Guidance

Modal comparisons: notes and definitions

Updated 19 December 2024

About this release

These notes and definitions accompany the statistical release Transport Statistics Great Britain, and provide background information for the modal comparison tables. It also describes the main sources of the data and considerations when using the statistics.

Passenger transport

Information on table TSGB0101

Buses and coaches: historically, passenger kilometres were derived from other data collected from bus and coach operators, such as receipts, vehicle kilometres and patronage. Because this proxy method had to be used, the series gives only a broad guide to trends. From 2004, data is based on the average distance travelled by bus and coach per person, per year, from the National Travel Survey (NTS), using population estimates from the Office for National Statistics (ONS) to gross up to total passenger kilometres. Bus and coach covers the London bus, other local bus, non-local bus and private hire bus categories recorded in the NTS. Due to the change in the methodology used to compile the figures, comparisons between figures for earlier and later years should be interpreted with caution.

Cars, vans, taxis and motorcycles: estimates for cars (which include taxis) and motorcycles (which include mopeds and scooters) are derived from the traffic series shown in the Department for Transport’s (DfT) TRA0101 (vehicle miles) and average occupancy rates (person per vehicle) from the NTS. Estimates for personal use of light vans are derived from the NTS (average van distance travelled per person per year) and population estimates. If population estimates are unavailable at the time of publication, population projections may be used instead. The average occupancy rates were revised in 2017 to use 3-year averages to improve the consistency of the series. Due to the impact of the coronavirus (COVID-19) pandemic on NTS data collection, occupancy rates for 2020, 2021 and 2022 are for single years only.

Pedal cycles: estimates are from the DfT’s traffic series shown in TRA0401. Occupancy rates for 1996 onwards are based on weighted NTS data. As data prior to 1996 has not been weighted, this produces a discontinuity in the data. This does not affect the underlying rate of growth.

Rail: figures include National Rail, London Underground, Glasgow Underground, public metro, and light rail systems.

Air: figures are revenue passenger kilometres on scheduled and non-scheduled domestic services on UK airlines only. Further details are available in the Aviation’s Notes and Definitions for table AVI0201.

All modes: figures exclude travel by water.

Information on table TSGB0102

The data in this table are derived from:

Rail: Office of Rail and Road

London underground: Transport for London

Light rail and trams: returns from operators to DfT

Air: Civil Aviation Authority

Local bus: bus passenger journeys are estimated based on returns supplied by a sample of bus operators. Where an operator is not sampled, or does not respond, an imputation is made. Imputations for earlier years can on occasion be improved by using data for later years, which can result in (typically minor) revisions to previously published data (back to the financial year ending 2005), although trends are rarely affected substantially.

Passenger casualty rates

Information on table TSGB0107

Passenger casualty rates given in the table can be interpreted as the risk a traveller runs of being injured, per billion kilometres travelled. The coverage varies for each mode of travel and the definitions of injuries and accidents are different. Thus, care should be taken when drawing comparisons between the rates for different modes. The table provides information on passenger casualties and, where possible, travel by drivers and other crew in the course of their work has been excluded. Exceptions are for private journeys and those in company-owned cars, and vans where drivers are included.

Figures for all modes of transport exclude confirmed suicides and deaths through natural causes. Figures for air, rail and water excluded trespassers and rail excludes attempted suicides. Accidents occurring in airports, seaports and railway stations that do not directly involve the mode of transport concerned are also excluded; for example, injuries sustained on escalators or falling over packages on platforms.

See the below table for the definitions by mode.

Mode	Definition
Air	Accidents involving UK registered aircraft in UK and foreign airspace. Fixed wing and rotary wing aircraft are included.
Rail	Train accidents and accidents occurring through movement of railway vehicles in Great Britain. The rail figures cover National Rail only, so exclude accidents on underground and tram systems, Eurotunnel, and minor railways. Rail figures are based on financial years.
Water	Figures for travel by water include both domestic and international passengers carrying services of UK registered merchant vessels. Further information can be found in the Marine Accident Investigation Branch’s (MAIB) annual reports.
Road	Figures refer to Great Britain and include reported personal injury accidents occurring on the public highway (including footways) in which at least one road vehicle, or a vehicle in collision with a pedestrian, is involved and which becomes known to the police within 30 days of its occurrence. More information is provided in the Road Accident and Casualties notes and definitions.

