Simulation-Based Dynamic Traffic Assignment Modeling for Urban Expressway Network: A Case Study of Suzhou Expressway in China

Expressway networks undertake huge demands of urban travel, and its traffic condition directly influences the level of service of the urban road network. This study proposes the application of a simulation-based dynamic traffic assignment (DTA) model on Suzhou inner ring expressway network in China. The total length of the analyzed expressway network is 24.6 km with approximately 4,500 veh/h for each direction during peak hours in 2017. The model is implemented by DTALite, and the process of model building including data quality control, calibration of traffic flow parameters, time-dependent OD estimation, network preparation, model validity checking, and validation of model results. Validation results indicate that the DTA model can represent the time-dependent changing traffic conditions with acceptable accuracy. Results of the scenario test show that the model can represent and evaluate daily and special traffic conditions quantitatively and reliability.