TableBuilder: Road Freight Movements, Australia

1 This TableBuilder release 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, Australia 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.

3 The scope of the 2014 Road Freight Movements, Australia 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).

7 The Road Freight Movements, Australia 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, Australia 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.

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.

16 The Road Freight Movements, Australia 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, Australia survey produces estimates by origin and destination whereas the SMVU produces estimates by state of registration, state of operation and area of operation.

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

19 As well as the statistics included in this TableBuilder release, the ABS has un-released microdata available for a charge. Inquiries should be directed to the National Information and Referral Service on 1300 135 070.

1 When interpreting the results of a survey it is important to take into account factors that may affect the reliability of estimates. The survey procedures as well as sampling and non-sampling errors should be considered. Examination of the following quality indicators will assist users in determining fitness for purpose of the Road Freight Movements, Australia survey.

2 Estimates in this product are based on information collected from a sample of registered articulated and rigid trucks rather than a full enumeration, and are therefore subject to sampling error. The Road Freight Movements, Australia survey estimates may differ from the figures that would have been produced if the information had been obtained for all registered articulated and rigid trucks.

3 The sampling error associated with any estimate can be calculated from the sample results. One measure of sampling error is given by the standard error, which indicates the extent to which an estimate might have varied by chance because only a sample of articulated and rigid trucks was included. There are about two chances in three that a sample estimate will differ by less than one standard error from the figure that would have been obtained if all articulated and rigid trucks had been included, and about 19 chances in 20 that the difference will be less than two standard errors.

4 Another measure of sampling variability is the relative standard error (RSE), which is obtained by expressing the standard error as a percentage of the estimate to which it refers. The RSE is a useful measure as it provides an immediate indication of the percentage error likely to have occurred due to sampling. In this release, RSEs are selectable within TableBuilder.

5 Estimates with a RSE between 25% and 50% are considered to be high and should be used with caution. Estimates with a RSE higher than 50% are considered unreliable for general use.

6 The Road Freight Movements, Australia survey was designed primarily to minimise relative standard errors for estimates of total tonnes carried, total distance travelled and total tonne-kilometres at the state/territory of registration and vehicle type level.

7 An example of the RSEs relating to the Road Freight Movements, Australia survey estimates are shown in the following table.

8 For more information about relative standard errors and the Road Freight Movements, Australia survey see Road Freight Movements, Australia, Cat. No. 9223.0 Technical Note.

9 Non-sampling error covers the range of errors that are not caused by sampling and can occur in any statistical collection whether it is based on full enumeration or a sample. For example, non-sampling error can occur because of non-response to the statistical collection, errors or omissions in reporting, definition or classification difficulties, errors in transcribing and processing data and under-coverage of the frame from which the sample was selected. If these errors are systematic (not random) then the survey results will be distorted in one direction and therefore will be unrepresentative of the target population. Systematic errors result in bias.

Response and non-response

10 A potentially important factor relating to non-sampling error is the response rate achieved. For the Road Freight Movements, Australia survey, the response rate was 77% for vehicles included in the sample.

11 Non-response to the survey predominately occurred because the ABS was unable to trace the selected vehicle or the form was not able to be completed despite all reasonable efforts being taken. Where appropriate, mail reminders and telephone follow-up were used to attempt to contact initially non-responding vehicle owners.

12 For the Road Freight Movements, Australia survey it was assumed that the characteristics of non-responding vehicles were the same as for like responding vehicles. Non-response has the potential to cause non-response bias, which occurs if the usage patterns of the non-responding vehicles differ from those of the responding vehicles.

13 Usable responses were received from 79% of all of the selections for 2014, comprised of 74% from registered vehicles and 5% from unregistered vehicles, out of scope and duplicates. After removing those vehicles that had been found to be deregistered or out of scope, the response rate for the 2014 FMS was 77%.

14 Response rates for each state and territory, and for each vehicle type, are shown in the following tables:

Frame quality

15 The scope of the survey comprised all articulated and rigid trucks that were registered with a motor vehicle authority for road use at some stage during the 12 months ended 31 October 2014. A population or survey frame 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. From this frame a stratified sample of 16,000 vehicles were selected for reporting on vehicle use.

16 Vehicle classification anomalies arose when respondents indicated an alteration has been made to the vehicle body, resulting in a different vehicle type to that recorded on the frame. These changes happened during the time-lag between finalising the frame and collection of data (between 9 and 21 months). Vehicle classification anomalies can also result from data supplied by state and territory vehicle registration authorities.

Imputation

17 Partial imputation is the process whereby a value is generated for missing data items, based on the responses for similar vehicles which were operating for the reference period. As for the Survey of Motor Vehicle Use (SMVU), for which this survey shares its frame, the need for imputation of unanswered items on the returned questionnaires was quite high.

18 Full imputation was used for entire questionnaire non-response. The tables below show the percentage contribution to the estimates from both partial and full imputation.

