when are you allowed to sound your vehicle's horn?

Ah, the horn—the automotive equivalent of a polite throat clear or a full-throated shout. In Australia, you're allowed to sound your horn to warn other road users of your presence or an imminent danger, not to express your dismay at a slow driver or a rogue kangaroo. Using it for any other reason, like road rage or musical performances, is a ticket magnet.

So, in short, use your horn as a warning device only, ideally sparingly, to avoid annoying your fellow Aussies and attracting fines. If you want to practice your horn skills, perhaps consider a trumpet lesson instead.