The report summarises the chief findings of an empirical research project designed to determine the validity of the concept of a daily travel time budget. Utilising data drawn from three surveys conducted during the early nineteen seventies, total daily travel times were examined over a range of distinct population groupings. The analysis was applied at both household and individual level and was extended to include travel by different modes and for various purposes. For a given sample, the range of variation in mean daily travel times for weekdays was 19 per cent. Mean daily travel times for a given sub-population were similar for weekdays for a given sample,though the day-to-day correlation for an individual's total daily travel time was weak. Mean daily travel times were shown to be dependent on several socioeconomic and demographic variables, including household income, car ownership, employment status, sex and age. Even the most powerful discriminatory factors proved unsatisfactory because of the large amount of variability about the mean total travel times. The results provided little evidence to support the hypothesis of a constant daily travel time budget over different population groupings, or between weekdays and weekends. Stability over longer periods of time was not examined. (Author/publisher)
Samenvatting