1200 New Jersey Ave., SE

 Washington, D.C. 20590

August 22, 2011 

In Reply Refer To: 

 HSST/B-223 and 

HSST/CC-119 

Mr. Dallas James

Armorflex International Ltd.

8 Paul Matthews Road, 

North Harbour 0751 

New Zealand

Dear Mr. James:

This letter is in response to your request for the Federal Highway Administration (FHWA) acceptance of 

a roadside safety system for use on the National Highway System (NHS). 

Name of systems: ArmorZoneTM Plastic Longitudinal Barrier; and, 

 ArmorZoneTM Plastic End Treatment

Type of system: Longitudinal Barrier and End Treatment 

Test Level: NCHRP Report 350 Test Level 2 and MASH Test Level 2

Testing conducted by: Holmes Solutions Ltd (HSL) and Safe Technologies, Inc (STI). 

Date of request: December 14, 2010 

Request initially acknowledged: December 17, 2010 

Task Force 13 Designator: SWM17 (Barrier)

 SCI29 (End treatment) 

You requested that we find your system acceptable for use on the NHS under the provisions of the 

National Cooperative Highway Research Program (NCHRP) Report 350 “Recommended Procedures for 

the Safety Performance Evaluation of Highway Features” and the AASHTO “Manual for Assessing 

Safety Hardware” (MASH).

Requirements

Roadside safety devices should meet the guidelines contained in the NCHRP Report 350 when tested 

prior to January 1, 2011, and the American Association of State Highway and Transportation Officials’ 

Manual for Assessing Safety Hardware (MASH) if tested after that date. The FHWA Memorandum 

“Identifying Acceptable Highway Safety Features” of July 25, 1997 provides further guidance on crash 

testing requirements of longitudinal barriers.

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Decision

The following devices are found to be acceptable, with details provided below:

• ArmorZoneTM Plastic Longitudinal Barrier Mash TL-2 Design (System “B”)

• ArmorZoneTM Plastic End Treatment NCHRP Report 350 Design (System “C”)

The following device was not found acceptable: 

• ArmorZoneTM Plastic Longitudinal Barrier NCHRP Report 350 Design (System “A”) 

Description

ArmorZoneTM is a relatively low cost longitudinal barrier designed with an integral end treatment for use 

in work zone applications. The system will contain or redirect an errant vehicle when impacted beyond 

the beginning length of need, and is a gating design when impacted at or nearer to the upstream end 

terminal. Each ArmorZoneTM unit is made from High Density Polyethylene (HDPE). It is a one piece 

roto-molded unit with a fill hole located on the top for internal access and a drain hole, complete with 

bung, at the bottom. The original design was filled with 520 liters (137 gallons) of water. The modified 

design, tested with the MASH pickup truck, contained 440 liters (116 gallons). The unit also has a 

series of ‘through holes’ which provide additional strength to the barrier during impact and also allow 

the unit to maintain its shape when filled with water. The units tested to MASH specifications each 

contain a 2152-millimeter (85-inch) galvanized steel bar, 75-millimeter (3-inch) wide by 6-millimeter

(1⁄2-inch) thick. The steel bar is fitted through each unit, approximately 120-millimeters (5-inches) from 

the top of the barrier, and has 2 holes at either end which line up with the connection holes at each end 

of the HDPE unit. The ArmorZoneTM unit has a nominal joined length of 2000-millimeters (79-inch), is 

450-millimeters (18-inch) wide and 860-millimeters (34-inch) high. When multiple units are connected 

to each other and filled with water, they form a longitudinal barrier. They are connected with ‘twin pin’

connectors, consisting of two 37-millimeter (11⁄2-inch) diameter by 850-millimeter (331⁄2-inch) long steel 

pipes complete with internal RHS reinforcement. Enclosure 1 shows the design details for the MASH 

design. The NCHRP Report 350 design is identical but does not include the steel bar. 

