A lattice model of reduced jamming by barrier

TL;DR

This paper investigates how a solid barrier affects particle flow in a lattice model, revealing non-monotonic residence time behavior and potential ways to reduce jamming in crowded environments.

Contribution

It introduces a lattice model with a barrier that demonstrates non-monotonic residence time and proposes simplified models to understand obstacle effects on transport.

Findings

Non-monotonic residence time as a function of barrier length

Faster-is-slower effect observed in the model

Barrier can reduce jamming and fluidize transport

Abstract

We study an asymmetric simple exclusion process in a strip in the presence of a solid impenetrable barrier. We focus on the effect of the barrier on the residence time of the particles, namely, the typical time needed by the particles to cross the whole strip. We explore the conditions for reduced jamming when varying the environment (different drifts, reservoir densities, horizontal diffusion walks, etc.). Particularly, we discover an interesting non--monotonic behavior of the residence time as a function of the barrier length. Besides recovering by means of both the lattice dynamics and mean-field model well-known aspects like faster-is-slower effect and the intermittence of the flow, we propose also a birth-and-death process and a reduced one-dimensional model with variable barrier permeability to capture qualitatively the behavior of the residence time with respect to the parameters. We report our first steps towards the understanding to which extent the presence of obstacles can fluidize pedestrian and biological transport in crowded heterogeneous environments.