Suggested Citation:
Baldauf, Richard, Greg McPherson, Linda Wheaton, Max Zhabg, Thomas A. Cahill, Chad Bailey, Christina Hemphill-Fuller, Earl Withycombe, Kori Titus (2013) Integrating Vegetation and Green Infrastructure into Sustainable Transportation Planning. Transportation Research Board 2013, 14 - 18

International consensus has emerged that people living, working, and going to school near high-traffic volume roads face increased risks for a number of adverse health effects.(1)  These health effects have been attributed to acute and chronic exposures to elevated levels of air pollution near these roads, including particulate matter (PM), gaseous criteria pollutants, and air toxics.  Field measurements conducted throughout the world, including the U.S., have shown highly elevated air pollution levels near high volume roadways.(2)  Pollutant concentrations are often highest within the first 100-150 meters, with increased concentrations of some pollutants as much as an order of magnitude.  Pollutant concentrations from traffic emissions can remain elevated 300-500 meters or more from the road.(1,2) Evidence exists that roadside vegetation barriers have the potential to improve near-road air quality, and positively affect public health for populations spending significant amounts of time near high volume roadways.  Although questions still remain on the optimum design features of effective vegetation barriers, our current scientific understanding warranted the initiation of pilot studies to further investigate this potential air quality mitigation strategy. Three-dimensional modeling of PM transport and deposition in roadside barriers combined with field monitoring and verification studies are contributing valuable new knowledge to the design and management of effective barriers.