In recent years considerable interest has focused on the potential benefits for transport modelling and appraisal of moving from trip-based to activity-based models of travel demand, and significant developments have beenmade. A key element in most activity based modelling approaches is the interplay between the utility obtained from participating in activities undertaken at different times and locations and the disutility associated withtravelling to these activities. Thus the issue of how to measure the utility of an activity is of central importance. The conventional approach adopted in the activity based modelling literature is to conceive of the utility of an activity as a function of its duration and timing, sometimes modified by contextual and personal characteristics. This reflects both the importance of scheduling considerations in most activity based frameworks and the fact that for activities undertaken in a physical, face-to-face context, duration and timing are indeed likely to be major components of the overall benefit that individuals derive from activity participation. However, this is not necessarily true in the case of activities involving the use of electronic and mobile service, such as e-shopping, e-banking and other forms of e-commerce and m-commerce (mobile commerce). In these cases, the strong connection between the utility derived from an activity and its timing and duration is weakened and may in some cases be broken altogether. Thus, to deal satisfactorily with these activity participation contexts,a new approach to conceiving of the utility of an activity is required. Anew approach is proposed to measuring the utility of activity participation, which is based on idea of an activity production function. This function explicitly identifies the inputs (e.g., time, money, technology etc.) necessary to perform an activity and the outputs derived from the activity (wages, consumption of goods etc.). It is shown how this approach generalises existing activity utility models and can easily be extended to deal with activities performed in electronic and mobile contexts. The first section briefly reviews the approaches adopted in the existing transport literature to defining the utility of an activity, highlighting relevant strengths and weaknesses. The second section presents a new approach which combines elements of the existing transport literature with ideas from householdand firm production theory. The third section outlines a stated choice exercise developed to estimate models based on this new framework. In this exercise, respondents are presented with the choice between undertaking a shopping activity either conventionally (by personally visiting a shop) or by means of a mobile service (while travelling on public transport). The fourth section presents the empirical results of this excise and the final section draws together overall results and implications. For the covering abstract see ITRD E145999
Samenvatting