Looking back, it was a giant leap of faith, but 34 years after the Adelaide O-Bahn rolled out its first guided bus from the CBD to Paradise, it has answered its doubters.
The German-inspired transport system was first flagged in 1979 by the incoming Liberal Government, which shelved Don Dunstan's plans for a light rail transit line along the River Torrens corridor to service the growing north-eastern suburbs.
On paper, the O-Bahn stacked up: it was less costly than light rail; the track was narrower, reducing the environmental impact; it offered flexibility, allowing buses to enter and exit from the road system; and it promised a faster, quieter and more reliable ride than other transport options.
It was also the first guided busway in the southern hemisphere.
More than three decades on, has it lived up to expectations?
A new paper co-authored by University of South Australia Adjunct Professor Derek Scrafton, a former Director-General of Transport in SA during the O-Bahn's construction, provides an insight into the guided busway's history and the lessons learned.
Prof Scrafton, one of Australia's foremost urban planning experts, says around 31,000 passenger trips are made each weekday on the O-Bahn.
"The O-Bahn is far more efficient than Adelaide's rail network in terms of patronage per kilometre. Its popularity is also increasing each year, with 50 per cent more people using it than in the early 1990s," he says.
Until 2011, it was the longest full-scale operational guided busway in the world, taking passengers the 15 kilometres from Tea Tree Plaza, via Paradise and Klemzig, to the city centre in under 20 minutes. The park-and-ride concept provides around 2000 car spaces in total across the three interchanges, easing traffic congestion in the burgeoning north-east corridor.
"It is nowhere near its capacity, either," says Prof Scrafton. "It could conceivably carry 18,000 passengers an hour in each direction with the use of articulated buses. The only constraint to the existing system is the availability of kerb space in the CBD for bus stops, picking up and delivering people to their destination."
A bonus has been the development of the River Torrens Linear Park alongside the O-Bahn, transforming a rundown urban drain into a picturesque open space with 150,000 trees, plants and shrubs, and a cycle/walkway for thousands of commuters and recreational cyclists.
The question on everyone's lips is, given its success and popularity, why hasn't it been replicated in Adelaide?
Prof Scrafton says in 2000, the Labor Government under John Bannon assessed the feasibility of extending the O-Bahn to serve the southern corridor. "Despite a clear economic case mounted for it, the bias to rail led to no further action and instead the main train lines were electrified."
A controversial $168 million extension of the guideway from Gilberton to the CBD via a tunnel under the parklands was completed in 2017, reducing travel time by four minutes.
"There was a lot of opposition to the extension - mainly due to the cost and environmental disruption - but the long-term objectives are sound: to clear congestion on the arterial roads and improve conditions for the remaining traffic," Prof Scrafton says.
"The extension has benefitted both motorists and bus commuters, as well as improving conditions for cyclists and pedestrians."
More recently, a major transport study has recommended the O-Bahn be extended to Golden Grove, but the proposal is yet to be discussed in Parliament. It would require the acquisition of extensive tracts of private property, a major hurdle.
Prof Scrafton and his co-author, Professor David Bray from the University of Queensland, have published their analysis of Adelaide's O-Bahn in a book chapter in Developing Bus Rapid Transit: The Value of BRT in Urban Spaces. The book compares bus rapid transit systems around the world.
Notes to Editors
Professor Derek Scrafton is an Adjunct Professor of the School of Natural and Built Environments at the University of South Australia. He was Director-General of Transport for South Australia during the construction of the O-Bahn, from 1979-1988. Professor David Bray was a consultant economist and engineer on the O-Bahn project.