Bounded Acceleration Capacity Drop in a Lagrangian Formulation of the Kinematic Wave Model with Vehicle Characteristics and Unconstrained Overtaking

In this contribution a model-based analysis of the application of bounded acceleration in traffic flow is considered as a cause for the capacity drop. This is performed in a Lagrangian formulation of the kinematic wave model with general vehicle specific characteristics. Unconstrained overtaking is presumed, which allows a demonstration to be given of the influence that constraints in traffic flow may have on the capacity drop. An experimental case demonstrates that bounded acceleration in traffic flow with unconstrained overtaking has very limited effect on the capacity drop. This implies that the capacity drop when incurred through bounded acceleration must make use of (semi-)constrained traffic flow, in which variety in vehicle acceleration ability may also be required to increase inhomogeneity. This is an important conclusion as it further defines the conditions required for capacity drop. The application of a Lagrangian formulation with advection invariant combined with bounded acceleration is also novel. The contribution further shows that the application of bounded acceleration in the presented model is feasible, although adjustments are required to capture the capacity drop through bounded acceleration.