Refer to: HSA-10/WZ-167 

Mr. Bill Fisher 

Ply-Glo Safety Devices 

RR # 2 

Crossfield AB T0M 0S0 CANADA 

Dear Mr. Fisher: 

Thank you for your letter, received on December 17, 2003, requesting Federal Highway 

Administration (FHWA) acceptance of your company’s illuminated road tubes as crashworthy 

traffic control devices for use in work zones on the National Highway System (NHS). 

Accompanying your letter were reports of informal crash testing you had conducted, 

dimensioned drawings of the devices, and a DVD containing video of the tests. You requested 

that we find these devices 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.” 

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 

are those lightweight devices which are to be self-certified by the vendor, Category II devices are 

other lightweight devices which need individual crash testing but with reduced instrumentation, 

Category III devices are barriers and other fixed or heavy devices also needing crash testing with 

normal instrumentation, and Category IV devices are trailer mounted lighted signs, arrow panels, 

etc. for which crash testing requirements have not yet been established. 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 devices follows: 

The Ply-Glo Illuminated Safety Device is a low-density polyethylene road tube delineator 

mounted on a detachable rubber base. A light source is mounted in the base such that the light 

shining up through the tube illuminates it from within increasing nighttime visibility. 
2

Testing 

Roadtubes are nominally considered Category 1 devices by the FHWA, meaning they do not 

have to be individually tested. The addition of the lighting device to this product had the 

potential to significantly affect the crash performance, and resulted in the device requiring at 

least informal crash testing as a Category 2 device. Because the trajectory of the tube with its 

lighting device installed was our principal concern, informal vehicle testing was conducted on 

your company’s device. Stand-alone examples of the devices were tested in numerous impacts, 

at various speeds, and with and without the lighting hardware. In every case the tube separated 

from the base. In those tests with the lighting device, no part of the device appeared to approach 

the windshield. 

 

This crash-testing program used a van of a mass larger than the standard 820C test vehicle. 

There are significant constraints involved in using such a non-standard test vehicle, some of 

which are: 

1. The potential vehicle velocity change must be considered insignificant. 

2. The crush characteristics of an automobile bumper must not be expected to have a 

 significant affect on the trajectory of the test article. 

3. No part of the test article may have a trajectory that could propel it over the hood and 

 into the windshield area of an 820C vehicle after impact. 

In this case, testing of the Ply-Glo traffic safety marker device with the van was done within 

these constraints. 

Findings 

No part of the delineator or lighting device was projected up into the air or otherwise jeopardize 

the occupant compartment of the test vehicle. The results of the informal testing met FHWA 

requirements and, therefore, the devices described above and detailed in the enclosed drawings 

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

State. 

Please note the following standard provisions that 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 
3

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-167 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 Ply-Glo Illuminated Safety Device is a patented device and is 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 by a highway 

agency for use on Federal-aid 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. These 

provisions do not apply to exempt Non-NHS projects. Our regulations concerning 

proprietary products are contained in Title 23, Code of Federal Regulations, Section 

635.411, a copy of which is enclosed. 

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

use, manufacture, or sell any patented device. Patent issues are to be resolved by the 

applicant and the patent owner. 

Sincerely yours, 

 John R. Baxter 

 Director, Office of Safety Design 

 Office of Safety 

Enclosures 

FHWA:HSA-10:NArtimovich:tb:x61331:12/17/03 

File: h://directory folder/nartimovich/WZ167-PlyGloFIN 

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

 N. Artimovich, HSA-10)