CABLE MEDIAN BARRIER

frizzflowerUrban and Civil

Nov 29, 2013 (3 years and 8 months ago)

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A Focus Technology of the

American Association of State Highway and Transportation Officials (AASHTO)

Technology Implementation Group (TIG)


CABLE MEDIAN BARRIER

Best Practices Guidelines

Cable Median Barrier

Share & Sponsor Technology Transfer


Promote Transportation Advancements


Encourage Implementation

Cable Median Barrier

Why Median Barriers ….

200 Miles of Highway = 1 Crossover Fatality


250 Killed Annually in Crossover Crashes


23,139 Road Departure Fatalities


16,214 Fatalities from Run
-
Off
-
The
-
Road Crashes


740,000 Road Departure Injury Crashes


267 Crossover Head
-
On Fatal Collisions

Cable Median Barrier

Safe


Effective


Cost Efficient


Proven Results


Replaceable

What Is Cable Barrier …

Cable Median Barrier

Why Cable Median Barrier? And Why Now?

R E S U L T S

Cable Median Barrier

20 Reported Cable Median Barrier Impacts

0 Penetrations


0 Crossover Fatalities

First vehicle to impact cable barrier (March 2005)

No Injuries


2001 2002 2003 2004 2005

Crossover Crashes

Fatalities

Cable Barrier Installed

(May 2005 thru April 2006)

Cable Median Barrier

Minimize Cross
-
Median Crashes


Lower Deflection Rates


Less Maintenance


Residual Safety Value


Lower Market Prices

Cable Median Barrier

“For every one fatal
across median crash
there were 10 non
-
fatal
across median
crashes.”

“Median Barriers in North Carolina,”
AASHTO Subcommittee on Design, 2006

Cable Median Barrier

Fatalities

Fatal Crashes

1994
-
1998 1999
-
2003

Across
-
Median Crashes
Decreased or Eliminated


Lives Saved


Millions in Crash Cost
Savings

Cable Median Barrier

Generic Cable



$8.33/Foot


High Tension Cable


$12.23/Foot


W
-
Beam



$13.65/Foot


Pre
-
Cast Concrete


$24.64/Foot


Single Slope Concrete


$44.94/Foot


Cast in Place Concrete

$79.36/Foot

Issues & Concerns: Barrier Costs

Cable Median Barrier

Issues & Concerns: The Choices

Safence

Trinity Cable Safety Systems

(CASS)

Brifen Wire Rope Safety Fence

Gibraltar Cable Barrier

Nucor Marion U.S.

High Tension

Cable Median Barrier

Issues & Concerns: Maintenance & Repair

Barrier Hits Per Mile


Cost Recovery


Frequency of Repair


Cable Downtime


Moving


Tension, Temperature & Elasticity

Cable Median Barrier

Issues & Concerns: Roadway Design

Cable Type


Cable Placement


Barrier Design


Transition from Cable to

Other Types of Systems

Cable Median Barrier

Case Study: Utah Department of Transportation

Lessons Learned:



Compacted surface


Facilitate winter maintenance and avoid erosion


Foundation sockets flush to ground


1:6 steepest slope


System hits effective


Cable Median Barrier

Case Study: Ohio

6:1 Slope


Socketed System


Cable Heights

High Tension System


10’ Offset from Ditch Centerline

Cable Median Barrier

Case Study: North Carolina

8’ Offset at 60’ Median Widths



Cable Height


Design Specifications


Median Barrier Drawings

70’ Median Width or Less


500 Miles of Low Tension Barrier


14’ Designed Deflection


4’ Offset from Ditch Line

Cable Median Barrier

Case Study: Texas



High Tension Cable System




6:1 Slope




Standard Details and Specifications




Cable Barrier Behind W
-
Beam




10’ to 12’ Off Edgeline

Cable Median Barrier

Case Study: Washington



Cable Height




Pre
-
Cast Concrete Barrier




NCHRP 350 Test Level 3




High Tension and Low Tension




6:1 Slope and 10” Offset




70 Miles in 8 Counties

Cable Median Barrier

Issues & Concerns: Motorcycle Safety

Barrier Performance

Barrier Type

Total Collisions

Injury Collisions

Fatal Collisions


Percent


Percent

Concrete



40



85%


7.5%


Beam Guardrail


65



81.5% 9.2%


Bridge Rail


10



80% 10%

Washington State Highways, 2003
-
2004

Cable Median Barrier

Resources Available: AASHTO TIG Web Site



Contact Information



Challenges



Roadway Design Issues



Maintenance Issues



Benefits & Evaluations



System Threats



You’ll also find links to:

Lead States Team Studies

FHWA Evaluation

Texas Transportation Institute

Vendors

And more ….

Cable Median Barrier

Resources Available: The Lead States Team

North Carolina


Kevin Lacy


(919) 733
-
3915

jklacy@dot.state.nc.us


Terry Hopkins


(919) 715
-
7818

thopkins@dot.state.nc.us


Brian Mayhew


(919) 715
-
7818

bmayhew@dot.state.nc.us


Shawn Troy


(919) 733
-
5692

story@dot.state.nc.us


Brian Murphy


(919) 755
-
3668

bgmurphy@dot.state.nc.us


Roger Thomas


(919) 250
-
4016

rthomas@dot.state.nc.us


Scott Capps


(919) 733
-
3725

scapps@dot.state.nc.us


Washington


Dick Albin


(360) 705
-
7451

albind@wsdot.wa.gov


Ohio


Dean Focke


(614) 466
-
2847

dean.focke@dot.state.oh.us


Utah


Rob Clayton


(801) 964
-
4521

robertclayton@utah.gov


Texas


Rory Meza


(512) 416
-
2678

ameza@dot.state.tx.us

Cable Median Barrier

Resources Available: For the Media

Cable Median Barrier

Resources Available: Evaluations, Case Studies & More

Cable Median Barrier

Resources Available: To Learn More

Federal Highway Admininstration:

http://www.safety.fhwa.dot.gov


Brifen U.S.A.




http://www.brifenusa.com


Gibraltar




http://gibraltartx.com


Nucor Steel Marion



http://nsmarion.com


Safence





http://www.safence.com


Trinity





http://www.highwayguardrail.com

AASHTO TIG http://www.aashtotig.org