Page tools: Print Page Print All | ||
EXPLANATORY NOTES
METHODOLOGY 7 The Road Freight Movements survey was conducted as an additional component of the 2014 Survey of Motor Vehicle Use (SMVU). Results from the SMVU are published in Survey of Motor Vehicle Use, Australia (cat. no. 9208.0). 8 The Road Freight Movements survey had a sample of 16,000 articulated and rigid trucks. This consisted of 8,000 trucks selected only in the road freight movements component, and 8,000 trucks also selected in the SMVU 2014. Respondents reported over a one week period within the reference year. The sample size was chosen to give a suitable level of precision for total distance travelled, tonnes carried and tonne-kilometres travelled at the state/territory of registration level. 9 In addition, to help correct for under coverage on the population frame, adjustments were made to the estimation process to account for new and re-registered articulated vehicles not given a chance of selection in the survey. 10 In order to encourage record keeping, confirm ownership and vehicle characteristics, update contact details, and to capture an odometer reading, owners of the articulated and rigid trucks selected in the survey received a pre-advice form. Providers were advised that they would receive a follow up questionnaire (a trip form) asking for details of the freight moved during a randomly allocated one week period. Examples of the main items requested in the trip form were included, together with an information sheet about the survey. 11 Trip forms were despatched weekly to selected providers. For each road freight movement conducted in the reference week, the following information was collected:
13 Where the selected vehicle owner had not owned the vehicle for the whole weekly survey period, the details provided for the period of ownership were adjusted to give a one week equivalent, except where the vehicle was deregistered, in which case only the use up to deregistration was included. 14 Estimates were produced for each of the 52 weekly reporting periods and aggregated to produce totals in approximately four month periods over the reference year, these were further aggregated to produce annual figures relating to the complete survey reference period. RELIABILITY OF ESTIMATES 15 When interpreting the results of a survey it is important to take into account factors that may affect the reliability of the estimates. Such factors can be classified as either survey methodology, sample error or non-sampling error. Information on these factors is provided in the Technical Note. COMPARISON WITH SURVEY OF MOTOR VEHICLE USE 16 The Road Freight Movements survey and 2014 SMVU were designed together to provide coherent estimates at the state of registration by vehicle type level for total distance travelled, tonne-kilometres and total tonnes. 17 However, it should be noted that the two collections use different survey methodologies and use different classifications for the outputs. The estimates are not comparable at finer levels. For example, the geographic concepts used are different; the Road Freight Movements survey produces estimates by origin and destination whereas the SMVU produces estimates by state of registration, state of operation and area of operation. RELATED RELEASES AND PRODUCTS 18 Users may also wish to refer to the following publications and products which contain information relating to motor vehicles in Australia:
ABS DATA AVAILABLE ON REQUEST 19 As well as the statistics included in this publication, the ABS has unpublished data available for a charge. Inquiries should be directed to the National Information and Referral Service on 1300 135 070. Document Selection These documents will be presented in a new window.
|