The Relationship between Hysteresis and String Stability in Traffic Flow. A Simulation-Based Investigation

In this paper a preliminary analysis concerning the relationship between string stability and traffic hysteresis phenomena is presented. The possible implications in terms of safety and capacity drop are analyzed, in order to support the design and evaluation of automated driving strategies. The authors investigate platoons of vehicles reacting to a perturbation in velocity induced by the leader. The Intelligent Driver Model (IDM) is the car-following model adopted and 1000 combinations of the IDM parameters are considered. The results show that in case of instability, hysteretic platoons are identified every time. However, hysteretic string stable platoons are also detected. The authors find that the cases related to significant dampening of the oscillation produce poor flow, implying a reduction of the road capacity. The effect of each IDM parameter is studied and the results agrees with the theory that the hysteresis can be explained by the coexistence of timid and aggressive drivers. Finally, minimum values of time to collision and actual time headway are considered in order to evaluate the safety level. The authors find that hysteresis may lead to the emergence of unsafe situations, even for string stable platoons. In setting the requirements for future automated driving systems both string stability and traffic hysteresis should be considered to achieve a more efficient and safer traffic flow.

• Record URL:
  https://annualmeeting.mytrb.org/OnlineProgram/Details/15866
• Supplemental Notes:
  • This paper was sponsored by TRB committee ACP50 Standing Committee on Traffic Flow Theory and Characteristics.
• Corporate Authors:

  Transportation Research Board

  ,    
• Authors:
  • Albano, Giovanni
  • Mattas, Kostantinos
  • Ciuffo, Biagio
• Conference:
  • Transportation Research Board 100th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2021-1-5 to 2021-1-29
• Date: 2021

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 14p

Subject/Index Terms

• TRT Terms: Autonomous vehicles; Car following; Drivers; Headways; Highway capacity; Highway safety; Hysteresis; Microsimulation; Traffic flow; Traffic platooning
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 01763956
• Record Type: Publication
• Report/Paper Numbers: TRBAM-21-02972
• Files: TRIS, TRB, ATRI
• Created Date: Feb 4 2021 10:57AM