Finding the world's longest Guided Busway

At 12 kilometres, Adelaide's O-Bahn Busway is the world's longest and fastest guided busway. As I am visiting Adelaide, to give a talk, I thought I would take a ride before it is eclipsed by the Cambridgeshire Guided Busway. However, for the visitor it can be a bit hard to find. Adelaide Metro have a web page describing the busway, saying it travels through Adelaide's River Torrens Linear Park to Tea Tree Plaza Interchange, but not where from. Google's trip planner seems to say this is route M44. I will see if I can plot a trip on the new Glenelg Tram and the busway.