Pedestrian Counting Methods at Intersections

Resources for implementing countermeasures to reduce pedestrian collisions in urban centers are usually allocated on the basis of need, which is determined by risk studies. Risk studies commonly rely on the determination of pedestrian volumes at intersections. The methods used to estimate pedestrian volumes include direct counts and surveys, but few studies have addressed the accuracy of these methods. This paper investigates the accuracy of three common counting methods: manual counts with sheets, manual counts with clickers, and manual counts with video cameras. The counts took place in San Francisco, California. For the analysis, the counts obtained with video images were assumed to represent the actual pedestrian volumes. The video recordings were made at the same time as the clicker and sheet counts. The results indicate that manual counts with either sheets or clickers systematically underestimated pedestrian volumes. The error rates ranged from 8% to 25%. Additionally, the error rates were greater at the beginning and at the end of the observation period, possibly because of the observer's lack of familiarity with the tasks or fatigue.