Relationships among discretionary activity duration, its travel time spent and activity space indices in the Jakarta Metropolitan Area, Indonesia

Abstract

This study examines the interdependencies among an individual's time allocation for different activities and the travel time spent on a given day, socio-demographic and built environment variables on these in-home and out-of-home discretionary activities time duration, and how interaction of those variables on discretionary activities time duration influences an individual's activity space indices in the Jakarta Metropolitan Area (JMA), Indonesia. The 3SLS model and the 2004 SITRAMP household travel survey were used to achieve this objective. The results show that the time allocation for certain discretionary activities significantly influences the time allocation for other discretionary activities. Workers, students and non-workers have different complex mechanisms pertaining to how they allocate time across different activities and journeys. This unique trade-off mechanism gives an individual a unique distribution of activity locations and spatial movement patterns. This is observed via his/her activity space indices throughout time and space. For example, the estimation result shows that workers' and students' time-use allocation, activities participation and activity space indices are highly influenced by their engagement in mandatory activities. However, this is not the case for non-workers. Furthermore, the mandatory travel time variable has a stronger impact on an individual's discretionary activities time-use pattern than the duration of mandatory activities. This may lead to the argument that, in order to provide more opportunities and flexibilities among the JMA's workers and students for undertaking discretionary activities, travel time reduction policies can play more significant role in shaping the discretionary activity-travel patterns than reduction in working/school hour policies. Additionally, in-line with previous findings in developed countries, locating grocery shops closer to residential areas in the CBD and in suburban areas creates more opportunities for workers and students to spend more time on out-of-home maintenance activities; with a shorter travel time, especially on Fridays.