14007_om_not-searchable
/en/transport-og-reiseliv/statistikker/godstrans/kvartal
14007_om
statistikk
2019-11-15T08:00:00.000Z
Transport and tourism
en
false

Carriage of goods by lorryQ3 2019

Content

About the statistics

Definitions

Name and topic

Name: Carriage of goods by lorry
Topic: Transport and tourism

Next release

Responsible division

Division for Energy, Environmental and Transport Statistics

Definitions of the main concepts and variables

Carrying capacity

Carrying capacity is the difference between the maximum permissible weight of the vehicle and the sum of the unladen weight of the vehicle and the weight of driver (75 kg). 

Total weight of the vehicle

The maximum permissible weight of the vehicle included people and goods.

National road goods transport

Transport of goods with both loading and unloading in Norway.

International road gods transport

Transport between Norway and another country, loaded or unloaded.

Includes cross-trade (transport between two other countries) and cabotage (transport within another country). 

Cabotage

Place of loading and unloading of goods in the same country outside the declaring country. 

Cross-trade

Place of loading and place of unloading of goods in two different countries outside the

declaring country.

Transport for own account

Transport of own goods on own account.

Transport for hire or reward

The carriage for remuneration of persons or goods on behalf of third parties.

Vehicle-kilometres

Driven kilometres with and without load.

Tonnage carried

Gross weight of the transported goods, packaging included.

Does not include the weight of container or swap body.

Goods transport performance

The transport work which is performed when a vehicle carries a certain amount of goods over a definite distance.

The weight of the goods in one transport operation multiplied by the transport distance of the operation. Is measured by the unit tonne kilometre.

Rate of empty kilometres

The percentage share of unloaded vehicle-kilometres. 

Commodity

Type of commodity defined according to the EU's standard goods classification for transport statistics. Up to the 4th quarter of 2007 the NST/R nomenclature was used. The NST 2007 nomenclature was introduced as from the 1st quarter of 2008. The nomenclatures are described in the Database for standard classifications.

Volume goods

The weight of the cargo is less than the vehicle's carrying capacity when the cargo-hold's volume is fully utilised. 

Imports of goods

Imports cover goods declared by customs, directly or through a warehouse. Single items with a value of less than NOK 1.000 are not included in the statistics. 

Exports of goods

Exports of goods are mainly based on customs declarations. Single items with a value of less than NOK 1.000 and some specific movements of goods, such as goods for repair, are not included in the statistics.

Standard classifications

CTSE: The goods are grouped in accordance with the Commodity Classification for Transport Statistics in Europe (CSTE). This standard was used in the statistics on the carriage of goods by lorry across the national border up to and including the 4th quarter of 2017.

NST 2007: EU’s statistical nomenclature for transported goods: Standard Goods Classification for Transport Statistics. The standard has been used in the survey of lorries since the 1st quarter of 2008 and in the statistics on the carriage of goods by lorry across the national border since the 1st quarter of 2018.

NST/R: Standard Goods Classification for Transport Statistics/Revised. This standard was used in the survey of lorries up to and including the 4th quarter of 2007.

In the statistics on the carriage of goods by lorry across the national border, gross weight in tonnes is used.

ISO 3166: Country codes.

NUTS 3: Regional codes for the EU and Norway. In Norway, NUTS 3 corresponds to county.

In the statistics on the carriage of goods by lorry across the national border, imports (country of origin and country of despatch) and exports (country of destination) are broken down into EU/EFTA countries, selected European countries, other EU/EFTA countries and other countries outside the EU/EFTA. The lorry’s country of registration is specified where this is a country in Europe. For other lorries, the world region is specified.

Administrative information

Regional level

Road goods transport by Norwegian lorries: The municipality is the lowest mandatory reporting level for loading and unloading in Norway. Post codes and towns are often reported as well. World region (NUTS 2) is the lowest mandatory reporting level for loading and unloading abroad within the EU/EEA area. Post codes and towns abroad are often reported as well. Country is the lowest reporting level for loading and unloading abroad outside the EU/EEA area. The lowest level of publishing is county (NUTS 3 region). For international transports the lowest level of publishing is country. For annual data, county is the lowest publishing level.

