An analysis of day-to-day variations in individual space–time accessibility

Traditional studies about the planning and equality of public service delivery have treated accessibility of services as if it were a static concept of physical proximity. This paper extends and empirically substantiates the conceptual argument for the incorporation of time in measures of accessibility. It does so by examining the variability in person-based accessibility to urban opportunities over a 1-week period. Accessibility is specified on the basis of persons rather than places and measured for each day of the week rather than for a single day. An empirical case of government offices in the city of Ghent (Belgium) is used to demonstrate how space–time accessibility may fluctuate between persons and per person from day to day. The case study provides evidence that, even for fulltime workers on weekdays, considerable day-to-day variability in the accessibility level of a single person can exist as a consequence of differences in space–time constraints.