The Impact of Density Measurement on the Fundamental Diagram

Abstract

With the increasing demand for crowd simulations, validation and verification of the simulation becomes more important. As simulations often concern the safety of real persons it is critical that the simulated behavior is validated to be comparable to behavior of real people. Validation is often done by comparison to the pedestrian fundamental diagrams. These diagrams capture the relation between speed, density and flow in a crowd. However, many conflicting versions of these diagrams exist. Furthermore, the methods used to measure density and flow differ between papers.

In this work we take a critical look at existing density measurement methods. We compare the classic method, a Gaussian-based, and a Voronoi-based method with one another in multiple scenarios. Results show that each of these methods has different strengths and weaknesses, depending on the environment. By using video data from a real crowd to create fundamental diagrams, we show that choice for a measurement metric has a large impact on the resulting diagram. Results indicate that a measurement metric should be chosen carefully, as it directly influences reliability of the validation.

This project was conducted as part of a collaboration between Utrecht University and Movares Nederland B.V. and has been supported by the COMMIT/ project (http://www.commit-nl.nl/).