Analysis of Air Pollution from Vehicle Emissions for the Contiguous United States

Road transport remains a significant contributor to air pollution, particularly in the form of nitrogen oxides (NO_x). Using multiple data sources to offer a comprehensive perspective on air pollution from vehicles, this study explores the spatial distribution of NO_x emissions associated with the United States (US) interstate highway system. The study integrates satellite data from the TROPOspheric Monitoring Instrument (TROPOMI), emission inventories from the Emissions Database for Global Atmospheric Research (EDGAR), and traffic data from the Motor Vehicle Emission Simulator (MOVES) to map and quantify pollution along major highways. TROPOMI’s high spatial resolution allows for the detection of NO₂ vertical column densities (VCD) over highways and urban areas, while EDGAR provides a detailed inventory of emissions across the United States. MOVES simulates emissions from mobile sources, offering insight into the impact of vehicle type and usage on air quality. The study found that the highest NO₂ VCD was recorded on the west and east coasts of the country where the largest metropolitan areas are located, with readings ranging from 100 to 300 μmol/m². Results indicate a strong correlation between traffic volume and NO_x emissions, with higher NO₂ levels concentrated along these coasts. This trend underscores the need for continued policy efforts to mitigate emissions from road transport, focusing on areas with the highest traffic density. The study’s multi-source approach provides valuable findings for policymakers, aiding in the development of targeted emission reduction strategies to address air quality concerns in densely populated regions. The significant contribution of the transportation sector to these emissions underscores the importance of addressing vehicle-related pollution to improve air quality and public health.