A stochastic optimal velocity model and its long-lived metastability

TL;DR

This paper introduces a stochastic cellular automaton traffic model that extends existing exactly solvable models, revealing multiple stable states and metastability phenomena in traffic flow dynamics.

Contribution

It presents a novel stochastic extension of the optimal velocity model, demonstrating coexistence of multiple stable states and metastability in the fundamental diagram.

Findings

Multiple stable states coexist at the same density.

Long-lived metastable states are observed.

Sharp transitions occur between metastable states.

Abstract

In this paper, we propose a stochastic cellular automaton model of traffic flow extending two exactly solvable stochastic models, i.e., the asymmetric simple exclusion process and the zero range process. Moreover it is regarded as a stochastic extension of the optimal velocity model. In the fundamental diagram (flux-density diagram), our model exhibits several regions of density where more than one stable state coexists at the same density in spite of the stochastic nature of its dynamical rule. Moreover, we observe that two long-lived metastable states appear for a transitional period, and that the dynamical phase transition from a metastable state to another metastable/stable state occurs sharply and spontaneously.