It’s worth asking, what makes for a good interchange? Many routes intersecting, obviously, but I’d say there’s more to it than just that. It’s better when it’s a place that has interesting things to do nearby if one has to wait a bit for their next service. It’s also nicer to wait somewhere that has activity and people around for safety, especially when interchanging at night. I’d much rather interchange in an area with shops and restaurants than in an industrial estate.
The perfect interchange is a place that’s a destination in itself, because it will naturally have many routes going there, without them having to make diversions and doglegs to get there. And it’s more likely to have those things I suggested above.
None of these stations really have that status yet, but let’s consider, which of them could become that one day? Salisbury has an advantage here, because it’ll be the junction station when the line to Flagstone eventually opens. That itself brings some activity. On top of that, both Salisbury and Moorooka have an entire side of their stations that has stayed above the water in every major flood. That’s important, not so much for positioning a bus interchange, but for shops and restaurants and dense housing being built around it, to make it a destination as well as an interchange. Current Rocklea will always be a big risk for this.
The area around Railway Terrace has some properties outside historical flood levels, but not many, especially on the northern side. While the southern side has more, the access roads will get cut off in a major flood. So I can’t see it being all that attractive for developers. Without that, it’ll never be a destination in and of itself. I fear it would become the southside’s version of Enoggera, a pretty unloved and underutilised interchange at a minor train station, surrounded by industrial estates and low density housing.
To resolve the point about different bus services located on either side of Salisbury station, I wonder if that can be fixed by linking up the separated sections on Lillian Avenue.