Looking ahead, future research directions include forecasting future exposure levels, scenario analyses such as electrification and demand reduction simulations, and quantifying health impacts associated with traffic-related air pollution. However, our study acknowledges several limitations, including the exclusion of emissions from roadways not covered by the HPMS dataset, which includes residential streets, rural roads, and potentially high-traffic routes like those leading to warehouses and ports. Additionally, our exposure estimates do not consider secondary emissions formed in the atmosphere, which pose broader regional air quality challenges. Addressing these complexities and limitations will be crucial for advancing effective policies and interventions aimed at improving air quality and achieving environmental justice in communities across the United States.