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                Safety Eligibility Letter WZ-232
  
  **Hardware Type:**
            Work Zone Devices
                          **Code:**
            WZ-232
                          **Date:**
            04/13/2007
                          **Testing Criteria:**
            NCHRP 350
                          **Manufacturer:**
            Davidson Plastics Corp
                          **Device Description:**
            X-Tube on a 40# Portable Rubber Base
                          **View PDF:**
            wz232rev.pdf (322.27 KB)
    
    
Skip to contentSkip to contentUnited States Department of Transportation - Federal Highway AdministrationApril 13, 2007
In Reply Refer To:

HSSD/WZ-232
Mr. Peter
  Speer
Davidson
  Traffic Control Products
Filtrona
  Extrusion, Inc.
3110 70th Avenue East
Tacoma,
  WA 
  98424
Dear Mr. Speer:
Thank you for your letter of October 12, 2006, requesting the
  Federal Highway Administration (FHWA) acceptance of your company's modified
  X-tube mounted to a 40 pound portable rubber base as a crashworthy traffic
  control device for use on the National Highway System (NHS).  Accompanying your letter was background
  information regarding informal tests conducted.  You requested that we find this device 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."
A drawing of the proposed modified X-tube mounted to a 40
  pound portable rubber base is enclosed.  The complete assembly is comprised of the following components:
Component
    Composition/Brand
    Dimensions/Notes
    Weight
    Quantity12 x 44 sign
    0.125 inch UHMW
    12 x 44 x 0.125 thick
    2.7 lbs
    1 -2 eachModified X-tube
    Co-polymide TPE
    3 x 2 x 48 tall x 0.15 thick
    1.9 lbs
    1 eachYeti Rubber Base
    Recycled rubber/steel
    17.5 x 27 x 3.8 thick
    40 lbs
    1 eachBased on our records of successfully crash tested vertical
  panels, equivalent designs such as yours are inherently safe.  Therefore, lightweight vertical panels with
  no lights attached, mounted to a flexible or a low-profile weighted base, and
  with a top panel height measuring no more than 48 inches, are now accepted by
  the FHWA as a Category 1 device and may be self-certified by the vendor.  Your vertical panel measures 52 inches tall.  Although the height is 4 inches taller than
  many previously tested designs, it is not a significant difference.  As a reminder, crash testing is still needed
  to determine the FHWA acceptance of vertical panels with lights attached.
Please note the following standard provisions that apply to the
  FHWA letters of acceptance:
·        This 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 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 the FHWA and the NCHRP
  Report 350.
·        To prevent misunderstanding by others, this
  letter of acceptance, designated as number
WZ-232, 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
  device is a patented product and considered proprietary.  If proprietary devices are specified by a
  highway agency 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 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
  device for which the applicant is not the patent holder.  The acceptance letter is limited to the
  crashworthiness characteristics of the candidate device, 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,
John R. Baxter, P.E.
John R. Baxter,
  P.E.
Director, Office
  of Safety Design
Office of Safetyproduct image
Enclosure U.S. DEPARTMENT OF TRANSPORTATION

**Federal Highway Administration**

1200 NEW JERSEY AVENUE, SE

WASHINGTON, DC 20590

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