Lura wrote: I'm not familiar with the rail gauges in use, but I think I can say with confidence that very few trains would actually cross state borders because they aren't practical to get anywhere fast in Australia. They pretty much only service movement of resources.
Movement of resources is no small matter though. It's one of those demand-->supply-->demand things, and before aircraft it was Passengers (for comfort and speed) and Mail (for speed and reliability) which got lines started. Having some bulk freight on the same line was a bonus.
There needs to be a huge quantity of goods to be moved (eg coal, iron-ore) to make a line profitable only with goods.
It's a shame sleeper cars aren't used more. If Sydney-Melbourne or Sydney-Brisbane were a reliable 10 hours, people could save awake-time even compared to air, have a hotel bed, and arrive in time to start a business day without having to wake up at sparrows fart in their home city. Is it cleaning or security costs which make it so expensive? Having to share cabins? Give people a discount if they leave the cabin spotless, and keep their deposit if they vomit all over it. Sleepers shouldn't be luxury-priced, just add more cars.