People Flow Monitoring

General about People Flow Monitoring

People flow rate represents the number of people passing through a certain passage per unit time. People flow sensor—also called a pedestrian or visitor counter—is a device capable of measuring people flow rate and often also the direction of passing people. The sensor is triggered by physical signals caused by the pedestrians like visual appearance, heat emission, reflections of the body surface, or pressure against the path (Bauer, Brandle, Seer, Ray, & Kitazawa, 2009).

Knowledge of the people flow sensor performance is important as the more reliable data a sensor provides, the better are the results of applications utilizing it (Cessford et al., 2002). Manual counting by human observers is tedious, expensive, and typically used only for a short period of time, making the results quite unreliable in general (Heikkilä & Silvén, 2004). Thus it is usually used only to check the accuracy of sensor-based counting. Sensor technologies have been widely tested for pedestrian and bicycle traffic counting and safety related presence detection (Bu, Greene-Roesel, Diogenes, & Ragland, 2007; Chan & Bu, 2005; Dharmaraju, Noyce, & Lehman, 2001; Diogenes, Greene-Roesel, Arnold, & Ragland, 2007; SRF Consulting Group, 2003). For presence detection purposes, the detection reliability of people in a certain area is often more important than counting every individual in the possible group or crowd. Previous people flow sensor comparisons have been mostly accomplished in the context of outdoor applications.