Why do some people reduce car use after a major life change, while others do not? In our research on everyday travel routines, we apply psychological theories to understand how individual decision-making and habit formation influence transport choices. Our aim is to support transitions toward more sustainable travel behaviour, recognizing that reducing car dependency is crucial for addressing environmental challenges such as climate change and urban air pollution. This article summarises our recent work on how life events and habit disruption create opportunities for change. Drawing from applied psychological frameworks (e.g., Verplanken et al., 2008; Wood & Neal, 2007), we examine when people are most open to switch from the car to more sustainable transport modes such as walking, biking, or public transit.

Life events, such as starting university, changing job, moving, getting married, or retiring, can signal key transitions in a person's life course. These events often lead to new social roles, daily schedules, and environments. From a psychological perspective, they create an opening to reconsider routines that are otherwise habitual and automatic. However, not all life events have the same impact on travel behaviour, and the timing and context in which these events occur play a critical role in determining their influence.

To better conceptualize this, we developed a theoretical framework called FRUIT: Framework of RoUtIne Transitions in Daily Travel (Johansson Rehn, Olsson, & Friman, 2024). The name hints at the variety of life experiences, but also at the importance of not comparing “apples and pears.” In other words, not all life events are equal in their capacity to trigger change. For example, moving to a new home in a neighbourhood with excellent cycling infrastructure may create a strong impetus to shift away from car use, whereas other events like retiring may not always impact travel routines significantly unless accompanied by other factors.

Much of our daily travel is guided by habit rather than conscious choice. If someone always drives to work and the environment supports car use, this behaviour becomes automatic. Habits form when a specific cue (e.g., location, time of day) is consistently linked to an action (e.g., driving). These cue-response associations become strong over time (Wood & Neal, 2007). Such habitual behaviour can make it difficult for individuals to consciously change their travel choices, even when they recognize the environmental benefits of alternative modes.

But when the context changes, say, a person moves to a new area with good public transit or cycling infrastructure, this link is weakened. The familiar cues disappear, and the habit loses strength. That disruption is a precondition for forming new habits (Verplanken et al., 2008). This “window of opportunity” can facilitate reflective decision-making, allowing people to consciously explore and adopt more sustainable travel behaviours. Understanding these windows is essential for designing interventions that target moments when people are naturally more receptive to change.

In a recent study, we asked participants whether they had experienced any of nine significant life events in the past year (e.g., moving, having a child, separating, etc.) and how much these events affected their daily travel. The results showed that life events vary greatly in how they influence routines. For instance, 48% of those whose child moved out reported no change in travel behaviour, while only 18% said their travel stayed the same after childbirth. Overall, 24% of participants reported no change in travel routines despite experiencing one or more life events.

This led us to distinguish between life events (major transitions) and key events (events that actually trigger a change in travel behaviour). A life event may or may not be a key event. For instance, moving house could be both a life and a key event if the move makes the person change travel behavior (see also Bamberg, 2006). We then asked: when do life events become key events? To explore this question, we examined what differentiates people who changed their routines after a life event (key event phase) from those who did not. Based on the FRUIT framework (Johansson Rehn et al., 2024), we expected to find differences in habit strength, motivation to reduce car use, current levels of car use, norms and attitudes. Indeed, people in the key event phase reported weaker car use habits, stronger motivation to drive less, and stronger norms related to environmentally friendly behaviour (Johansson Rehn et al., 2024; 2025). Interestingly, we found a similar pattern even in a reference group: people who hadn’t experienced life events but had changed their routines (perhaps due to external circumstances like infrastructure improvements). This suggests that it is not just the life event that matters, but whether it triggers routine disruption.

To better understand the psychological mechanisms behind this, we conducted a path analysis (PLS-SEM) to explore the causal links. We found that routine disruption weakens habitual behaviour, and that weakened habits increase openness to alternative modes of travel. This openness, combined with motivational and normative factors, increases the likelihood of actual behaviour change. In short, life events do not open windows of opportunity by default. A disrupted routine is the key ingredient. Only when habits are weakened and new options are available can deliberate decision-making lead to lasting change (cf. Verplanken & Wood, 2006).

Our findings have important implications for sustainable transport policy and practice. First, interventions should leverage windows of opportunity by targeting moments when people are already re-evaluating routines. These windows often occur during routine disruption, not just during life transitions. For instance, infrastructure changes may interfere with established travel routines, by altering accessibility, routes, or travel time, thereby prompting individuals to reconsider their habitual choices. Second, focusing solely on life events may miss other critical moments when people begin changing their daily practices for other reasons, such as changes at work or school schedules.

Third, we recognize that habits fade gradually. Old travel routines are persistent and relapse is common without sustained support. Hence, providing positive experiences with new travel modes is essential. Enjoyable and convenient use of walking, cycling, or public transit helps reinforce the new behaviour and makes it more likely to stick (Redman et al. 2013). Additionally, policymakers should consider the broader social and infrastructural context, ensuring that sustainable transport options are accessible, safe, and integrated into people’s daily lives.

Finally, our research highlights that external key events, such as changes in infrastructure, policy, or workplace practices, can influence travel behaviour alongside life events. These may disrupt daily travel routines even without personal life changes, underscoring the role of broader systemic factors in shaping sustainable travel transitions.
As researchers in applied psychology, we believe that a better understanding of behavioural mechanisms is essential for designing effective interventions that support sustainable transport choices. Infrastructure and policy changes alone are not enough—psychological timing and support are crucial. By identifying key events and targeting moments of routine disruption, we can more effectively encourage sustainable behaviour. This behavioural lens offers valuable guidance for policymakers, urban planners, and practitioners working to reduce car dependence and promote long-term environmental sustainability.

References

Bamberg, S. (2006). Is a residential relocation a good opportunity to change people’s travel behavior? Results from a theory-driven intervention study. Environment and Behavior, 38(6), 820–840. https://doi.org/10.1177/0013916505285091

Johansson Rehn, H., Friman, M. , & Olsson, L. E. (2025). Key events as signifiers for the ‘window of opportunity’ to reduce car use. Unpublished manuscript.

Johansson Rehn, H., Olsson, L. E., & Friman, M. (2024). A framework of routine transitions in daily travel. Transportation Research Part A: Policy and Practice, 179, Article 103891. https://doi.org/10.1016/j.tra.2023.103891

Redman, L., Friman, M., Gärling, T., & Hartig, T. (2013). Quality attributes of public transport that attract car users: A research review. Transport Policy, 25, 119-127. https://doi.org/10.1016/j.tranpol.2012.11.005

Verplanken, B., Walker, I., Davis, A., & Jurasek, M. (2008). Context change and travel mode choice: Combining the habit discontinuity and self-activation hypotheses. Journal of Environmental Psychology, 28(2), 121–127. https://doi.org/10.1016/j.jenvp.2007.10.005

Verplanken, B., & Wood, W. (2006). Interventions to break and create consumer habits. Journal of Public Policy & Marketing, 25(1), 90-103. https://doi.org/10.1509/jppm.25.1.90

Wood, W., & Neal, D. T. (2007). A new look at habits and the habit-goal interface. Psychological Review, 114(4), 843–863. https://doi.org/10.1037/0033-295X.114.4.843