One sign I haven't found in Australia

The above sign is quite common in Europe. Most of the European countries have it and in Greece the official name translates to “Start of residential area marked as traffic calm”. 

In Netherlands is called “woonerf” which is the most used international term from the Dutch words wonen 'reside' + erf 'premises, ground'.

Historically this scheme originates from Holland. The Dutch government developed traffic regulations for woonerfs in 1976, though the first woonerf was built in the city of Delft a decade earlier.

In the UK they have the “Home Zone” sign which is much similar. 

In Australia we have the 10 Km Shared Zone which is a quite different in colours. 

 Maybe we need to rethink about not only the sign design but the sign usage as well.