Adelaide's O-Bahn system is unique and for good reason. This guided busway system was specifically designed to meet the city's public transport needs, thanks to Adelaide's linear urban layout. The system not only provides a fast and reliable mode of transport but also reduces congestion on roads. The reason why it's only in Adelaide is primarily due to the city's geographic layout and public transport requirements, which may not be the same for other cities. Ultimately, it's a tailor-made solution that has successfully addressed Adelaide's commuting challenges.