Abstract
There are over half a million heavy vehicles registered in Australia as of September 1982. They travel a total distance of 11.6g109 kilometers throughout the nation which leads to a total fuel consumption of 3.8g109 litres, i.e. an average of 32 1 /100 km. In order to develop an efficiency improvement program for heavy vehicles, operational statistics are vital. Categorising of vehicles is necessary to derive representative statistics