Stability of travel time expenditures and budgets - Some preliminary findings

There has been discussion now for four decades on the issue of whether or not people around the world have a constant travel-time budget. Most of the research into travel-time budgets has used large aggregate data sets and has shown that average amounts of time spent travelling are on the order of 1 to 1 1/2 hours. There have also been a number of studies that have failed to find evidence of constancy in travel-time budgets. In this paper, the authors report on some preliminary research that uses data from a panel of 200 households that provided GPS data for a period of 7 days. In the research to date, the analysis deals only with evidence from one wave of the panel, to determine whether there is evidence over a period of one week of stability in travel-time expenditures. The data set provides very precise times of travel for each person for up to 7 consecutive days of travel. The analysis looks at travel time expenditure on a daily basis per person and then aggregates this to a week.