Travel times in quasi-dynamic traffic assignment

Paper authored by Jeroen P.T. van der Gun, Adam J. Pel and Bart van Arem in 2020.

Journal article published in Transportmetrica A: Transport Science, volume 16(3), pages 865–891 by Taylor & Francis in London, United Kingdom, ISSN 2324-9935.

Full text PDF available (2.75 MB)


By extending static traffic assignment with explicit capacity constraints, quasi-dynamic traffic assignment yields more realistic results while avoiding many disadvantages of dynamic assignment. We analyse the computation of travel times in quasi-dynamic assignment models. We formulate and check requirements for the correctness of resulting travel times, addressing both the calculation of travel times for individual routes and links itself, as well as the differences between travel times of different travel choices. We demonstrate that existing approaches for travel time computation in literature fail to satisfy all requirements and derive a new link travel time formula from vertical queuing theory that does meet all requirements. We discuss expected changes to assignment results and methodological advantages for pathfinding and model extensions, including horizontal queuing. The new link travel time formulation is finally applied to three example scenarios from literature.

Keywords: quasi-dynamic traffic assignment, link travel time, vertical queuing theory, capacity constraint, link performance function.

Citation: Van der Gun, J.P.T., Pel, A.J., Van Arem, B. (2020). Travel times in quasi-dynamic traffic assignment. Transportmetrica A: Transport Science, vol. 16(3), pp. 865–891. London, United Kingdom: Taylor & Francis. ISSN 2324-9935. doi:10.1080/23249935.2020.1720862