Validating Traffic Flow-detectors using Manual Counting from Video Data (FAST Freeway Flow Detectors Verification)

According to the FAST/NDOT inter-local agreement for the freeway management system (FMS) scope of service, traffic volumes from freeway flow detectors (FDD) need to be compared and verified. The total lane-by-lane traffic counts need to be verified to assure that the FDD is properly aligned and calibrated. This Scope of work outlines tasks for the implementation of traffic count verification for the freeway flow detectors on segments of I-15, US-95 and CC 215. FAST provided traffic counts and corresponding videos of traffic flow extracted from the FMS database and freeway surveillance videos of the same time periods and locations to be verified. The University of Las Vegas (UNLV) Transportation Research Center (TRC) verified the traffic counts (lane-by-lane) from the videos. Data analysis was applied to the traffic counts and verification, and this report was generated to document the verification results. This report provides various methods for analysis and hypothesis testing for paired data where one source of data has to be tested against a noisy source for validation. In this work, traffic counts for some highway locations obtained from flow detectors have to validated against the data obtained by manual counting of video data obtained from those sites. However, the video data has various levels of clarity that is recorded by the human observers, and hence a technique that performs validation with such recorded noisy data is needed. The various techniques that have been developed include weighted percent difference test, and combined variance test. The techniques are applied to the sample data and results presented. The research obtained the mean percent difference between the detector data and the normalized observed data to be 0.858%, and the 95% confidence interval for the mean to be (0.855%, 0.860%).

  • Record URL:
  • Supplemental Notes:
    • Final report can be found at Other project information can be found at


  • English


  • Status: Completed
  • Contract Numbers:


    PO 4500136999-401

  • Sponsor Organizations:

    Research and Innovative Technology Administration

    ITS - Joint Program Office
    1200 New Jersey Avenue, SE
    Washington, DC    20590

    Regional Transportation Commission of Southern Nevada

    600 S Grand Central Pkwy
    Suite 350
    Las Vegas, NV  United States  89106
  • Project Managers:

    Shlayan, Neveen

  • Performing Organizations:

    Transportation Research Center

    University of Nevada, Las Vegas
    4505 Maryland Parkway, MS 4007
    Las Vegas, NV  United States  89154
  • Principal Investigators:

    Kachroo, Pushkin

  • Start Date: 20100515
  • Expected Completion Date: 0
  • Actual Completion Date: 20100630
  • Source Data: RiP Project 28308

Subject/Index Terms

Filing Info

  • Accession Number: 01467992
  • Record Type: Research project
  • Source Agency: Transportation Research Center
  • Contract Numbers: DTRT06-G-0034, PO 4500136999-401
  • Files: UTC, RiP, USDOT
  • Created Date: Jan 3 2013 3:43PM