Safety barriers
and guard rails address the issue of improved
safety on roadways.
Far too often, we turn on the evening news or pick
up the local newspaper and see stories like these:
“Two people were killed and two injured after the
driver of a Jeep Cherokee lost control...in the southbound lanes of
Interstate 270... The jeep crossed into the grassy median and flipped into
the paths of two vehicles going north...” The Columbus Dispatch.
“The second of three crashes on the George Bush
Turnpike in recent weeks prompted calls for a median barrier on the highway.
[A westbound driver] died in a crash after he swerved to avoid another
vehicle...then crossed the turnpike’s median and hit an eastbound car head
on. He was the third person in less than a week to die in a head-on crash on
the Bush Turnpike...” The Dallas Morning News.
Highway crossover accidents are becoming more common
every year as more vehicles enter the roadways. We all know that something
needs to be done to prevent these in the future, but finding the right
solution can be a real challenge.
Highway median barriers are one solution being
considered by many highway officials.
Concrete barriers will almost certainly prevent
crossover accidents, but there are some drawbacks. One is that these
barriers sometimes bounce the vehicle back into same-direction traffic lanes
which can cause accidents. Another is that a concrete barrier guarantees
that drivers who veer into the median will strike a solid object, possibly
causing severe injuries or death. However, there are places where concrete
barriers may be the only choice.
Some view post-and-cable barriers as the best
option. The cables catch errant vehicles, preventing them from crossing over
or bouncing back into same-direction traffic, and they are less expensive to
install than concrete barriers.
Officials at the North Texas Tollway Authority were
considering their options while waiting for accident reports to be completed
before deciding what measures to take on the George Bush Turnpike, if any,
to prevent future crossover accidents. They are considering barriers as an
option.
The officials at the Ohio Department of
Transportation, however, spent $800,000 to install cable barriers along
stretches of I-270 and Route 315 — two areas of high numbers of crossover
accidents (see Better Roads, February 2004, RoadWorks, pp 13).
Crossover accidents are just one of the issues
facing highway officials today. Other issues include work-zone safety,
roadside safety, and the list goes on. Whatever your particular problem may
be, here are a variety of safety barriers and guard rails for you to
consider.
Barrier Systems, Inc.
Moveable barrier system
A moveable barrier system from Barrier Systems uses
concrete barrier sections similar to conventional California barrier that
hinge together to form a single chain that can be picked up and moved
laterally across lanes by a specially designed transfer machine. This
barrier system was called upon during reconstruction of the Chicago Skyway.
The 2.5 miles of barrier is moved twice daily as part of a contra-lane
design to provide an additional lane to carry rush hour traffic into or out
of the city. The entire process takes 30 to 40 minutes, including the
installation of tapers.
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Trinity
Industries
Cable safety system
 Trinity
Industries’ Cable Safety System addresses the issue of crossover accidents
on highway systems, providing a forgiving, cost-effective alternative to
rigid, concrete barriers. The system exhibits excellent life-cycle costs
with maintenance-free service and quick repair after an impact.
Using C-shaped posts and tensioned cables, CASS is
designed to capture and redirect errant vehicles that would otherwise
traverse the median of a roadway. The specially designed post employs a
wave-shaped slot that works in tandem with strategically positioned cables
and highly increases the system’s ability to safely restrain various types
of vehicles. The system has been extensively crash tested in the U.S. and
Europe.
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Energy
Absorption/Quixote Transportation
Concrete barrier end treatment
 Energy
Absorption Systems, a division of Quixote Transportation Safety, introduced
a new gating, non-redirective, water-filled concrete end treatment for work
zones. The Triton CET System consists of six standard Triton Barrier
sections and a transition piece designed to easily attach to a portable
concrete median barrier and measures 40 feet in length, 21-inches wide, and
32-inches high. Empty weight is 140 pounds per section; filled weight is
1,350 pounds per section.
The system is available as either a TL-2 or TL-3
system by removing or adding pedestals. The water-filled portable barrier
features an internal steel frame, partial reusability after design impacts,
and flexibility for use as both a positive barrier and a crash cushion.
Deployment of the system involves four simple steps: unload without the need
for heavy equipment; position the barrier and pin sections together; pin the
transition hardware to the PCMB; and fill with water.
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Advanced Barrier Technologies, Inc.
