A multi-class first-order traffic flow model to explain the disordered behaviour of vehicles

Abstract

Disordered traffic streams are generally characterised by the presence of numerous vehicle classes having different sizes and operational characteristics. Unlike homogeneous traffic flow, smaller vehicles percolate between the bigger ones, invalidating the lane discipline and therefore requiring a different modelling approach. Each vehicle traverses through a series of opportunities created by other vehicles that are not only viable but also accessible, thus defining a permeable medium. Our objective is to develop an analytical traffic flow model that quantifies such opportunities for individual vehicle classes to traverse downstream. Equilibrium speed functions have been redefined based on a new metric termed as traversable distance. The inter-class flow dynamics of small-sized vehicles has further resulted in a significant reduction in their travel time. © 2021 Hong Kong Society for Transportation Studies Limited.