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                Safety Eligibility Letter WZ-108
  
  **Hardware Type:**
            Work Zone Devices
                          **Code:**
            WZ-108
                          **Date:**
            02/08/2002
                          **Testing Criteria:**
            NCHRP 350
                          **Manufacturer:**
            TrafFix Devices, Inc.
                          **Device Description:**
            Various portable sign stands under requests of 7-9-01 and 1-9-02
                          **View PDF:**
            wz108.pdf (2.01 MB)
    
    
Refer to: HSA-10/WZ-108
Mr. Dave Gertz
  TrafFix Devices, Inc.
  220 Calle Pintoresco
  San Clemente, CA  92672
Dear Mr. Gertz:
Thank you for your letter of January 
  9, 2002, requesting Federal Highway Administration (FHWA) acceptance of your 
  company's portable sign stands and barricades as crashworthy traffic control 
  devices for use in work zones on the National Highway System (NHS).  Accompanying 
  your letter was a report of the crash testing conducted by Karco Engineering 
  and a video of the tests.  You also asked for our review of the results of tests 
  1, 2, 3, and 5 that accompanied your July 9, 2001, letter (as you requested 
  at the time we limited our review to the Little Buster stand, the subject of 
  test 4.)  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 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 devices in 
  the two letters follows:
July 9, 2001
Test 1. Sign Stand. Rubber Pole Base 
  with 30 pound ballast, 36 x 36 inch aluminum sign, and light.  The vertical 
  mast of this stand was 2 x 2 inch square 16 gage steel tubing, 66 inches long.  
  The aluminum signs were supported 18 inches above the ground.
Component
      Material
      Height to top
      Width
      Thickness
      WeightBase
      Rubber
      n/a
      16 
          x 18 in
      2 
          inches
      30 
          poundsMast
      Steel
      66 
          in long
      2 
          inches
      16 
          gage
      9 
          poundsSign
      0.080 
          Al
      69 
          inches
      36 
          x 36 in
      0.080 
          in
      9 
          poundsLight
      Empco 
          Light
      78 
          inches
      n/a
      n/a
      4.5 
          poundsTest 2. Big Buster Sign Stand with 48 x 48 inch aluminum 
    sign.  The vertical mast of this stand is telescoping square aluminum 
    tubes.  The aluminum sign is mounted 66 inches above the ground.
Component
      Material
      Height to top
      Width
      Thickness
      WeightLegs
      Aluminum
      n/a
      1.25 
          in
      0.100 
          in
      3 
          pounds ea.Outer Mast
      Aluminum
      n/a
      1.50 
          in
      0.100 
          in
      3 
          poundsInner Mast
      Aluminum
      n/a
      1.25 
          in
      0.100 
          in
      3 
          poundsSign
      Aluminum
      133 
          inches
      48 
          x 48 in
      0.080
      16 
          poundsLight
      none
      n/a
      n/a
      n/a
      n/a
Test 3. Aluminum Buster Sign Stand 
  with 48 x 48 inch aluminum sign bolted to inner mast and Plastic Flag Holder.  
  The vertical mast of this stand is 1.50 inch square aluminum with 0.100 wall, 
  and 1.25 inch square PVC tubing with 0.250 inch wall.  The 0.080 inch thick 
  aluminum sign weighed 16 pounds and  was mounted at a height of 18 inches above 
  the ground.
Component
      Material
      Height to top
      Width
      Thickness
      WeightLegs
      Aluminum
      n/a
      1.25 
          in
      0.100 
          in
      2 
          pounds eaOuter Mast
      Aluminum
      n/a
      1.50 
          in
      0.100 
          in
      3 
          poundsInner Mast
      PV
      n/a
      1.25 
          in
      0.25 
          in
      5 
          poundsSign
      Aluminum
      86 
          inches
      48 
          x 48 in
      0.080 
          in
      16 
          poundsLight
      [flag 
          bracket]
      n/a
      n/a
      n/a
      n/a
Test 4. Little Buster Sign Stand with 
  1220 x 1220 mm (48 x 48 inch) Aluminum Sign bolted to Full Length Inner Mast 
  and TrafFix Flag holder.  Sign mounted 460 mm (18 inches) above ground.  
  This device was accepted in FHWA Acceptance Letter WZ-81.
Test 5. Rubber Base Sign Stand with 
  Pinned Inner Mast, 48 x 48 inch aluminum sign and B-Light.  The vertical 
  mast of this stand was 1.75 x 1.75 inch square 16 gage steel tubing, 72 inches 
  long.  The 0.080 inch aluminum signs weighed 16 pounds and was supported 12 
  inches above the ground.  The Type B warning light weighed 4.5 pounds and was 
  attached to the top of the mast using an Emco plastic flag bracket.
Component
      Material
      Height to top
      Width
      Thickness
      WeightBase
      Rubber
      n/a
      17 
          x 27 in
      2 
          in
      40 
          poundsMast
      Steel
      72  
          in
      1.75 
          x 1.75 in
      16 
          gage
      9 
          poundsSign
