The APRAC-1A urban diffusion model computer program is described which estimates concentrations of carbon monoxide resulting from the emissions from a traffic network at specified receptor locations under specified weather conditions. Required input for the model includes emission factors, traffic distribution, and meterological data. An option of the model allows estimates of the street canyon effect. Use of the model for developing isopleth contour maps is made possible by means of the grid point mode in which estimates for a given hour of the day are made at a large number of receptor locations. Details of receptor spacing, traffic input data, and weather are discussed, and comments are made on the application of the model, and data processing considerations. A mobile emission inventory model that integrates traffic emissions and other traffic information in a highly flexible technique is described. The model has been developed as a computer program called GRIDSUM. The importance of the cold-start correction and the trip-making process is discussed, and comments are made on automating computations.

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    • Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved. Presented at the Conference on the State of the Art of Assessing Transportation-Related Air Quality Impacts, Washington, D.C. October 22-24, 1975.
  • Corporate Authors:

    Transportation Research Board (TRB)

    Washington, DC   
  • Authors:
    • Ellis, George W
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  • Publication Date: 1976

Media Info

  • Media Type: Digital/other
  • Features: Figures; References;
  • Pagination: pp 152-162
  • Monograph Title: Assessing transportation-related air quality impacts
  • Serial:

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Filing Info

  • Accession Number: 00139659
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Sep 16 1976 12:00AM