Reference metadata describe statistical concepts and methodologies used for the collection and generation of data. They provide information on data quality and, since they are strongly content-oriented, assist users in interpreting the data. Reference metadata, unlike structural metadata, can be decoupled from the data.
The (road_eqs) group of tables provides data about the stock of road transport vehicles by age, type of motor energy, engine size, unloaded weight, while the (road_eqr) group of tables is about the new registration of road transport vehicles, with similar breakdown except age.
Only aggregated national data are reported by the participating countries; no micro data or confidential data are transmitted.
The Common Questionnaire is not supported by a legal act, but is based on a goodwill agreement with the participating countries; its completeness may therefore vary from country to country. Eurostat, UNECE and ITF cooperate for the coordination and streamlining of the data collection at international level with the aim of reducing the administrative burden on national administrations, as many of the about 50 reporting countries are members of more than one of the organisations.
Data is generally provided by the national statistical institutes or responsible transport administrations.
Eurostat cooperates closely with the European Alternative Fuels Observatory (EAFO) and the European Automobile Manufacturers' Association (ACEA) with respect to statistics on the road transport equipment. Indeed, the EAFO collects stock of vehicles and new registration of alternative fuels vehicles and the ACEA analyses new registration of road vehicles by types of motor energy. These data are used for gap-filling and then flagged "i" for "imputed by Eurostat or another European agency".
Eurobase tables based on the Common Questionnaire cover annual data from the EU Member States, EFTA countries, candidate countries and potential candidates to the EU. Data from other participating countries are available through the ITF and the UNECE websites. In total, comparable transport data collected through the Common Questionnaire are available for close to 50 countries worldwide.
The Common Questionnaire is organised by datasets, typically a dataset by mode of transport (Rail, Road, Inland Waterways, Oil pipelines). Each dataset is usually structured by chapters (I Infrastructure, II Transport Equipment (vehicles), III Enterprises, investment and maintenance, IV Traffic, V Transport Measurements, VI Accidents). This organisation of the Common Questionnaire is consistent with the structure of the Glossary for transport statistics was published since 1994 (1st edition) with the purpose of assisting countries during this data collection.
The road transport equipment covered by these datasets corresponds mostly to the scope of the road vehicle registers, which are administrative registers. Nevertheless, some road vehicles such as cycles and Personal Light Electric Vehicles (PLEV) are usually not registered, and this is also sometimes the case for mopeds.
As for road transport equipment, the definitions are listed between entries B.II-01 and B.II-45 in the Glossary.
In particular, the definition B.II-02 "Stock of road vehicles in use" specifies that an administrative registration is not enough: vehicles which can be estimated out of traffic (no roadworthiness test, no insurance, etc.) should be subtracted.
The definition B.II-03 "New vehicles registered" explains that imported second-hand vehicles are excluded.
3.5. Statistical unit
The statistical units observed are the vehicles running on wheels and intended for use on roads, at national level (country of registration).
3.6. Statistical population
The population of road vehicles in use is observed at the end of the civil year. The new registration of road vehicles is counted on an annual basis.
3.7. Reference area
Member States of the European Union; EFTA states; European Union candidate countries and potential candidate(s). Other countries are covered by the ITF and UNECE.
3.8. Coverage - Time
Main aggregated data are available as from 1970.
3.9. Base period
Not applicable.
Number of road transport vehicles.
Data are collected on a yearly basis.
The reference period is the end of the year (31st December).
6.1. Institutional Mandate - legal acts and other agreements
The Common Questionnaire is not supported by any legal acts; it is a voluntary data collection, based on a goodwill agreement with the participating countries.
6.2. Institutional Mandate - data sharing
Data are shared with the United Nations Economic Commission for Europe (UNECE) and the International Transport Forum (ITF) at the OECD.
7.1. Confidentiality - policy
The Common Questionnaire is a voluntary data collection of aggregated national data. No confidential data are reported by the participating countries. Therefore, no confidentiality policy applies.