Modular glare screen barrier
 Advanced
Barrier Technologies’ modular glare screen Z Barrier, ABT-78TF was developed
for the new F-rail precast concrete barrier. The screen barrier is made of
resilient high-density polyethylene plastic which won’t shatter on impact.
They attach atop concrete barriers by screwing them into the concrete or by
inserting steel posts into preformed postholes. The panels are designed in a
vertical zigzag pattern that allows reflective adhesive, directional
markers, and/or reflective letters or numbers to be applied to relay
messages to motorists. The Z Barrier is reusable and 100% recyclable, thus
reducing the overall cost to construction companies and states.
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Traffic Safety Devices, Inc.
Self-locking portable barriers
The tough and versatile RoadGuard Barrier from
Traffic Safety Devices is a portable, water-ballasted, energy-absorbing,
polyethylene safety barrier. These easy-to-handle, quick-to-install barriers
have a self-locking design that keeps them firmly connected without
additional hardware. They are perfect for work-zone protection, traffic
channeling and control, and lane delineation. Each barrier can curve up to
15 degrees in either direction at each connection, allowing highway workers
to set up self-locking barrier straight-aways and curves that meet the
contour of the job situation. The barriers are 6-feet long, 3.5-feet high,
and 2-feet wide at the base. The lightweight 125-pound barriers are a secure
1,675 pounds when filled with water. Barriers are available in orange,
natural, and yellow.
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Transpo
Industries, Inc.
Precast polymer concrete barrier
 The
Visi-Barrier, manufactured by Castek Inc. (a subsidiary of Transpo
Industries), is a high-visibility precast polymer concrete traffic barrier
that solves poor roadway delineation problems during nighttime and rainy
conditions while performing as a safety barrier. The continuous visi-stripe
is an integral part of each panel consisting of highly retroreflective glass
beads placed in a wide stripe for year-round, all-weather visibility.
The barrier is available in standard and custom
sizes and colors to suit a variety of applications including median
barriers, tunnel panels, and bridge parapets and rails.
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Road Systems, Inc.
Roadside and median hazard treatment
The BEAT-SSCC (single-sided crash cushion) from Road
Systems attaches directly to bridge abutments and rigid barriers along the
roadside to provide protection. Its short 28-foot length makes it ideal for
restrictive site conditions in both permanent and temporary locations. The
system is available with a ground-mounted post design when a concrete
foundation is not required; a surface-mounted post option is also available.
The system is low cost, easy to install and maintain, and all above-ground
components are the same. The stand-alone, self-contained system meets all
requirements of NCHRP 350 and is FHWA accepted.
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Fender Enterprises
Breakaway Type III barricade
The Fendercade Type III barricades from Fender
Enterprises are lightweight and easy to handle, resulting in fewer workplace
injuries. The barricade panels are made of high-impact rigid polyvinyl
chloride — three to five times stronger than other plastic or wood barricade
panels — and are UV stabilized. Panels won’t rust, rot, splinter, or
corrode; won’t sag or warp due to sun or heat exposure; and never need
painting. Barricade frames are made from Unistrut’s Telespar 12-gauge steel
tubing. The breakaway base design yields to impacting vehicles, increasing
safety for workers and motorists. Modular design allows for easy replacement
or repair of damaged components; parts are reusable after impact.
The barricade meets NCHRP-350, MUTCD, and TxDOT
requirements.
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The Yodock Wall Company, Inc.
Traffic control system
The Yodock water-ballasted Traffic Control System is
capable of being installed and relocated in 30- and 60-foot sections. The
system is centered on one core product, a ballastable energy disbursement
cell made of heavy-duty polyethylene, that can be accessorized to meet
several traffic control demands. The light weight ensures portability, ease
of installation, and low transportation costs. With the addition of the 350
Rail Kit, the system is a replacement for concrete barrier wall and meets
NCHRP 350
TL-2 and TL-3 with only 25 units.
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Gomaco
Variable concrete barrier
Gomaco’s New Generation Commander III slipforms
concrete barrier at variable heights and thicknesses, as well as curb and
gutter and road paving. The unit has recently been used in several projects
across the nation with great results.
