A study by researchers at Tsinghua University in China has concluded that the overall impact of autonomous vehicle deployment on greenhouse gas emissions is not significant in the near-to mid-term.

In the study, published in the journal Energy Policy, the researchers found that autonomous vehicles potentially affect the total greenhouse gas emissions in multiple ways, including reducing vehicle ownership, increasing vehicle use intensity, and changing the vehicle fuel consumption rate. These impacts are mostly internally offset—thus resulting in insignificant impact in the near-to mid-term.

In their study, the researchers used China’s passenger vehicle fleet as an example for evaluating the effects of autonomous vehicle deployment on greenhouse gas emissions in different scenarios of autonomous vehicle penetration rates and fuel consumption changes. They conducted a comprehensive literature review to support the study.

Sensitivity analysis of the changes in the fully AV VMTs, AV fuel consumption rates and GHG emissions. Liu et al.

As more companies join the AV technology competition, AVs are considered a new way to change people’s lives and mobility choices. Meanwhile, the energy consumption levels and GHG emissions of passenger vehicles have drawn much attention. AVs will bring changes in vehicle ownership, travel distance, fuel economy, etc. Though AVs will provide a convenient mobility choice for people, as one fully AV may replace several cars, it will still take a long time to eliminate car ownership, especially in China. Therefore, a conservative prediction is assumed in this article. The assumptions of the changes in vehicle sales and travel distances are not aggressive. The travel distance per vehicle and fuel economy will play important roles in the final results.

… Based on the existing research, passenger vehicle fleet GHG emissions are calculated in China with AV deployment. By aligning the changes caused by AVs and passenger vehicle fleet GHG emissions, the results indicate that the introduction of AVs does not lead to GHG emission reductions before 2050. With higher fuel consumption rates, AVs may even lead to more emissions in most cases. Although the increase is not large in absolute terms, in terms of the relative magnitude, the increase can even reach 14.1%. With a better fuel economy, after 2045, a larger share of AVs in the passenger vehicle fleet can begin to show the advantages of AVs in GHG emission reduction. A long-term plan for AVs may have a better result. Passenger vehicle fleets with different deployments of partially AVs will not show significantly different results.

—Liu et al.

Resources

• Feiqi Liu, Fuquan Zhao, Zongwei Liu, Han Hao (2019) “Can autonomous vehicle reduce greenhouse gas emissions? A country-level evaluation,” Energy Policy, Volume 132, Pages 462-473 doi: 10.1016/j.enpol.2019.06.013