7.2. Confidentiality - data treatment
Not applicable.
8.1. Release calendar
The intention of Eurostat is to publish all data on reference year N by the end of year N+1. The data release calendar for transport domain is available on the Eurostat website
Datasets checked for consistency are available free of charge through Eurostat’s online dissemination database.
In line with the Community legal framework and the European Statistics Code of Practice Eurostat disseminates European statistics on Eurostat's website (see item 10 - 'Accessibility and clarity') respecting professional independence and in an objective, professional and transparent manner in which all users are treated equitably. The detailed arrangements are governed by the Eurostat protocol on impartial access to Eurostat data for users.
There are 2 releases of road transport equipment data:
official data completed by early estimates at the end of July N+1, together with the SE article "Passenger cars in Europe";
more official data completed by definitive estimates in mid-December N+1, together with other data collected by Common Questionnaire and with the SE article "Transport equipment statistics".
10.1. Dissemination format - News release
News articles usually accompany Statistics Explained articles, published when the CQ data are released (respectively, on passenger cars in July, and on transport equipment of any mode in December).
10.2. Dissemination format - Publications
The data on road transport equipment are commented in annual Statistics Explained article (SE):
Datasets checked for consistency are available free of charge through Eurostat’s online dissemination database, under the theme ‘Transport’, node 'Road transport', folders 'Road transport equipment - stock of vehicles (road_eqs)' and 'Road transport equipment - new registration of vehicles (road_eqr)'.
Only aggregated annual data at national level are available.
Similar Common Questionnaire transport data for countries other than EU/EFTA/candidate countries and potential candidates are available from ITF and UNECE.
10.4. Dissemination format - microdata access
Not applicable; only aggregated national data are reported.
10.5. Dissemination format - other
Not applicable.
10.6. Documentation on methodology
The Glossary for transport statistics provides the definitions and lists the classifications used for the Common Questionnaire data collection. The Glossary is available on the websites of the three organisations.
10.7. Quality management - documentation
Not available.
11.1. Quality assurance
The Common Questionnaire is a voluntary data collection, not supported by legal acts. It is completed by the competent national authorities, who are responsible for the main quality assurance. National data are reported through EDAMIS portal. Upon transmission of a file, a validation process takes place in EDAMIS which contains a number of data checks and controls in two validation systems:
EDAMIS notifies the file sender if errors are found in the overall structure of transmitted Common Questionnaire file. This validation system is called Struval (structural validation).
EDAMIS notifies the file sender if errors are found in the content/data of the file (mainly differences between totals and the sum of their breakdown values). This validation system is called Conval (content validation).
All files transmitted to EDAMIS are first validated by Struval and then by Conval. In case a file fails to pass the level of Struval, it does not reach Conval. The data provider is notified about the error(s) at Struval level and needs to resubmit a corrected file. Similarly, if a file succeeds in passing Struval but is rejected at Conval level, the data provider is again notified about the error(s) and has to submit a corrected file.
Further plausibility checks, growth rate checks and data validation control are carried out by Eurostat in the form of quality reports by theme sent to the countries shortly after their data submission.
11.2. Quality management - assessment
Eurostat routinely assesses timeliness, completeness and accuracy and follows this up with the data providers.
12.1. Relevance - User Needs
Key users of the statistics are: the European Commission, Directorate-General Mobility and Transport (DG MOVE); the United Nations Economic Commission for Europe (UNECE); and the International Transport Forum (ITF/OECD). These users are strongly involved in the design and development of the Common Questionnaire, thus user needs are generally considered to be well covered and integrated in the development process. Indicators for policy needs are constantly extracted from the Common Questionnaire, such as the indicators on road transport equipment, of which Zero Emission Vehicles (ZEV).
12.2. Relevance - User Satisfaction
Not available.
