Multiclass first-order simulation model to explain non-linear traffic phenomena

D. Ngoduy, R. Liu

Research output: Contribution to journalArticleResearchpeer-review

57 Citations (Scopus)


With the first-order traffic model of Lighthill, Whitham and Richard (LWR), many simple traffic problems can be represented analytically such as a shock formation. However, the LWR model has some deficiencies. For example, among the other things, it fails to replicate interesting non-linear phenomena such as hysteresis and capacity drop as well as the dispersion of traffic platoon when there exists a distribution of desired speeds in heterogeneous traffic. To this end, in this paper, we propose a novel multiclass first-order simulation model based on an approximation of Riemann solver. In the developed model, each vehicle class is only characterized by their desired speeds in a free-flow traffic state where overtaking is allowed. However, when traffic is congested, all vehicle classes must travel at the same congested speed and overtaking is not possible. Numerical results show that the proposed model is not only more accurate and reliable than the existing models but also able to explain non-linear traffic phenomena on freeways.

Original languageEnglish
Pages (from-to)667-682
Number of pages16
JournalPhysica A: Statistical Mechanics and its Applications
Issue number2
Publication statusPublished - 15 Nov 2007
Externally publishedYes


  • First-order model
  • Multiclass
  • Non-linear traffic phenomena
  • Traffic flow

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