Modelling the Impact of Rain in Traffic Assignment Procedures

  • Ivan IVANOVIĆ Faculty of Transport and Traffic Engineering, University of Belgrade
  • Nikola ČELAR Faculty of Transport and Traffic Engineering, University of Belgrade
  • Vladimir ĐORIĆ Faculty of Transport and Traffic Engineering, University of Belgrade
  • Dragana PETROVIĆ Faculty of Transport and Traffic Engineering, University of Belgrade
Keywords: rain impact, volume-delay function, transport model, traffic assignment


The efficiency of urban transportation system is un-der the influence of weather conditions. It is necessary to incorporate these impacts into transport system analysis, in order to prepare adequate mitigation measures. Trans-port models are often used in different types of transport system analysis and forecasting of its future characteris-tics. This paper focuses on implementation of the impact of rain in transport modelling, particularly into a traffic assignment process as a part of a macroscopic transport model. This aspect of modelling is important because it can indicate parts of the network where this impact leads to a high volume/capacity ratio, which is a good input for defining mitigation measures. Commonly, transport models do not consider weather impacts in its standard procedures. The paper presents a methodology for cali-brating volume-delay function in order to improve traf-fic assignment modelling in case of rain. The impact of different rain categories on capacity and free-flow speed was quantified and implemented in the volume-delay function. Special attention is given to the calibration of the part of volume-delay function for over-saturated traf-fic conditions. Calibration methodology is applicable for different types of volume-delay functions and presents a solid approach to incorporate weather conditions into common engineering practice.


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How to Cite
IVANOVIĆ I, ČELAR N, ĐORIĆ V, PETROVIĆ D. Modelling the Impact of Rain in Traffic Assignment Procedures. Promet [Internet]. 2022Feb.18 [cited 2022Aug.11];34(1):69-8. Available from: