Multistate Nonhomogeneous Semi-Markov Model of Daily Activity Type, Timing, and Duration Sequence

Understanding travelers’ daily travel activity pattern formation is an important issue for activity-based travel-demand analysis. The activity pattern formation concerns not only complex interrelations between household members and individuals’ sociodemographic characteristics but also urban form and transport system settings. To investigate the effects of these attributes and the interrelationship between conducted activities, a multistate semi-Markov model is applied. The underlying assumption of the proposed model is that the state transition probability depends on its adjoining states. The statistical tests of significance affirm that the duration of activity depends not only on its beginning time of day but also on the duration of travel or activity previously conducted. An empirical study based on the Belgian mobility survey is conducted to estimate individuals’ daily activity durations of different episodes and provides useful insight for the effects of sociodemographic characteristics, urban and transportation system settings on the activity pattern formation.