      Aluminum
      80 
          in
      48 
          x 48
      0.080 
          in
      16 
          poundsLight
      Type 
          B
      n/a
      n/a
      n/a
      n/a
January 9, 2002
Test 1. Little Buster Sign Stand with 
  48 x 48 inch aluminum sign with Slip-over Tube Mast. The vertical mast outside 
  sleeve of this stand was 1.5 inch square steel 12 gage tube.  The 0.080 inch 
  thick aluminum sign weighed 16 pounds and was mounted at a height of 18 inches 
  above the ground.
Component
      Material
      Height to top
      Width
      Thickness
      WeightBase
      Steel
      16 
          inches
      2.5 
          inches
      0.250 
          wall
      30 
          poundsMast
      Steel
      86 
          inches
      1.2 
          inches
      16 
          ga
      7 
          poundsSign
      Aluminum
      85 
          inches
      48 
          x 48 in
      0.080
      16 
          poundsLight
      [flag 
          bracket]
      n/a
      n/a
      n/a
      n/a
Test 2. Type 3 Plastic Barricade with Plastic Posts and Pinned Rubber Bases, 
  carrying a 48 x 48 inch diamond sign.  The vertical posts are extruded PVC 
  plastic, as crash tested by Davidson Plastics and found acceptable in our letter 
  WZ-39.  The extruded plastic rails are High Density Polyethelene, also tested 
  previously.  They were attached to the vertical posts using grade two 1/4 inch 
  bolts.  This barricade carried a lightweight corrugated plastic diamond sign 
  mounted 12 inches above the pavement.  It was attached to the rails with grade 
  two 1/4 inch bolts.
Component
      Material
      Height to top
      Width
      Thickness
      WeightBase
      Rubber
      n/a
      17 
          x 27 in
      2 
          in
      40 
          poundsVertical posts
      X 
          section Plastic
      72 
          in
      1.75 
          in
      1.75 
          inHoriz.  Panels
      Extruded 
          Plastic
      60 
          in
      8 
          ft x 8 in
      3/4 
          in
      6 
          pound eaSign
      Corrug. 
          Plastic
      80 
          in
      48 
          x 48 in
      0.4 
          inch
      4.5 
          pounds
Test 3.  Econo Buster Sign Stand with 
  48 x 48 inch aluminum sign with Slip-over Outer Tube Mast.  The vertical 
  mast outside sleeve of this stand was 1.5 inch square steel 12 gage tube.   
  The 0.080 inch thick aluminum sign weighed 16 pounds and  was mounted at a height 
  of 16 inches above the ground.
Component
      Material
      Height to top
      Width
      Thickness
      WeightBase
      Steel
      13 
          inches
      1.0 
          inch
      1/8 
          inch
      19 
          poundsMast
      Steel
      84 
          in
      1.2 
          x 1.2 in
      16 
          gage
      7 
          poundsSign
      Aluminum
      84 
          in
      48 
          x 48
      0.080
      16 
          poundsLight
      [flag 
          bracket]
      n/a
      n/a
      n/a
      n/a
Test 4. Type III Plastic panel Barricade with Steel Post uprights and Lights, 
  tested with 48 x 48 inch aluminum sign.  The vertical uprights were 1.75 inch 
  square 16 gage steel posts, 72 inches long.  The panels were 96 inches long 
  by 8.5 inches wide and 3/4 inch thick corrugated plastic.  The lights were Empco 
  lights weighing 4.5 pounds mounted on the vertical uprights.
Component
      Material
      Height to top
      Width
      Thickness
      WeightBase
      Rubber
      n/a
      17 
          x 27 in
      2 
          in
      40 
          poundsVertical posts
      Steel
      72 
          in
      1.75 
          x 1.75 in
      16 
          gage
      9 
          poundsHoriz.  Panels
      Corrug. 
          Plastic
      72 
          in
      8 
          ft x 8 in
      3/4 
          in
      6 
          pound eaLight
      [Empco 
          Light]
      90 
          inches
      n/a
      n/a
      4.5 
          pounds
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 complete device as tested 
  is shown in Enclosure 1.  The crash testing is summarized in the table below:
Test # (6/9/2001 letter)
    Test 1
    Test 2
    Test 3
    Test 5Test Article
    Sign 
        Stand
    Big 
        Buster
    Al. 
        Buster
    Rubber 
        BaseVehicle Inertial Mass
    809 
        kg
    904 
        kg
    904 
        kg
    885 
        kgImpact Speed, Head-on
    101.43 
        km/h
    100.42 
        km/h
    100.40 
        km/h
    101.33 
        km/hImpact Speed, 90 Deg.
    99.81 
        km/h
    99.05 
        km/h
    99.80 
        km/h
    97.49 
        km/hVelocity Change
    0.45 
        m/s
    0.38 
        m/s
    0.0.2 
        m/s
    1.04 
        km/hVehicle crush
    Moderate
    None
    Minor
    ModerateOccupant Compart. Intrusion
    None
    None
    None
    NoneWindshield Damage
    Major
    Moderate
    None
    NoneOverall Assessment
    Marginal
    Pass
    Pass
    PassWindshield damage in Test 1 was primarily 
  due to the flat impact of the warning light.  A small but dense area of cracking 
