Car-Following Interaction and the Definition of Free-Moving Vehicles on Two-Lane Rural Highways

This paper presents an investigation into car-following interactions on two-lane rural highways. Empirical data from several study sites on two-lane and four-lane rural highways in the state of Montana was used in this investigation. Three separate yet relevant analyses are presented in this paper. The first analysis involves a preliminary characterization of time headways and their distributions and shows how they are affected by passing restrictions on two-lane highways. The second analysis presented in this paper involves an investigation of speed-headway relationship to establish a headway threshold that could be used in defining free-moving vehicles on two-lane highways. The third and last analysis investigates the “following by choice” phenomenon on two-lane highways using data from two-lane as well as four-lane study sites. The study found that the car-following interaction generally ceases when headways exceed a value of approximately six seconds. Also, a significant proportion of drivers choose to maintain relatively short headways while following other vehicles on two-lane highways regardless of passing restrictions.

• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Al-Kaisy, Ahmed
  • Karjala, Sarah
• Conference:
  • Transportation Research Board 87th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2008-1-13 to 2008-1-17
• Date: 2008

Language

• English

Media Info

• Media Type: DVD
• Features: Figures; References; Tables;
• Pagination: 14p
• Monograph Title: TRB 87th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Car following; Four lane highways; Headways; Operations; Passing; Passing zones; Rural highways; Traffic platooning; Two lane highways; Types of roads by number of lanes; Vehicle spacing
• Geographic Terms: Montana
• Subject Areas: Administration and Management; Highways; Operations and Traffic Management; Planning and Forecasting; I72: Traffic and Transport Planning;

Filing Info

• Accession Number: 01099336
• Record Type: Publication
• Report/Paper Numbers: 08-2200
• Files: TRIS, TRB
• Created Date: May 21 2008 7:05AM