Dynamic Queuing and Spillback in Analytical Multiclass Dynamic Network Loading Model

A new analytical multiclass dynamic network loading (DNL) model is proposed as part of a simulation-based dynamic traffic assignment (DTA) model. In contrast to many other proposed DNL models, this model explicitly deals with queuing and spillback without relying on link travel time functions as input. Different vehicle types (e.g., cars and trucks) are considered with different speeds. Use of link travel times is likely to under-or overestimate the true travel times in a dynamic model if queues are considered. The proposed DNL model consists of a link model and a node model. The link model computes queue inflows and potential outflows, whereas the node model determines the actual outflows depending on the node structure. In the end, the link travel times are computed backward in time for each vehicle type separately. The model has been implemented in the Indy DTA software, and an application shows that the approach is viable in real-life networks.