February 28, 2003

Refer to: HSA-10/WZ – 140

Mr. Greg Hannah
Impact Recovery Systems
246 West Josephine Street
P.O. Box 12637
San Antonio, TX  78212

Dear Mr. Hannah:

This is in response to your letter of December 3, 2002, requesting Federal Highway Administration (FHWA) acceptance of your company's Flexible Traffic Control Products with an Empco Lite as crashworthy traffic control devices for use in work zones on the National Highway System (NHS).  Accompanying your letter were reports of crash testing conducted by    Karco Engineering and 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 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 follows:

Test Article 1:  12 inch x 48-inch Double sided Vertical Panel with No. 103QR Portable One Base and Light.  The Portable One Base is solid recycled rubber measuring 355 mm (14 inches) wide by 864 mm (34 inches) long and weighing 22 kg (48 pounds).  The vertical panel consists of a 60.3 mm (2 3/8 inch) diameter, 1220 mm tall (48 inch) polyethylene plastic tube.  To the front and back of the tube are attached 305 mm (12 inch) by 1220 mm (48 inch) tall vertical panels.

They are attached to the tube using standard grad 3/8 inch x 2 ¾ inch carriage bolts with tee nuts and plastic washers.

Test Article 2: 24 inch x 36 inch Directional Indicator Barricade with 103QR Portable One base and Light.  The Portable One Base is as described above.  The Directional Indicator Barricade also consists of a polyethylene tube as described above except at a height of 890 mm (35 inches).  To it is attached a single 610 mm (24 inch) tall by 914 mm (36 inch) wide directional panel.

Testing

Full-scale automobile testing was conducted on your company' devices.  One stand-alone example of each 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.  Because the basic structure is the same and both have been previously accepted without warning lights attached, this single test is appropriate for assessing their crashworthiness.  The automobile exceeded the tolerance for the 820C vehicle called for in NCHRP Report 350.  Again, in this case we will accept that because this is a re-test of the device, using lights.

The tests are summarized in the table below.

Findings

Damage was limited to sheet metal damage and minor cracking of the windshield.  The cracking was due to the impact of the plastic lens of the warning light.  The glass did not deform nor was a hole caused by the impact.  As the performance of the conventional Type A and C warning light was comparable to the omni directional Type D light, these two lightweight warning lights may be used interchangeably on these devices.  The results of the testing met the FHWA requirements and, therefore, the devices described in the various requests 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.

In a letter dated December 3, 2002, you also asked us to consider the use of warning lights atop your type III barricades. These plastic barricades were the subject of our letter to you, WZ-110, dated March 22, 2002.  Because the top of the barricade struck the test vehicle in the lower part of the windshield causing light to moderate cracking, we expect that the addition of a light would cause additional damage.  Unfortunately, we are not able to estimate how severe the damage would be in the head-on test. Therefore, we must recommend that these barricades be crash tested with lights in place before we can take action.

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 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-140 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.
  
  
• Impact Recovery Systems devices 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 S. Griffith
Acting Director, Office of Safety Design
Office of Safety

2 Enclosures