I just purchased Forza Horizon 3 - it's a video game for the Xbox One and PC. It's an open world driving game set in Australia.
They've taken a bit of artistic licence with the map. There are 4 areas on the single map - Byron Bay, Surfers Paradise, the Yarra Ranges and the Outback (Coober Pedy), and they're all located within this 15km x 15km map.
So, how faithfully have the game developers recreated the Aussie roads? Here are a few screenshots:
Freeway exit signage - this is slightly off because the 'exit' is actually an intersecting street. The styling appears to be a mix between Victoria and Northern Territory.
Speed limits appear to be set realistically, but urban areas all seem to have a 40km/h speed limit.
There's a decent set of speed traps and average speed cameras (you're meant to fly past them at the fastest speed possible), and there's no signage for the approaches. So a bit like Victoria...

An example of the artistic licence taken with the map design in the game - Sea Cliff Bridge is part of the Great Ocean Road...which links Byron Bay and Surfers Paradise.

NSW School Zone speed limit painted on the road in Byron Bay, complete with dragon's teeth! No corresponding school zone signage, though.
Urban roundabout:
Intersection Signage:
Railway crossings. Gotta hand it to the developers, they really went out of their way to make the AI cars act realistically by flying through the railway crossing without stopping.

Surfers Paradise looks lovely
NSW number plates have a Californian flavour