A car-following framework for traffic instability and lane changes

TL;DR

This paper introduces a computational framework based on a car-following model to analyze traffic instability and lane-changing behavior, revealing critical reaction times for stability and the impact of psychological factors on lane changes.

Contribution

It extends Newell's classical model by identifying a vehicle-density-dependent critical reaction time and incorporates a psychology-based lane-changing mechanism.

Findings

Critical reaction time determines traffic stability.

Lane-changing behavior affects traffic load balancing.

More frequent lane changes marginally improve velocity.

Abstract

This paper develops a computational framework based on a car-following model to study traffic instability and lane changes. Building upon Newell's classical first-order car-following model, we show that, both analytically and numerically, there exists a vehicle-density-dependent critical reaction time that determines the stability of single-lane traffic. Specifically, perturbations to the equilibrium system decay with time for low reaction time and grow for high reaction time. This critical reaction time converges to Newell's original result in the continuum limit. Additionally, we propose a psychology-based lane-changing mechanism that builds a quantitative connection between the driver's psychological factor (frustration level) and the driving condition. We show that our stochastic lane-changing model can faithfully reproduce interesting phenomena like load-balancing of different lanes. Our model supports the result that more frequent lane changes only marginally benefit the driver's overall velocity.