A Modified Cell Transmission Model Incorporating Capacity Drop at Merge Bottleneck Considering On-Ramp Flow

Abstract

Capacity drop is one of the most famous and confusing phenomena in the dynamic of motorway traffic and is closely related to the occurrence of congestion and the magnitude of travel delay. Traffic flow theory and traffic flow model play an important role in testing and developing efficient motorway traffic control strategies, while macroscopic models of the Lighthill-Whitham-Richards (LWR) type fail to reproduce the capacity drop. This paper proposes a modified Cell Transmission Model(CTM) based on the special contribution of on-ramp flow on the capacity drop to reflect the capacity drop at merge in the first-order traffic flow model. We calibrate and validate the presented model with real traffic data, the validation results show that this model is robust and capable to capture capacity drop phenomenon.