of South Road, Cross Road and the Seaford railway line in Adelaide, South Australia. South Road crosses north–sou ...

and the Goodwood Overpass would require alteration. The estimated cost of construction, $182 million, was considered too expensive, and the proposal was suspended in 2001. Since then, the Government has focused on upgrading

South Road South Road and its southern section as Main South Road outside of Adelaide is a major north–south conduit connecting Adelaide and the Fleurieu Peninsula, in South Australia. It is one of Adelaide's most important arterial and bypass roads. As ...

and extending the

. There was a 2009 plan that bus routes serving the O-Bahn would be enhanced from Hackney Road along Grenfell and Currie Streets and extended to West Terrace on the far side of the CBD along dedicated bus lanes. However, the Federal Government announced in January 2011, as part of its response to the

2010–11 Queensland floods 1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length 1. I ...

, that the extension would be cancelled "as a result of a significant scope reduction of the original project, resulting in only limited transport benefits".

O-Bahn City Access Project

In 2015, the Department of Planning, Transport & Infrastructure announced a $160 million proposed O-Bahn City Access Project. The existing entry/exit at Hackney Road was retained, but upgraded bus-only lanes on Hackney Road now lead to a new tunnel portal with bus guide rails commencing near the

. The tunnel passes under the Botanic Road intersection, then curves west under

Rundle Park / Kadlitpina Rundle Park / Kadlitpina (formerly spelt Kadlitpinna), also known as Park 13, is a part of the Adelaide Park Lands in Adelaide, South Australia. It was known as Rundle Park until its Kaurna name was assigned as part of the dual naming initiative ...

Rundle Street Rundle Street, often referred to as "Rundle Street East" as distinct from Rundle Mall, is a street in the East End of the city centre of Adelaide, the capital of South Australia. It runs from Pulteney Street to East Terrace, where it becomes ...

and surfaces in

leading to a redesigned intersection at

and

. Construction started in late 2015 and completed in 2017. The contract to complete the detailed design and construct the tunnel was let to

McConnell Dowell McConnell Dowell is a major infrastructure construction company founded in New Zealand in 1961. In 2003 it became a wholly owned subsidiary of Aveng, which is listed on the Johannesburg Stock Exchange in South Africa. History McConnell Dowell wa ...

in October 2015. Sage Automation provided expertise in the mechanical and electrical aspects of the tunnel including ventilation and safety systems. Construction started in March 2016 with the removal of the median strip and preparation of central bus lanes. The tunnel opened on 10 December 2017, with limited services starting the next day. It started full operation on 17 December.

Effects on local development

The O-Bahn has caused a clustering of commercial and community development near the Tea Tree Plaza Interchange, as service-providing organisations and businesses have sought to exploit the area's easy accessibility to public transport and the city centre. Market imperatives have also been aided by the zoning of the land around the area as commercial rather than residential. The area around Tea Tree Plaza is one of five designated regional centres within the Adelaide metropolis. According to Robert Cervero, the O-Bahn has "accelerated the conversion of Tea Tree Gully from a somewhat sterile new town designed around a regional shopping mall to an emerging urban village featuring a wide range of land uses". The large

Modbury Hospital Modbury Hospital is a hospital that provides inpatient, outpatient and emergency services to a population of over 400,000 people living primarily in Adelaide Adelaide ( ) is the capital city of South Australia, the state's largest city and ...

is adjacent to the interchange, and the Torrens Valley campus of

TAFE Technical and further education or simply TAFE (), is the common name in English-speaking countries in Oceania for vocational education, as a subset of tertiary education. TAFE institutions provide a wide range of predominantly vocational cour ...

was built directly to the east of the busway after it opened. One government high school, three primary schools, one Christian school and three retirement villages are within a kilometre of the interchange. In contrast, there has been opposition to the area surrounding Klemzig Interchange and Paradise Interchange being used for any purpose other than low-density housing and no

transit-oriented development In urban planning, transit-oriented development (TOD) is a type of urban development that maximizes the amount of residential, business and leisure space within walking distance of public transport. It promotes a symbiotic relationship between ...

has occurred.

Environment

The construction of the O-Bahn, rather than the previously proposed Modbury Freeway, was motivated by a desire to reduce

car dependency Car dependency is the concept that some city layouts cause cars to be favoured over alternate forms of transportation, such as bicycles, public transit, and walking. Overview In many modern cities, automobiles are convenient and sometimes nec ...

. $6 million was used for the redevelopment of the Torrens Gorge, in which the

was created. About 150,000 trees, plants and shrubs were planted alongside the track for aesthetic, environmental and noise-reduction purposes; planting was completed in 1997. Walking trails and cycling paths were built along the park to encourage public use. Torrens Linear Park rejuvenated the river, which had deteriorated to the extent of being a de facto "urban drain, littered with rubbish and inaccessible to the public". Arising from environmental considerations, the O-Bahn is

carbon-neutral Carbon neutrality is a state of net-zero carbon dioxide emissions. This can be achieved by balancing emissions of carbon dioxide with its removal (often through carbon offsetting) or by eliminating emissions from society (the transition to the "p ...

due to the absorption of carbon dioxide by the trees alongside it. The track itself is situated in a valley due to it being near a riverbed and the elevation was further lowered by digging further depressions in order to reduce the noise impact on adjacent dwellings. The original buses ran on

diesel fuel Diesel fuel , also called diesel oil, is any liquid fuel specifically designed for use in a diesel engine, a type of internal combustion engine in which fuel ignition takes place without a spark as a result of compression of the inlet air and t ...

, but the system allows for buses that run on alternative energy sources. Biodiesel fuel and natural gas have been trialled; as of 2014, 20% of the Adelaide bus fleet uses compressed natural gas, 48% B20 and 32% B5 biodiesel blends. The design of the O-Bahn allows for the installation of

overhead wires An overhead line or overhead wire is an electrical cable that is used to transmit electrical energy to electric locomotives, trolleybuses or trams. It is known variously as: * Overhead catenary * Overhead contact system (OCS) * Overhead equipment ...

for

trolleybus A trolleybus (also known as trolley bus, trolley coach, trackless trolley, trackless tramin the 1910s and 1920sJoyce, J.; King, J. S.; and Newman, A. G. (1986). ''British Trolleybus Systems'', pp. 9, 12. London: Ian Allan Publishing. .or trol ...

es.

Notes

*Transport Department reference documents are held by the

State Library of South Australia The State Library of South Australia, or SLSA, formerly known as the Public Library of South Australia, located on North Terrace, Adelaide, is the official library of the Australian state of South Australia. It is the largest public research l ...

. They are not published works, but a collection of in-department papers and brochures for the general public.

References

* * * *

External links

*
The Adelaide O-Bahn
Adelaide Metro. Internet Archive. Archived from the original on 2011-05-21.
O-Bahn map PDF
Internet Archive. Archived from the original on 2019-08-22.

Citytransport.info website {{Adelaide public transport Busways Bus rapid transit in Australia Transport infrastructure completed in 1986 1986 establishments in Australia