The ArmorZoneTM end treatment is similar in appearance to the barrier segments, but is not filled with 

water and has additional holes and slots which reduce the strength of the unit to ensure crashworthiness. 

It does not include the steel bar found in the MASH barrier units. Enclosure 2 shows these details. 

In all ArmorZoneTM installations, every unit forming the barrier (except the ArmorZoneTM end treatment 

unit) must be filled with the correct amount of water. Also the individual units must be connected to 

each other with the ‘twin pin’ connector but not fixed or anchored to the ground in any way. 

Crash Testing

I. Testing Summary and Results for the ArmorZoneTM longitudinal barrier:

Test 2-10 and 2-11 were conducted by Holmes Solutions Limited in New Zealand. Both tests were 

run on the original all-plastic barrier design (System “A”) and on 50-meter (164-foot) long 

installations with the impact points 13.6 meters (45 feet) from the upstream end. Though Test 2-10 

met NCHRP Report 350 evaluation criteria, in Test 2-11, the pickup truck was re-directed and came 

to rest on top of the barrier after very nearly going over the top. Barrier deflection was reported to 

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be 2.1 meters (83 inches). Because the truck was not contained by the barrier, FHWA considers this 

result a failure of the NCHRP Report 350 version of the device. Enclosures 3 and 4 are summaries of 

both tests. 

 

Test 2-11 was re-run by Safe Technologies, Inc. using the MASH pickup truck to validate the design 

changes noted above (the addition of an internal steel bar and another ‘through hole’, plus reducing 

the water volume by 80 liters (21gallons). This test installation was also 50 meters (164 foot) long 

but the impact point was 23 meters (75 feet) from the upstream end. The pickup truck was smoothly 

re-directed with a maximum barrier deflection of 4.1meters (13.5 feet). Enclosure 5 is the test 

summary sheet (System “B”).

II. Testing Summary and Results for the ArmorZoneTM end treatment:

Each of the three end treatment tests were conducted by Safe Technologies, Inc. (System “C”). 

Tests 2-40 and 2-41 were run on 26-meter (85-foot) long installations backed up to free-standing 

concrete barrier segments. In both tests the vehicles were brought to controlled stops and the 

occupant risk values where within the preferred limits. However, in Test 2-40, the end treatment and 

adjacent barrier units slid up and across the hood of the small car, resulting in extensive windshield 

damage. Enclosures 6 and 7 are summaries of these two tests.

Test 2-43 was run on a 40.2-meter (132-foot) long installation. The vehicle gated through the 

system as designed and came to rest approximately 30 meters (98 feet) downstream on the backside 

of the test installation. Enclosure 8 is the test summary sheet.

NCHPR Report 350 requires five tests for a non-redirective, gating terminal or crash cushion. You 

omitted Test 2-42 from the test matrix for the end treatment because Test 2-40 is a worse case test 

for occupant risk for the 820C vehicle and Test 2-43 is a worse case test for vehicle trajectory with 

the 2000P vehicle rather than the small car. The FHWA agrees with your reasoning for omitting 

Test 2-42. 

You also omitted Test 2-44 which is intended to test the crashworthiness of a non-redirective terminal 

used to shield a rigid object. Because your barrier is not rigid, it is more appropriate to determine the 

point at which the barrier/terminal combination ceases to be gating but, instead, captures or redirects 

an impacting vehicle. The FHWA agrees with your analysis that NCHRP Report 350 Test 2-11 is a 

good substitute for Test 2-44 since that test was run with the impact point 13.6 meters (45 feet) from 

the upstream end and the vehicle was redirected. Your MASH Test 2-11was run with the impact 

point 23 meters (75 feet) from the upstream end of the test installation and the heavier MASH truck 

was also redirected. Since the Test 2-11 impact angle is 25 degrees and the 2-44 impact angle is only 

20 degrees, we agree that test 2-44 can be waived. Based on these two barrier tests, the beginning 

length of need point should begin approximately 13.6 meters (45 feet) downstream from the nose of 

the installation for the Report 350 design and 23 meters (75 feet) downstream for the MASH design. 