For the carriage of goods by lorry across the national border and the carriage of goods by foreign-registered lorries: Country.

Frequency and timeliness

Road goods transport by Norwegian lorries: Quarterly. The figures are published about 16 weeks after the end of the reporting quarter.

For the carriage of goods by lorry across the national border:  Quarterly. The figures are published about 4-5 weeks after the end of the reporting quarter.

For the carriage of goods by foreign-registered lorries: Annually. The figures are published in October the year after the reference year.

International reporting

Road goods transport by Norwegian lorries: Transmission of data to Eurostat for each quarterly period of observation.

For the carriage of goods by lorry across the national border: Not relevant here. There is no requirement to report the data internationally.

For the carriage of goods by foreign-registered lorries: Not relevant here. The figures on the carriage of goods by foreign-registered lorries to/from and in Norway are retrieved from Eurostat.

Microdata

Road goods transport by Norwegian lorries: Production data are lang-term saved as SAS- and txt-files on LINUX.

For the carriage of goods by lorry across the national border: Production data are saved as SAS- and ASCII-files on LINUX.

For the carriage of goods by foreign-registered lorries: Production data are saved as SAS- and txt-files on LINUX.

Background

Background and purpose

Road goods transport by Norwegian lorries: The purpose of the survey is to describe the Norwegian-registered vehicles’ (carrying capacity 3.5 tonnes and over) transport performance, and to help identify transport patterns in Norway and abroad.

The first national survey on road haulage was conducted in 1954, and the second one was in 1963. It was then conducted every five years up to 1988. From 1993, the survey was conducted quarterly. The international survey was introduced in 1996, and was conducted up to the 4th quarter of 2002. In the 1st quarter of 2003, the national and the international survey were merged into one survey with one questionnaire. Major changes were made to the questionnaire in the 1st quarter of 2016 in order to make it compatible for use in Altinn, the reporting channel for the public sector. The paper version of the questionnaire was also discontinued at this point.

For the carriage of goods by lorry across the national border: The purpose is to map the activity of different countries’ lorries across the Norwegian border.

Statistics showing the breakdown of border crossings in road haulage according to the vehicle’s country of registration were established in 1961. These statistics were based on monthly reporting from the Norwegian Customs Service. This data collection was discontinued after 2002.

In 2007, the statistics were restarted, and these were based on Statistics Norway’s external trade statistics. Figures are available dating back to the year 2000.

For the carriage of goods by foreign-registered lorries: The purpose is to describe the transport performance of foreign-registered vehicles in connection with journeys to, from and in Norway.

The statistics were first produced in 2009, with figures for the years 2000–2008.

The statistics are based on lorry surveys in all EU/EEA countries.

Users and applications

For the carriage of goods by Norwegian-registered and foreign-registered lorries: The statistics are primarily used by public authorities and research institutions (TØI, SINTEF, the Norwegian Public Roads Administration, etc.) for transport planning and in transport models. Transport companies, transport planners and consultancy firms are also important user groups, as well as trade organisations. Internally in Statistics Norway, the data is included in the calculations of domestic transport performance. Internationally, the data is used by the statistical office of the European Union, Eurostat, among others.

For the carriage of goods by lorry across the national border: The statistics are used for transport planning by transport authorities and the transport industry. Trade organisations and research institutions are also important users. The statistics show, among other things, the market shares of Norwegian-registered vehicles in the competition with foreign-registered vehicles, and help to inform discussions about the framework conditions in the lorry transport industry.

Equal treatment of users

No external users have access to statistics before they are published and available to everyone at 08.00 hrs on Statistics Norway’s website, ssb.no. At least three months’ advance notice is given in the statistics calendar. This is one of Statistics Norway’s most important principles for safeguarding the equal treatment of users (the principle of equal treatment).

Coherence with other statistics

Data from the survey on the carriage of goods by Norwegian-registered lorries is used in the statistics on domestic transport performance. The statistics stem from a sample survey that only covers Norwegian-registered lorries with a carrying capacity of 3.5 tonnes and over, and up to 35 tonnes in total weight. The tonnage carried is stated in gross weight. Goods transported by lorry on ferry are included.

