Supporting Information

Additional background information on the SHS

The Scottish Household Survey (SHS) started in February 1999. Its principal purpose is to collect information to inform policy on Transport, Communities and Local Government, but other topics are covered, such as household composition, amenities, employment or unemployment, income, assets and savings, credit and debt, health, disabilities and care, and other topics. The SHS provides the first representative Scottish data on many subjects, such as access to the Internet, daily travel patterns, etc.

Where appropriate, the SHS uses the harmonised concepts and questions for government social surveys which have been developed by the Government Statistical Service, to facilitate comparison with the results of other government surveys. However, differences in sampling and survey methods mean that SHS results will differ from those of other surveys.

The SHS is intended to be a survey of private households. For the purposes of the survey, a household is defined as one person or a group of people living in accommodation as their only or main residence and either sharing at least one meal a day or sharing the living accommodation. A student's term-time address is taken as his/her main residence, in order that they are counted where they live for most of the year.

The sample was drawn from the Small User file of the Postcode Address File (PAF), which is a listing of all active address points maintained by the Post Office. The Small User file excludes addresses where an average of more than 25 items of post is delivered per day. Blocks of flats etc, which have several dwellings at the same address, are not excluded from the Small User file: in such cases, the file's Multiple Occupancy Indicator is used to count each dwelling separately for the selection of the sample.

People in certain types of accommodation (such as nurses’ homes, student halls of residence etc.) will be excluded from the SHS unless the accommodation is listed on the Small User file of the PAF and it represents the sole or main residence of the people concerned. People living in bed and breakfast accommodation may be included, if it is listed in the Small User file of the PAF and if it is their sole or main residence. Prisons, hospitals and military bases are excluded. This exclusion of some forms of accommodation may have particular effects upon the inclusion of certain groups in survey, such as disabled people.

Further information on the Scottish Household Survey can be found on the Scottish Government website.

The data collected for the SHS is made available via the UK Data Service and may be made available on request, subject to consideration of legal and ethical factors. Please contact shs@gov.scot for further information.

Comparability with previous years

The results of the 2020 and 2021 SHS telephone surveys are not directly comparable to SHS face-to-face survey results for other years. We would expect some genuine changes in people’s views, experiences, and habits relating to transport during the pandemic. However, response rates for the telephone survey were lower than for previous face-to-face surveys, and there was a change in the profile of respondents (e.g. home owners and people with degree level qualifications were over-represented).

The results of the 2022 survey onwards are comparable with results for 2019 and earlier years.

The annual SHS Methodology Reports provide more detail on the changes in approach, and how this may have impacted the results.

Improvement to the estimation of journey distance

Since the publication of 2017 data, statistics involving journey distance have been based on the road network distance, calculated as the shortest distance by road between the start and end points of the journey. This was adopted to replace the previous straight line distance measure, as the straight line measure was found to be underestimating the actual distance travelled by around a third. 

However, using this approach the road network distance of some journeys was calculated as zero. This occurred where the journey was circular, i.e. had the same start and end point. These journeys were mostly single stage and often started and ended at the respondent’s home. The calculation has now been updated to impute an estimate of distance for these journeys by multiplying the time spent on the journey by an average speed for the mode of transport.

The time series has been revised back to 2012. The impact has been to reduce the percentage of very short (under 1km) journeys and increase slightly the percentages for the other distance categories. The modes most affected are walking and car journeys. The summary statistics in tables TD5 and TD5a have increased (by less than 1km).

Changes to the frequency of questions and collection of journey stage data

In advance of the 2024 SHS, a questionnaire review was carried out, with the aim of shortening the survey interview from 1 hour to 45 minutes. This was to reduce the burden on respondents, increase the likelihood of respondents giving valid and reliable answers, and improve response rates. Social surveys are increasingly costly to run as it has become more difficult to persuade people to take part.

As a result of the questionnaire review, many transport-related questions in the social survey section were changed to be asked every two years rather than every year (some questions were already asked every two years). Most of the biennial transport-related questions are now asked in even years, so the next version of this publication (presenting data from 2025), will present a reduced set of findings compared to this report.

In addition, a small number of questions were removed from the survey, including from the travel diary section. The changes are detailed in the annex document available on the Scottish Government website.

From 2025 onwards, further changes have been made to the collection of journey data. Again, this has been made to reduce the burden on survey respondents and to improve the experience for respondents and interviewers. The changes mean that a reduced set of information will be collected on the component stages of journeys. Whilst the different modes used over the course of the journey will be recorded, start and end locations and duration will only be collected for the journey as a whole. Where a journey involves switching from a car to public transport or vice versa, the location of that switch will be collected.

Other Transport findings from the Scottish Household Survey

Disability and Transport

A publication providing further analysis of the Scottish Household Survey for disabled people, as well as measurements from other sources, Disability and Transport, was updated on 19th March 2025 to include 2022 and 2023 data. An update to include 2024 data will be published early next year.

Transport Scotland Statistics

The full range of transport statistics publications are available on the Transport Scotland website.