Australia

National Highway System. This is analagous to the Interstate Highway System in the United States.

Original route numbering system

National Route
This is analagous to the U.S. Highway System. The National Highway System used to be part of this system.

State Route
This marker is no longer used in Tasmania, South Australia, and Victoria.

Alphanumeric route numbering system

Alphanumeric route in Tasmania, Victoria, South Australia, and Queensland

Source: Wikipedia. Licensed for use under the GFDL.

Alphanumeric route in New South Wales

Source: Wikipedia. Licensed for use under the GFDL.

The alphanumeric route number system was adopted in principle by the Australian states and territories in 1997. There are four prefixes: M for motorways (freeways), A for main roads, B for secondary roads, and C for all others.

Tasmania and Victoria have converted to this system. South Australia, Queensland, New South Wales, and the Northern Territory are in the process of converting. West Australia and the Australian Capital Territory have no imminent conversion plans.

Metroads

Metroad

Source: Wikipedia. Licensed for use under the GFDL.

Metroads are used to number major metropolitan roads in Sydney and Brisbane.


New Zealand

State Highway. State Highways are actually national in scope.