For the carriage of goods by lorry across the national border: The external trade statistics show imports and exports using all means of transport. The figures are published in net weight (without packaging). These statistics are revised up to April of the following year, while the statistics on the carriage of goods by lorry across the national border are extracted from the preliminary data files.

The carriage of goods by lorry across the national border is a special variant based on the external trade data and shows tonnage carried over the part of Norway’s border that is accessible by road. The statistics include lorries registered in all countries, not just EU countries.

For the carriage of goods with foreign-registered lorries: The Norwegian lorry survey shows Norwegian-registered lorries’ transport domestically and abroad. Figures from these two statistics can be merged in order to form a picture of all carriage of goods by lorry to, from and in Norway.

Legal authority

Road goods transport by Norwegian lorries: The Statistics Act, §§ 10, 20.

For the carriage of goods by lorry across the national border: The Statistics Act, §§ 10, 20.

For the carriage of goods with foreign-registered lorries: Not relevant here.

EEA reference

The statistics are produced and reported to Eurostat in accordance with Regulation (EU) 70/2012 of the European Parliament and of the Council of 18 January 2012 on statistical returns in respect of the carriage of goods by road as amended in Council Regulation (EU) 517/2013.   

Other relevant regulations for the area:

  • Commission Regulation (EU) 2163/2001 concerning the technical arrangements for data transmission for statistics on the carriage of goods by road as amended in Commission Regulation (EU) 973/2007.
  • Commission Regulation (EU) 642/2004 on precision requirements for data collected.
  • Commission Regulation (EU) 1304/2007 amending previous directives and regulations with respect to the establishment of NST 2007 as the unique classification for transported goods in certain transport modes.
  • Regulation (EU) 223/2009 of the European Parliament and of the Council on European statistics.
  • Common Position (EU) 6/2003 amended by Commission Regulation (EU) 202/2010 concerning the dissemination of statistics on the carriage of goods by road.

The survey is conducted according to Eurostat’s reference manual: Road Freight Transport Methodology.

For the carriage of goods by lorry across the national border: Not relevant here. The data is retrieved from the external trade statistics, which have their own statutory basis. 

For the carriage of goods by foreign-registered lorries: The data is received from Eurostat.

Production

Population

Road goods transport by Norwegian lorries: The survey population consists of Norwegian-registered lorries in vehicle groups from 320 to 381 in the Norwegian Public Roads Administration’s motor vehicle register, with a carrying capacity of 3.5 tonnes and over, up to 35 tonnes in total weight and less than 30 years old. Vehicles for which it is not possible to assign an organisation number to the owner are removed from the population before the sample is drawn. The total population consists of about 35 000 goods vehicles.

For the carriage of goods by lorry across the national border: The statistics include goods that have been transported by road into or out of Norway on a lorry. Goods transported by lorry on ferries are not included. For the sake of clarity, however, total figures are given for transport by vehicles and trailers on ferries, but these are not broken down into country of registration of the vehicle.

For the carriage of goods by foreign-registered lorries: The statistics include transport by lorries registered in EU/EEA countries and some EU candidate countries on journeys to, from and in Norway. The number of countries covered in the statistics has increased from year to year. See the table below:

Country 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
Austria x x x x x x x x x x x x x x x x x x x x
Bosnia and Herzegovina                                        
Belgium x x x x x x x x x x x x x x x x x x x x
Bulgaria             x x x x x x x x x x x x x x
Switzerland                 x x x x x x x x x x x x
Cyprus     x x x x x x x x x x x x x x x x x x
Czech Republic x x x x x x x x x x x x x x x x x x x x
Germany x x x x x x x x x x x x x x x x x x x x
Denmark x x x x x x x x x x x x x x x x x x x x
Estonia       x x x x x x x x x x x x x x x x x
Spain x x x x x x x x x x x x x x x x x x x x
Finland x x x x x x x x x x x x x x x x x x x x
France x x x x x x x x x x x x x x x x x x x x
United Kingdom x x x x x x x x x x x x x x x x x x x x
Greece       x   x x x x x x x x x x x x x x x
Croatia                 x x x x x x x x x x x x
Hungary   x x x x x x x x x x x x x x x x x x x
Ireland x x x x   x x x x x x x x x x x x x x x
Italy x x x x x x x x x x x x x x x x x x x x
Liechtenstein           x x x x x x x x x            
Lithuania       x x x x x x x x x x x x x x x x x
Luxembourg x x x x x x x x x x x x x x x x x x x x
Latvia     x x x x x x x x x x x x x x x x x x
Montenegro                                 x x x x
Macedonia, Former Yugoslav Rep. Of                               x   x x x
Netherlands x x x x x x x x x x x x x x x x x x x x
Poland         x x x x x x x x x x x x x x x x
Portugal x x x x x x x x x x x x x x x x x x x x
Romania             x x x x x x x x x x x x x x
Serbia                                        
Sweden x x x x x x x x x x x x x x x x x x x x
Slovenia   x x x x x x x x x x x x x x x x x x x
Slovakia       x x x x x x x x x x x x x x x x x
Kosovo                                        
Total 15 17 19 23 22 25 27 27 29 29 29 29 29 29 28 29 29 30 30 30