Travel to work

Information on tables TSGB0108 to TSGB0112

We note that the Office for National Statistics (ONS) have highlighted that ongoing challenges with response rates and the approach to weighting mean that labour market statistics derived from the Labour Force Survey (LFS) will be labelled as ‘official statistics in development’ until further review.

Further information on the quality and methodology for the LFS is published in the ONS quality and methodology information note and their regular performance and quality monitoring reports. We understand ONS will be releasing further guidance on how LFS data can currently be used and what the limitations are, which users of these data should review once available.

The questions on usual method of travel to work and usual time taken to travel to work are asked of all respondents in employment, excluding those on government schemes and those working from home or using their home as a working base. In 2020 and 2021, respondents were asked about their usual travel to work arrangements, as if coronavirus restrictions were not in place. The results seen in 2020 and 2021 will therefore differ from other sources, such as the National Travel Survey, which report on actual travel patterns.

Data is collected between October and December annually since 2006. Before this, only data from October and November were used. The questions on usual method of travel to work and usual travel to work time have been asked since 1992. Despite the survey’s large sample size (approximately 20,000 responding households per quarter), data for some cells are not shown because the sample sizes could result in issues around disclosure.

Further information can be found in the LFS methodology note.

Overseas travel

Information on tables TSGB0113 to TSGB0115

These tables are derived from the ONS’ International Passenger Survey (IPS). In this survey, a large sample of passengers are interviewed as they enter or leave the United Kingdom by principal air and sea routes, and via the Channel Tunnel.

These tables are based on IPS “main flow” interviews, such as United Kingdom residents returning to, and overseas residents leaving the United Kingdom. The unit of measurement is therefore the visit and not the journey. The mode of travel is that used by a United Kingdom resident returning, or by an overseas resident departing. Fly cruises are an exception to this rule as they are counted as “sea” even though United Kingdom residents interviewed will have returned by air. The “European Union” category in TSGB0114 and TSGB0115 includes all 27 member states. All other regions are defined according to the United Nations geoscheme.

The figures given in the tables are annual totals, but monthly and quarterly, as well as annual analyses, are published in the Overseas Travel and Tourism release.

More information can be found in the IPS methodology note.

Employment in transport-related occupations

Information on table TSGB0116

In the years prior to 2021, the ONS Labour Force Survey (LFS) was used to produce these figures, with data derived from interviews carried out during the April to June period of each year. From 2021 onwards, the ONS Annual Population Survey (APS), which consists of Labour Force Survey quarterly data, has been used to produce these figures, with data derived from all interviews carried out during the calendar year in question. This results in a larger sample size and therefore increases the reliability of the estimates. Nevertheless, since the data are derived from a sample, estimates are still subject to sampling error, and where possible confidence intervals are displayed to indicate this.

Despite the survey’s large sample size (approximately 20,000 responding households per quarter), data for some cells are not shown because of the small sample sizes involved.

For the years prior to 2021, a slightly narrower definition of transport related occupations was used in the table, while from 2021 onwards a wider range of occupations were included. As a result, the total number of transport related occupations is not directly comparable for the years before 2021 and 2021 onwards.

TSGB0116 includes people who are employees, self-employed, on government employment and training programmes, or unpaid family workers. Those whose industry or occupation was unknown are not included in the transport industry and occupation categories are included in the “all jobs” and “all industries” totals.

Standard Occupational Classification 2020 (SOC2020) was used for  2021 data onwards, while Standard Occupational Classification 2010 (SOC2010) was used from 2011 to 2020, and Standard Occupational Classification 2000 (SOC2000) was used from 2003 to 2010. While efforts have been made to maintain comparability where possible, due to changes in classifications, it has not always been possible to do so. Any changes between the latest figures and previous years should therefore be interpreted with caution. Further information on differences between SOC2010 and SOC2020 can be found on the ONS website.

Similarly, data between 2003 and 2008 use Standard Industrial Classifications 1992 (SIC1992) Section I Transport Storage and Communications), whilst data from 2009 onwards use Standard Industrial Classifications 2007 (SIC2007) (Sector H Transport and Storage). This again limits the ability to draw direct comparisons between the data for the 2 periods.

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