November 26, 2002

Refer to: HSA-10/WZ-125

Mr. Grant Dicke
Dicke Tool Company
1201 Warren Avenue
P.O. Box 518
Downers Grove, Illinois  60515

Dear Mr. Dicke:                                                           

Thank you for your letter of March 29, 2002, and facsimile message of November 21, 2002, requesting Federal Highway Administration (FHWA) acceptance of your company's portable sign stands as crashworthy traffic control devices for use in work zones on the National Highway System (NHS).  Accompanying your letter was a report of crash testing conducted by the Midwest Roadside Safety Facility.  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.”  Most of the sign support systems that were tested in this phase were reviewed previously and are the subject of our November 21, 2001, letter to you, designated WZ-99.  This present letter of acceptance, WZ-125, will only deal with the one remaining sign stand that was tested with successful results.

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 AINFORMATION: 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:

Systems 58 and 59, Test No. D-30 DF-4000 Stand - A heavy duty, double torsion spring mounted portable sign support with a 1219 x 1219 mm vinyl sign mounted at a height of 305 mm from the ground and with three wood-staffed flags at a height of 2299 mm. This stand supported a RUNR48 reflective vinyl roll up sign.  Tested at both 90 degrees and head-on.

Testing

Full-scale automobile testing was conducted on your company's devices.  Two stand-alone examples of the device were tested in tandem, one oriented at 90-degrees (i.e., turned away from oncoming traffic) and the next placed six meters downstream head-on, as called for in our guidance memoranda.  The complete device as tested is shown in Enclosure 1. The crash test is summarized in the table below:

Findings

Damage was limited to dents, and minor windshield cracking.  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-125 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 Dicke Tool Company signs 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,

Carol H. Jacoby, P.E.
Director, Office of Safety Design       

Enclosure