Around the world, governments and city planners have long struggled with the issue of transport. Getting people where they need to be in a timely fashion is key to making a city a comfortable, attractive place to live. As far as public transport is concerned, this typically consists of buses on the roads, and trams and trains on rails.
Down in the city of Adelaide, Australia, things get a little muddled, however. Nestled in a river valley lies a special transportation network known as the O-Bahn, where buses ride on concrete rails and the drivers can even take their hands off the wheel. The system remains a rarity worldwide, and was spawned by a perfect storm of conflicting requirements.
A Child of Circumstance
In the 1970s, the South Australian government found itself backed into a corner. Facing a booming population in the north-eastern suburbs, new transport links with greater capacity were needed to get people to the central business district. Original plans from the 1960s had called for more freeways to be built all over the city to solve the problem. In the face of stiff public opposition, legislation was passed in 1970 blocking the construction of any new freeways for a full decade, forcing the government to consider alternatives.
Despite plans being shelved, a corridor of land stretching from the city to the north-east had already been acquired for freeway construction. This was retained, and studies were commissioned to determine the best transportation solution to suit the needs of the area. The “North East Adelaide Public Transport Review” suggested light-rail or a busway would be the best solution.
Initial plans were proposed to link the north-east with a light-rail tramway that would connect with the existing tramline from the city proper to Glenelg in the west. However, the City of Adelaide protested the plan, believing that extending the existing tramline to the east would damage the city’s carefully planned structure. Plans were made to rectify this by running part of the line underground, massively increasing costs, and the proposal was shelved.
It was at this time, the guided busway in Essen, Germany came to the attention of the state government. Aiming to help reduce congestion by allowing buses to share tram tunnels, it began as a demonstration which later developed into the Spurbus network. The system offered lower cost and higher flexibility than light rail, and avoided the need to carve up the city to hook in to the existing light rail network. Had Adelaide laid out its existing heavy or light rail networks differently, the O-Bahn might not have gotten a look in. However, back in the early 1980s, it was an easy solution in a sea of difficult choices.
It Drives Like It’s On Rails
The O-Bahn was designed around the concept of the curb-guided busway, a type of public transportation system rarely implemented in practice. Indeed, it’s very name comes from the combination of the German words for bus (omnibus) and path (bahn).
Rather than trains riding on rails or buses driving on normal roads, the O-Bahn consists of a concrete track which the buses drive upon. To enable the thoroughfare to be as narrow as possible without compromising safety, the track has large curbs. Buses are then outfitted with guide wheels, which ride along the curbs and control the steering when the bus is on the track.
There are many compelling benefits to the guided busway concept, and the O-Bahn in particular. With the buses being guided by the track, there’s no need for steering or the wide lanes you’d find on a typical road. This allows for the construction of an O-Bahn busway in a much narrower space than would typically be practical, while still allowing travel in both directions.
Additionally, the precast concrete tracks are much cheaper and easier to build than laying conventional railroad tracks. Vehicles that ride on the tracks need only minor modifications to fit guide wheels; this can be achieved easily with virtually any passenger bus. The dedicated tracks allow the buses to maintain high speeds, rather than being stuck in the same congestion as other road vehicles. But, as a bonus, since the system relies on lightly-modified buses, the vehicles can serve dual duty, driving on normal roads as well as the O-Bahn track. This allows services to take advantage of the high-speed dedicated network, and then seamlessly transition on to suburban streets, delivering passengers to their destinations without requiring transfers.
The system does come with some disadvantages, however. Buses tend not to last as long as trains, requiring more regular replacement and maintenance. Additionally, trains generally have a higher capacity and are able to deal with larger numbers of passengers per day. Finally, there’s the always-amusing attempts drivers make to navigate the O-Bahn track in regular passenger cars – usually by accident.
Despite many warning signs, between one and four motorists finds themselves stuck on the track each year. Often, the car falls into the center of the track, or ends up sideways, blocking traffic in both directions. There are no known successful attempts of unauthorized civilian vehicles reaching an O-Bahn station via the track; this author, and many others, dream of achieving such a feat one day. To do so, a high-riding vehicle is a must – a heavy duty sump-buster installed at the Hackney Road entrance will rip the oil pan out of the average passenger car.
The system is often compared to Bus Rapid Transit (BRT), a highly effective system that gives buses dedicated rights-of-way and other features to improve service quality. However, the O-Bahn’s special tracks avoid the problem that has stifled BRT for decades – where local municipalities begin to take away separated bus lanes away over time, repurposing them for general traffic. This quickly kills the efficiency of a BRT system, and happens so often it has a name – BRT creep – and its own Wikipedia article.
The O-Bahn does share many commonalities though – high speeds, physically separated tracks, and specialized “stations” instead of “stops”. One thing the O-Bahn could learn from the BRT handbook, however, is off-board fare payment. Currently, in line with all other buses in the Adelaide region, ticket purchase and validation is done upon boarding. This can cause significant delays during high traffic periods. Unfortunately, given the O-Bahn’s integration with the rest of the bus network, implementing this would be impractical.
Overall, the O-Bahn has served the Adelaide region well, even if the idea hasn’t caught on worldwide. The buses are fast, mostly on time, and continued investment has been made to the system over the years, including a major improvement in city access with new tunnel construction in 2015. It’s likely the system will continue to serve the region for decades to come. No government could justify tearing up the track to replace it with rails when the concrete rails are cheap to maintain and new buses can be purchased whenever needed. While trams certainly would have felt a touch fancier, and a full-blown train line would have been a heavy duty solution, buses flying along concrete rails is an oddball concept that worked, and there’s nothing more Adelaide than that!