Windows of change as precursors to changing travel behaviour aligned with sustainable mobility

There is an increasing focus on ways in which we can achieve behavioural change associated with improved sustainability outcomes in the transport sector. In societies where the car is the dominant passenger transport mode with all of its associated interpretations of convenience, we continue to search for ways to change travel habits that result in a switch out of the car in favour of public transport and active modes. Beyond the existing research on mobility biographies, this study proposes the concept of “Windows of Change” (WoC), representing the cycle of key events driving travel behaviour changes of individuals. The study demonstrates that WoC works in ways that support sustainability outcomes. We categorise the WoC into four broad classes: lifestyle and household changes (e.g., changes in living arrangements, family structure, or personal habits); work and commuting-related changes (e.g., changes in employment, workplace incentives or commuting patterns); transport and mobility changes (e.g., changes in vehicle ownership, public transport use or travel habits); and social and environmental considerations (including awareness and influence of others). In particular, the study applies a series of negative binomial count models to identify the relationship between the key events in WoC and modal one-way trip frequency in a typical week associated with the WoC period, after controlling for various socioeconomic effects and country dummy variables. Data is collected from over 4,000 respondents spread across Australia, Finland, New Zealand, the United States, the United Kingdom, Singapore, and Sweden, investigating respondents’ local travel behaviour changes over the period 2023–2025, showing the concept of WoC can be applied across countries and cultural contexts. The findings provide a rich array of policy advice on what key WoC influences suggest actionable ways to support the switch to more sustainable modes, and what remain as clear barriers to achieving such an outcome.