Is the North East railway line between the two largest cities in Australia?
North East railway line:  It is a key component of the Sydney–Melbourne rail corridor. Sydney–Melbourne rail corridor: The Sydney–Melbourne rail corridor is an approximately 960 km standard gauge railway corridor that runs between Melbourne and Sydney, the two largest cities in Australia.
The Sydney–Melbourne rail corridor is an approximately 960 km standard gauge railway corridor that runs between Melbourne and Sydney, the two largest cities in Australia.