You can always submit your ideas to Infrastructure SA…
Bear in mind some of the basic parameters I think you will find they are looking at, and unlikely to change in their planning, include:
The proposed CBD underground rail loop that allows through running with the three proposed stations – Adelaide, Hindmarsh Sq and Victoria Sq-Central Mkt, and to address specific future high-volume passenger journey start/stop & transfer points at:
Hindmarsh Sq – rail & O’Bahn
Victoria Sq – rail & tram
Adelaide – rail & tram
Rail lines – keep in mind volumes - descending order in current passenger volumes – Gawler, Seaford, Outer Harbor, Flinders (anticipated volume), Belair, and the lowest usage, the Grange branch line - which may not exist by the time a CBD rail loop is built. To put into perspective, the current O’Bahn weekday passenger trips is approx 35K now, Gawler line >20K and Seaford <20K. The other existing lines combined approx 20K. Extension of Gawler & Seaford lines will happen, just a case of how many years away in their planning. I put volumes forward as they obviously influence planning.
Tram lines - extension to North Adelaide still in the long-term plan, but another case of how many years away, same for the City Loop, but more complex because there is no consensus on the best & final route yet within the CBD.
New creative ideas on how to link other existing transit points, such as Parklands Rail Terminal and Central Bus Station are worthwhile, but don’t expect any massive shift in the basics of the overall CBD plan. For example, you won’t get a new transport hub elsewhere in the CBD, just won’t happen, but at the same time creative ideas on how to return non-suburban trains to Adelaide may be worthwhile. Or a plan on how to better manage the Grenfell / Currie St PT high volume corridor etc…that sort of thing worth spending your time on if you want to be realistic.
Just trying to put some reality back into the discussion, to save peoples time.