Public Transport Statistics Northern Ireland - Background Quality Report (BQR)

This report provides information on the quality of the data used to produce Public Transport Statistics Northern Ireland.

It informs users about the quality of the information upon which they may be drawing conclusions and making decisions.

The report is structured around the five quality dimensions for statistical outputs (from the European Statistics Code of Practice, PDF (458 KB)). The UK Statistics Authority’s Code of Practice for Statistics requires that:

Q3.3 The quality of the statistics and data, including their accuracy and reliability, coherence and comparability, and timeliness and punctuality, should be monitored and reported regularly.


Context for the quality report.

Analysis, Statistics and Research Branch (ASRB), a Northern Ireland Statistics and Research Agency (NISRA) branch within the Department for Infrastructure (DfI) is responsible for the compilation and publication of the Public Transport Statistics Northern Ireland report.

This report was produced and published following user engagement that identified a need for statistics on Public Transport in Northern Ireland.

A user engagement exercise carried out on Northern Ireland Transport Statistics identified an interest in the statistics formerly produced within Chapter 2 of the Transport Statistics bulletin. This alongside the need for openness and transparency in data highlighted that there is a demand for published robust statistics on public transport in Northern Ireland.

The Public Transport Statistics Northern Ireland report which includes user guidance is published on the DfI website.

ASRB collate statistical data and information from Translink. After validating the data, ASRB produce and publish the report on the DfI website. Information about the background to the publication, the quality of the data contained in it and definitions of terms are included in the report.


The degree to which the statistical product meets user needs in both coverage and content.

Public Transport Statistics Northern Ireland is a new Official Statistics report published to meet stakeholder needs. Transport Statistics are published by the Department of Transport and the Central Statistics Office Ireland.

The quality and reliability of the transport network in Northern Ireland is recognised as a key factor impacting on its competitiveness and growth potential. The Translink 2030 Corporate Strategy highlights that, an effective and successful public transport network is vital for the economic, social and environmental well-being of our society. Increasing the uptake of active transport and public transport will help reduce pressure on the strategic road network, alleviate congestion and improve journey times on key economic corridors. Official public transport statistics are therefore required by a wide variety of users for a range of purposes including the monitoring of changes over time, policy development/review and benchmarking. The Public Transport Operations Division within DfI has also indicated that there is a need for official statistics on public transport to support the independent and transparent monitoring of the new Public Service Agreement with Translink and to facilitate evidence-based decision making. The report aims to meet the needs of both internal and external users.

The statistical product includes an html publication containing charts, infographics and associated commentary.  There are also detailed tables and a standalone infographic available to meet the needs of different users. The background to the publication, as well as key quality information is included within the publication. In addition, all data are provided in Open Document Spreadsheets (ODS).

More details on the relevance of the report to users, was identified through a user engagement exercise that is summarised in a document on the DfI website.

Accuracy and Reliability

The proximity between an estimate and the unknown true value.

All sample data and tables are supplied by Translink and the timings and provision of data are agreed within an Information Sharing Agreement (ISA) between ASRB and Translink. Data are derived from administrative systems which have good coverage and incorporate validation checks. Translink carry out daily, monthly and annual checks on the passenger journey, mileage and income data.  These data are also subject to both internal and external audits.  Translink interrogates the relevant administrative data systems to provide the specified data to ASRB.   Checks on the sample data are also carried out by ASRB to assess levels and quality of completion as well as to look for erroneous data and detect any missing data.

Tables of data for passenger journeys along with information on staff, and Translink’s fleet are provided to ASRB. Further validation checks are carried out on these data prior to publication. A Quality Assurance of Administrative Data (QAAD) has been developed for the relevant Translink datasets.

The QAAD is a quality assessment of the administrative data sources which are used to produce the public transport statistics. This assessment found that the level of risk of quality concerns in these sources is low. Whilst the report is fully comprehensive in terms of data on public transport provided by Translink, users should however note that data from private providers of transport in Northern Ireland are not included in the report.

Users should also note that passenger numbers include fare paying, concessions and school children. Free journeys given to health and social care workers during COVID-19 pandemic are excluded.

Also, it’s important to note that the number of journeys taken using multi-journey tickets e.g. weekly, monthly and annual bus and rail tickets are not electronically recorded and are therefore estimated by Translink using journey factors.

For all data and tables received, variance/ logic checks are employed by statisticians as an integral part of the production process with any large discrepancies between current and previous year queried with the data provider. As part of their quality assurance processes, statisticians also analyse trends and check that values fall within acceptable ranges.

Previous data will be revised if necessary and appropriate. All revisions are conducted in line with ASRB’s Revisions and Errors Policy.

Timeliness and Punctuality

Timeliness refers to the time gap between publication and the reference period. Punctuality refers to the gap between planned and actual publication dates.

