A dynamic mesoscopic network loading model for spillback queuing assessment

Traffic flow modelling is the most significant component undertaken by the static and dynamic network loading models in the traffic assignment. In particular, dynamic network loading models represent the fundamental element in estimating the dynamic interaction between demand and supply in oversaturation conditions. In this context, when traffic conditions get worse, queue spillback evaluation is necessary to prevent gridlocks and excessive delays. To this aim, this paper proposes a novel dynamic spillback model based on a mesoscopic network loading model using the Greenshields speed-density relationship. We introduce a link-based model where the dynamic spillback of the queue is explicitly simulated. The proposed model is applied to a simple network for easily assessing the spillback impact. Moreover, a comparison with a commercial traffic simulator is provided to highlight the effectiveness of the proposed model in oversaturation conditions.