Impact of urban morphology on vehicular pollutant dispersion: a modelling and experimental approach in the city of Lecce (Italy)

This study, conducted within the framework of the PNRR Italian National Centre for Sustainable Mobility CNMS (European Union – Next Generation EU - PNRR – MISSIONE 4 – COMPONENTE 2- INVESTIMENTO 1.4 – Spoke 7 - Code CN00000023, CUP: F83C22000720001), investigates the impact of urban morphology on the dispersion of vehicular pollutants, specifically nitrogen dioxide (NO₂) and particulate matter ≤10 µm (PM₁₀). The aim is to analyse pollutant concentration patterns in areas characterised by different urban forms and to evaluate potential strategies for improving air quality in sensitive locations such as school environments.

The primary phase of this study focuses on the city of Lecce, integrating modelling with ADMS-Roads, QGIS elaborations and meteorological analyses to estimate pollutant dispersion under varying urban morphologies. In this initial phase, traffic data is kept constant for consistency. The preliminary modelling results indicate a strong influence of urban morphology on the dispersion of traffic-related pollutants. Urban forms characterised by a low planar area index (λ_p) have been observed to lead to increased NO₂ and PM₁₀ levels, with concentrations decreasing in areas with higher λ_p.

In addition to modelling efforts, experimental measurement campaigns will be carried out near two schools in Lecce to assess real-world pollutant concentrations. These campaigns will employ an air quality monitoring station, a meteorological station and a traffic-counting camera. The meteorological and traffic flow data collected will enable the reproduction of real scenarios in ADMS-Roads and will be used to validate the model through comparison with measured air quality data and enabling future scenario simulations that assessmitigation measures to reduce traffic-related emissions. This, in turn, will improve air quality in sensitive areas such as school environments.