12.3. Completeness
Completeness for this group of indicators in Common Questionnaire is very high for EU Member Staes (77%).
13.1. Accuracy - overall
The issue of accuracy for this group of indicators should be only related to concepts (in particular vehicles in use, of which "dead souls" have to be excluded).
13.2. Sampling error
There is no sampling issue, but there could be partial non-response.
13.3. Non-sampling error
The cleaning of the administrative registers from its "dead souls" to get the "vehicles in use" can be an issue.
Some types of motor energy are not considered separately in all national road vehicle registers, even the distinction between plug-in hybrids and non plug-in hybrids, or between petrol and diesel hybrids. .
14.1. Timeliness
The deadline for the data transmission is 6 months after the end of the reference period (calendar year) for the early estimates, 10 months for the definitive data (general release). The expected deadline for the data dissemination is a little less than 12 months after the end of the reference period, i.e. about mid-December N+1.
14.2. Punctuality
These road transport equipment indicators are among the most punctual of the Common Questionnaire, especially the ones related to the new registration of road vehicles.
15.1. Comparability - geographical
Geographical comparability is generally high due to harmonised definitions used by the national authorities to report data.
15.2. Comparability - over time
Comparability over time is generally good. The indicators on road transport equipment in Common Questionnaire have sometimes been unchanged for 35 years.
Nevertheless, there was a break in series between reference years 2024 and 2025 due to the inclusion (since 2025) of "special purpose vehicles" in international categories (M1 for "passenger cars", etc.).
Eurostat addresses every year a 'request for clarifications' to countries, relying mainly on possible inconsistencies over time. Time series breaks that cannot be avoided are flagged "b".
15.3. Coherence - cross domain
The coherence between road transport equipment (road_eqs) and road traffic (road_tf) was strenghthened with the CQ streamlining as of reference year 2025.
15.4. Coherence - internal
There is a good internal coherence, due to Conval rules.
Each time a new data collection is launched on reference year N, normally in April N+1:
the CQ template of the reference year is pre-filled with the "static data" of the previous 5 years, which helps the countries to identify breaks or gaps in series, or only the need to revise some figures;
pre-filled CQ templates are availabe for revision for all reference years since 2013.
When Eurostat observes an inconsistency in time series, it encourages the countries to revise data since reference year
All reported errors (once validated) result in corrections of the disseminated data, as soon as possible.
A country can also ask for an ad hoc revision, so that nationally published data are consistent with data disseminated by Eurostat.
18.1. Source data
Data for the Common Questionnaire are collected and compiled by the competent national authorities (national statistical institutes or transport administrations). Only aggregated national annual data are reported to Eurostat.
18.2. Frequency of data collection
Annual.
18.3. Data collection
The data collection methodology is determined by the competent national authorities and may vary from country to country.
These national authorities send Excel files (1 per country, theme and year) to EDAMIS portal.
18.4. Data validation
Data validation is first carried out by the competent national authorities. Only aggregated national data are reported to Eurostat. National data are reported through the EDAMIS portal, which contains a number of data checks and controls (Struval rules for the structure validation, Conval rules for the content validation). Further plausibility checks, growth rate checks and data validation controls are carried out by Eurostat in the form of quality reports / requests for clarifications addressed to countries.
18.5. Data compilation
The data collection and compilation methodology is determined by the competent national authorities and varies from country to country.
Eurostat compiles EU totals and, in this particuler case of road transport equipment indicators, can fill in some gaps on the basis of EAFO or ACEA publications.
The (road_eqs) group of tables provides data about the stock of road transport vehicles by age, type of motor energy, engine size, unloaded weight, while the (road_eqr) group of tables is about the new registration of road transport vehicles, with similar breakdown except age.
Only aggregated national data are reported by the participating countries; no micro data or confidential data are transmitted.
