I've been meaning to write a comment about public transport in Perth for some time now but this article sums it all up quite nicely and in better prose than I could hope to produce.

The only thing I'd add is that Perth's public transport is much like Sydney's - concentrated in the inner suburbs and practially non-existant outside of that area. Plus, outside of very narrow peak hours it tapers off to virtually nothing. For example, express trains stop leaving the city before 6PM.

While the government has invested in the Mandurah train line (which is being used to capacity - a good thing), public transportation needs to be an ongoing spend. And as the article above points out, it needs to be combined with other (dis)incentives if it is to work correctly.