The study was created in the form of an app, using Unity 3D game engine. It was available on Apple App Store and Google Playstore. Data from forty-seven participants was collected. They answered a set of questions and took part in two simulations.
To measure behavioural trust, participants need to be engaged in a situation where they can act as they please, and their behaviour can be observed. For this purpose an OpenVR simulation was developed. In OpenVR, the participant holds their mobile device, which provides a ‘window’ to the virtual world.
An important concept to consider when designing VR simulations is presence, which relates to whether participants react to stimuli in the simulation the same way as they would in real life. For this the simulation needs high psychological fidelity. To ensure high psychological fidelity of the driving experience, a realistic traffic system was developed that closely matches the European road style. Traffic sign and lane sizes, traffic sign distances to crossroads, and traffic light timings were kept compliant to regulation.
In the simulation the participants were tasked with driving to a destination in a Level 4 autonomous vehicle. The drive started in a city, where automation is not available. They navigated out of the city and onto the motorway. After reaching the motorway, which is a context where full automation can be utilised, they were able to choose whether to engage the autopilot. The time to engage the system was measured from the point when autonomy was made available to the point when it was engaged. This was the measure of behavioural trust.