On the temporal variation of human activity spaces

Abstract

The idea that individuals establish stable, relatively fixed travel patterns has been a convenient, compelling and widely adopted assumption among transport researchers. If highly routinised habitual behavior was to exist, then it would be welcomed, for its ease of predictability and for the fact that only a snapshot of such a behavior would be needed to capture it adequately in a survey. The problem has always been to define what should be the period of observation in which we can see no net change in the behavior. This paper first discusses various measures of activity spaces (Ellipses and kernel densities) and then analyses the Mobidrive and the Uppsala databases in three blocks of a fortnight each (weeks 1 and 2; weeks 3 and 4; weeks 5 and 6). Then the measures were analysed using various socio demographic variables and studied if certain routinised patterns exist. The results suggest that people (mostly the fulltime workers) develop stable travel patterns during the workdays, but during the weekends, they look for variety and leisure opportunities and consequently have a more variability in their travel pattern.