What are important factors to determine CO2 reduction by car sharing? Simulation of car-sharing impact in cities with different car dependencies considering variable uncertainty

The spread of car sharing is influenced by the characteristics of cities, such as the convenience of existing public transportation and degree of car dependencies. In this study, 60 Japanese cities were categorized into five clusters based on car-use share, household car ownership, and population density, and seven cities including a representative city of each cluster and two extreme cities were used as case studies to simulate the CO2 emissions associated with the introduction of car sharing. To determine the significant factors that affect CO2 emissions, we took up multiple variables and performed Monte Carlo simulations on them to calculate the final distribution of CO2 emissions. The cities with lower car dependency show significant CO2 increases in the simulation. The fuel economy of cars is one significant influential factor for CO2 reduction, whereas the transition from public transportation to car sharing is the most significant factor for CO2 increases.

Automated summary

This study categorizes 60 Japanese cities into clusters and uses seven representative cities to simulate the CO2 emissions associated with car sharing. The results show that the cities with lower car dependency experience a significant increase in CO2 emissions when car sharing is introduced, indicating that the transition from public transportation to car sharing plays a major role in CO2 increases.