The Australian Bureau of Statistics (ABS) defines a bus [or coach], based on the current definition (1989) under Australian Design Rules (ADR) as a motor vehicle constructed for the carriage of passengers, with 9 or more seats, including the driver’s seat. When not specified, the term ‘bus’ applies to a bus or a coach type motor vehicle.

The bus and coach industry defines the construct of a bus as:

• a buggy type chassis (2, 3 or 4 axle) and associated mechanical components (engine, steering, axle, etc.) and the body (panels, floors, seating, etc.)
• a composite bus (also called monocoque) which does not have a traditional buggy chassis, is a composite of all mechanical and body components as an integral unit.

The bus and coach industry generally defines the size of a bus as:

• large – a bus that has a GVM of 10 tonne or more, a body length of 12.5 to 18 metres with a seat capacity (including driver) of 26 or more
• medium – a (midi) bus that has a GVM of less than 10 tonne, a body length of 8 to 10 metres with a seat capacity (including driver) of 16 to 25
• small – a (mini) bus that has a GVM of less than 4.5 tonne, a body length of less than 8 metres with a seat capacity (including driver) of 9 to 15.

Buses can also vary in style based on its primary area of operations (urban or regional) and/or primary duties (route, school, charter, long distance) and can be:

• single deck or double deck
• articulated or rigid
• high floor or low floor accessible.