When simulator experiences shape later choices: Measuring behavioural spillover on travel preferences

Behavioural spillover, where one behaviour affects others, non-targeted behaviours, is widely studied in psychology but underexamined in transport, despite its potential to improve sustainability. We offer a novel contribution by combining an immersive and feedback-supported driving simulator experiment with stated choice (SC) components before and after the simulator to test spillover effects on preferences for travel time and carbon emissions. Our design captures how real-time, experience-based feedback, augmented by personalised driving advice, influences behaviour. We find evidence of behavioural shifts, and a link between those shifts in SC preferences and behaviour in the simulator. Crucially, we reveal substantial heterogeneity in responses, underscoring the need to move beyond homogeneous assumptions, with a strong impact of messaging on eco-driving. The relative importance of CO2 emissions increased by 52.89% following the driving simulator intervention among respondents receiving eco-driving advice, compared with an increase of 31.73% among those who experienced the intervention without advice. The findings highlight the potential for immersive simulator experiences and personalised eco-driving advice to influence short-term environmental preferences and provide a foundation for future research on behavioural spillover in transport.