The Common Questionnaire is not supported by a legal act, but is based on a goodwill agreement with the participating countries; its completeness may therefore vary from country to country. Eurostat, UNECE and ITF cooperate for the coordination and streamlining of the data collection at international level with the aim of reducing the administrative burden on national administrations, as many of the about 50 reporting countries are members of more than one of the organisations.
Data is generally provided by the national statistical institutes or responsible transport administrations.
Eurostat cooperates closely with the European Alternative Fuels Observatory (EAFO) and the European Automobile Manufacturers' Association (ACEA) with respect to statistics on the road transport equipment. Indeed, the EAFO collects stock of vehicles and new registration of alternative fuels vehicles and the ACEA analyses new registration of road vehicles by types of motor energy. These data are used for gap-filling and then flagged "i" for "imputed by Eurostat or another European agency".
Eurobase tables based on the Common Questionnaire cover annual data from the EU Member States, EFTA countries, candidate countries and potential candidates to the EU. Data from other participating countries are available through the ITF and the UNECE websites. In total, comparable transport data collected through the Common Questionnaire are available for close to 50 countries worldwide.
The Common Questionnaire is organised by datasets, typically a dataset by mode of transport (Rail, Road, Inland Waterways, Oil pipelines). Each dataset is usually structured by chapters (I Infrastructure, II Transport Equipment (vehicles), III Enterprises, investment and maintenance, IV Traffic, V Transport Measurements, VI Accidents). This organisation of the Common Questionnaire is consistent with the structure of the Glossary for transport statistics was published since 1994 (1st edition) with the purpose of assisting countries during this data collection.
As for road transport equipment, the definitions are listed between entries B.II-01 and B.II-45 in the Glossary.
In particular, the definition B.II-02 "Stock of road vehicles in use" specifies that an administrative registration is not enough: vehicles which can be estimated out of traffic (no roadworthiness test, no insurance, etc.) should be subtracted.
The definition B.II-03 "New vehicles registered" explains that imported second-hand vehicles are excluded.
The statistical units observed are the vehicles running on wheels and intended for use on roads, at national level (country of registration).
The population of road vehicles in use is observed at the end of the civil year. The new registration of road vehicles is counted on an annual basis.
Member States of the European Union; EFTA states; European Union candidate countries and potential candidate(s). Other countries are covered by the ITF and UNECE.
Data are collected on a yearly basis.
The reference period is the end of the year (31st December).
The issue of accuracy for this group of indicators should be only related to concepts (in particular vehicles in use, of which "dead souls" have to be excluded).
Number of road transport vehicles.
The data collection and compilation methodology is determined by the competent national authorities and varies from country to country.
Eurostat compiles EU totals and, in this particuler case of road transport equipment indicators, can fill in some gaps on the basis of EAFO or ACEA publications.
Data for the Common Questionnaire are collected and compiled by the competent national authorities (national statistical institutes or transport administrations). Only aggregated national annual data are reported to Eurostat.
There are 2 releases of road transport equipment data:
official data completed by early estimates at the end of July N+1, together with the SE article "Passenger cars in Europe";
more official data completed by definitive estimates in mid-December N+1, together with other data collected by Common Questionnaire and with the SE article "Transport equipment statistics".
The deadline for the data transmission is 6 months after the end of the reference period (calendar year) for the early estimates, 10 months for the definitive data (general release). The expected deadline for the data dissemination is a little less than 12 months after the end of the reference period, i.e. about mid-December N+1.
Geographical comparability is generally high due to harmonised definitions used by the national authorities to report data.
Comparability over time is generally good. The indicators on road transport equipment in Common Questionnaire have sometimes been unchanged for 35 years.
Nevertheless, there was a break in series between reference years 2024 and 2025 due to the inclusion (since 2025) of "special purpose vehicles" in international categories (M1 for "passenger cars", etc.).
Eurostat addresses every year a 'request for clarifications' to countries, relying mainly on possible inconsistencies over time. Time series breaks that cannot be avoided are flagged "b".
