For example - Inland Rail should almost have its own forum parallel to the NSW/VIC ones etc.  All items related to IR go in there making it easier to find historic conversations etc, perhaps preventing new threads asking old questions.

Others would include
- Murray Basin
- New long distance Victorian trains
- Ballarat line upgrades
- Other geographies of rail (eg South West Queensland, Townsville line)
- Sydney Metro Northwest

There would be many others that other posters could suggest. 

The only thing might be were one thread might cover 2 topics with might need some more thinking.

The current forums would remain as is as there needs to be places to discuss grain harvest, sightings etc.