Note that vehicle kilometres and transport performance includes the total transport distance even though parts of it was covered abroad.

Data sources and sampling

Road goods transport by Norwegian lorries: The main data source for the lorry survey is quarterly representative sample surveys based on questionnaire data. Technical data on the vehicles is also retrieved from the Norwegian Public Roads Administration’s motor vehicle register, and this is linked to the questionnaire data. The motor vehicle register is also used to ascertain the carrying capacity of trailers used in the transport of goods.

The sampling plan was reorganised in the 3rd quarter of 2015, mainly because the Norwegian Public Roads Administration’s register of community licences was discontinued. This had been an important source for identifying vehicles that were assumed to be used abroad. Furthermore, there had long been a desire to reduce the reporting burden on big companies with large fleets of vehicles. At the same time, mileage data obtained from vehicle controls (PKK-data) was improved and used to establish the new sampling plan. This data from meter readings is updated quarterly for the lorries in the target group.

In December 2017, a minor adjustment was made to the sample design, with a view to extracting more vehicles used for international transport.

The sample is selected in two steps.

Step 1: Sample of companies engaged in road haulage.

Step 2: Sample of lorries within the selected companies.

The lorries are distributed into 16 categories, based on annual mileage (4 groups) and vehicle class derived from the vehicle group (4 classes).

From the 1st quarter of 2020 the lorries are distributed into 12 categories, based on annual mileage (3 groups) and vehicle class derived from the vehicle group (4 classes).

About 1 900 lorries are selected every quarter to participate in the survey.

For the carriage of goods by lorry across the national border: In the new routines that were introduced in 2007, data is retrieved from Statistics Norway’s external trade statistics. This is based on administrative forms obtained from the Norwegian Customs Service. For more information on the external trade statistics, see the web page for external trade.

For the carriage of goods with foreign-registered lorries: The statistics are based on the results of the EEA countries’ lorry surveys. These surveys are carried out as sample surveys in the individual countries, and sampling plans and calculations will vary somewhat from country to country. Eurostat’s recommendations for conducting the surveys and producing the statistics can be found in its reference manual: Road Freight Transport Methodology. Eurostat has prepared an overview of the individual countries’ methodological adaptations: Methodologies used in surveys of road freight transport in Member States, EFTA and Candidate Countries.

For the carriage of goods by lorry across the national border:

For detailed information on data collection, editing and calculations of the external trade data, see the web page for external trade.

For the carriage of goods by foreign-registered lorries: Eurostat receives three data files every quarter from each of the participating countries. These files are extracts from the individual countries’ lorry surveys and contain specified variables on the vehicles, journeys and consignments. Figures from these data files are assembled in annual files which in turn are distributed to the participating countries.

In addition to the individual countries’ control and audit routines, all data is subject to extensive error checks in Eurostat. When absolute errors are identified, notification is sent to the participating country, which then needs to correct and resubmit its data.

The only calculations from the different countries are the summing up of the results.

Collection of data, editing and estimations

For the carriage of goods by Norwegian-registered lorries: From the 1st quarter of 2016, all information is reported online via the reporting channel Altinn. From the 4th quarter of 2016, all letters and messages are also sent digitally. Companies that have several vehicles still receive a cover letter in hard copy.

