PERFORMANCE CHARACTERISTICS OF AN ULTRASONIC DETECTOR FOR MEASUREMENTS OF VEHICLE OCCUPANCY

The article describes calibration performance tests carried out on a chekar usd-scp ultrasonic traffic detector used for the measurement of vehicle occupancies. The tests showed that errors in individual detector readings were several times greater than those predicted by theory based on the mode of operation of the detector and that, on average, some 6.5 per cent of vehicles were undetected during the observation periods. Whilst it is possible to correct for these factors in calibration, the random nature of these errors means that it is necessary to measure occupancies with a sample size of at least 50 vehicles if the overall error is not to exceed 10 per cent with 95 per cent confidence. (A) /TRRL/

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  • Corporate Authors:

    Printerhall Limited

    29 Newmart Street
    London W1P 3PE,   England 
  • Authors:
    • Ashworth, R
    • Kentros, A
  • Publication Date: 1976-12

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00153308
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: Analytic
  • Files: ITRD, TRIS
  • Created Date: Sep 20 1977 12:00AM