Time Gaps in Work Zones Based on Follower-Leader and Under Various Temporary Traffic Control Methods

Time gaps are microscopic flow characteristics related to driver behavior, traffic safety and capacity. Knowing time gap characteristics enables monitoring of traffic flow and taking appropriate safety measures, particularly in work zones. The objective of this study is to explore how mean time gaps change based on vehicle type and traffic control treatment in single-lane work zones. For this purpose, thirteen data sets that involved over 8250 vehicle observations were collected from six Interstate work zones in various traffic control conditions. In terms of vehicle type, trucks exhibited significantly greater mean time gaps than cars, possibly due to longer stopping distance they require compared to passenger cars. Besides, in nearly half of the data sets, the mean time gaps of trucks following cars were significantly greater than trucks following other trucks. Hence, the time gap preference of the truck drivers differed significantly based on the vehicle type of their immediate leaders. On the contrary, such driving behavior was generally not observed in the car drives. Next, it is also essential to identify the effects of work zone traffic control treatments on time gaps. In this study, the effects of flagger and Police presence were explored. According to the results, the mean time gaps of all vehicle types increased significantly due to flagger presence. However, the mean time gaps of only cars following cars and trucks following cars increased significantly due to Police presence. So compared to Police presence, flagger presence had a more pronounced effect on spacing out vehicles, which led to a “safer” environment, but reduced number of vehicles processed.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AND10 Vehicle User Characteristics
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Avrenli, K A
  • Benekohal, R
  • Ramezani, H
• Conference:
  • Transportation Research Board 91st Annual Meeting
  • Location: Washington DC, United States
  • Date: 2012-1-22 to 2012-1-26
• Date: 2012

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 17p
• Monograph Title: TRB 91st Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Automobiles; Car following; Headways; Microscopic traffic flow; Trucks; Vehicle spacing; Work zone safety; Work zone traffic control
• Uncontrolled Terms: Time gaps
• Subject Areas: Highways; Operations and Traffic Management; Safety and Human Factors; I71: Traffic Theory; I73: Traffic Control;

Filing Info

• Accession Number: 01373769
• Record Type: Publication
• Report/Paper Numbers: 12-2658
• Files: TRIS, TRB
• Created Date: Jun 25 2012 2:53PM