U.S. Department

of Transportation 400 Seventh St., S.W.

Federal Highway Washington, D.C. 20590

Administration

Refer to: HSA-10/WZ-104

Mr. Donald D. Diecks

President

PMG Limited Lobo

POBox 552

Chagrin Falls, OH 44022-0552

Dear Mr. Diecks:

Thank you for your letter of October 24 requesting Federal Highway Administration (FHWA)

acceptance of your company’s Sentinel Type III Plastic Panel Barricade as a crashworthy traffic

control device for use in work zones on the National Highway System (NHS). Accompanying

your letter was a report of crash testing conducted by E-Tech Testing Services and a video of the

tests. You requested that we find these devices acceptable for use on the National Highway

System under the provisions of National Cooperative Highway Research Program (NCHRP)

Report 350 “Recommended Procedures for the Safety Performance Evaluation of Highway

Features.” Mr. Nicholas Artimovich of my office gave you an initial response via fax on

November 5, 2001, and asked for additional information which you subsequently provided.

Introduction

The FHWA guidance on crash testing of work zone traffic control devices is contained in two

memoranda. The first, dated July 25, 1997, titled “INFORMATION: Identifying Acceptable

Highway Safety Features,” established four categories of work zone devices: Category I devices

were those lightweight devices which could be self-certified by the vendor, Category II devices

were other lightweight devices which needed individual crash testing, Category III devices were

barriers and other fixed or massive devices also needing crash testing, and Category IV devices

were trailer mounted lighted signs, arrow panels, etc. The second guidance memorandum was

issued on August 28, 1998, and is titled “INFORMATION: Crash Tested Work Zone Traffic

Control Devices.” This later memorandum lists devices that are acceptable under Categories I, II,

and III.

A brief description of the device follows:

The Sentinel Type III barricade is a compact lightweight device featuring blow molded high

density polyethylene upper and lower supports and hollow extruded plastic panels. The upper and

lower supports are joined together with a simple slip-fit connection. The 210 mm high by 

1219 mm long barricade panels are made from a specially formulated polyolefin plastic and

surfaced with reflective sheeting. Each of the three panels is secured to the uprights with four 

9.5 mm diameter by 76.2 mm long ASTM A307 hex bolts and nuts with plain washers front and 

back. The mass of each test article was 13.4 kg. Each was placed on a flat, clean, and dry asphalt

surface with three 15.9 kg sandbags placed on the lower support legs of each barricade for ballast.

 The complete devices as tested are shown in the enclosed drawings for reference.
2

Testing

Full-scale automobile testing was conducted on your company’s devices. Two stand-alone 

examples of the device were tested in tandem, one head-on and the next placed six meters

downstream turned at 90 degrees, as called for in our guidance memoranda. The crash test is

summarized in the table below:

Test Number 38-8707-001 , NCHRP Test 3-71

Test Article Sentinel Type III Plastic Panel Barricade

Height to Top of Barricade 1524 mm (60 inches)

Flags or lights none

Test Article Mass (each) 13.4 kg

Vehicle Inertial Mass 824 kg

Impact Speed, Head-on 101.8 km/hr

Impact Speed, 90 Deg. 97.7 km/hr

Velocity Change, Head-on 1.14 m/sec

Velocity Change, 90 deg. 1.14 m/sec

Vehicle crush Slight hood damage

Occupant Compart. Intrusion None

Windshield Damage None - only glancing contact with first test article

Findings

When struck the upper portions of the barricades came out of the base sections and were knocked

ahead of the vehicle. Damage was limited to dents and scrapes in the hood. There did not appear

to be any potential for passenger compartment intrusion. The results of the testing met the FHWA

requirements and, therefore, the devices described above and shown in the enclosed drawings for

reference are acceptable for use on the NHS under the range of conditions tested, when proposed

by a State.

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

! Our acceptance is limited to the crashworthiness characteristics of the devices 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 device 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 device being marketed is

significantly different from the version that was crash tested, it reserves the right to modify

or revoke its acceptance.

! You will be expected to supply potential users with sufficient information on design and
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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 they will meet the crashworthiness requirements of FHWA and

NCHRP Report 350. 

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

WZ-104 shall not be reproduced except in full. This letter, and the test documentation

upon which this letter is based, is public information. All such letters and documentation

may be reviewed at our office upon request. 

! The Sentinel Type III Plastic Panel Barricade may include patented components and if so

are considered "proprietary." The use of proprietary work zone traffic control devices in

Federal-aid projects is generally of a temporary nature. They are selected by the

contractor for use as needed and removed upon completion of the project. Under such

conditions they can be presumed to meet requirement "a" given below for the use of

proprietary products on Federal-aid projects. On the other hand, if proprietary devices are

specified for use on Federal-aid projects, except exempt, non-NHS projects, they: (a) must

be supplied through competitive bidding with equally suitable unpatented items; (b) the

highway agency must certify that they are essential for synchronization with 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, a copy of which is enclosed. 

 

 

Sincerely yours,

Michael L. Halladay 

Acting Program Manager, Safety 

Enclosure

FHWA:HSA-10:NArtimovich:tb:x61331:1/07/02

File: WZ104PMGLoboFin.wpd

cc: HSA-10 (Reader, HSA-1; Chron File, HSA-10;

 N. Artimovich, HSA-10)

Sec. 635.411 Material or product selection. 

(a) Federal funds shall not participate, directly or indirectly, in payment for any premium or royalty on 

any patented or proprietary material, specification, or process specifically set forth in the plans and 

specifications for a project, unless: 

(1) Such patented or proprietary item is purchased or obtained through competitive bidding with equally 

suitable unpatented items; or 

(2) The State highway agency certifies either that such patented or proprietary item is essential for 

synchronization with existing highway facilities, or that no equally suitable alternate exists; or 

(3) Such patented or proprietary item is used for research or for a distinctive type of construction on 

relatively short sections of road for experimental purposes. 

(b) When there is available for purchase more than one nonpatented, nonproprietary material, 

semifinished or finished article or product that will fulfill the requirements for an item of work of a 

project and these available materials or products are judged to be of satisfactory quality and equally 

acceptable on the basis of engineering analysis and the anticipated prices for the related item(s) of work 

are estimated to be approximately the same, the PS&E for the project shall either contain or include by 

reference the specifications for each such material or product that is considered acceptable for 

incorporation in the work. If the State highway agency wishes to substitute some other acceptable 

material or product for the material or product designated by the successful bidder or bid as the lowest 

alternate, and such substitution results in an increase in costs, there will not be Federal-aid participation in 

any increase in costs. 

(c) A State highway agency may require a specific material or product when there are other acceptable 

materials and products, when such specific choice is approved by the Division Administrator as being in 

the public interest. When the Division Administrator's approval is not obtained, the item will be 

nonparticipating unless bidding procedures are used that establish the unit price of each acceptable 

alternative. In this case Federal-aid participation will be based on the lowest price so established. 

(d) Appendix A sets forth the FHWA requirements regarding (1) the specification of alternative types of 

culvert pipes, and (2) the number and types of such alternatives which must be set forth in the 

specifications for various types of drainage installations. 

(e) Reference in specifications and on plans to single trade name materials will not be approved on 

Federal-aid contracts. 

ENCLOSURE 2