1200 New Jersey Ave., SE

 Washington, D.C. 20590

May 3, 2011 

In Reply Refer To: 

HSST/B-220 

Mr. John Addy 

Hill & Smith. Inc.

Springvale Business and Industrial Park 

Bilston, Wolverhampton, West Midlands, UK, WV14 OQL 

Dear Mr. Addy: 

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

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

Name of system: ZoneguardTM, Portable Steel Barrier Expansion Joint Units 

Type of system: portable longitudinal steel barrier

Test Level: NCHRP Report 350 (Report 350) Test Level 3 (TL-3)

Testing conducted by: TRL Limited

Date of request: December 7, 2010 

Date of follow-up: December 8, 2010 

Task Force 13 Designation: SWM10 

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

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

Procedures for the Safety Performance Evaluation of Highway Features” for both the standard

and minimum deflection arrangements of ZoneguardTM. 

Requirements

Roadside safety systems should meet the guidelines contained in the NCHRP Report 350, 

"Recommended Procedures for the Safety Performance Evaluation of Highway Features".

FHWA Memorandum “ACTION: Identifying Acceptable Highway Safety Features” of July 25,

1997 provides further guidance on crash testing requirements of longitudinal barriers. 

Decision

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

• ZoneguardTM, Expansion Unit for the Zoneguard Portable Steel Barrier

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Description

The ZoneguardTM, Portable Steel Barrier Expansion Joint Unit is an appurtenance to the 

previously accepted ZoneguardTM portable longitudinal barrier system as per FHWA acceptance 

letter HSSD/B-176 (as per Report 350). The test article description is as follows and in addition 

to the originally tested barrier as per HSSD/B-176. 

The as tested barrier consisted of eight 12 meter (39.37 feet) ‘speed joint’ barriers. Each 12 meter

(39.37 feet) length of barrier consisted of three 4 meter (13.12 feet) sections that were bolted 

together. The 4 meter (13.12 feet) section at impact point was a three part expansion joint with 

longitudinal expansion provided by eight sleeved tubes. Each of the expansion joint inner tubes 

measured 694 millimeters (27.32 inches) x 70 millimeters (2.75 inches) and passed through an 

outer sleeve (276 millimeters (10.86 inches) x 80 millimeters (3.15 inches)). Each inner tube was 

fitted with an end cap. 

The approach side of the expansion joint was pinned on the traffic side at 29 meters (95.14 feet) 

and on the rear at 30 meters (98.42 feet), to the running surface using two 30 millimeter (1.18 

inches) diameter 500 millimeter (19.68 inches) long pins. The base of each 12 meter (39.37 

feet) barrier section had twelve rubber feet fitted that were fixed using contact adhesive. Some of 

these rubber feet were displaced from their original location. Due to variations in test site levels, 

not all of the feet were in contact with the ground; the foot at impact point was lifted off the 

running surface by 5 millimeters (0.197 inches) and barrier section number 4 was lifted off of the 

test surface by a nominal 20 millimeters (0.79 inches). The complete barrier installation was 

nominally 0.815 meters (2.67 feet) high, 0.7 meters (2.3 feet) wide and 96 meters (315 feet) long.

The approach terminal was pinned using four 30 millimeter (1.18 inches) diameter 450 

millimeter (17.72 inches) long terminal pins located at 0.45 meters (1.47 feet) and 4.45 meters 

(14.6 feet) measured from the start of the barrier. The departure terminal was pinned using four 

30 millimeter (1.18 inches) diameter 500 millimeter (19.68 inches) long terminal pins located at 

0.45 meters (17.72 inches) and 4.45 meters (14.6 feet) measured from the end of the barrier. The 

barrier was installed so that the vehicles center line intersected the barrier at a point 32.67 meters 

(107.19 feet) from the start of the barrier, with the point of first contact being 31.08 meters (102 

feet) (0.92 meter (3 feet) before the end of the expansion joint barrier). To aid post test analysis 

two lines were painted behind the barrier at 1.7 meters (5.6 feet) and 2.7 meters (8.86 feet) 

measured from the front edge of the impact side of the barrier. 

