A safety adapted car following model for traffic safety studies

Kaveh Bevrani, Edward Chung

Research output: Chapter in book / Conference proceedingChapter in an edited book (as author)Academic researchpeer-review


Traffic safety studies demand more than what current micro-simulation models can provide as they presume that all drivers exhibit safe behaviors. All the microscopic traffic simulation models include a car following model. This paper highlights the limitations of the Gipps car following model ability to emulate driver behavior for safety study purposes. A safety adapted car following model based on the Gipps car following model is proposed to simulate unsafe vehicle movements, with safety indicators below critical thresholds. The modifications are based on the observations of driver behavior in real data and also psychophysical notions. NGSIM vehicle trajectory data is used to evaluate the new model and short following headways and Time To Collision are employed to assess critical safety events within traffic flow. Risky events are extracted from available NGSIM data to evaluate the modified model against them. The results from simulation tests illustrate that the proposed model can predict the safety metrics better than the generic Gipps model. The outcome of this paper can potentially facilitate assessing and predicting traffic safety using microscopic simulation.

Original languageEnglish
Title of host publicationAdvances in Human Aspects of Road and Rail Transportation
PublisherCRC Press
Number of pages10
ISBN (Electronic)9781439871249
ISBN (Print)9781439871232
Publication statusPublished - 1 Jan 2012
Externally publishedYes


  • Behavioural modelling
  • Car following
  • Safety metrics
  • Simulation

ASJC Scopus subject areas

  • Engineering(all)


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