DEVELOPMENT OF PHOTOGRAPHIC TECHNIQUES FOR PERFORMING CONDITION SURVEYS

The objective of this study was to develop a technique for surveying heavily trafficked highways that is compatible with a visual condition survey but does not restrict the flow of traffic. Because of the need to be able to conduct a survey at a speed of at least 30 miles per hour (48 km/h), the possibility of utilizing photographic techniques was investigated. Accuracy, speed, and reasonable cost are important criteria for a successful condition survey on urban highways. Previous studies showed that only a few important distress types need to be surveyed and that sections can be selected from a construction project for a condition survey without a sacrifice in the quality of the results. It was found that by mounting a camera with a shutter speed of up to 1/2000 second and capable of taking 4 to 5 frames per second on a boom hanging in front of a vehicle so that the line through the camera lens is perpendicular to the road surface, a birdseye view of the distress can be seen on film. By adjusting the vehicle speed and equipment, a survey of condition of a CRCP pavement is possible. The difference is quality between a visual and a photographic survey is minimal with proper sampling. If a 300-ft (91.44-m) section of every mile is surveyed, the quality of the survey is still high and slight cost savings materialize. A cost study indicates that a photographic survey is more economical than a visual condition survey. Although the photographic survey is based on only a six percent coverage, there are the additional advantages that the mean crack spacing can be easily determined from the photographs and that visual records of the pavement condition can be obtained for future reference. The use of color film was also found to be beneficial. /Author/

  • Supplemental Notes:
    • Sponsored by Texas State Department of Highways and Public Transportation and performed in cooperation with DOT, Federal Highway Administration.
  • Corporate Authors:

    University of Texas, Austin

    Center for Highway Research, 200 West 21st Street
    Austin, TX  USA  78712
  • Authors:
    • STRAUSS, P
    • LONG, J
    • McCullough, B F
  • Publication Date: 1977-5

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 29 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00178336
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-TX-78-17710 Intrm Rpt., FCP 45D2-424
  • Contract Numbers: Res Study 3-8-75-177
  • Files: TRIS
  • Created Date: Jul 29 1978 12:00AM