Improving Truck and Speed Data Using Paired Video and Single-Loop Sensors

Real-time speed and truck data are important inputs for modern freeway traffic control and management systems. However, these data are not directly measurable by single-loop detectors. Although dual-loop detectors provide speeds and classified vehicle volumes, there are too few them on our current freeway systems to meet the practical needs of advanced traffic management systems. This makes it extremely desirable to develop appropriate algorithms to calculate speed and truck volume from single-loop outputs or from video data. To obtain quality estimates of traffic speed and truck volume data, several algorithms were developed and implemented in this study. These algorithms are (1) a speed estimation algorithm based on the region growing mechanism and single-loop measurements; (2) a set of computer vision-based algorithms for extracting background images from a video sequence, detecting the presence of vehicles, identifying and removing shadows, and calculating pixel-based vehicle lengths for classification; and (3) a speed estimation algorithm that uses paired video and single- loop sensor inputs. These algorithms were implemented in three distinct computer applications. Field-collected video and loop detector data were used to test the algorithms. Our test results indicated that quality speed and truck volume data can be estimated with the proposed algorithms by using single-loop data, video data, or both video and single-loop data. The Video-based Vehicle Detection and Classification (VVDC) system, based on proposed video image processing algorithms, provides a cost-effective solution for automatic traffic data collection with surveillance video cameras. For locations with both video and single- loop sensors, speed estimates can be improved by combining video data with single-loop data.

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  • Corporate Authors:

    Washington State Transportation Center

    University of Washington, 1107 NE 45th Street, Suite 535
    Seattle, WA  United States  98105

    Washington State Department of Transportation

    Transportation Building, 310 Maple Park Avenue SE, P.O. Box 47300
    Olympia, WA  United States  98504-7300
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  • Publication Date: 2006-12


  • English

Media Info

  • Media Type: CD-ROM
  • Edition: Final Research Report
  • Features: Figures; Photos; References; Tables;
  • Pagination: 128p

Subject/Index Terms

Filing Info

  • Accession Number: 01046414
  • Record Type: Publication
  • Report/Paper Numbers: WA-RD 656.1
  • Contract Numbers: Agreement T2695 Task 61
  • Created Date: Apr 13 2007 8:13PM