Planting vegetation as an air quality mitigation strategy may be most useful along existing roadways.
Article summarizing the results of a 2010 EPA workshop Research Triangle Park, North Carolina on “The Role of Vegetation in Mitigating Air Quality Impacts from Traffic Emissions.” Workshop participants agreed that further exploration of the use of vegetative barriers to mitigate adverse air quality is worth pursuing; however, care must be taken in both communicating the potential benefits of such a program and implementing this approach as a mitigation strategy. This approach should be viewed as one component of a set of mitigation strategies that need to be considered in addressing near-road health concerns. Caution was expressed that near-road vegetation may be used for “green-washing,” justifying road expansion over transportation and urban design alternatives and reducing efforts to control vehicular emissions.
Participants also agreed that planting vegetation as a mitigation strategy may be most useful along existing roadways. For new and widened roadways, retaining existing vegetation is an important consideration. While vegetation within a highway’s right-of-way is frequently restricted for safety reasons, state departments of transportation use planting for other aims (e.g., erosion control) and measures on adjacent land may be feasible alternatives. (2011) Air & Waste Management Association magazine.