Dimensions in elderly travel behaviour: A simplified activity-based model using lifestyle clusters

The current lack of a detailed description of elderly travel characteristics and behaviours, particularly one that examines the issue at a level involving activity engagement, was a deficiency addressed by this research. Using data from the 1994/95 Portland, Oregon, Household Activity and Stated Preference Survey a simplified activity-based travel model for the elderly was developed and validated. The modelling framework makes use of lifestyle groups which are delineated through advance analyses. The final cluster solution chosen to provide a categorical basis for the modelling framework identified six distinct lifestyle groups based on sociodemographic variables. The clusters were subjectively labelled Workers, Mobile Widows, Granny Flats, Mobility Impaired, Affluent Males, and Disabled Drivers. The clusters were found to have statistically significant differences in travel behaviour and activity engagement patterns. These findings are useful to policy-makers who attempt to balance the mobility needs of the elderly with the prospect for stricter driving license policies in response to traffic safety concerns. The model framework successfully replicated all facets of the base data set used for its development. Using a sequential process, the micro-simulation model employs a bottom-up approach by stochastically developing daily activity itineraries for individuals which are subsequently assembled into trip tours. Elements of travel behaviour synthesized for individuals being modelled included total daily activities ( with and without travel), activities engaged in by class ( with and without travel), total daily trip tours, and mode splits. The research has shown that a categorical approach using lifestyle groups with unique activity and travel characteristics can be successfully combined within an activity-based framework. Although this approach was applied specifically to the elderly, it can be extended to other heterogeneous groups including the population as a whole. Furthermore, the study has provided a more comprehensive understanding of the varied lifestyles, activity patterns, and subsequent travel behaviour and needs of the elderly.