The questionnaires are sent out every week throughout the year, with about 140 questionnaires sent each week. The deadline for returning the questionnaire is three weeks after the end of the survey week.

A number of controls have been incorporated into the questionnaire in order to reduce the extent of errors.

When the completed questionnaires are received, the data is subject to mathematical and logical controls. Respondents are contacted where individual questions have not been answered or in the event of other significance errors. Some missing answers are estimated using data from other responses for the same variable.

Weighting of the sample takes place in six steps. In the first step, sample weights are calculated based on the ratio of the number of vehicles in the population and the number of vehicles selected in each vehicle category.

In the second step, these weights are adjusted using known population totals in different subpopulations derived from an updated vehicle population.

In the third step, the calibration weights of the vehicles that were driven in the survey week are weighted according to a set of factors, based on a sample-based calibration model. This step is performed in order to compensate for the lack of information from vehicles that participated in the survey but were not driven during the reporting period.

In the fourth step, a further adjustment is made to ensure consistency between the estimates of the tonnage carried from the international part of the lorry survey and quarterly figures from the external trade statistics on imports and exports. This adjustment is made for vehicles that transported goods internationally in the reporting week.

In step five, the sample weights for vehicles that only transport goods domestically are further adjusted to ensure consistency between the sample estimates for these vehicles and the associated population totals.

In the final step, the sample weights are multiplied by 13 in order to convert the results from a reporting week to a quarter.

From the 1st of 2020 the estimation methodology has been changed. The new method provides more precise estimates, especially for tonnage carried and transport performance. In addition, a winsorization method is applied to the weighted values to even more increase the precision.   

Expansion weights, which are used to estimate the Road Goods Transport statistics, are calculated in several steps.

At the first step, initial weights are calculated for each lorry in the sample. These weights are simply obtained by dividing the total number of lorries in the up-to-date population by the number of lorries in the sample within each vehicle stratum. These weights can be treated as proxy weights for the design weights, which, by definition, are the inverse of the selection probabilities of lorries.

At the second step, a machine learning algorithm, namely random forest, is used to predict vehicle kilometre and transportation amount for all lorries in the lorry population.

At the third step, a multiple model-calibration method is used to make the sample estimates consistent with the population totals for a given set of variables. With calibration, the weighted sum of sample totals becomes equal to the population totals for the whole population and/or some subpopulations. This consistency is achieved for the total number of lorries in the lorry population, total import and export at national level coming from the Foreign Trade Statistics, total predicted vehicle kilometres and tonnage carried within some subpopulations. Proxy weights calculated at step one are used as initial weights in the calibration.

At the fourth step, calibration weights are multiplied by some factors to compensate for underreporting of survey variables. These factors are calculated using the ratios of average vehicle kilometres from periodic vehicle control data and estimated average vehicle kilometres from the survey Carriage of goods by lorry within three groups constructed based on age of vehicles and vehicle class.  The yearly survey data from 2016 to 2019 are used. The final factors are the averages of the factors calculated for the period of 2016-2019.

At the last step, quarterly survey weights are calculated by multiplying the final weights obtained at step four by 13 to weight the results up from a reporting week to a quarter.  

After the weighting procedure, a winsorization method is applied to the weighted values for vehicle kilometres, tonnage carried and transport performance to increase the precision.

For the carriage of goods by lorry across the national border:

For detailed information on data collection, editing and calculations of the external trade data, see the web page for external trade.

For the carriage of goods by foreign-registered lorries: Eurostat receives three data files every quarter from each of the participating countries. These files are extracts from the individual countries’ lorry surveys and contain specified variables on the vehicles, journeys and consignments. Figures from these data files are assembled in annual files which in turn are distributed to the participating countries.

In addition to the individual countries’ control and audit routines, all data is subject to extensive error checks in Eurostat. When absolute errors are identified, notification is sent to the participating country, which then needs to correct and resubmit its data.

The only calculations from the different countries are the summing up of the results.

Seasonal adjustment

The results are not subject to seasonal adjustments.

Confidentiality

Road goods transport by Norwegian lorries and for the carriage of goods by foreign-registered lorries: The data collected is used in accordance with the Statistics Act.

