A regional air quality impact assessment screening tool based upon MOVES-Matrix and AERMOD

In air quality impact analysis, screening models are often applied to assess whether more detailed and labor-intensive modeling is required. The screening model estimates the impacts of a “worst case” analysis and if no potential air quality impacts are estimated, it can be assumed that a more refined analysis with detailed data is not needed. This reduces the need to obtain high-resolution meteorology data, fleet composition data, on-road operating condition data, etc. This study presents a user-friendly and computationally efficient methodology for regional-scale air pollutant concentration screening modeling based on the MOVES-Matrix and the dispersion model AERMOD, thus allowing users to quickly evaluate multiple alternatives. The methodology allows the entire region to be quickly evaluated. During the development of this air quality impact assessment screening tool, Atlanta, Georgia was used as the case study. The team connected MOVES-Matrix directly with the Atlanta Regional Commission’s (ARC) Activity-Based Model 2015 (ABM15) outputs (for vehicle miles traveled, speeds, etc.) and a simplified AERMOD dispersion model approach to predict pollutant concentration profiles at a high-spatial resolution (15 meters) using the PACE supercomputing cluster. The research team utilized AERMOD creating the equivalent of a line-source model for the entire metropolitan area. The sensitivity analysis suggests that the total amount of PM2.5 emissions in the study area may vary depending on traffic and meteorology conditions. For example, the total emissions vary by seasonal variations in vehicle miles traveled and surface temperature. The dispersion analysis could help easily figure out which regions in Atlanta area are likely to be worse in air quality. The case study shows that in certain conditions of heavy traffic and bad meteorology conditions, some regions in Atlanta area may suffer from high PM2.5 concentrations. The regional screening tool speed and efficiency should be of interest to a broad readership including those interested in vehicle emission modeling, near-road air quality modeling, transportation conformity analysis, state implementation plan development, and transportation and air quality regulatory analysis.