There are two basic types of PPPs in Australia.
• The first is where the private sector's primary revenue stream takes the form of a service (or availability) payment from government. The Australian policy guidance calls these 'social infrastructure PPPs' because this model is typically used for schools, hospitals, prisons and other 'social' (i.e. non-income producing) infrastructure.
• The second is where the private sector's primary source of revenue takes the form of charges paid by the users of the infrastructure, such as tolls paid by the users of a toll road. These PPPs are often called 'economic infrastructure PPPs' because they are used for roads, railways and other 'economic' (i.e. income producing) infrastructure.
The terminology is confusing, however, as the first model has also been used to deliver the roads, railways and other economic infrastructure (such as the Peninsula Link road project in Victoria, the Waratah train project and the Sydney Metro Northwest project). It is more apt to call the first model a service-payment PPP, and the second a user-charge PPP.
Both models share common features. There are, of course, hybrids and other variants of these two basic models. Unlike other established PPP markets, which are dominated by service-payment PPPs, the Australian PPP market has seen many user-charge PPPs.