For the carriage of goods by foreign-registered lorries: Figures based on fewer than 10 vehicles are not published.

Comparability over time and space

Road goods transport by Norwegian lorries: Despite changes in the structure and implementation of the survey, it is possible to follow the main trends in the lorries’ transport performance dating back to 1963. The historical statistics give some key figures from the previous 5-yearly surveys, and the quarterly statistics date back to 1993.

The tables with results from the lorry surveys published before the 1st quarter of 2000 are not directly comparable with the tables published between the 1st quarter of 2000 and the 4th quarter of 2002. This is because the goods vehicles group with a carrying capacity between 1 and 3.5 tonnes is not included from the 1st quarter of 2000. Apart from the fact that the small lorries are no longer included in the survey, the results are comparable at the vehicle level. Tables have been published which show the transport performance of the vehicle groups that were taken out of the survey.

Improvements were made in the 1st quarter of 2003 to the methodology used in the survey, and a new questionnaire was drawn up. The results from 2003 will therefore not be directly comparable with the results from before 2003. Nevertheless, even with the change, the main trends in the lorries’ transport performance can still be followed over time.

The methodology for weighting figures for journeys abroad was changed in the 1st quarter of 2006. The change entailed calibrating the figures from the external trade statistics on imported and exported tonnage carried. Figures for international journeys before and after 2006 are therefore not directly comparable.

From the 1st quarter of 2007, the sample was reduced from 2 400 to 1 800 vehicles per quarter. The reduction was generally only of significance for the international category, which was halved from 1 200 to 600 vehicles. This followed the introduction of an annual survey of which vehicles are likely to be used for journeys abroad by companies that are licensed to carry out such activity.

New stratification and sampling plans were devised in the 3rd quarter of 2015. The method is described above. This change is not expected to affect the results to any great extent.

A completely new questionnaire based on Altinn was introduced in the 1st quarter of 2016. At the same time, the estimation routines were improved (see the section on Editing and calculations above). This change means that comparisons with previous quarters must be made with a degree of caution and that the main variables are not directly comparable going backwards in time. A new method for reporting types of goods may have led to differences in the types of goods classification. For example, it seems that less is reported under general cargo and other goods, which may indicate that this group is used as a miscellaneous item to a lesser extent than before. There also seems to have been a shift from self-transport to rental transport, a correction that seems to be more in line with what the transport industry itself estimates.

Beginning 1st quarter of 2020 the estimation methodology has been changed. The new method provides more precise estimates, especially for tonnage carried and transport performance. This change is not expected to affect the results to any great extent.

For the carriage of goods by lorry across the national border: The statistics for the years 1961 to 2002 show the number of border crossings and the tonnage carried (gross weight in tonnes), distributed by customs office and the vehicle’s country of registration. The results were based on a separate survey that was conducted in connection with the border crossing points.

In 2007 (with figures dating back to 2000), these statistics were replaced with data on imports and exports by lorry based on the external trade data. The statistics show the tonnage carried (gross weight in tonnes) by type of goods, country of origin of the goods, country of dispatch and country of destination, and the vehicle’s country of registration.

Figures for the years 2000–2002 have been published, both according to the new and old methodologies. These figures are based on different sources and are therefore not comparable.

In the 3rd quarter of 2014, much of the timber exports that have long been incorrectly registered as transported by lorry were moved to rail. New figures have been updated dating back to the 1st quarter of 2013. Consequently, the statistics will be not be comparable between the 4th quarter of 2012 and the 1st quarter of 2013. This primarily affects the comparability of total figures and market shares of exports.

For the carriage of goods by foreign-registered lorries: The number of countries included in the statistics has varied over the years. See the table above showing which figures can be compared.

Accuracy and reliability

Sources of error and uncertainty

Road goods transport by Norwegian lorries: The questionnaire has been thoroughly reviewed, including by users, and many unclear questions and other ambiguities have been weeded out in this process.

The survey is arranged in such a way that the lorry owner records all driving every day for a specific week. If the vehicle use is not noted every day, journeys may be forgotten when completing the questionnaire. A particular problem with the survey is that journeys with an empty load are not reported. Furthermore, a vehicle may be used by several drivers, so the person completing the questionnaire may not have a full overview of the use of the vehicle during the survey period. There is considerable contact with the enterprises involved in this survey.

