U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
Many States are installing cable median barriers in locations where there is a high potential for crossover crashes. Studies in Washington State and North Carolina have shown substantial reduction in fatal and injury crashes compared to other types of median barriers. The FHWA recommends that States review median crossover crash histories to identify locations where median barriers may benefit safety, and consider use of cable median barriers where appropriate.
Suitable for use on flat or moderately sloped terrain, cable barriers deflect laterally to absorb collision forces and reduce the impact on vehicle occupants. Installation costs are relatively inexpensive compared to concrete and metal beam barriers, and repair and maintenance costs can be off set by safety benefits.
Cable barriers are ideal for retrofit application on existing median areas. Median crossover crashes tend to be severe, and median encroachments are likely to increase with higher traffic volumes. In the 2006 AASHTO Roadside Design Guide, chapter 6 update, the warrants for median barriers were revised to encourage use of barriers in medians of up to 50 feet wide. Most States that have installed cable median barriers report a decrease in cross-median crash fatalities of 90 percent or more. [M.H. Ray for Washington State DOT, 2007]
Source: Brifen USA, Inc.
Appropriate barrier selection and placement are critical to crash performance. Some key design considerations for cable barriers are discussed below.
Agencies should carefully review the FHWA eligibility letters on cable barriers systems for conditions and cautions that they should consider when designing roadside features. The AASHTO Roadside Design Guide is also a source of information that designers should use to help select and design barrier installations.
AASHTO's Technology Implementation Group Cable Median Barriers Website:
AASHTO-AGC-ARTBA Online Barrier Hardware Guide:
FHWA Crash Test Eligibility Letters for Longitudinal Barriers:
FHWA Corporate and Research Technology Web Site on Cable Barriers:
FHWA Information Memorandum: Cable Barrier Considerations. July 20, 2007:
Roadside Design Guide, AASHTO, 2006:
1 "Performance Evaluation of Low-Tension, Three-Strand Cable Median Barriers on Sloped Terrains," prepared by NCAC under contract to the FHWA, April 2007. [ Return to note 1. ]
2 "Analyses of Placement Effects on Cable Barrier Systems for Varying Median Cross Sections," prepared by NCAC under contract to the FHWA, June 2007. [ Return to note 2. ]