Scientists elucidate the emission mechanism of standardized driving behavior

Vehicle driving behavior is closely related to people's daily travel, and the resulting emissions have become an important source of air pollution. Previous studies have mostly discussed transport emission reduction control measures and expected effects from the perspectives of governments, policymakers, and automakers, but few studies have explored the long-term impact of driving behavior and its evolution on transport emissions from the driver's perspective. As the executor of driving behavior and the responsible person for transport emissions, research focusing on drivers can reveal the impact mechanism of driving behavior on transport emissions, advocate for low-emission driving behavior, enhance drivers' environmental awareness, and promote transport emission reduction and sustainable development.

Recently, Prof. CHEN Xiqun, vice dean of ZJUI and director of the Institute of Intelligent Transportation Systems at Zhejiang University, published a paper titled “Future reductions of China's transportation emissions impacted by changing driving behavior” as the corresponding author in the journal Nature Sustainability. The paper was selected as a highlight in the journal, elucidating the emission mechanisms of standardized driving behavior. Additionally, a research briefing titled “Impact of Aggressive Driving on Transport Emissions in China” was simultaneously published in the journal Nature Sustainability.

The subtle differences and evolutionary trends in daily driving behavior can have significant environmental impacts at the macro level. Focusing on micro driving behavior, the research team proposed the Standardized Driver Aggressiveness Index (SDAI)to classify and project drivers’ car-following behaviors.By analyzing datasets of micro vehicle trajectories in China from 2013 to 2021, they first predicted key related factors, including annual vehicle sales, vehicle electrification rate, and future Chinese vehicle emission standards. They subsequently estimated the additional vehicle emissions arising from aggressive driving in China from 2013 to 2050.Their results indicate that by 2050, the cumulative emissions linked to driving behavior that could be prevented will amount to 400.5 million tons of CO2. The findings highlight the importance of improving drivers' daily driving behavior as part of the solution to mitigate transport emissions and underline the urgent need for interventions that can lead drivers to adopting more sustainable driving behavior.

Fig. 1 Categorization of driver aggressiveness and prediction of changes in driving behavior.a, Typical vehicle trajectories of drivers categorized as calm, neutral or aggressive (left) as well as the corresponding deceleration and acceleration responses (top right), gap to preceding vehicle (bars; bottom right) and speed changes (lines; bottom right). Aggressive driving is characterized by intensive braking and acceleration during car following. b, Predicted changes in the number of each driver category in China until 2050.

The Editorial Team of Nature Sustainability commented that “We found this work an important addition to the literature as the role of human behavior in everyday practices is too often neglected but can have substantial sustainability implications. Here, the authors calculate the amount of emissions from driver behavior and project how much carbon emissions will be emitted based on current trends or could be avoided through behavioral changes.”

Source: Zhejiang University-University of Illinois Urbana-Champaign Institute (the ZJU-UIUC Institute or ZJUI)