Situational Trust Scale for Automated Driving (STS-AD): Development and Initial Validation

Abstract

Trust is important in determining how drivers interact with automated vehicles. Overtrust has contributed to fatal accidents; and distrust can hinder successful adoption of this technology. However, existing studies on trust are often hard to compare, given the complexity of the construct and the absence of standardized measures. Further, existing trust scales often do not consider its multi-dimensionality. Another challenge is that driving is strongly context- and situation-dependent. We present the Situational Trust Scale for Automated Driving, a short questionnaire to assess different aspects of situational trust, based on the trust model proposed by Hoff and Bashir. We evaluated the scale using an online study in the US and Germany (N=303), where participants faced different videos of an automated vehicle. Results confirm the existence of situational factors as components of trust, and support the scale being a valid measure of situational trust in this automated driving context.