Analyzing the Effects of Car Sharing Services on the Reduction of Greenhouse Gas (GHG) Emissions

Jiyeon Jung,Yoonmo Koo

doi:10.3390/su10020539

Abstract

This study examines the environmental impacts of roundtrip car sharing services by investigating transportation behavior. Car sharing should contribute to reduced greenhouse gas GHG emissions; however, such schemes include both positive and negative environmental effects, including: (1) reduced CO2e (carbon dioxide equivalent) from substituting private vehicle use for more fuel-efficient car sharing vehicles, (2) increased CO2e as car-less individuals switch from public transit to car sharing vehicles and (3) reduced CO2e due to fewer vehicles. This study examines the impacts of this modal shift on greenhouse gas (GHG) emissions using three types of models: a mixed logit model to analyze car sharing service preferences; a binary logit model to analyze whether individuals are willing to forgo vehicle ownership or planned purchases to use car sharing services; and a linear regression to determine how much private vehicle or public transportation use would be replaced by car sharing and the resulting effects on mobility. Total emissions from the current car sharing market equal 1,025,589.36 t CO2e/year. However, an increase in electric vehicle (EV) charging stations to 50% of the number of gasoline-fuel stations would increase the probability of electric car sharing vehicle use, thereby reducing emissions by 655,773 t CO2e. This study shows that forgoing vehicle purchases does not offset the increased GHG emissions caused by the shift from public transportation or private vehicle use to car sharing.

Highlights

Automobiles have long been considered to be a private means of transportation
Car sharing allows individuals to benefit from vehicle use without the fixed costs and responsibilities associated with ownership, because maintenance, repairs and insurance costs are included in the car sharing tariff [2]
This study examines the effects of car sharing services on greenhouse gas (GHG) emissions by considering changes in travel mode, mobility and decisions on vehicle ownership

Summary

Introduction

Automobiles have long been considered to be a private means of transportation. with the introduction of car sharing services, cars can be rented on an “as needed” basis for as little as 10 min [1]. This study examines the effects of car sharing services on greenhouse gas (GHG) emissions by considering changes in travel mode, mobility and decisions on vehicle ownership. A further study by Martin and Shaheen [17] estimated the impacts of roundtrip car sharing in North America on net GHG emissions as a result of changes in travel behavior. It included observed impacts (emission changes are physically observable and measurable) and unobserved impacts (such as going without vehicles that otherwise would have been driven). Martin and Shaheen [24] have examined the impacts of car sharing vehicles on car ownership, transportation modal shifts, vehicle miles traveled and greenhouse gas emissions in five North American cities. It analyzes the effects of car sharing on the willingness to own a vehicle if supplementary services, such as vehicle delivery or one-way drive, are introduced

Data Description

Survey Design

Methodology

Empirical Model

Framework for Analyzing GHG Emission Impacts

Empirical Results

Estimating Car Sharing Impacts on GHG Emissions

Limitations and Future Research Topics