Driver Expectations for Automated Vehicle Driving Styles in Mixed-Traffic Interactions

As highly automated vehicles (AVs) are deployed in various countries, mixed-autonomy traffic will become common and persist for the foreseeable future. In such environments, AVs must operate in ways which are both predictable and acceptable to human drivers, particularly in complex intersections where negotiation is crucial. However, how human drivers expect AVs to interact with them, particularly in scenarios where the right-of-way is ambiguous, remains unclear. In this research, we conducted a simulation-based video survey of UK drivers (N = 87), investigating their perception of aggressive and defensive AV driving styles under unclear right-of-way scenarios. The analysis indicates that a defensive driving style is generally preferred by human drivers, while an aggressive style can also be acceptable at lower-speed interaction zones. These findings provide empirical evidence for algorithm engineers seeking to design motion control and negotiation strategies that align with human expectations in mixed traffic.