Some considerations on crowd Congestion Level

TL;DR

This paper explores the theoretical foundations and practical applications of the crowd Congestion Level (CL), analyzing its mathematical nature, proposing a related pure number, and validating findings through simulations and human experiments.

Contribution

It offers a new perspective on the mathematical nature of CL, proposes a related pure number, and provides empirical validation through simulations and human experiments.

Findings

Theoretical link between integral/differential definitions of CL

Proposal of a related pure number for CL

Empirical validation with simulated and human data

Abstract

The concept of (crowd) Congestion Level ($CL$) was introduced in Feliciani et al (Transportation Research, 2018) and presented at the PED 2018 conference by C. Feliciani. Following the PED presentation, along with appreciation for the novel contribution, a few interesting questions were raised, concerning the integral/differential nature of the definition of $CL$, and the possibility of defining a related pure number. In these short notes we are going, although with no attempt at rigour or formality, to present some considerations suggesting that the two problems are related, and providing a possible solution. Furthermore, using both theoretical arguments and analysis of simulated data in complex scenarios, we will try to shed further light on the meaning and applications of this concept. Finally, we analyse some results of an experiment performed with human participants in a ``crossing-flows'' scenario.