Navigating mobility in later life: How vehicle access and community context shape travel behaviour among older adults

Older adults face distinct mobility limitations due to aging, limited access to private vehicles, and structural barriers in their communities, such as inadequate transit, spatial isolation, and environmental burdens. This study examines the travel behaviour of 3,769 older adults aged 65 and over in the Puget Sound region, focusing on how household vehicle access and community-level structure influence both the likelihood of travel and trip frequency. The study develops a unique database by integrating person-level behavioural data from the Puget Sound Household Travel Survey with the National Community Indicators database at the census tract level. A Mobility-Constrained Framework (MCF) was quantified using a Zero Hurdle Negative Binomial regression model. It jointly estimates whether older adults made any trips (extensive margin) and, if so, how many (intensive margin). Vehicle access emerged as the strongest predictor of mobility. Living in a household with at least one vehicle significantly increased the odds of traveling (odds ratio, OR = 1.453) and overall trip frequency (incidence rate ratio, IRR = 3.607). A higher vehicle-to-adult ratio further raised trip counts (IRR = 1.773). In contrast, residing in a burdened community without a vehicle sharply reduced trip frequency (IRR = 0.517), highlighting spatial and infrastructural constraints. Rural residents were also associated with lower travel frequency (IRR = 0.537), reflecting longer distances and fewer modal options. Mobility was further constrained among adults aged 85 and above (OR = 0.347) and those with disabilities (IRR = 0.884), while living alone was linked to more travel. Car-sharing (IRR = 1.550) and transit use (IRR = 2.950) were positively associated with trip frequency. Guided by the MCF, findings highlight how individual, household, and community-level factors collectively shape travel behaviour. The study underscores the need for age-friendly transportation investments, especially in rural communities, expanded ADA-compliant services, and mobility innovations supporting aging populations.