Modeling the joint choice of daily activity patterns of household members in large cities

Due to the type of role and duty that members have in their households, they can directly or indirectly affect the decision of another member in choosing the type of activity and the pattern of their trip. In recent years, the way in which household members influence each other's choices has attracted the attention of many researchers. Each of these studies has examined the effect of a particular factor on how member's choices are shaped, but each has some shortcomings despite the efforts made in this regard. In this study, a multinomial logit model was considered for all household's members in which, the joint daily activity patterns chosen by the members of the household, having interaction with each other, is discussed in here in order to build the utility function of the household. This model in this study which is based on three basic activity pattern categories -'mandatory', 'non-mandatory' and 'staying at home'- examines a type of choice structure in which all combinations of activity-pattern of household members are modeled as possible household alternatives. The utility function of each alternative includes various individual and group characteristics that examine how interactions between different members work. The data used in this study was a questionnaire from households in Mashhad in which they were divided into: 1)self-employee, 2)homemaker, 3)pre-school children, 4)employee, 5)school student, 6)Unemployed adult and 7)university student. Finally, the model’s output shows the tremendous impact of the housekeeper and the child on the choice of pattern-activity shared by different combinations of individuals. The behavior of individuals with different characteristics and in the form of different pairwise combinations was modeled in choosing their daily activity pattern. Taking into account these kind of interactions, it is possible to make more accurate decisions on the macro levels of transportation planning.