Traffic dynamics in bi-modal urban networks: a cross-comparison of outflow 2D-NMFD and 3D-NMFD

Mansour Johari, Mehdi Keyvan-Ekbatani, D. Ngoduy

Research output: Contribution to journalArticleResearchpeer-review

7 Citations (Scopus)


Network macroscopic fundamental diagram (NMFD) has provided practical convenience to simulate network-level traffic dynamics using NMFD-based models. Nevertheless, only a few works have been conducted on traffic dynamics in bi-modal urban networks. This paper provides a comparison of the application of outflow 2D-NMFD and 3D-NMFD through simulating different scenarios using accumulation-based model in a single reservoir system. The models are verified using micro-simulation data as ground truth performed on a Manhattan-style grid network and a real network. The results reveal the outflow 2D-NMFD can provide accurate traffic state evolution, while the goodness of fit is the main challenge in the application of outflow 3D-NMFD. Besides, the accumulation-based model needs modifications to construct the bus accumulation profile in the test-bed with a low share of buses. Last but not least, the accuracy of the existing network-level speed models in mixed-traffic condition and its effects on traffic dynamics simulation are validated and discussed.

Original languageEnglish
Pages (from-to)555-585
Number of pages31
JournalTransportmetrica B
Issue number1
Publication statusPublished - 21 Jan 2022


  • 2D-NMFD
  • 3D-NMFD
  • bi-modal urban networks
  • macroscopic modelling
  • Traffic flow theory

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