The role of travel time budgets – Representation of a demand derived from activity participation

The recognition that travel is a derived demand from activities has stimulated the analysis of the duration of activities. In this activity-based framework, authors have paid special attention to the relationship between activities duration, including transport.First the paper presents the type of microeconomic and econometric models found in the transport economics literature, that deal with the relationship between transport and other activity duration. Using the microeconomics formalism, a link between activities duration is introduced in the model of allocation of time between activities of Jara-Diaz (2003). It leads to a value of time that incorporate the value of constrained time.The second part proposes to explore the form of the link between travel time budget and activity time budgets for Swiss and French cities. Following the findings of Kitamura et al. (1992) and Dijst et Vidakovic (2000) we test the paradigm of proportional activities duration. First, the proportionality of activities duration with respect to the total disposable time is tested for the paid work, shopping, leisure, travel and in-home activities. Second, the travel-time ratio is analysed for each out-of-home activity type