How do winter conditions affect passengers’ intentions to use shared autonomous vehicles?

• We compared real-life perceptions of using SAVs with help of behavioral theory TPB. • Readiness to use SAVs was at a relatively high level both in summer and winter. • In winter, there were more differences among user groupś perceptions. • The importance of speed was a key finding of our study. • If the speeds of SAVs remain slow, they will not be beneficial for large masses of users. Weather conditions can significantly impact the demand for shared autonomous vehicles (SAVs). The aim of this study was to assess how difficult winter conditions affect passengerś intentions to use SAVs. This study compares passengers’ real-life perceptions and feelings between winter and summer conditions, and provides the first insights to the effects of difficult winter conditions. A quantitative convenience sample (n = 195) was collected from passengers traveling on SAVs in three trials in Finland in 2020–2023. We applied the Theory of Planned Behavior and analyzed the data using a nonparametric Kruskal-Wallis H test and post-hoc pairwise comparisons tests. According to the results, passengers’ perceptions in winter and summer conditions showed no statistically significant differences. Passengers’ attitudes, subjective norms, and perceived behavioral control, and through that, their intentions to use SAVs were at a high level in both summer and winter conditions. Still, there were many differences between different user groups, especially in winter. In difficult winter conditions, passengers’ readiness to use SAVs and their willingness to shift from non-motorized modes of transport to SAVs can affect positively the use of SAVs. As the most important key finding, the study highlights the significance of speed. If the speed cannot be increased, the use of SAVs will not be beneficial for large masses of users. The article concludes that more research is needed both on winter condition-related factors and also on changes in passenger attitudes as the speeds of SAVs increase and remote operators replace safety drivers.