Patent ID: 7747041
Filing Date: 2010-06-29
Classification: G08G

Abstract:
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.