A pertinent comment on a news item:

"Why is it so expensive ? Perth is building a 8.5 km underground rail
line to the airport for $1.86 billion, or $220 m per kilometer including
3 stations. For Melbourne Airport rail line a 15 km line with a 9
km underground section is being touted at $10 billion, or $670 m per
kilometer."

WA can build railways, even underground ones, cheaper than NSW can build
tramways!

Tony P