Details of this system are provided as enclosures to this correspondence. 

Crash Testing

The barrier was crash tested at the test facilities at TRL Limited, United Kingdom according to 

the following testing criteria for the evaluation of temporary longitudinal barriers used in work 

and construction zones. This report describes the dynamic impact test of a ZoneguardTM, Portable 

Steel Barrier fitted with ZoneguardTM, Portable Steel Barrier Expansion Joint Unit to test 

designation level 3-11 as per NCHRP Report 350. The impact conditions of this test are met with 

a total test mass of 2,000 kg (4.4 kips) at a speed of 100 (± 4 %) km/h (62.13 mph) and at an 

angle of 25 (± 1.5) degrees to the line of the barrier traffic face. The impact speed was 100.6 

km/h (62.5 mph) and the impact angle was 24.9 degrees and therefore satisfactory. However the 

vehicle’s actual total test mass was 2,139 kg (4.715 kips), which is outside the recommended 

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value specified in Report 350 and therefore this test was not fully compliant with the 

requirements of Report 350. However this non compliance represents a worst case test in terms 

of test item performance. The dynamic deflection was 0.97 meter (3.18 feet) and the working 

width was 1.64 meters (5.38 feet). The permanent deflection was 0.82 meter (2.69 feet).

Analysis of the high speed footage, together with witness marks on the barrier, show that the 

right hand side of the vehicle remained in contact until the end of barrier number 4. After this 

point only the vehicle’s right-hand side wheel track remained in contact with the toe of the 

barrier. The vehicle continued on this path, travelling parallel to, and on the toe of the barrier. 

Once past the end of the departure terminal, the vehicle’s remotely operated brakes were applied

and the vehicle came to a rest 34 meters (111.5 feet) beyond the end of, and 3 meters (9.84 feet) 

behind the barrier. 

Findings

The analysis of the Report 350 TL3 testing showed there were no detached elements from the 

impacting vehicle or system that penetrated the occupant compartment of the impacting vehicle 

or presented hazards to others in the area. There was no significant deformation of the roof, 

windshield or occupant compartment. The occupant impact velocities and ridedown 

accelerations were within the recommended limits for the impacting vehicle. 

Therefore, the system described in the request above and detailed in the enclosed drawings is 

acceptable for use on the NHS under the range of conditions tested, when such use is acceptable 

to a highway agency. 

The Crash Test Summary details of this system are provided as enclosures to this 

correspondence.

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

• This acceptance provides a AASHTO/ARTBA/AGC Task Force 13 designator that should be 

used for the purpose of the creation of a new and/or the update of an existing Task Force 13 

drawing.

• This acceptance is limited to the crashworthiness characteristics of the systems and does

 not cover its 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 the 

 NCHRP Report 350. 

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

B-220 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 ZoneguardTM, Portable Steel Barrier Expansion Joint Units Steel Barrier 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, non-NHS 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 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 

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B3670 Zoneguard Expansion (96m) Page 17 of 33 

10 DRAWINGS AND INSTALLATION OF THE TEST ITEM

The drawings have been supplied by the Client. The test house has checked main 

dimensions only. 

10.1 Drawing 1 

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10.2 Drawing 2 

This test was to evaluate the 4 m expansion joint assembly. The length of the tested 

assembly was 12m (39’41⁄2”). Another configuration of this assembly is to use the expansion 

joint and two 5.08 m (16’8”) barriers to give an assembly length of 46'51⁄2" (14.16m). 

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10.3 Drawing 3 

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10.4 Drawing 4 

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10.5 Drawing 5 

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10.6 Drawing 6 

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10.7 Drawing 7 

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10.8 Drawing 8 

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10.9 Drawing 9 

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10.10 Drawing 10 

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10.11 Drawing 11 

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10.12 Drawing 12 

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10.13 Drawing 13 

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10.14 Drawing 14 

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10.15 Drawing 15 

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