19 The survey was comprised of three independent samples, with a different one used for each four month period in the overall 12 month survey period. Within each four month period, the sample was divided to cover all 52 weeks of the reference year. Estimates from each of these samples were aggregated to produce annual estimates.

Coherent estimates

20 The results published as Road Freight Movements, Australia (cat. no. 9223.0) in this release are from the Road Freight Movements, Australia survey, which was run as an additional road freight component of the 2014 Survey of Motor Vehicle Use (SMVU). The 2014 SMVU and the road freight component 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.

Adjustments

21 The Road Freight Movements, Australia survey aims to measure the use of all articulated and rigid freight vehicles registered during the reference year. Because selections were taken from vehicles registered some time before the beginning of each collection period, adjustments were made to account for the change in size of the registered motor vehicle fleet since the population frame was created. The frame was created on 31 January 2013 and adjustments involved two categories:

• re-registrations / de-registrations - typically older vehicles that were either leaving or returning to the registered vehicle fleet after a period of de-registration, and
• new motor vehicles - vehicles which had not been previously registered.

22 These activities occur continuously and the adjustments were made to account for the registrations that are estimated to have been added to or removed from the registered vehicle fleet between the population frame date and the end of the reference period. The adjustment process also accounted for de-registrations. This means it is possible for the re-registration factor to be negative.

Pre-advice methodology

23 The quality of survey responses was improved by employing the Survey of Motor Vehicle Use pre-advice methodology. This involved vehicle owners receiving early advice about their inclusion in the survey and encouragement of a higher degree of record keeping. In addition, the reporting of odometer readings taken at the start of the survey period aided in providing reliable estimates of total distance travelled.

Nil use

24 Some providers reported nil use for the reference period in which they were selected. Nil use vehicles are registered vehicles that report no travel during that specific reference period. Nil use vehicles were included in the survey as their reported nil use is representative of other vehicles in the population. Vehicles may have nil use due to factors such as seasonal usage, mechanical faults or economic conditions. Where a provider gave a nil use response, a follow-up phone call was used to check the veracity of the response.

25 The survey methodology used for the Road Freight Movements, Australia survey involved a one week collection period. The data collected was therefore more variable than usage data collected for a longer period such as the Survey of Motor Vehicle Use (SMVU) which uses a four month collection period. It was expected that the rate of nil use (and high use) for the Road Freight Movements, Australia survey would be above the rate of nil use (and high use) for the SMVU.

26 The rate of nil use for Road Freight Movements was 16%, compared with 8% for the articulated and rigid trucks segment of the 2014 SMVU.

Articulated trucks

Motor vehicles constructed primarily for load carrying, consisting of a prime mover which has no significant load carrying area, but with a turntable device which is linked to a semitrailer.

Commodity carried

The publication of commodities carried is based on the 10 sectional groupings of the Australian Transport Freight Commodity Classification (ATFCC), with the addition of Tools of Trade and the Australian Pack Classification (APC), (cat. no. 1210.0).

Containerised

Goods carried in a shipping container.

Dangerous goods

Those goods classified as dangerous or hazardous based on the Australian Dangerous Goods Code, 7th ed., AGPS, Canberra.

Destination

Represents the point to which the trip ended, coded to the ASGS (Australian Statistical Geography Standard). i.e. the load carried or configuration changed or goods were delivered.

Freight

Includes all goods and materials transported excluding freight moved by vehicles of the defence forces and by pipeline. Movements made under prime account, own account and subcontract arrangements were reported in the survey.

Imputation

The replacement of either missing or invalid data with accepted data. Normally done in accordance with predetermined decision rules and often combined with editing.

Gross Combination Mass (GCM)

Tare weight (i.e. unladen weight) of the motor vehicle and attached trailers, plus their maximum carrying capacity. GCM is the weight measurement used for a prime mover/semitrailer combination, or a rigid truck/trailer combination.

Gross Vehicle Mass (GVM)

Tare weight (i.e. unladen weight) of the motor vehicle plus its maximum carrying capacity.

Laden distance

Distance travelled by rigid trucks and articulated trucks from one destination to another when carrying freight.

Liquid Bulk

Liquid, melted, gaseous and substances in a slurry form containerised by the structure of the transport unit other than containers e.g. petroleum in tankers.

Method of transport

Identifies whether the commodity was moved in bulk (solid or liquid), was containerised or moved as 'other' freight.

Number of axles

The count of axles when viewing a vehicle from the side (e.g. one or more wheels on either side of a vehicle at the same point when measured from the front is classed as one axle).

Non-freight carrying trucks

Specialist motor vehicles or motor vehicles fitted with special purpose equipment, and having little or no goods carrying capacity (e.g. tow trucks).

Origin

Represents the point at which a trip started, coded to the ASGS (Australian Statistical Geography Standard). i.e. the load carried or configuration changed or goods were picked up.

Prime account

An agreement to move freight made between the original consignor of the freight and the transport operator.

