Determinants of Public Transport Usage Frequency Among Older Adults in Four EU Countries

Public transport plays a crucial role in supporting autonomy, social inclusion, and quality of life for older adults. This study, part of the Horizon Europe OptiPEx project, explores factors influencing public transport use among older adults in four European countries (Austria, Finland, Germany, and Spain), with the goal of promoting inclusive and sustainable mobility in later life. A sample of 478 individuals aged 65 or older participated in an online survey assessing demographic characteristics and patterns of public transport usage. A decision tree analysis identified four key predictors of high-frequency public transport use (defined as daily or weekly): (1) preferred mode of transport, (2) use of mobile applications, (3) country of residence, and (4) age. Participants who primarily used local modes of transport (bus, tram, or metro) were significantly more likely to be frequent users. Likewise, individuals who used transport-related mobile apps also reported higher usage frequency. Among the countries studied, participants from Spain showed the highest levels of public transport use, and younger seniors (aged ≤71.5 years) were more likely to be frequent users compared to older participants. The decision tree model achieved an overall classification accuracy of 73.6%, exceeding chance levels by 36.8%. It also reduced classification error by approximately 15.4% relative to a model with no predictors. Cross-validation results confirmed the model’s generalizability and low risk of overfitting. These findings highlight the importance of enhancing local transport accessibility, fostering digital inclusion, and tailoring services to national and age-specific contexts.