On the I-26 project through the mountains near
Asheville, North Carolina, subcontractor Summers-Taylor Inc. of
Elizabethton, Tennessee used the Commander III with auger to slipform
variable barrier — bottom width varied between 29 and 30.25 inches and
height ranged between 51 and 57 inches. Features such as the G21 controller,
fast tracking speed for jobsite mobility, and concrete auger on the unit
enabled them to slipform 41,414 feet of barrier wall in 47 days.
S & N Contractors used the Commander III on a
reconstruction project on U.S. 131 through Grand Rapids, Michigan. The
machine was used for both road paving and for a variable concrete barrier
that ranged in height from 42 to 84 inches with no reinforcing. Fred
O’Keefe, owner and president of S & N Contractors, was impressed with the
machine’s versatility and how well it handled.
Weaver Bailey Contractors in central Arkansas
ordered the Commander III specifically for barrier work on I-30 south of
Little Rock. Approximately 100,000 feet of different types of barrier wall
needed to be slipformed on the project — the most challenging included a
stretch of barrier that grew from 42 to 82 inches in height. They worked
with Gomaco to design and develop a mold with a hydraulic front that would
allow them to open or close it depending on whether they were pouring over a
full steel cage or just running vertical bars through it. “I don’t think
there’s another machine out there that will do this type of barrier work,
with the steel cage and all,” says Don Weaver, vice president of Weaver
Bailey.
On Route 9 in Ossining, New York, Syrstone, Inc.
used their Commander III to slipform — in one pass — double median barrier
with a 2-inch open joint. The barriers were 34-inches high by 44-inches
wide. They couldn’t access one side of the double wall, so they slipformed
them both at the same time. “We took a mold that we already had and put a
sandwich right down the middle of it,” says David Leith, concrete
superintendent for Srystone. “It was quite simple and it went very well.”
Approximately 450 feet of the double barrier was slipformed in four hours.
They
also used the machine to pour 6,000 feet of
34-inch-tall by 21-inch-wide parapet on the Walt Whitman Bridge in
Philadelphia, Pennsylvania. “The Commander III is a very good all-around
slipform paver,” says Leith.
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SafeRoads
High-tension cable barrier
The SafeRoads U.S. High Tension Barrier System is a
low-cost alternative to traditional roadside longitudinal median or guide
rail barriers. The system uses three cables, anchored on two ends and
attached in the middle by specially designed locking hook bolts to
galvanized 4-pound Marion Steel Rib-Bak u-channel signposts. The posts can
be driven in soil or installed in sleeves set in asphalt or concrete
foundations. The end treatments consist of uniquely designed CRP breakaway
posts anchored in cement; the non-stretched cables are tensioned up to 5,600
pounds on the job site via turnbuckles which allow installers to customize
deflections to meet the needs of specific locations. According to the
manufacturer, the system costs roughly 75% less than concrete median
barriers; about 50% less than W-beam guardrail systems; and, because of the
use of strong Rib-Bak signposts, up to 20% less than competitive three-cable
systems. The system is NCHRP approved.
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MasterMind Systems, Inc.
Guardrail inventory and maintenance module
MasterMind’s RailMaster 6 Guardrail/Right-of-Way
Maintenance Module helps with the complete inventory of guardrail and
maintenance that needs to be performed. Simply set up your DOT’s rail type
descriptions and RailMaster calculates rail, posts, spacer blocks, and end
treatments. Inspections can be logged in by road or part of road; hazards
can be defined and their offset from edge of the pavement listed. GPS
information is stored with the rail’s other location information and can be
imported into your GIS system for mapping purposes. Easily locate any
guardrail by ID number or by the number assigned by RailMaster when the
assembly is input.
The Work Item window displays all work cataloged in
the system, including guardrail or bridge rail maintenance, new or
additional installation of guardrail, or right-of-way problems that need to
be addressed. Once the work is completed, fill in the data and the work is
filed away in history for easy recall any time you need it.
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Safety Barriers Corp. of Colorado
Lightweight alternative to concrete
Safety Barriers Corporation manufactures the E-Z
Barrier, a lightweight and versatile alternative to the conventional
concrete barrier system. The barrier is constructed of a low-density
polyethylene that resists cracking, breakdown, and damaging ultraviolet
light. At an empty weight of only 125 pounds, the barrier can be transported
and assembled efficiently without using cranes or expensive machinery.
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Reprinted from Better Roads Magazine
November 2004 |