Prime movers

Motor vehicles constructed primarily for towing trailers. Prime movers have no significant load carrying area but are fitted with a turntable for linking to a trailer.

Own account

Freight that is owned and transported by the same legal entity.

Refrigerated

Identifies those goods carried which require insulation, chilling or freezing during transportation.

Road

Includes all roads, public and private, in all states and territories of Australia, on which freight has been carried.

Rigid trucks

Motor vehicles exceeding 3.5 tonnes GVM, constructed with a load carrying area. Included are normal rigid trucks with a tow bar, draw bar or other non-articulated coupling on the rear of the vehicle.

Relative standard error (RSE)

The standard error expressed as a percentage of the estimate to which it refers.

Solid bulk

Solid substances constrained by the structure of the transport unit other than containers e.g. grain, coal, sand.

Standard error

Indicates the extent to which an estimate might have varied by chance because only a sample of vehicles was included.

State/territory of registration

The state or territory motor registry at which a vehicle is registered.

Stratification

Stratification is the process where a population is divided into homogeneous groups called strata that are non-overlapping, and together comprise the whole population. This technique uses auxiliary information to increase the efficiency of a sample design and units are selected independently within each stratum.

Tonne-kilometres

Total tonne-kilometres is the aggregation of the number of tonnes moved multiplied by the distance travelled in kilometres for each individual vehicle carrying freight. Note that it is not the aggregation of the total number of tonnes moved by total kilometres travelled by all vehicles carrying freight.

Tonnes carried

Total tonnes carried is the total weight of goods and freight carried during the survey period. The estimate of total tonnes carried relates to goods and freight uplifted by vehicles and therefore will overstate the actual physical quantity of goods and freight moved during the survey period to the extent that transhipment occurs (i.e. the transfer of goods and freight from one vehicle to another).

Trailer configuration

The configuration of an Articulated or Rigid Truck (see Articulated trucks or Rigid trucks above) with or without a trailer/s.

Trip

A trip is a journey made by a vehicle (with or without trailer/s attached) from one location to another where the load carried or vehicle configuration changes. Trips include all loaded, empty, fuelling and maintenance transport legs and exclude rest stops.

Type of goods

The type of good carried (e.g. Dangerous goods or Refrigerated goods).

Unladen distance

Distance travelled by rigid trucks and articulated trucks from one destination to another when not carrying freight.

Vehicle group

The type of truck (e.g. Articulated or Rigid trucks)

Year of manufacture

The age group of the vehicle (e.g. 1998 and earlier, 1999 to 2008, 2009 and after).

For information on the institutional environment of the Australian Bureau of Statistics (ABS), including the legislative obligations of the ABS, financing and governance arrangements, and mechanisms for scrutiny of ABS operations, please see ABS Institutional Environment.

Results from Road Freight Movements, Australia provide a nationwide picture of road freight movement by articulated and rigid trucks over the reference period November 2013 to October 2014. These data are used for policy and planning purposes, including the allocation of Federal road funding; road planning, building and maintenance; enhancing road safety and other activities.

Road Freight Movements, Australia collects information from 16,000 registered articulated and rigid trucks in Australia. Estimations based on detailed cross classifications are likely to result in high relative standard errors.

Vehicle movements are classified to the Australian Statistical Geography Standard (ASGS) as broadly defined and reported by respondents.

The main output data items are total kilometres travelled, tonne-kilometres and tonnes carried. The tonne-kilometres is not obtained directly but is derived for all records from collected distance and load weight information.

The population frame for Road Freight Movements, Australia was generated from the Motor Vehicle Census (MVC) as at 31 January 2013.

There are 16,000 selections used for the three reference periods. The first period beginning November 2013 with the third and final period finishing in October 2014.

The survey is designed to obtain quality estimates for key data items of total kilometres travelled, tonne-kilometres and tonnes carried.

The overall response rate for 2014 was 77%. The need for imputation of unanswered questions on returned questionnaires is quite high, with the percentage contribution to the estimates of tonne-kilometres from both partial or full imputation being 34%.

For further information refer to the Data Quality section of the Technical Note.

The Road Freight Movements, Australia survey was undertaken as an additional component to the 2014 Survey of Motor Vehicle Use (SMVU), published in (cat. no. 9208.0). The SMVU 2014 and the road freight component 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.

Care should be taken in drawing inferences between transport surveys such as the 2000 Freight Movements Survey and the Survey of Motor Vehicle Use. These surveys are designed for level estimates not movement estimates, and are collected using different methodologies. Refer to the Technical Note.

The Road Freight Movements, Australia publication contains detailed Introductory Notes, Explanatory Notes, Technical Note and Glossary that provide information on the data sources, terminology, classifications and other technical aspects associated with these statistics.

If the information you require is not available as a standard product or service, then ABS Consultancy Services may be able to help you with customised services to suit your needs. Inquiries should be made to the National Information and Referral Service on 1300 135 070. The ABS Privacy Policy outlines how the ABS will handle any personal information that you provide to us.