What drives people to carpool? Explaining carpooling intention from the perspectives of carpooling passengers and drivers

The negative impact of motorized private mobility on the environment can be decreased successfully by encouraging more people to carpool. From a psychological perspective, only little is known about the determinants of carpooling. Therefore, this study investigated carpooling behavior based on a theoretical background that integrates (1) the theory of planned behavior, (2) the norm activation model, and (3) dispositional trust. Additionally, we studied carpooling from two separate perspectives: Passengers sharing rides, and the drivers offering rides. We conducted a survey with a representative sample of 342 participants in Switzerland. The results showed that for both, passengers and drivers, normative aspects such as descriptive and personal norms, in combination with perceived behavioral control predicted carpooling intention. Attitude toward carpooling behavior, however, did not have any predictive power regarding carpooling intention, neither for passengers nor drivers. Dispositional trust displayed an indirect effect on intention to carpool as a passenger or driver via perceived behavioral control. Based on these results, we discuss practical implications for designing measures to promote carpooling successfully in the future