Emissions Evaluation of CACC-Human Driven Mixed Traffic Considering the Degeneration of CACC System

The vehicle-to-vehicle (V2V) equipments on human-driven vehicles (HDVs) are absent nowadays, which requires the cooperative adaptive cruise control (CACC) degenerate to the adaptive cruise control (ACC) when V2V communication is not available. By using real experiments, California PATH program indicated that ACC vehicles are apt to be unstable at the present control level, which may have negative influence on traffic emissions. Hence, this paper studies the impacts of the mixed CACC-HDV traffic on emissions, by taking into consideration partial degenerations from stable CACC vehicles to unstable ACC vehicles. To deal with this, microscopic simulations were adopted by using car-following models. Then an appropriate emission model was used for evaluating the emission impacts under different CACC market penetration rates (MPRs). In order to obtain reliable evaluation results, the models validated by PATH program using real experimental data were employed as the CACC and ACC car-following models. In addition, the authors also analytically investigated string stability of the mixed traffic scenario under different CACC MPRs. The research results show that the emissions firstly increase and then decrease with the increase of the CACC MPR. This means the mixed traffic under some ranges of CACC MPRs will product more emissions, compared with the full HDVs traffic. It indicates that the string stability situations of the mixed traffic qualitatively influence the impact trend of CACC MPRs on the emissions.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee ADC20 Standing Committee on Transportation and Air Quality.
  • Corporate Authors:

    Transportation Research Board

  • Authors:
    • Qin, Yanyan
    • Wang, Hao
    • Ran, Bin
  • Conference:
  • Date: 2019


  • English

Media Info

  • Media Type: Digital/other
  • Features: References;
  • Pagination: 7p

Subject/Index Terms

Filing Info

  • Accession Number: 01698052
  • Record Type: Publication
  • Report/Paper Numbers: 19-00786
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 7 2018 9:45AM