Through the Gloaming: Using Variable Speed Limits to Address Safety during Fog Events on I-77 in Virginia

There is a 12-mile section of Interstate 77 running through the mountains of southwestern Virginia that experiences severe fog events, causing several multi-vehicle chain-reaction crashes over the past 20 years. Agencies sometimes install countermeasures, such as weather advisory systems (WAS) and variable speed limits (VSLs) in order to mitigate safety concerns in areas where fog events are common. While WAS that include dynamic message signs (DMS) to relay weather information, speed advisories, and VSLs have been installed in many states and countries, there have been very few quantitative evaluations performed of these systems. When the Virginia Department of Transportation (VDOT) awarded a $7.5 million contract in 2014 to build a variable speed limit (VSL) system that posts speeds based on available visibility and observed real-time traffic conditions on I-77, an algorithm was used at each VSL location to determine what the posted VSL should be. Further details of the evaluation of this VSL are presented.

• Record URL:
  • https://www.roadsbridges.com/through-gloaming
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/11660022
• Authors:
  • Fontaine, Michael
• Publication Date: 2019-1

Language

• English

Media Info

• Media Type: Print
• Features: Figures; Maps; Photos; Tables;
• Pagination: pp 48-50
• Serial:
  • Roads & Bridges
  • Volume: 57
  • Issue Number: 1
  • Publisher: Scranton Gillette Communications
  • ISSN: 8750-9229
  • Serial URL: http://www.roadsbridges.com/rb/

Subject/Index Terms

• TRT Terms: Advanced traveler information systems; Algorithms; Case studies; Evaluation; Fog; Hazard mitigation; Traffic safety; Variable message signs; Variable speed limits; Visibility
• Identifier Terms: Interstate 77; Virginia Department of Transportation
• Geographic Terms: Virginia
• Subject Areas: Highways; Operations and Traffic Management; Safety and Human Factors;

Filing Info

• Accession Number: 01712508
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 26 2019 11:50AM