Disposition towards automated driving scale (DADS): Development and psychometric properties of a brief self-report measure to assess subject's disposition towards automated driving

Positive disposition and trust in automated vehicle systems is a fundamental requisite for using, buying and taking full advantage of automated vehicles (AVs). The present study aims at developing a short, but psychometrically sound, measures of AVs acceptance that could be administered to both large samples and during experimental sessions. To this aim, in a preliminary study, we developed the Disposition towards Automated Driving Scale (DADS), an 11-item self-report measure. To test the psychometric properties of the DADS, 590 adult participants were administered the Disposition towards Automated Driving Scale (DADS). The DADS showed adequate factor structure and internal consistency. Additionally, the DADS showed negative and significant associations with theoretically relevant constructs, including subject's interest in car driving (Spearman r = −0.11, p < 0.01), Driver Behavior Questionnaire Aggressive Violations scale scores (Spearman r = −0.13, p < 0.0125), and Big Five Inventory Neuroticism scale scores (Spearman r = −0.14, p < 0.01). To test the practical utility of the DADS in an experimental context, an independent sample of 55 participants completed the DADS during an experimental automated driving study using a dynamic driving simulator. Notably, the DADS scores were provided with adequate reliability also in this context and showed positive and significant associations with the involvement experienced during the automated driving experimental session (Spearman r = 0.32, p < 0.05), and the subjective experience of realism (Spearman r = 0.37, p < 0.01). As a whole, the use of the DADS may contribute to understanding AVs acceptance across different populations and contexts, while paving the way for future studies on the barriers that still hinder the acceptance of AVs.