USA Banner
  U.S. flag
              An official website of the United States government Here's how you knowOfficial US Government Icon
              **Official websites use .gov**A **.gov** website belongs to an official government organization in the United States.
            Secure Site Icon
              **Secure .gov websites use HTTPS**
                  A **lock** ( A locked padlock ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. 
 U.S. Department of Transportation Icon United States Department of Transportation
 Search DOT
            Search
                    About FHWAFHWA Organization
                Headquarters Offices
                Field Offices
                Strategic Plan
                Business Opportunities
                Staff Directories
                Careers
                Highway History
                Contact UsProgramsAcquisition Management
                Civil Rights
                Federal Lands Highway
                Infrastructure
                Innovative Program Delivery
                Operations
                Planning, Environment, and Realty
                Policy
                Research, Development, and Technology
                Safety
                Browse by TopicsResourcesCore Highway Topics
                Federal Aid Essentials
                Automation
                Complete Streets
                Laws and Regulations
                Policy & Guidance Center
                Section 508
                Publications and Statistics
                Professional Development
                National Highway Institute
                Resource Center
                Accessibility Resource Library
                FHWA Research LibraryNewsroomPress Releases
                Speeches & Testimony
                Photos
                Videos
                Media ContactsMenu FHWA Highway Safety Programs Home
                        Safety
                        Roadway Departure Safety
                        Reduce Crash Severity
                        Hardware Eligibility Letters


            
            In This Section
        Roadway Departure Safety
                Strategic Approach
                                Strategic Plan
                Crash Emphasis Brochures
                Focused Approach
                Noteworthy Practices
                Partner Resources
                Keep Vehicles on the Road
                                Pavement Friction
                Horizontal Curve Safety
                Rumble Strips and Rumble Stripes
                Nighttime Visibility
                Provide for a Safe Recovery
                                SafetyEdge
                Clear Zones
                Reduce Crash Severity
                                Overview
                Hardware Eligibility Letters
                Focus on Reducing Rural Roadway Departures (FoRRRwD)
                                Overview
                All Public Roads
                Proven Countermeasures
                Systemic Approach
                Safety Action Plans
                FoRRRwD Resources
                
                Safety Eligibility Letter WZ-147
  
  **Hardware Type:**
            Work Zone Devices
                          **Code:**
            WZ-147
                          **Date:**
            04/01/2003
                          **Testing Criteria:**
            NCHRP 350
                          **Manufacturer:**
            Reflexite
                          **Device Description:**
            Endurance 10 mm equivalence
                          **View PDF:**
            wz147.pdf (98.99 KB)
    
    



Refer to: HSA-10/WZ-147
Mr. Geoff Grzywinski
Reflexite Americas
315 South Street 
New Britain,
Connecticut  06051
Dear Mr. Grzywinski
This is in response to your letters of December 20, 2002,
and January 9, 2003, requesting Federal Highway Administration (FHWA)
acceptance of your company's 10 mm thick Endurance® sign substrate material for
use on crashworthy traffic control devices in work zones on the National
Highway System (NHS).  Accompanying your
letter was a comparison of the Reflexite Endurance 10 mm material with other
sign substrates.  You requested that we
find 10 mm Endurance 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.” Specifically, you requested that 10 mm
Endurance be accepted wherever the following substrates have been previously
tested and/or accepted for use:
Reflexite
Americas Endurance 16 mm
Stabler
Industries 5/8 injection molded high density polyethelene
Various
10mm corrugated plastics, including IntePro, CoroPlast, and SafetyCor
Aluminum /
Plastic composites, including Alpolic, Renalite, and Aluswiss
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.
Most crash testing of portable sign stands was for specific
combinations of sign substrate and stand. Early testing focused on roll-up
signs on X-footprint sign stands. Recent testing has looked at rigid substrates
and the “worst case scenario” tests. 
The testing has included the most critical combination(s) of stand and
sign.  FHWA has accepted a range of
substrates on various manufacturers' stands by observing tests that “bracketed”
the materials that the stand could be expected to support.
Testing
Comparison to 16 mm Endurance
Full scale crash testing was conducted on 16 mm Endurance
signs by Reflexite using Dicke Tool sign stands.  These devices were found acceptable via FHWA Acceptance Letter
WZ-52 dated September 21, 2000.  Because
the 16 mm Endurance substrate can be considered a “worst case scenario” when
comparing it to 10 mm Endurance, the lighter substrates will be acceptable for
use on any stand successfully tested with the16 mm material.
Comparison to 10 mm polypropylene
Various manufacturers' 10 mm thick polypropylene substrates
have been tested on a number of different stands that have received FHWA
letters of acceptance, namely:
WZ-23 dated October 26, 1999,
WZ-46 dated July 21, 2000, 
WZ-74 dated March 15, 2001, 
WZ-78A dated June 15, 2001
WZ-103A dated March 6, 2002
The 10 mm Endurance substrate is fabricated from the same
high performance thermoplastic material as 16 mm Endurance, but in the same
structure (cell wall thickness, spacing of ribs, etc.) as the 10 mm
polypropylene substrates.  Your in-house
bending tests show that its static behavior is similar to that of 0.080 solid
aluminum, though it is approximately half the weight.  Those flexibility tests showed the 10 mm Endurance was stiffer
than the polypropylene substrates, however their mass and construction is very
similar (less than a 10 percent difference in weight.)  We believe that the difference in real-world
performance between these 10 mm plastics will not likely be observable.
Findings
We concur in your request that 10 mm Endurance sign panels
will be acceptable on sign stands successfully crash tested with heavier /
stiffer substrates such as
Reflexite Americas Endurance 16 mm
Stabler
Industries 5/8 injection molded hdpe
Aluminum /
Plastic composites, including Alpolic, Renalite, and Aluswiss
It will also be considered acceptable on sign stands
successfully crash tested with the other 10 mm corrugated plastic substrates
such as
IntePro, CoroPlast, and SafetyCor
This action does not make all lightweight substrates
interchangeable on all sign stands. Although 10 mm Reflexite may be used on
stands tested with other 10 mm corrugated plastics, the 16 mm Reflexite (and
similar heavier, stiffer substrates) may not. 
The 10 mm Reflexite can be used on stands were the heavier stiffer
substrates listed above are acceptable.
As discussed above 10 mm Reflexite sign substrate material
is acceptable for use on the NHS under the range of conditions specified, 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, or 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 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-147 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.
Reflexite Endurance sign material 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 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 S.
Griffith
Acting
Director, Office of Safety Design
Office
of Safety
Enclosures U.S. DEPARTMENT OF TRANSPORTATION

**Federal Highway Administration**

1200 NEW JERSEY AVENUE, SE

WASHINGTON, DC 20590

202-366-4000Subscribe to email updates
                    About
  

        
              About FHWA
                Careers
                Org Chart
                Staff Directories
                Work with UsPrograms
  

        
              Acquisition Management
                Civil Rights
                Federal Lands Highway
                Infrastructure
                Innovative Program Delivery
                Operations
                Planning, Environment, and Realty
                Policy
                Research, Development, and Technology
                SafetyPolicies, Rights, Legal
  

        
              About DOT
                Accessibility
                Budget and Performance
                Civil Rights
                FOIA
                Information Quality
                No FEAR Act
                Office of Inspector General
                Privacy Policy
                USA.gov
                Web Policies and Notices
                Web StandardsNews & Events
  

        
              Newsroom
                Press Releases
                Speeches & Testimony
                Media Contacts
                Connect with Us