Exploring heterogeneity in travel time expenditure of aging populations in the Netherlands: results of a CHAID analysis

• We provide recent results on elderly’s travel behavior using Dutch travel data 2009.
• We investigate the heterogeneity within the aging population using CHAID analysis.
• Aging population can be systematically broken down into homogeneous cohort segments.
• Elderly’s travel time depends significantly on travel motivation and modes.
• There is less heterogeneity in travel time of elderly who are older than 75.

The aim of this paper is to contribute to the increasing literature on travel behavior and time use of the elderly. The Dutch National Travel Survey, administered in 2009, was used as a data source. First, various facets of activity-travel patterns of the elderly were compared against overall sample averages. Results indicate that the new generation of elderly people do not differ that much from other age groups in terms of their activity-travel behavior. Differences in behavior can be largely understood in terms of constraints acting on agendas. Moreover, travel patterns of elderly are affected by socio-demographic variables. Second, to further qualify the average findings, the Chi-square automatic interaction detection (CHAID) method was applied to explore heterogeneity among the elderly in terms of travel time expenditure. It is analyzed how differences in travel time co-vary with socio-demographics, in addition to activity type, activity duration and travel aspects. The results suggest that the aging population can be systematically broken down into several homogeneous cohort segments. Travel time of elderly groups depends significantly on transport modes, travel motivation, and seven socio-demographic variables (gender, age, living environment, personal net-income, household size and season). Moreover, there is less heterogeneity in travel time of elderly who are older than 75 years old. However, for younger elderly people, especially the group aged from 65 to 74 years old, heterogeneity affects their travel.