What determines the acceptance of socially optimal traffic coordination?: A scenario-based examination in Germany

Social optimization emerged as a strategy for the attainment of more efficient road traffic (i.e., minimal total or average travel time). In order to achieve efficiency benefits, collective action is needed. A major challenge is that not every individual benefits equally from social optimization. Thus, a corresponding technological implementation (i.e., a social optimizing traveler information system (SOTIS)) is prone to rejection. The question remains as to which factors underlie the acceptance of such a system. Therefore a sample of 391 car drivers in Germany, stratified by kilometers driven per year, age and gender, completed a scenario-based questionnaire addressing attitudinal acceptance of a SOTIS. The results indicate that participants reacted rather hesitantly towards incorporating a SOTIS into daily driving. Indeed, structural equation modeling revealed that the behavioral intention to use it was promoted by its perceived usefulness. However, this intention was negatively affected by elicited subjective ambivalence (i.e., simultaneous conducive and opposing affect towards the SOTIS). Opposition in subjective ambivalence could be explained by perceived injustice. Social factors (i.e., a social norm and image gains due to using the system) were positively associated with perceived usefulness. The high social dependency and the effect for perceived injustice were not replicated in a second sample of 111 drivers that evaluated a user-optimizing traveler information system (UOTIS). The results suggest to taking active ambivalence reduction through transparent prevention of injustice, and the promotion of a conducive social norm into account in the planning and design of a SOTIS. Additionally, this study provides an empirically tested framework for examining the emergence and maintenance of acceptance of such a system