The research presented here develops a methodology to model travelers' activity-type choice for participation, home-stay duration before participation in an out-of-home activity and out-of-home activity duration of participation jointly, and applies this methodology to examine travelers' activity behavior after returning home at the end of the work tour (i.e., travelers' post home-arrival activity participation behavior) using data from a Boston region household activity survey. The methodology accommodates the interdependencies among the activity type, home-stay duration and out-of-home activity duration choices of travelers and the structural relationships of these activity choices with relevant exogenous variables. The empirical results underscore the importance of accommodating the inter-relationships among different elements of an individual's activity behavior. In particular, ignoring these interdependencies is likely to lead to biased and inconsistent estimates of the effect of exogenous variables on activity behavior characteristics. The results also provide important insights into the determinants of travelers' post home-arrival activity participation behavior.