Analyzing the Effects of Car Sharing Services on GHG Emission Reduction

Abstract

The use of automobiles, which have long been considered private means of transportation, is now shifting toward car-sharing, which allows short-term rental of a vehicle on an as-needed basis. With the increasing concern for environmental issues, it is anticipated that car-sharing will contribute to the reduction of GHG emissions. However, there exist both positive and negative environmental effects from car-sharing. Carless individuals can drive instead of using public transit because car-sharing has enabled individuals to acquire personal auto-mobility at low cost, and individuals who had planned to purchase a vehicle may decide not to, and instead use car-sharing services. In this study, the environmental effects on greenhouse gas emissions (GHG) caused by this shift in mode of transportation were examined. The analysis was based on the use of three types of models. A mixed logit model was used to analyze preferences for using car-sharing services. A binary logit model was used to analyze whether individuals were willing to dispose of owned vehicles or to forego vehicle purchases to use car-sharing services. A linear regression model was used to understand how much car-sharing would replace driving of owned vehicles or public transportation and how the mobility change by using car-sharing services. This also involved estimation of environmental impacts caused by car-sharing. To estimate the total effects of the introduction of car-sharing services on GHG emissions, three things were considered: mode-shift proportion, mobility change and reduction in vehicle ownership. In this study, scenario analysis was used to examine the effects of car-sharing services on GHG emission in various car-sharing-market situations. From the results, suggestions are made about operating car-sharing services so that they are more environmentally compatible.