Australian road signs are very popular motif for their postcards. In many cases you can get a card where several road signs with typical Australian wildlife are depicted on a sign. They are funny and visually convincing people about approaching an area with koalas, kangaroos or wombats.
Some of them inform about direction in busy locations or about danger of swimming in the open ocean. Almost all of them (once not having numbers about speed limits, for example) emanate with this special Australian humour not seen anywhere else.
They are everywhere, south or north Australia, only having different images of animals.