January 29, 2003

Refer to: HSA-10/WZ-136

Mr. Henry Ross
United Rentals Highway Technologies
880 North Addison Road
P.O. Box 7050
Villa Park, Illinois 60181-7050

Dear Mr. Ross:                                                           

Thank you for your July 24, 2002, letter that you hand delivered to Mr. Nicholas Artimovich of my office on October 23, 2002.  In that letter you are requesting Federal Highway Administration (FHWA) acceptance of your company's 8-foot wide Type III barricades using 0.450-inch solid polyethylene plastic panels and X-tube plastic uprights as crashworthy traffic control devices for use in work zones on the National Highway System (NHS).  Accompanying your letter was a summary report of crash testing conducted by E-Tech Testing Services and a CD with photos 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:

The frame of the barricade consists of 44.5 mm (1.75 inch) square plastic X-tube uprights. The skids are 2 PPF U-channel posts. The socket for supporting the uprights is a 6-inch long piece of 50.8 mm (2 inch) perforated square steel tube welded to a piece of 7 ga flat steel. The flat steel piece is drilled to accommodate bolts used to attach the socket to the skid. The uprights are simply inserted into the socket. The barricade rails measured 2438 mm long by 203 mm high by 11.4 mm thick (8 feet by 8 inches x 0.14 inch) polyethylene board. The entire barricade (without ballast or lights) weighs 32.8 kg (72.3 pounds.)  Each barricade also had two lightweight warning lights mounted to the top of the upright.

Testing

Full-scale automobile testing was conducted on your company's devices.  Two stand-alone examples of the device were tested in separate tests, one head-on and one turned at 90 degrees, as permitted in our guidance memoranda.  The complete device as tested is shown in Enclosure 1. 

The crash test is summarized in the table below:

* In this end-on test the top two rails impacted the windshield causing moderate deformation and cracking.  One of the lights hit in such a manner as to snag briefly on the windshield trim and causes a hole through the glass near the roofline.  This dime-sized hole did not penetrate the inside metal rim of the windshield mount.  Although this nominally violates the FHWA windshield damage criteria for work zone devices, we have carefully considered the implications. This barricade is similar in many respects to other Type III barricades that have been successfully tested.  Because of a unique occurrence, it caused a hole in this test.

Findings                                 

 Damage was limited to moderate to severe cracking of the windshield and minor sheet metal damage to the hood and roof.  There did not appear to be a potential for penetration of the occupant compartment.  With the exception noted above, the results of the testing met the FHWA requirements and, therefore, the devices described above and shown in the enclosed drawings for reference 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 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-136 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 United Rentals traffic control 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,

Harry W. Taylor,

Acting Director, Office of Safety Design

Enclosure