Considerations for Green Infrastructure in Urban Transportation Planning and Right-of-Way Design to Improve Local Air Quality

Air pollution has been identified by the World Health Organization as one of the leading causes of illness and death in the world. In many cities, transportation facilities such as highways, rail-lines, ports and other freight movement corridors experience some of the highest air pollution levels. These transportation facilities are often located where people spend significant amounts of time living, working and going to school. Methods to reduce the impact of air pollution near large transportation sources are needed to improve public health. Roadside vegetation has been shown to impact air quality downwind of these sources, with some studies identifying reductions in air pollution concentrations and others indicating increases in pollutant levels when vegetation is present. These contradictory results can be confusing when one considers the capability of vegetative barriers to mitigate air pollution impacts. Studies have examined existing roadside vegetation (usually consisting of mixtures of trees and shrubs or plantings of individual trees) to better understand the impact of different types and conditions of vegetation barriers and urban forests. This presentation will summarize recommendations for roadside vegetation characteristics that can lead to improved local air quality, with some studies measuring concentration reductions as high as 50 percent. These recommendations also highlight vegetation characteristics to avoid for roadside applications in order not to degrade local air quality. These recommendations can be used by transportation and urban planners for improved right-of-way and urban street designs to improve local air quality. The presentation will also describe pilot projects using roadside vegetation to achieve air quality benefits.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee ADC60 Standing Committee on Resource Conservation and Recovery.
  • Corporate Authors:

    Transportation Research Board

  • Authors:
    • Baldauf, Richard
  • Conference:
  • Date: 2019


  • English

Media Info

  • Media Type: Digital/other
  • Features: Maps; Photos; References;
  • Pagination: 11p

Subject/Index Terms

Filing Info

  • Accession Number: 01697353
  • Record Type: Publication
  • Report/Paper Numbers: 19-01840
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 7 2018 9:25AM