The majority of figures presented in the Public Transport Statistics, Northern Ireland report relate to either the financial year or the position at the end of the financial year.

As the release at the end of March 2023 was the first report in this statistical series, there was a lag of 12 months between the end of the financial year being reported on and the publication date (this lag was in part due to the move away from PDF to R/html and to the processes in place for accessing the Translink data).  ASRB continued to work with Translink to improve the timeliness of the report and the second edition of the report was published in September 2023.

Advance notice of ASRB publication dates is available in the upcoming statistical releases calendar on the DfI website.  Publication dates are also pre-announced on GOV.UK.  The first and second editions of this publication were released on time.  In the event of a change to a pre-announced release date, the delay would be announced and explained on both the DfI website and GOV.UK and the new publication date specified.  If necessary, updates would be given regularly.

Accessibility and Clarity

Accessibility is the ease with which users are able to access the data, also reflecting the format in which the data are available and the availability of supporting information. Clarity refers to the quality and sufficiency of the metadata, illustrations and accompanying advice.

The report is published in html and is available free of charge on the DfI website.

The statistical tables are also available to download in MS Excel format and ODS (Open Document Spreadsheet) format, from the webpage.  If requested, ASRB can provide hard copies or other suitable media.

The publication is accessible through the UK Official and National Statistics Publication Hub.

User Information is included in the publication to help users to understand and make the best possible use of the data.  In addition, where necessary, explanatory footnotes are included in the Excel/ODS tables.

Every effort has been made to comply with the AA standard under the WAVE Web Accessibility Evaluation Tool (

The publication contains contact details of the responsible statistician who can be contacted for further information.

Coherence and Comparability

Coherence is the degree to which data that are derived from different sources or methods, but refer to the same topic, are similar.  Comparability is the degree to which data can be compared over time and domain.

Translink is the sole data provider for the public transport statistics; the provision of transport by other providers is not considered (details for all active service permits issued by the Department and also details of new applications for service permits, is available on the Department’s website). 

Comparisons can be made over time and the latest data are always compared with previous years’ data, where appropriate, and any significant changes are thoroughly checked, validated and explained to users. The public transport data published for 2020-2021, 2021-22 and 2022-23 highlight the impact of the Coronavirus pandemic and the commentary and guidance reflect that.

Links to Transport Statistics published for Great Britain and Ireland are included in the report.

Trade-offs between Output Quality Components

Trade-offs are the extent to which different aspects of quality are balanced against each other.

There are not considered to be any trade-offs.

Assessment of User Needs and Perceptions

The processes for finding out about users and uses, and their views on the statistical products.

In line with the ASRB User Engagement Strategy, the content of the publication is informed by an understanding of customers’ information needs. The data presented in the publication aims to meet the needs of both internal and external users. A user engagement exercise carried out on Public Transport Statistics in summer 2023 identified the uses that were being made of the statistics and the need for further statistics to be included. This survey, along with stakeholder engagement, informed the second publication of Public Transport Statistics, NI.

There is an ongoing ASRB customer satisfaction survey, which includes a question on whether ASRB publications meet customers’ needs. The link to the survey is issued every time users are notified that a report has been published or when an ad-hoc query is answered. Results are collated on an annual basis.

Performance, Cost and Respondent Burden

The effectiveness, efficiency and economy of the statistical output.

In the production of this publication, ASRB endeavour to operate efficiently by placing the minimum load necessary on Translink as data providers. The only cost to the data providers is their time involved in extracting/transferring data and any follow up queries. Translink are content to bear this cost given the benefits of publishing the statistics and the need for open and transparent data.

ASRB has worked closely with Translink to agree the most effective and efficient way to format and transfer data. The exchange of data is outlined in an ISA signed by both ASRB and Translink. There is ongoing communication with data providers to ensure the timely receipt of data.

On receipt of the information, statisticians validate data and prepare for publication.

This may involve further liaison with data providers. Once data are verified, statisticians prepare for publication within a short timeframe.

Confidentiality, Transparency and Security

The procedures and policy used to ensure sound confidentiality, security and transparent practices.

ASRB adhere to the UK Statistics Authority (UKSA) Code of Practice for Statistics in the dissemination of the Public Transport Statistics report.

The data are transferred via Secure File Transfer Protocol service and are subsequently stored on a secure and accredited network drive that is only accessible to relevant ASRB staff. Personal information is not collected, and statistical disclosure control methods do not need to be applied to the data. The transfer, security and storage of data are referenced in the signed ISA.

Further Information

For further information relating to the quality of ‘Public Transport Statistics, Northern Ireland’, please contact

User Engagement

We welcome feedback from users on this statistical report. Please send any comments you may have to .

Users can also provide feedback through our ongoing ASRB Customer Survey 

Last updated: September 2023


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