A general survey is presented of the techniques by which the impact of highways on air quality may be measured and predicted. The processes by which air pollution emitted by moving vehicles is dispersed by atmospheric turbulence and transported by the wind are stated to be central to this problem. Application of mixrometeorological theory and experience shows that the Richardson number is the most important parameter governing turbulent dispersion. The major existing theories available for the development of air quality models are discussed. An analysis is presented of a typical highway air quality impact study that included a measurement program and the development of a model to predict air quality in 1990. It is concluded that the measurement program was inadequate to verify the model and that little confidence could be placed in the future air quality projection. Four general conclusions are as follows: The mixroclimate is an important key to the problem of highway air quality because it determines the ability of the atmosphere to disperse air pollution and is closely related to land use pattens; the Richardson number should be a standard part of any air quality measurement program; better and more comprehensive measurement programs should have a higher priority than the development of more complex air quality models; and more attention should be paid to the inherent properties of the models. /Author/

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 75-95
  • Monograph Title: Air pollution controls for urban transportation
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00157796
  • Record Type: Publication
  • ISBN: 0309021995
  • Files: TRIS, TRB
  • Created Date: Sep 28 1977 12:00AM