The Role of Algorithmic and Environmental Factors in the Acceptability of Autonomous Vehicles: A Study on a Priori and in Situ Perceptions

As acceptability is often studied through psychological components, we investigate how “atomic” elements of fully autonomous driving influence passengers' in situ acceptability. Thirty participants were immersed in a virtual reality simulation and experienced a journey in a level-5 autonomous vehicle. Before the experiment, some participants received information emphasising the vehicle's safety to test a priming effect on acceptance. During the journey, passengers encountered roundabouts, traffic-light junctions, stop-sign junctions and straight-line overtaking. Each situation varied in traffic density and waiting time to assess their impact on acceptability. Results show that safety priming has a strong positive influence on in situ acceptability of autonomous vehicle behavior. Behavioral parameters and gender also play a role, with women reporting higher acceptability. At stop signs, the most acceptable waiting time is around 10 s. At roundabouts, acceptability increases with waiting time in heavy traffic but remains unchanged in light traffic conditions.