During the third year of the project, the main focus is on modeling for estimating atmospheric pollutant concentrations at the metropolitan and urban scale. Specifically, work continues on creating a new baseline case at the metropolitan scale to study pollutant concentrations in the city of Milan and its surrounding areas. By the end of the three-year research period, air quality simulations at the national and metropolitan scales will provide a solid reference for evaluating mobility policies at different spatial scales. Compared to previous RSE studies, the two simulations at the national and metropolitan scales have higher spatial resolution and are completely updated in terms of both the emission inventories used and the reference meteorological year. Furthermore, since air pollution is particularly problematic in densely populated urban areas, a third, more detailed modeling level has been introduced, based on the LPiG (Lagrangian Particle in Grid) sub-grid module. Compared to Eulerian-type models, LPiG allows for a more accurate spatial reconstruction of the physical and chemical phenomena related to road traffic. To fully exploit the potential of LPiG, an upstream modeling chain has been implemented, capable of directly incorporating road traffic data and managing emissions from this source using a bottom-up approach. This aspect covers both exhaust emissions from internal combustion vehicles and wear emissions from tires, brakes, and road surfaces, which affect all types of vehicles. Thanks to this new methodology, a scenario of electrification of the vehicle fleet in central Milan was analyzed. This scenario aligns with some of the objectives of the Air and Climate Plan (PAC), which aims to improve air quality and mitigate climate change.