Research on travelers’ transportation mode choice between carsharing and private cars based on the logit dynamic evolutionary game model

The rapid increase in private cars has exacerbated urban traffic and environmental problems. As an alternative to private cars, carsharing is more economical and environmentally friendly than private cars and is becoming internationally recognized as sustainable transportation. However, the benefits of carsharing in alleviating traffic and environmental problems would only be significant when many travelers switch from private cars to carsharing. Thus, understanding travelers' dynamic selection processes when choosing between carsharing and private cars is important in promoting carsharing. Assuming that travelers' behavior regarding travel mode choice conforms to the principle of maximizing random utility, a logit evolutionary game model based on logit dynamics and evolutionary game theory was constructed to explain and analyze the dynamic selection processes and mechanisms by which travelers choose between carsharing and private cars. In addition to the traditional time and monetary cost, the psychological benefit of the driving experience was also considered in the travelers’ payment functions. The unique global stable equilibrium point of the logit dynamic evolution model was derived through mathematical analysis. Data computed from a simple interview survey in Qingdao City were then used to perform an experimental numerical analysis on the evolutionary model of this study to further explain the dynamic evolution. Moreover, the relationships between the evolutionarily stable points and the time cost, monetary cost, and driving experience benefit differences between carsharing and private cars are discussed. The relationships between the benefits of the negative externalities of carsharing and private cars and the evolutionarily stable points are also examined. Furthermore, four scenarios are established, and their corresponding evolutionarily stable points are discussed to explain the influence of adjusting the external circumstances on the evolutionarily stable point. Finally, based on practical application, suggestions for encouraging travelers to use carsharing rather than private cars are provided to help carsharing organizations, government departments, and other related institutions.