Statistics Netherlands / Centraal Bureau voor de Statistiek (CBS)

Department of traffic and transport

Maritime transport data refer to gross weight of goods (in tonnes), passenger movements (in number of passengers) as well as for vessel traffic (in number of vessels and in gross tonnage of vessels).

The following classifications are applicable:

Maritime Coastal area: the nomenclature is based on the Geonomenclature (the country nomenclature for the external trade statistics of the Community and statistics of trade between Member States, originally drawn up by the Council Regulation (EEC) N°1736/75) in force in the year to which the data refer (RAMON: https://showvoc.op.europa.eu/#/datasets/ESTAT_Geonomenclature_2021_%28GEONOM_2021%29/data).

Ports: the codes used are the official UN/LOCODEs, when they exist. If a port does not have an official UN/LOCODE a provisional (numeric) code is attributed to the port. As soon as an official UN/LOCODE is attributed by the United Nations Economic Commission for Europe (UNECE) to the port at the request of the competent national authority, the provisional (numeric) code is replaced by the final official one. In exceptional cases (see for example one-port transport or special aggregation for minor ports) permanent numeric codes are attributed to special locations or activities. The code list of UN/LOCODE is available by country through the following link: http://www.unece.org/cefact/locode/service/location.html. According to the relevant directive, Eurostat draws up a list of ports, coded and classified according to countries and maritime coastal areas. The list of ports is included in implementing legal acts and as such is published in the Official Journal of the European Union (the "official" list). The most recent list of ports published in the Official Journal is found in Commission Decision (EU) 2018/1007

Nationality of registration of vessels: the nomenclature used is the Geo-nomenclature (the country nomenclature for the external trade statistics of the Community and statistics of trade between Member States, originally drawn up by the Council Regulation (EEC) N°1736/75) in force in the year to which the data refer (RAMON: https://showvoc.op.europa.eu/#/datasets/ESTAT_Geonomenclature_2021_%28GEONOM_2021%29/data).

The type of ship classification is harmonised with an internationally agreed International Classification of Ship by Type (ICST).

The type of cargo classification, available in Directive 2009/42/EC, has been established in conformity with the United Nation ECE Recommendation N°21.

Maritime transport statistics concerns the carriage of goods and passengers by sea-going vessels, on voyages undertaken wholly or partly at sea. The data collected from the National Institute of Statistics are port statistics: information on goods handled in ports, passengers embarked and disembarked and vessel traffic. Detailed information is collected on the type of cargo and passengers, geographical areas where the partner ports are located, type, size and nationality of ships used to carry out that transportation.

Main concepts used in this domain are the following and for more information on the concepts and methodology, please consult the Reference Manual on Maritime Transport Statistics.

Port -A place having facilities for merchant ships to moor and to load and/or unload cargo or to disembark and/or embark passengers to or from vessels, usually directly to a pier.
Statistical Port -A statistical port consists of one or more ports, normally controlled by a single port authority, which is able to record ship, passenger and cargo movements.
Reporting Port-A statistical port for which statistics of inward and outward maritime transport flows are compiled.
Main port -A main port is a statistical port which has annual movements of no less than 200 000 passengers or recording more than one millions tonnes of cargo. For ports selected on the basis of only one of these cargo or passenger criteria, detailed statistics are required only for that transport.
Maritime coastal area (MCA) -A maritime coastal area is defined as a contiguous stretch of coastline, together with islands offshore. Within a country, an MCA is defined either in terms of one or more ranges of ports along its coastline, or in terms of the latitude and longitude of one or more sets of extremities of the coastal area. Riverbanks can be included. Normally the coastline of each country is allocated to a single maritime coastal area and the coastlines of more than one country may form a single maritime coastal area. There are some exceptions. For example, the USA is separated into a number of maritime coastal areas to cover its overall coastline. For some countries, two separate stretches of coastline may be counted as one maritime coastal area, as, for example, the Atlantic and Pacific coastlines of Mexico.
Carriage of goods and passengers by sea -The movement of goods and passengers using seagoing vessels, on voyage which are undertaken wholly or partly by sea. The scope of the Maritime Directive 2009/42/EC also includes goods:

1. Shipped to offshore installations;
2. Reclaimed from seabed and unloaded in ports.

Bunkers and stores supplied to vessels shall be excluded from the scope.

