Air emission impacts of low-level automated vehicle technologies in U.S. metropolitan areas

Abstract Reduction of the transportation sector's air emissions has been an essential goal for decreasing the emissions' externalities and slowing climate change. This study evaluated the emission impacts of low-level automated vehicles (LAVs) in 86 metropolitan areas in the United States, based on county-specific emission costs of morbidity, mortality, and environmental damages. Twelve LAV technologies were investigated to estimate their impacts on CO2, CO, NOx, PM2.5, SOx, NH3, and VOC. The study analyzed the LAV technologies' direct and indirect emission impacts, including accident-related and non-accident-related congestion reductions, aerodynamic force reduction, the operational load of equipment, and traffic rebound. The results show that the LAV technologies could reduce the annual social costs of emissions by between 9 and 20 billion USD2019 in these metropolitan areas. This is equal to approximately 20% of the vehicles' emissions. A sensitivity analysis was performed on the technologies' market penetration rates (MPRs), demonstrating that the rate strongly influences the emission savings. This study revealed that LAVs' savings per vehicle-miles traveled (VMT) vary between areas, with the technologies performing differently in different areas due to both geographical factors (e.g., population) and technological factors (e.g., internal combustion engine performance). The study provides extensive resources for policymakers to develop targeted incentives and maximize the social benefits of the LAV technologies.