An experimental instrumentation system for monitoring long lengths of traffic railings to detect encroaching vehicles and measuring impact conditions has been developed and subjected to preliminary evaluation. The system makes use of the traffic railing as part of a transmission line carrying two radiofrequency waves. The radiofrequency energy reflected from vehicles entering the electromagnetic field about the line is detected and used to determine vehicular speed, direction, angle, location, path and size. A solid-state, digital data acquisition system is triggered by a detected encroachment to record pertinent data. Capability to record data on up to 50 encroachments is available. Computer data processing generates plots of vehicle path and tabulates data on time, speed, angle, location of encroachment, vehicle size and nature of encroachment. The system is packaged to be suited for unattended roadside installation and will operate continuously from a self-contained 12 V battery for periods of up to 10 days without servicing.

  • Supplemental Notes:
    • See also PB81-235160.
  • Corporate Authors:

    Southwest Research Institute

    6220 Culebra Road, P.O. Drawer 28510
    San Antonio, TX  United States  78228-0510

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • King, J D
    • CERWIN, S A
  • Publication Date: 1981-5

Media Info

  • Pagination: 152 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00344406
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FHWA/RD-80/175, SwRI15-4017
  • Contract Numbers: DOT-FH-11-8498
  • Files: NTIS, USDOT
  • Created Date: Nov 23 2003 12:00AM