  was surrounded by more moderated spider web cracking.  A driver should be able 
  to see around the opaque area.
Windshield damage in Test 2 was due to 
  the impact of the sign's mast contacting the roof line. Moderate cracking radiated 
  from this impact point.
Test # (1-9-02 letter)
    Test 1
    Test 2
    Test 3
    Test 4Test Article
    Little 
        Buster Sign Stand
    Type 
        III Plastic Leg Barricade
    Econo Buster Sign Stand
    Type 
        III Steel Leg BarricadeVehicle  Mass
    873 
        kg
    886 
        kg
    873 
        kg
    886 
        kgImpact Speed Head-on
    99.52 
        km/h
    98.76 
        km/h
    100.0 
        km/hr
    99.92 
        km/hrImpact Speed 90 Deg.
    97.92 
        km/h
    97.39 
        km/h
    97.84 
        km/h
    97.47 
        km/hrVelocity Change
    0.44 
        m/s
    0.38 
        m/s
    0.60 
        m/s
    0.68 
        m/sVehicle crush
    Minor
    Minor
    Minor
    MinorOccupant Compart. Intrusion
    None
    None
    None
    NoneWindshield Damage
    Broken, 
        shattered
    Broken, 
        shattered
    Broken, shattered
    Broken, shatteredOverall Assessment
    Marginal
    Marginal
    Marginal
    MarginalWindshield damage in Tests 1 and 3 resulted 
  from the flat impact of the aluminum sign panel in the head-on test.  Cracking 
  was distributed over the whole windshields of both cars but did not significantly 
  impair the driver's ability to see.  Deflection of the glass was between two 
  and three inches.  Therefore, this device will be considered marginally acceptable.
Test 2 was of a plastic framed Type III 
  barricade.  The vertical supports of this barricade shattered upon impact, allowing 
  the horizontal rails to strike the windshield in both the head on and 90 degree 
  tests.  Although there was no windshield penetration in this case, the potential 
  for rigid horizontal panels to spear the vehicle is higher.  It is critical, 
  therefore, that this design use  flexible, lightweight horizontal rails as tested.  
  The corrugated plastic sign panel mounted on the barricade is acceptable for 
  use as tested.
Windshield damage in Test 4 also resulted 
  from the flat impact of the sign panel mounted to the barricade.  The light 
  gage steel vertical supports crumpled upon impact.  The performance of these 
  vertical supports was better than the plastic supports in Test 2, but did not 
  hold the barricade together as well as the hot-rolled, high carbon steel angles, 
  nor the perforated square steel tubes used in the generic Type III barricade 
  designs distributed by the FHWA in our letter WZ-85.  Even though the results 
  of this test were acceptable, FHWA discourages the use of rigid aluminum or 
  plywood sign panels centered on Type III barricades.  We prefer that lightweight 
  plastic sign substrates be used in this location, such as the sign in Test 2.
Findings
Damage to the windshields of the test vehicles varied as discussed above.  
  Our assessment of the tested devices is summarized here.
July 9, 2001
Test 1. Sign Stand.  Rubber Pole Base with 30 pound ballast, 36 x 
        36 inch aluminum sign, and light.
    Acceptable, but marginalTest 2.Big Buster Sign Stand with 
      48 x 48 inch aluminum sign.
    AcceptableTest 3.Aluminum Buster Sign Stand 
      with 48 x 48 inch aluminum sign bolted to inner mast and Plastic Flag Holder.
    AcceptableTest 4.Little Buster Sign Stand 
      with 1220 x 1220 mm (48 x 48 inch) Aluminum Sign bolted to Full Length Inner 
      Mast and TrafFix Flag holder.  Sign mounted 460 mm (18 inches) above ground.
    AcceptableTest 5.Rubber Base Sign Stand 
      with Pinned Inner Mast, 48 x 48 inch aluminum sign and B-Light.
    AcceptableJanuary 9, 2001
Test 1.Little Buster Sign Stand with 48 x 48 inch aluminum sign with 
        Slip-over Tube Mast.
    Acceptable, but marginalTest 2. Type III Plastic Barricade 
      with Plastic Posts and Pinned Rubber Bases, carrying a 48 x 48 inch diamond 
      sign.
    Acceptable, but marginalTest 3.Econo Buster Sign Stand 
      with 48 x 48 inch aluminum sign with Slip-over Outer Tube Mast.
    Acceptable, but marginalTube 4.Type III Plastic panel 
      Barricade with Steel Post uprights and Lights, tested with 48 x 48 inch 
      aluminum sign.
    Acceptable with lightweight plastic sign panelThe results of the testing 
  are compared to the FHWA requirements above.  The devices described above and 
  shown in the enclosed drawings for reference are acceptable as noted for use 
  on the NHS under the range of conditions tested, when proposed by a State.
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 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-108 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 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 U.S. DEPARTMENT OF TRANSPORTATION

**Federal Highway Administration**

1200 NEW JERSEY AVENUE, SE

WASHINGTON, DC 20590

202-366-4000Subscribe to email updates
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