Seagoing vessel -Floating marine structure with one or more surface displacement hulls. In the context of the Directive, sea-going vessels are vessels other than those which navigate exclusively in inland waters or in waters within, or closely adjacent to, sheltered waters or areas where port regulations apply.
Nationality of registration of seagoing vessel (Flag state) -Every ship is entered in a registry (i.e. list) of ships. Registries are maintained by many countries, each having a set of rules regarding safety procedures, inspection schedules, manning numbers and nationalities for crew and officers, training requirements, etc. Ship-owners select which registry to use based on the balance between the relative cost implications of the rules of each registry and possible penalties from insurance assessments dependent on these rules.
Type of cargo- The type of cargo classification, set according to the UNECE - Codes for types of cargo, packages and packaging materials, Recommendation 21, Geneva, March 1986, describes how the goods are being transported in terms of the vessels being used and the port facilities required to handle them. It is therefore very different from the categories of goods classification.
Freight container-Special box to carry freight, strengthened and stackable and allowing horizontal or vertical transfers.

Swap bodies are excluded. Although without internal volume flats used in maritime transport should be considered to be a special type of container and therefore are included here. For a fuller description, reference should be made to ISO 668 and 1496.The related term "container cargo" refers to containers, with or without cargo, which are lifted on or off the vessels which carry them by sea.

Ro-Ro unit- This means wheeled equipment for carrying cargo, such as a truck, trailer or semi-trailer, which can be driven or towed onto a vessel. Port or ships' trailers are included in this definition. Classifications should follow United Nations ECE Recommendation No 21 'Codes for types of cargo, packages and packaging materials'. Live animals on the hoof are included. Vehicles being transported as cargo as opposed to a means of transport for freight are recorded in the separate headings of the Ro-Ro cargo classification, when they are rolled on or rolled off a vessel on their own wheels.
Ro-Ro cargo -This means goods, whether or not in containers, on Ro-Ro units, and Ro-Ro units, which are rolled on and off the vessels, which carry them by sea.
Gross weight of goods -The gross weight of each consignment is the weight of the actual goods together with the immediate packaging in which they are being transported from origin to destination, but excluding the tare weight of containers or Ro-Ro units (e.g. containers, swap bodies and pallets containing goods as well as road goods vehicles, wagons or barges carried on the vessel). This measure of quantity is different from that used in trade statistics, namely the net weight of goods and different from statistics collected on other transport modes where the tare weight is included. Where goods are transported in a road goods vehicle, in a container, or other intermodal transport unit, the gross weight of the goods does not include the tare weightof the transport unit.
Gross tonnage -This means the measure of the overall size of a ship determined in accordance with the provisions of the International Convention on Tonnage Measurement of Ships, 1969.
Passenger Any person who makes a sea journey on a merchant ship. Service staff assigned to merchant ships is not regarded as passengers. Non-fare paying crewmembers travelling but not assigned and infants in arms are excluded.
Cruise passenger -This means a sea passenger making a sea journey on a cruise ship. Passengers on day excursions are excluded.
Cruise ship -This means a passenger ship intended to provide passengers with a full tourist experience. All passengers have cabins. Facilities for entertainment aboard are included. Ships operating normal ferry services are excluded, even if some passengers treat the service as a cruise. In addition, cargo-carrying vessels able to carry a very limited number of passengers with their own cabins are also excluded. Ships intended solely for day excursions are also excluded.
Cruise passenger excursion -This means a short visit by a cruise passenger to a tourist attraction associated with a port while retaining a cabin on board.

The data used in the domain are collected at port level.

Detailed data are provided for ports handling more than one million tonnes of goods or recording more than 200 000 passenger movements annually (Main ports). The other ports are required to provide summary data. However, detailed data may be included also for minor ports on a voluntary basis.

The Netherlands

The data are available from 1996.

Not applicable.

The units used depend on the variables collected within each data set and are: gross weight of goods expressed in thousands of tonnes; number of passengers in thousands, number of vessels.

TEUs: Twenty feet equivalent units, expressed in units or in thousands depending on the table. TEU calculation coefficients:
• 20-ft freight units (1 TEU)
• 40-ft freight units (2 TEU)
• Freight units over 20-ft and under 40-ft in length (1.5 TEU)
• Freight units over 40-ft long (2.25 TEU).

Quarters for datasets A1, A2, C1, D1 and F2.
Whole calendar years for datasets A3, B1 and E1.

National Level:

•  https://wetten.overheid.nl/BWBR0015926/2018-07-28

European Level:

• The statistics on maritime transport are collected within the framework of within Directive 2009/42/EC and Commission Decision 2008/861/EC, as amended by Commission Decision 2010/216/EU of the European Parliament and of the Council of 14 April 2010, by Regulation 1090/2010 of the European Parliament and of the Council of 24 November 2010 and by Commission Delegated Decision 2012/186/EU of 3 February 2012.
• The dissemination is based on the terms of Commission Decision 2001/423/EC on arrangements for publication or dissemination of the statistical data collected pursuant to Council Directive 95/64/EC on statistical returns in respect of carriage of goods and passengers by sea.

