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Median Barriers on Undivided Roadways | Safe Design

Median Barriers on Undivided Roadways

Image Source: FHWA

DEFINITION AND DESCRIPTION

Median barriers separate opposing traffic and reduce head-on crashes. In the U.S., median barriers on undivided roadways are uncommon; however, other countries (e.g., Sweden) have used them with positive results. Examples include cable barrier and double-faced guardrail.  Some State DOTs in the U.S. are piloting cable barrier in narrow medians.

Implementation Categories

Area(s) Design & Geometrics, HSIP, Operations & Maintenance
Safety Category 1

CONSIDERATIONS

  • Several barrier types may be used in the median. Sweden uses a solid steel barrier, which has lower maintenance costs than the cable barrier.
  • A median barrier would need to start and stop at intersections. It is easier to install on roads with partial access control or limited access points. In other countries median barriers are used on 2+1 roadways.
  • Barrier deflection caused by a vehicle may encroach into the opposing lane of traffic. However, if another vehicle is present in the other lane, the speed of the vehicle striking the barrier would be reduced from an unmitigated head-on collision and the impact would generate less kinetic energy.

APPLICATION

  • May be used on undivided roadways with buffered centerlines and partial access control or limited access points.  

example

Image Source: New Zealand Transport Agency

complementary Countermeasures

REFERENCES AND RESOURCES

FHWA. Safe System Approaches to Reduce Head-On Crashes. 2024 TRB International Roadside Safety Conference presentation.

Mohn, T. Road Innovation from Sweden Saves Lives Around the Globe. 2020, April 2. Forbes. https://www.forbes.com/sites/tanyamohn/2020/03/31/road-innovation-from-sweden-save-lives-around-the-globe/

Vedeby, A. Traffic Safety Effects of Narrow 2+1 Roads with Median Barrier in Sweden. 2016. Swedish National Road and Transport Research Institute. https://www.diva-portal.org/smash/get/diva2:920845/FULLTEXT01.pdf

Do you have more questions? Get in touch!

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CONTACT:

Jill Asher

Research Engineer 

jill.asher@uky.edu