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T1- Calibration of volume-delay functions using travel time data from TomTom

Johan Olstam and David Gundlegård

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Volume delay functions

  • Used in Static Traffic Assignment models (like Visum & Emme) to describe travel time as a function of travel demand
  • Common parameters
    • Free flow travel time
    • Capacity
    • Delay increase per increased flow unit
  • Different road categories

T1- Calibration of volume-delay functions using travel time data from TomTom

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AUGUST 31, 2026

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Calibration of Volume delay functions

  • Commonly using cross-sectional flow and speed data
  • Travel time data (Inrix, TomTom, etc.) give new possibilities to e.g. estimate free flow travel time per link
  • However, it requires map matching TomTom travel times to the Visum network

T1- Calibration of volume-delay functions using travel time data from TomTom

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AUGUST 31, 2026

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Aim and activities

Aim

  • Calibrate the Norrköping Visum model using TomTom travel time data.

Activities

  • Mapping TomTom links to Visum links
  • Compare Visum produced flows and travel times with TomTom data
  • Estimate suitable free flow travel times
  • Update free flow travel time parameters in Visum and compare the updated Visum produced flows and travel times with TomTom data

T1- Calibration of volume-delay functions using travel time data from TomTom

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AUGUST 31, 2026

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Johan Olstam

Johan.olstam@liu.se

www.liu.se