Not applicable.

National level:

• https://wetten.overheid.nl/BWBR0015926/2018-07-28

European level:

• (recital 24 and Article 20(4)) of 11 March 2009 (OJ L 87, p. 164), stipulates the need to establish common principles and guidelines ensuring the confidentiality of data used for the production of European statistics and the access to those confidential data with due account for technical developments and the requirements of users in a democratic society.

Article 4 of Commission Decision 2001/423/EC mention that: "the highest level of detail in which data may be published or disseminated is the level of port to and from maritime coastal area. The Commission may however publish at more aggregate level if the quality and/or completeness of information are not appropriate in such detail."

Maritime transport statistics is published quarterly, within five months after the reference quarter. Maritime Transport data are disseminated in the datawarehouse Statline on the website of Statistics Netherlands: www.cbs.nl.

The release calendar is publicly accessible on the website: https://www.cbs.nl/en-gb/publication-calendar.

Main results of maritime transport statistics are available free of charge to all users. For more detailed results the data user has to pay for accessing the data.

Datasets A1, A2, C1, D1 and F2 are transmitted to Eurostat quarterly. These datasets and the remaining datasets are also transmitted to Eurostat annually. 

Quarterly maritime transport statistics are published within 10 months after the reference period and annual maritime transport statistics within 16 months after the reference period on the website of Eurostat.

The results are published quarterly, five quarters after the reference quarter, on the website of Statistics Netherlands www.cbs.nl (https://opendata.cbs.nl/statline/#/CBS/nl/navigatieScherm/thema).

Publication of maritime transport statistics (figures) is done through Statline, the datawarehouse on our website (https://opendata.cbs.nl/statline/#/CBS/nl/navigatieScherm/thema). Articles are published on our main website www.cbs.nl.

The results can be found in the datawarehouse Statline (https://opendata.cbs.nl/statline/#/CBS/nl/dataset/00374hvv/table?dl=EF75) (Statistics > Verkeer en Vervoer > Vervoer personen en goederen > Vervoer over water).
Main results are available free of charge. For more detailed results the data user has to pay for accessing the data.

Not applicable to maritime transport statistics.

Open data access is available for the main results of maritime transport statistics.

Methodological notes are available in the online Statistics Explained articles on Maritime transport statistics and in the Reference Manual on Maritime Transport Statistics.
The whole set of definitions of the terms used in the frame of the statistics on maritime transport is available in the legal acts. Additional elements are available in the "Illustrated Glossary for Transport Statistics - Fifth edition" available online.

A description of the methodology used for the maritime transport statistics can be found on our website: https://www.cbs.nl/nl-nl/onze-diensten/methoden/onderzoeksomschrijvingen/korte-onderzoeksbeschrijvingen/zeevaart. This description is at the moment only available in Dutch.

The system follows as far as possible the European Statistics Code of practice and Quality Assurance Framework of the European Statistical System, more precisely Principle 4: Commitment to Quality:
Quality policy is defined and made available to the public. An organisational structure and tools are in place to deal with quality management. There are procedures in place to plan, monitor and improve the quality of the statistical processes. Procedures based on quality reporting are in place to internally monitor product quality. Results are analysed regularly and improving actions are undertaken, if needed (for example after obtaining annual summary results and mirror checks reports from Eurostat). There is a regular and thorough review of the key statistical outputs using also external experts where appropriate.

There is a set of validation rules and quality checks put in place, which detect various types of issues. In case of any issues detected, Statistics Netherland deals with these issues or the data providers are contacted to provide explanations or/and revise the data accordingly. Checks for the consistency over times are prepared and revised as well and the results are compared with aggragated data sended by the ports to Statistics Netherlands.

The weakness of the data is the amount of detail needed for Eurostat. Due to regulations in The Netherlands, customs don't recieve all relevant data Statistics Netherlands needs for the statistics for Eurostat, especially for the outgoing transport within Europe. Other datasources are used to fill these gaps, but not all the detailed data can be obtained.

Quarterly and annually, Eurostat provides a data quality report with a summary of the main findings affecting quality as well as showing the solution adopted and the materiality of the existing differences. Mirror checks and checks for the consistency over times are prepared as well.

If there are any inconsistencies Statistics Netherlands provides an explanation which is included in the Country Specific Notes (CSNs) available at Eurostat’s metadata page.

The main users of Maritime Transport Statistics are national and local authorities, universities, research institutes, port authorities and trade associations in the transport, environment and energy sectors.

Statistics Netherlands is interested in understanding who the users of the statistics it produces are, what the information needs are, whether they match production and if the statistics produced satisfy users.

To this aim Statistics Netherlands is constantly in contact with key users of the statistics (especially with national authorities and port authorities) discussing results and new needs from both sides. 

All data requested by Regulation 1090/2010 and Directive 2009/42/EC are transmitted. In some cases the outgoing direction is missing detailed information (especially ports and goods).

The overall accuracy is considered to be good. When data are compared with other sources, such as data compiled by local port authorities, discrepancies are usually found to be resulting from differences in the methodology, scope or definitions used in the various data collections. However, some errors may occur in the statistics due to measurement errors or processing errors (see 13.3). Detailed information is sometimes missing.

Not applicable for maritime transport data collection.

Measurement errors

No estimates of measurement errors are available. However, some measurement errors may occur as a result of codification errors by customs, port authorities, shipping agents and other respondents. A share of so-called “unknown codes” instead of specific codes for type of cargo, type of goods, partner port, etc. is also a factor which will reduce the accuracy of the maritime statistics on a more detailed level. Editing and imputation procedures are used to correct for measurement errors as much as possible.

Processing errors

Between data collection and the beginning of statistical analysis for the production of statistics, data must undergo a certain processing: metadata validation, data editing, linking with registers, etc. In addition, The Netherlands needs to combine several data sources available on national level, to obtain good total figures and more detailed information (espacially ports and goods).

Quarterly data should be transmitted by Member States to Eurostat within five months of the end of the period of observation; annual data within eight months. The Commission (Eurostat) shall disseminate appropriate statistical data with a periodicity comparable to that of the results transmitted (Directive 2009/42/EC).

The deadlines for transmission are usually met.

Geographical comparability is obtained via the application of common concepts and validation rules. The harmonised interpretation of the methodology is enhanced by the organisation of regular meeting of the Working Group on Maritime Transport Statistics, where all reporting countries are represented.

As from 2011 the statistics on maritime transport in the Netherlands are comparable over time, as the data is collected in the same way and the data is produced by the same production process and methodology. Time series checks are regularly made to detect inconsistencies in the data.

Comparisons with other transport statistics are only done partially and to a limited extent, since data are not collected at the same level of detail, different methods are used and underlying objectives are different.

The quality checks include intra-dataset checks, inter-dataset checks, time series checks and comparisons with overviews from port authorities. These quality checks detect data that could possibly be in error. Some errors are corrected before publication of the quarterly data. Other errors, which require further investigations, are corrected later and are published with the annual data.

The response burden is put on the customs, the four main ports in the Netherlands and ferry companies operating in the Netherlands, but is reduced to a minimum. The customs, the ports and the ferry companies provide the data (almost) automatically via a data interface or via email and are only contacted if errors cannot be solved by Statistics Netherlands. 

The results are published quarterly and annualy. Revision of the results may be required if for example the production process will be revised.

In case of any data change in the statistics, after the annual data is finalised, an explanation for the change is given in the table published on the national website. 

The datasets transmitted quarterly to Eurostat are (normally) revised once when the annual results are being transmitted. In 2023 The Netherlands finalized the revision of their production process for the maritime statistics. At this moment the data from 2021 are revised and send to Eurostat. In 2024 the data from 2015 till 2020 will be revised.

Statistics Netherlands is using administrative data from the Customs and the main port authorities to compile the maritime transport statistics. Next to that a direct survey is sended to ferry companies operating in The Netherlands to gather more detailed information about the vehicles and passengers on the ferries between the Netherlands and (mainly) the UK.

Information needed for the maritime transport statistics are collected on a montly basis and processed on quarterly basis.

The data transmission is possible via a secure fttp-port or via email.

Data validation procedure :

Validation of port codes, IMO numbers of vessels, goods codes, 'unknown' codes.
Comparison of the quarterly figures with overviews recieved from port authorities.
Consistency over time.

Actions taken when errors are detected:
- Investigation and correction of erroneous data.
- Request for new data at customs/ports/ferry companies if necessary.

After various recodings, plausibility checks, the data received from the customs, the port authorities and the ferry companies are compiled into quarterly data following the structure of the data sets which are preset by the regulation.

Not applicable for maritime transport data collection.

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