Satisfaction and uncertainty in car-sharing decisions: An integration of hybrid choice and random regret-based models

Car-sharing systems have attracted increasingly attention as one of several sustainable transportation systems. After joining a car-sharing organization, people can use a shared-car. Because sharing a car involves other members, there is some inherent uncertainty that originates from the possible non-availability of the shared-car. This uncertainty may trigger people to apply decision-making mechanisms other than the maximization of expected utility. In addition, variable satisfaction with current mobility options may affect individuals' decisions differently. Such uncertainty and satisfaction associated with car-sharing decisions have been largely ignored in previous studies. The present study is designed to examine the effects of latent satisfaction with current mobility options and uncertainty underlying car-sharing decisions. A random-regret minimization-based hybrid choice model is proposed to simultaneously estimate these effects. The model allows investigating car-sharing decisions in both risky and riskless choice contexts. The parameters are estimated based on stated choice data using a Bayesian D-efficient optimal design. The results show that satisfaction significantly affects the car-sharing decision, and that car availability has a significant effect on the likelihood of joining a car-sharing organization.