Abstract Manager

A traffic simulation model is an essential tool to support evidence-based decision making for transportation planning and design projects. While traffic microsimulation models provide detailed traffic operational insights at an individual vehicle level for a set of intersections or a corridor, it is quite challenging to use the tool for network wide traffic operational assessments. To bridge this gap, transportation practitioners are getting more interested in mesoscopic simulation models based on Dynamic Traffic Assignment (DTA) methodology. The City of Edmonton (COE), using Bentley’s DYNAMEQ, had developed a city-wide mesoscopic model and assessed wide area traffic impacts resulting from various types of transportation infrastructure projects such as roadway/bridge widening, transit planning, and construction detour program.  

As an evolving technique, DTA modeling is sensitive to time-dependent network congestion and able to capture queue spillback delay. Therefore, prediction of traffic performance measures and flow diversion impacts due to network capacity and/or land use changes appear more credible in DTA. However, developing a DTA model for a large-scale urban transportation system also has several challenges. This presentation shares COE’s journey in developing a comprehensive DTA model for the entire city of Edmonton. It focuses on important concepts and challenges encountered during the development process, including estimating travel demand across space and time, fine-tuning route selection behaviors, and troubleshooting dynamic user equilibrium convergence issues during periods of heavy congestion.

Since its launch,  COE’s city-wide DTA model has been extensively used  for wide varieties of projects ranging from construction detour program to planning and designing transportation infrastructure projects at short-term and long-term horizons. Through case studies, the presentation showcases how the DTA model can effectively analyze both the network wide and localized traffic impacts along with the greenhouse gas emissions. Additionally, the presentation shares insights gained and lessons learned from the development and practical application of the city-wide DTA model.