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Despite similar population densities, levels of urbanization, climates, and levels of economic development, road accidents across the province of Québec (and the rest of Canada) are twice as high as in Sweden, as measured by accident frequency and severity. Some of this disparity may be explained by differences in road design, but some of this disparity is hypothesized to also be attributed to latent behavioural factors present in the general population.  The objective of this research is to investigate these latent differences in road user behaviour and experience that may explain differences in accident history beyond any road safety effects derived from road design and traffic composition. To that aim, a number of roundabouts in Québec and Sweden are selected on the basis of similarity in design, for cross-sectional comparison. The %The  modern roundabout is chosen as a case study as its implementation in North America is identical to that of Europe (where the design originated), and because roundabout operation relies heavily on road user behaviour (right-of-way is performed exclusively through rules of priority). This approach to intersection control is in stark contrast with typical stop-sign and traffic light control used throughout North America. Analysis of behaviour and resulting safety is performed proactively using video data,  automated computer-vision-based video analysis for road user  trajectory extraction of road users from video data, coupled with and  surrogate safety methods. measures of safety.  Surrogatesafety  measures of safety of  interest for this study include speed and time-to-collision, modeled using motion-pattern motion-prediction. based on motion prediction with empirical motion patterns.  Accident records available at the sample of roundabouts studied are found to be consistent with national averages of each country respectively (twice as high and severe in Québec as in Sweden). After controlling for various geometric design features, land use, construction year, traffic exposure, and traffic patterns, an overall tendency of lower speeds and fewer serious conflicts (as measured by time-to-collision) are found at the Swedish roundabouts. These results would suggest that some important latent regional factors---possibly related to driver education, culture or traffic safety enforcement---are at play at the microscopic level.