Data describes the influence of vegetation growth on the barrier’s physical dispersion mechanisms, spatial decay of pollutant concentration at various growth stages, the influence of vegetation growth on the reduction of particles and tracer gas at extreme wind speeds, the Impact of vegetation growth on average concentration for various wind speeds and particle sizes, and the Influence of LAI, vegetation species, and LAD profile on pollutant reduction. This dataset is not publicly accessible because: Data belongs to Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA. It can be accessed through the following means: Contact K. Max Zhang at kz33@cornell.edu. Format: Medium sized format; no special equipment needed. This dataset is associated with the following publication: Hashad, K., B. Yang, J. Gallagher, R. Baldauf, P. Deshmukh, and M. Zhang. Impact of roadside conifers vegetation growth on air pollution mitigation. LANDSCAPE AND URBAN PLANNING. Elsevier Science Ltd, New York, NY, USA, 229: 0, (2023).