EXPLANATORY NOTES


INTRODUCTION

1 This publication presents estimates of freight moved by road in Australia for the period 1 November 2013 to 31 October 2014. The data were collected in the 2014 Road Freight Movements survey, which was designed to provide statistics about the size and characteristics of the road transport task, including freight flows between geographic areas. Specifically, the survey collected information in relation to origin-destination road freight movements.

2 The previous Freight Movements survey (cat. no. 9220.0) published in 2002 also included rail, sea and air freight movements within Australia, however these modes of transport are not in the scope of the current survey.

SCOPE AND FRAME

3 The scope of the 2014 Road Freight Movements survey includes all freight moved by articulated and rigid trucks exceeding 3.5 tonnes GVM, that were registered with a motor vehicle authority for road use at some stage during the 12 months ending 31 October 2014. Unregistered vehicles and freight moved by trucks or light commercial vehicles that were up to 3.5 tonnes GVM were out of scope. Freight moved by the defence forces, or substances moved by pipeline were also excluded from the survey.

4 These statistics relate to road freight movements whether goods were carried by transport operators for hire or reward, or moved by ancillary operators (i.e. manufacturers, retailers, wholesalers, etc. on their own account). All trips, laden and unladen, performed by articulated and rigid trucks were included.

5 Freight movements involving multiple modes of transportation are recorded separately. For example, freight moved from Sydney to Hobart by road and sea would be recorded as two separate trips, because the component by sea from Melbourne to Devonport is outside the scope of this survey. The trips recorded are one from Sydney to Melbourne and a second from Devonport to Hobart. This treatment, consistent with previous freight movement surveys, results in Tasmania having nil interstate road movements.

6 The survey population was identified using information obtained from the state and territory motor vehicle registration authorities, as part of the ABS Motor Vehicle Census (MVC) (cat. no. 9309.0) for 31 January 2013. The population information identified is referred to as the survey frame. The survey frame was stratified by:

• state/territory of registration
• vehicle type (articulated trucks or rigid trucks)
• area of registration (capital city or rest of state)
• age of vehicle (based on year of manufacture) and
• vehicle size (based on GCM).

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:

• start and finish odometer reading for the week;
• the usual garaged address for the vehicle;
• the vehicle's detailed use and movements for the week:
  • origin and destination of each trip;
  • commodity type carried;
  • weight of load carried;
  • distance travelled;
  • trailer configuration, and
  • method of transportation.
    

12 When the questionnaires for each reporting period were returned to the ABS they were checked for completeness and accuracy and, where possible, follow-up contact was made with owners to resolve reporting problems. Missing data items were imputed.

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:

• Motor Vehicle Census, Australia cat. no. 9309.0
• Sales of New Motor Vehicles - Electronic publication cat. no. 9314.0
• Survey of Motor Vehicle Use, Australia cat. no. 9208.0

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.