Passenger comfort and trust on first-time use of a shared autonomous shuttle vehicle

Abstract

Autonomous Vehicles (AV) may become widely diffused as a road transport technology around the world. However, two conditions of successful adoption of AVs are that they must be synchronously shared, to avoid negative transport network and environmental consequences, and that high levels of public acceptance of the technology must exist. The implications of these two conditions are that travellers must accept sharing rides with unfamiliar others in Shared Autonomous Vehicles (SAV). Two factors that have been identified as being positive influencers of acceptance are comfort and trust. The present paper undertakes a novel examination as to how comfort and trust ratings are affected by specific attributes of the ride experience of travelling in a fully-automated real-world, shared vehicle. To this end, 55 participants experienced riding in an SAV shuttle under experimental conditions at a test facility. Each experimental run involved two unrelated participants, accompanied by a safety operative and a researcher, undertaking four trips in the SAV, during which two conditions were presented for each of the independent variables of ‘direction of face’ (forwards/backwards) and ‘maximum vehicle speed’ (8/16 km/h). Order of presentation was varied between pairs of participants. After each run, participants rated the dependent variables ‘trust’ and ‘comfort’ (the latter variable comprised by six comfort factors). Expected and evaluative ratings were also obtained during pre-experimental orientation and debriefing sessions. Statistically significant relationships (p < .001) were found between trust and each of the independent variables, but for neither variable in the case of perceived comfort. A strong correlation was found between comfort and trust, interpreted as indicating trust in the SAV as an important predictor of perceived comfort. The before and after-experiment ratings for both variables showed statistically significant increases, and particularly for daily car drivers.