Effect of Connected and Automated Vehicles on Disturbance Suppression in Mixed Traffic Flow: Spatial Distribution and Stability

Abstract

With the progressive integration of connected and automated vehicles (CAVs) into existing transportation systems, the characteristics of mixed traffic flow comprising CAVs and human‐driven vehicles (HDVs) undergo a profound transformation. However, the combined effects of the CAV penetration rate and spatial distribution on mixed‐flow performance have not been thoroughly investigated. To address this gap, this study develops a generalised modelling framework for mixed traffic, in which separate car‐following models are specified for HDVs and CAVs, and microscopic traffic simulations are carried out under traffic oscillation scenarios. The results demonstrate that increasing the penetration rate of the CAV markedly enhances the operational performance of the mixed flow. On this basis, the impact of CAV spatial distribution strategies is examined. Numerical experiments reveal that platoon‐based arrangements of CAVs are not globally optimal; notably, when HDV stability is poor, the performance gains of platooning are minimal, while a uniform distribution of CAVs yields superior suppression of traffic disturbances. These findings indicate that, in realistic mixed traffic environments, CAV deployment strategies should go beyond traditional platooning and explore more diversified spatial distribution patterns to optimise traffic flow performance.