3: Operationalising Household Activity Scheduling Models: Addressing Assumptions and the Use of New Sources of Behavioural Data

It is only recently that operational models of the household activity scheduling process have begun to emerge. These models share a desire to realistically replicate the sequence of decisions that leads to observed patterns of human activities and travel - including the decision of what activities to conduct, by whom, for how long, at what time and location, and by what mode. Understanding the sequence of these decisions is crucial in developing a dynamic model of scheduling behaviour that can represent the way people reschedule over time in response to changing opportunities and constraints.

While a fairly well-developed theoretical basis exists for such models, one of the biggest stumbling blocks for their development has been the lack of observed data on the actual process of decision-making as it occurs within the household. Traditional trip-diary data provides limited insight into this process, since only the executed schedules, which are a product of a large number of scheduling decisions, are actually observed. Attempts to use trip-diary data as a basis for developing operational scheduling models require that many assumptions be made concerning the decision process. These assumptions include how decisions are ordered, how conflicts are resolved, how schedules are modified, and how/when group decisions are made.