It is assumed that any measurement and processing errors have not led to systematic errors in the results.

Non-responses in the lorry survey will either relate to vehicles for which we were unable to contact the owner due to the addressee being unknown, and where the vehicle has not been registered as having the number plates confiscated, or to owners who fail to respond and incur a compulsory fine. The non-response rate is about 20 per cent. Non-response leads to a participation bias and adds to the uncertainty caused by sampling errors.

Responses in the questionnaire are sometimes incomplete, and in some cases, this means that the questionnaire cannot be used. This can occur when the respondent has not included all the journeys that were carried out during the reporting period (for example, only entering one journey with an empty load or filling out the questionnaire for only one day during the reporting period).

Sampling errors are not errors per se, but an uncertainty due to the fact that the survey is based on a sample (probability sample) as opposed to a full count. On average, from all samples that we select, the sampling error will be zero. In the lorry survey, sampling errors occur when selecting which vehicles to include. Stratifying the population before selection is intended to minimise sampling errors. The lorry survey will have coverage errors due to delays in updating the motor vehicle register, which is used for selecting the sample. For vehicles that are sold, deregistered or scrapped just before or during the reporting quarter, the data will not be updated. The weighting that is carried out aims to correct this type of coverage error. There are also coverage errors in the data for vehicles that are driven abroad. The calibration of the total figures for imported and exported tonnage carried with the external trade statistics, which was introduced in the 1st quarter of 2006, aims to correct for the incomplete overview of enterprises and vehicles used in international transport. The calibration produces good-quality figures for total imported and exported quantities but can lead to skewed figures at country and type of goods level.

Sampling errors are quantified in the following table:

National and international transports. Transport performances. Quarter

  1st quarter 2020 2nd quarter 2020 3rd quarter 2020 4th quarter 2020
Vehicle kilometres, total (mill. km) 483.40 478.20 519.40 558.30
Relative standard error (%) 3.35 1.09 2.53 3.44
Lower bound 95% confidence interval 479.59 470.65 483.81 516.78
Upper bound 95% confidence interval 537.49 491.16 535.60 588.29
Vehicle kilometres with load (mill. km) 346.00 337.10 367.90 396.40
Relative standard error (%) 3.56 1.78 3.38 3.74
Lower bound 95% confidence interval 339.75 326.50 333.89 364.51
Upper bound 95% confidence interval 387.32 349.68 381.14 420.73
Tonnage carried (mill. tonnes) 54.10 61.70 62.70 65.00
Relative standard error (%) 2.03 1.25 2.85 2.72
Lower bound 95% confidence interval 52.86 60.62 60.33 64.64
Upper bound 95% confidence interval 56.77 63.18 68.01 70.97
Transport performance (mill. tonne-km) 5067.80 5299.80 5372.00 5667.20
Relative standard error (%) 3.58 1.86 3.74 3.85
Lower bound 95% confidence interval 4977.51 5038.52 4844.89 5450.10
Upper bound 95% confidence interval 5657.33 5418.57 5569.43 6261.46

Source: Statistics Norway

In addition to coverage errors, there will be uncertainties related to the adjustment for under-reporting.

For the carriage of goods by lorry across the national border: Collection errors in the statistical basis occur when incorrect information is given in customs declarations due to misunderstandings, and this is not intercepted by TVINN (Norwegian Customs’ electronic system for exchanging customs declarations) controls. Relevant error sources stem from the use of incorrect product codes, estimates of the quantity delivered instead of actual measurements, and the use of incorrect country codes.

For the form-based statistics from 1961 to 2002, one possible source of error may be that not all customs offices registered the actual tonnage carried for each vehicle that passed, and instead based the reporting on an average.

For the carriage of goods by foreign-registered lorries: Since these statistics are based on the lorry survey of EU/EEA countries, sources of error and uncertainty will vary from country to country. For documentation of the different countries’ methods, see Methodologies used in surveys of road freight transport in Member States, EFTA and Candidate Countries.

In addition to non-response in the reporting of individual countries, it may also be the case that certain countries have not reported to Eurostat.

Revision

Not relevant here.