Would love to see one of the Sydney routes developed for TS2021 or TSW2 https://transportnsw.info/sydney-trains-network-map This map shows the many routes available. Sam said Australian routes with the Netherlands are leading the way for future issues. Really love an Aussie route
Any Sydney route with a T set engine known as a Tangara would look absolutely fabulous in https://www.youtube.com/watch?v=cnysVflzSWU
I reckon the Central Coast and Newcastle line would be amazing. Sydney terminal to Newcastle interchange or Broadmeadow. Waratahs and Tangaras on the section from Sydney terminal to Gordon and Berowra, and OSCARs and V Sets to Wyong, Gosford and Newcastle. You could also potentially have freight, and XPT/Xplorer trains to Broadmeadow. You could then have the Hunter line as a seperate route from Broadmeadow or Newcastle interchange to Maitland, incorporating the North Coast line to Dungog, and the Main north line to Muswelbrook. As for stock, could use Endeavour and Hunter Railcars for local services, and coal trains. Maybe the odd XPT/Xplorer and also a 620/720 DMU. (one in CityRail livery and one as preserved)
I posted a suggestion once, over here, for a line between Sydney and Melbourne. Sadly, it's 1,100 km. I doubt it will get any attention. But we got a New Zealand route, so maybe small route segments will find their way in. This is definitely not a new request in this thread. More information on Sydney to Melbourne is in that thread. It pertains in ways here, too. Though you could just look at a route within Sydney proper, if there is good passenger rail there.
Sydney to Melbourne would be far too long for Train sim and personally I don't think anyone would really want to drive the whole route in one sitting (11hr trip, if driving passenger services). Although, you could probably get away with Sydney to as far as Moss Vale or Goulburn, with some suburban branches - The southern highlands line is pretty scenic in parts too. Although, Sydney to Newcastle, set in the early 2010s would be great as you'd get the line from Broadmeadow to Newcastle before it was turned into the light rail - and the section from Hawksbury River to Gosford would look amazing (especially around near Wondabyne).
Yeah, I already conceded that the top half of the Sydney to Melbourne route, over 700 miles, was unlikely to happen. Ever. Even by aspiring creators with time on their hands. Because it's way too long and people would run out of patience, and the editor out of memory, by a hundred miles or so. But that doesn't mean routes focused in or around Sydney or Melbourne are not possible, as you said. And Sydney is, I think, the busiest city in the country, meaning that it would be a great place to set up Australian city rail services. If only for the license for that, though, which is a bit of an objective first.
I mean if you wanted a prototypical sydney route, there'd need to be heaps of custom assets (The harbour bridge, etc). You could get away with using the Hell Gate bridge from NEC as it looks very similar. As for Melbourne routes, Possibly Melbourne - Seymour would be interesting - you could run freight, Suburban electric passengers to Craigieburn and Broadmeadows and V/Line and XPT services the rest of the way.