Automated estimation of average stopped delay at signalized intersections

  • US 7,747,041 B2
  • Filed: 09/23/2004
  • Issued: 06/29/2010
  • Est. Priority Date: 09/24/2003
  • Status: Active Grant
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First Claim
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1. A method for estimating an average stopped delay per vehicle at a signalized intersection, comprising:

  • initializing background intensities of a line of pixels in a background frame comprising a digital image of an actual traffic lane without vehicles, wherein the line of pixels extends along a path that vehicles travel down the traffic lane and wherein the line of pixels has a length that is sufficient to extend along a length of a plurality of vehicles within the traffic lane;

    identifying vehicle location through measuring differences between pixel intensity values along the line of pixels between the background frame and another digital image of the actual traffic lane with vehicles;

    calculating a stopped delay for each vehicle; and

    calculating the average stopped delay per vehicle;

    wherein calculating the stopped delay for each vehicle comprises monitoring a location of a front and rear of a vehicle between consecutive frames, calculating a speed and future position of the vehicle, determining whether the vehicle overlaps another vehicle, maintaining a division between the vehicles through a ratio of vehicle lengths before the vehicles were viewed as overlapping, determining the vehicle is stopped if the speed is below a specified stopping speed, and calculating a total stopped delay for the vehicle over consecutive frames.

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