Should you wish to establish a length of need closer to the beginning of the barrier, additional testing 

will be required to determine the point at which containment or redirection can be attained. 

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Findings

You requested FHWA acceptance of the following two configurations for the ArmorZoneTM 

longitudinal barrier: 

A. NCHRP Report 350 TL-2 design 

B. MASH TL-2 design. 

In addition, you requested FHWA acceptance of the following configuration for the ArmorZoneTM 

end treatment:

C. NCHRP Report 350 TL-2 design 

Systems “B” and “C” described above and shown in the Enclosures successfully passed all conducted 

testing. System “A” failed NCHRP Report 350 Test 2-11 due to vehicle override. The Occupant Impact 

Velocities (OIV) and Occupant Ridedown Accelerations (ORA) for all other tests were below the 

preferred limits. However, because your barrier is a “soft” system, deflections can be high and vehicles 

impacting the terminal at an angle can travel a significant distance behind the barrier. Thus, it is 

important that all users be aware of deflection distance requirements and of the necessity to keep the 

area behind and beyond the terminal clear of workers and/or construction materials and equipment. 

In summary, with the exception of system “A” above, the remaining systems described above (B & C)

and detailed in the enclosed drawings are acceptable for use on the NHS under the range of conditions 

tested, when such use is acceptable to a highway agency. 

Please note the following standard provisions that apply to FHWA letters of acceptance: 

• This acceptance letter provides an AASHTO/ARTBA/AGC Task Force 13 designator that 

should be used to create a new or revised Task Force 13 drawing. 

• This acceptance is limited to the crashworthiness characteristics of the systems and does not 

cover their structural features, nor conformity with the Manual on Uniform Traffic Control 

Devices.

• Any changes that may adversely influence the crashworthiness of the system will require a new 

acceptance letter.

• Should the FHWA discover that the qualification testing was flawed, that in-service performance 

reveals unacceptable safety problems, or that the system being marketed is significantly different 

from the version that was crash tested, we reserve the right to modify or revoke our acceptance.

• You will be expected to supply potential users with sufficient information on design and 

installation requirements to ensure proper performance. 

• You will be expected to certify to potential users that the hardware furnished has essentially the 

same chemistry, mechanical properties, and geometry as that submitted for acceptance, and that 

it will meet the crashworthiness requirements of the FHWA and NCHRP Report 350 or MASH. 

• To prevent misunderstanding by others, this letter of acceptance is designated as number 

B-223/CC-119 and shall not be reproduced except in full. This letter and the test documentation 

upon which it is based are public information. All such letters and documentation may be 

reviewed at our office upon request. 

• The ArmorZoneTM system is a patented product and considered proprietary. If proprietary 

systems are specified by a highway agency for use on Federal-aid projects, except exempt, nonNHS projects, (a) they must be supplied through competitive bidding with equally suitable 

unpatented items; (b) the highway agency must certify that they are essential for synchronization 

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with the existing highway facilities or that no equally suitable alternative exists; or (c) they must 

be used for research or for a distinctive type of construction on relatively short sections of road 

for experimental purposes. Our regulations concerning proprietary products are contained in 

Title 23, Code of Federal Regulations, Section 635.411. 

• This acceptance letter shall not be construed as authorization or consent by the FHWA to use, 

manufacture, or sell any patented system for which the applicant is not the patent holder. The 

acceptance letter is limited to the crashworthiness characteristics of the candidate system, and the 

FHWA is neither prepared nor required to become involved in issues concerning patent law. 

Patent issues, if any, are to be resolved by the applicant.

 

 Sincerely yours,

 Michael S. Griffith

Director, Office of Safety Technologies

Office of Safety

Enclosures 

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