Estimating AADT from Combined Air Photos and Ground Based Data: System Design, Prototyping, and Testing

Average annual daily traffic (AADT) is perhaps the most fundamental measure of traffic flow. The data used to produce AADT estimates are largely collected by in-highway traffic counters operated by traffic monitoring crews who must cover thousands of segments in their statewide systems on a continual basis. In addition to being costly, dangerous, and disruptive, the combination of limited resources and the large number of highway segments spread across the expansive geographic regions of the state requires that the state DOTs collect short-term sample volumes on a multi-year cycle. The authors have developed a method that combines the older, ground-based traffic data with traffic information contained in recent air photos in a statistically justified manner to produce more accurate estimates of AADT. To take advantage of this promising method in practice, it is necessary to develop an efficient way to use it on a widespread, repeated basis in an operational setting. The proposed work builds on previous efforts that led to conception, development, and preliminary testing of the estimation method. The authors designed the components of a software system that can be used to efficiently produce the improve AADT estimate, conducted empirical tests of the performance of the estimate, and worked toward gaining institutional acceptance for this novel estimation approach.

  • Record URL:
  • Supplemental Notes:
    • This document is disseminated under the sponsorship of the Department of Transportation, University Transportation Centers Program.
  • Corporate Authors:


    Purdue University
    3000 Kent Avenue
    Lafayette, IN  United States  47906-1075

    Research and Innovative Technology Administration

    Office of University Programs, 1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • McCord, Mark R
    • Goel, Prem
  • Publication Date: 2009-10-15


  • English

Media Info

  • Media Type: Print
  • Edition: Final Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 38p

Subject/Index Terms

Filing Info

  • Accession Number: 01149528
  • Record Type: Publication
  • Report/Paper Numbers: NEXTRANS Project No. 002OY01
  • Contract Numbers: DTRT07-G-005 (Grant)
  • Files: UTC, TRIS, USDOT
  • Created Date: Jan 15 2010 1:09PM