Everything about The O-bahn Busway totally explained
The
O-Bahn Busway in the
South Australian capital city of
Adelaide is the world's longest and fastest
guided busway. The O-Bahn — from the
Latin omnibus ("for all people") and the
German bahn ("way" or "road") — was conceived by
Daimler-Benz to enable buses to avoid traffic congestion by sharing
tram tunnels in the
German city of
Essen.
The route was introduced in 1986 to service Adelaide's rapidly expanding
northeastern suburbs, replacing an earlier plan for a
tramway extension.
The design is unique among
public transport systems; busways typically use dedicated bus lanes or separate carriageways, but the O-Bahn runs on specially-built track, combining elements of both bus and rail systems. The track is 12
kilometres (7.5 mi) long and includes one station and two interchanges:
Klemzig Station in
Klemzig,
Paradise Interchange in
Campbelltown and
Tea Tree Plaza Interchange in
Tea Tree Gully. Interchanges allow buses to enter and exit the busway and to continue on suburban routes, avoiding the need for passengers to change. Buses travel at a maximum speed of 100 km/h (62 mph), and the busway is capable of carrying 18,000 passengers an hour from the
Central Business District to Tea Tree Plaza in 15 minutes. Services are operated by
Torrens Transit under contract from
Adelaide Metro, an agency of the South Australian
Department for Transport, Energy and Infrastructure.
History
Adelaide has had significant population growth since the industrial expansion following
World War II, with the population having tripled from 321,400 in 1938 to 1,129,269 in 2005. Concurrent with this growth, a transport blueprint, developed with
American assistance, was presented in 1968: the
Metropolitan Adelaide Transport Study (MATS). The plan envisaged a large network of
freeways crossing the metropolitan area, together with an underground city loop
railway. One of the freeways to be constructed was the
Modbury Freeway, connecting a city bypass route with the then predominantly barren and undeveloped north-eastern suburbs. The freeway was to be built in a
linear park alongside the
River Torrens.
The size of the MATS plan resulted in considerable public opposition; several suburbs were to completely disappear under
interchanges, with
Hindmarsh to be removed to make way for a multi-entry interchange. Widespread images of
gridlock in similar overseas freeway networks also contributed to this opposition. The plan was abandoned by successive governments, and much of the land held by the Highways Department was sold off for housing developments. However, the land for the Modbury Freeway was retained and later renamed from "Modbury Freeway Corridor" to "Modbury Transport Corridor". The Modbury corridor was left to degrade, eventually becoming
landfill.
The population of the
Tea Tree Gully region increased from 2,561 in 1954 to 91,921 in 2001, through new housing developments. In 1973, the State Director-General of Transport spoke about using the Modbury corridor for public transport to improve services in the area, initially suggesting a heavy rail line be constructed to connect with the
railway system. Over the next four years, the Department conducted the North East Public Transport Review (NEAPTR), which considered heavy rail, light rail, busways and freeways as options for the corridor. The study concluded in 1978 that a light rail line or busway were most viable. The governing
Australian Labor Party, under Premier
Don Dunstan, decided on a
light rail proposal to extend the historic
Glenelg tram. The new route was to continue along
King William Street beyond the present terminus in
Victoria Square and weave through the
Adelaide Park Lands to the Modbury corridor.
The light rail system was to connect with feeder buses at stations along the length of the corridor to transfer passengers onto suburban routes. New light rail vehicles were to be bought to replace the ageing 1929 H-Class vehicles. However, public opposition to the project was broad; the
Adelaide City Council 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, significantly increasing the 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, which lies in the Modbury corridor. The
Liberal MP for
Torrens,
Michael Wilson, representing the north-eastern suburbs, vocally opposed the project on behalf of his constituents. The cost of the project totalled
$98 million, including the buses.
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 O-Bahn was completed in 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). Currently there are 22,000 passenger trips daily (8 million a year).
The southern O-Bahn proposal has 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. The O-Bahn would end there, with buses continuing on an upgraded (dual-carriageway)
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 and the
tram overpass would require huge alteration. The estimated cost of construction, AU$182 million, was considered too expensive, and the proposal was suspended in 2001. The current
Labor Government has focused on
road upgrades and an
inner-city light rail extension.
Track
The O-Bahn track is made of
concrete; it's elevated above ground because of the poor quality of soils along the
River Torrens, which frequently move due to seismic shifts. Large concrete
pylons were drilled into the ground to ensure stability, to a depth of up to four metres. On top of the pylons are concrete sleepers on which the track runs. 5,600 pylons were drilled in place to support 5,600 sleepers and 4,200 prefabricated L-shaped track pieces, sited at 12-metre (40-ft) intervals. The width of both tracks, sitting on the sleepers, is 6.2 metres (20 ft).
At the city end, the O-Bahn begins at
Hackney Road, opposite the
East Parklands, where it enters a 60-metre (200-ft) tunnel at a speed limited to 40 km/h (25 mph), due to the tight initial corner, ensuring that the rear tyres (especially trailer tyres of
articulated buses) don't 'scrub' against the track. Speed is gradually increased to 80 km/h (50 mph) for most of the trip to
Klemzig Station. Once en route to
Paradise Interchange, the speed limit is 100 km/h (62 mph), with 90 km/h (56 mph) on tighter corners. The limit on the remaining section to
Tea Tree Plaza Interchange varies between 100 km/h (62 mph), 90 km/h (56 mph), and 80 km/h (50 mph). The average speed including stops is about 60 km/h (37 mph). On some sections, 115 km/h (70 mph) has been easily achieved in tests. On entering interchanges the O-Bahn ends and the speed limit is 40 km/h (24 mph). In the interchange area, the speed limit is 20 km/h (12 mph).
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 bus
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 40 km/h (24 mph).
Tea Tree Plaza Interchange is the terminus, 12 kilometres (7.5 mi) from the city centre, in
Modbury,
Tea Tree Gully. Adjacent to the
Tea Tree Plaza shopping centre, it's 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 500 carparking spaces.
Ticketing
The O-Bahn uses the standard
Adelaide Metro ticketing system. Single-trip adult tickets are subsidised by
$2.90 by the
South Australian Government, compared with the $8.80 subsidy for a journey on the
rail system. Tickets are sold at interchanges and on buses. There are different fares for students and concession-card holders and at off-peak times.
A standard peak ticket costs $4.10 and an off-peak single-trip ticket costs $3.80 and is valid for two hours. Unlimited day ticket and 10-use multi-trip tickets ($26.90) are available. The prices for single trip concession tickets are $2.00 on peak and 1.20 off peak. Tickets can be used across all Adelaide Metro services, including
trams and
railways; they require validation upon entry to a vehicle. Failure to produce a ticket incurs a $210.00 fine.
Environment
From the start, the construction of the O-Bahn—rather than the previously touted Modbury Freeway—was motivated by a desire to reduce
car dependency. Six million dollars of the total cost was used for the redevelopment of the
Torrens Gorge, in which the
Torrens Linear Park 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. Arising from environmental considerations, the O-Bahn is
carbon-neutral.
The original buses ran on
diesel fuel, but the system allows for newer buses that run on alternative energy sources. Biodiesel fuel was trialled between July 2005 and May 2006. Buses using
natural gas have been trialled, although they've not seen regular usage due to a perceived lack of power, especially on the section of the down track immediately after Paradise Interchange where the track rises sharply. The design of the O-Bahn provides for the installation of
overhead wires for
trolleybuses.
