From individual behaviour to an evaluation of the collective evolution of crowds along footbridges

TL;DR

This paper develops a macroscopic crowd flow model based on microscopic observations, applied to footbridge pedestrian traffic, addressing inflow conditions, numerical methods, and parameter calibration for real-world engineering applications.

Contribution

It introduces a new macroscopic model derived from microscopic data and discusses practical issues like inflow conditions, numerical approximation, and parameter calibration.

Findings

Model accurately describes crowd flow on footbridges

Proposes solutions for inflow and boundary conditions

Provides calibration methods based on in situ data

Abstract

This paper proposes a crowd dynamic macroscopic model grounded on microscopic phenomenological observations which are upscaled by means of a formal mathematical procedure. The actual applicability of the model to real world problems is tested by considering the pedestrian traffic along footbridges, of interest for Structural and Transportation Engineering. The genuinely macroscopic quantitative description of the crowd flow directly matches the engineering need of bulk results. However, three issues beyond the sole modelling are of primary importance: the pedestrian inflow conditions, the numerical approximation of the equations for non trivial footbridge geometries, and the calibration of the free parameters of the model on the basis of in situ measurements currently available. These issues are discussed and a solution strategy is proposed.