Statistical Bulletin Trn/2005/2
Scottish Household Survey Travel Diary results for 2003
2. Background
2.1 This bulletin provides information, collected by the Scottish Household Survey (SHS), which started in 1999, about travel by a random sample of adults (aged 16+) living in private households across Scotland. Statistics are provided for Scotland overall and for 14 separate local authorities, or groups of local authorities, and for each category of an urban/rural classification which was developed for use in analysing the results of the SHS. The topics covered include the days of the week on which people travel, the means of transport used by different types of people, the purposes for which people travel, the distances that they go, the times of day at which trips start, the duration of journeys, the number of occupants for trips made as the driver of a car, delays due to congestion to car journeys, delays to bus and rail journeys, whether a car driver paid for parking, and journeys between and within groups of local authorities, with more detailed information on journeys into and within Glasgow and Edinburgh. There is also some information on estimated adult and household weekday trip rates. All this information is obtained from interviews with one randomly-chosen adult per household in the sample. This person is asked about his/her travel on the day prior to the interview. Each adult in the household has an equal chance of selection for these questions. The information about the person's travel is analysed in conjunction with data collected by questions about the household as a whole, which are answered by either the Highest Income Householder (please see paragraph A3.6 of the "Notes and Definitions", which appear after the tables) or his/her spouse/partner.
2.2 The statistics given here were mostly extracted from the Scottish Executive's SHS database in December 2004, so will not take account of any subsequent revisions to the data (e.g. due to improvements to the imputation process). The statistics for 1999 to 2002 may differ slightly from those published in previous editions of this bulletin because further data cleaning has been carried out and the imputation process has been re-run. The results have been weighted to take account of differences in selection probabilities. As with all such surveys, sampling variability and non-response bias may affect the results. It is particularly important to keep this in mind when looking at any results which are based on small numbers of cases in the sample, and especially when looking at the results for individual local authority areas, or groups of local authority areas, because some of them may be affected by quite large percentage sampling errors. Section A7 provides information on the possible scale of sampling errors, and on other reasons why the SHS results may provide only broad indications for some types of people. Also, the figures for some local authority areas may be unrepresentative, because the interviewer(s) in those areas may conduct most of their interviews on certain days of the week. Although a reweighting process produces an even spread of interviews for Scotland as a whole, the distribution of reported journeys for some areas could depend greatly upon interviewing patterns as well as journeys made - see section A4.2 for more details.
2.3 The main changes from the previous edition of this bulletin are the inclusion of new tables on:
- whether part of a car driver's trip was delayed by congestion, and if so, how much time was lost;
- whether a bus or rail journey was delayed, the reason for the delay (bus journeys only), and how much time was lost;
- whether a car driver paid for parking at the end of their journey, and if so, the type of parking, the amount paid and the time parked;
- different types of shopping journeys; and
- the journey purposes of car drivers at different times of the day.
In addition, some tables have been improved, for example by incorporating analysis using the Scottish Index of Multiple Deprivation quintiles.