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U.S. Department of Transportation

Federal Highway Administration

400 Seventh St., S.W.
Washington, D.C. 20590

 

October 25, 2005

Refer to: HSA-10/WZ-216

Mr. Jan Miller
Traffix Devices Inc.
220 Calle Pintoresco
San Clemente, California 92672

Dear Mr. Miller:

Thank you for your letter of May 6, 2005, requesting Federal Highway Administration (FHWA) acceptance of your company's Type I/II Barricade Sign Stand as a crashworthy traffic control device 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 are those lightweight devices which are to be self-certified by the vendor, Category II devices are other lightweight devices which need individual crash testing but with reduced instrumentation, Category III devices are barriers and other fixed or heavy devices also needing crash testing with normal instrumentation, and Category IV devices are trailer mounted lighted signs, arrow panels, etc. for which crash testing requirements have not yet been established. 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 barricade/sign support consists of two main parts, the diamond sign panel and the support structure. The support structure was made of two legs (each with two horizontal rails) connected by a revolute joint. The lets pivoted at the joint to form an A-shape structure with an angle of 45 degrees when positioned on the ground. The height of the legs was 42 inches and the barricade had a foot print size of 36" x 25". The diamond sign was a 48"x 48" x 3/8" (10 mm) corrugated plastic panel. The sign was attached to the legs using two 1/" - 20 x 1 ¼" hex bolts with hex nuts and flat washers. The barricade components were made of high-density polyethylene plastic with a total height of 72" and a total weight of 15 pounds.

You also requested acceptance of the same sign affixed to previously accepted (and virtually identical) Traffix Devices Inc. traditional type Type I/II folding plastic barricade series.

Testing

Full-scale automobile testing was conducted on your company' devices. Two stand-alone examples of the device were tested in tandem, one oriented at 90 degrees and the next placed six meters downstream facing head-on, as called for in our guidance memoranda.

The tests are summarized in the table below.

 

NCHRP Report 350 Test 3-71

Test Number

TR-P25025-01-NC

Sign Stand Orientation

90 degrees

Head-on

Weight of Tested Stand

15 Pounds

Mounting heights

12 Inches

Flags? Lights?

None (48x48 diamond sign panel)

Mass of Test Vehicle

798 kg

Impact Speed

97.17 km/hr

Exit Speed

94.68 km/hr

Velocity Change

0.70 km/hr

Extent of contact

Glanced off windshield

Top slapped windshield

Windshield Damage

None

Minor to moderate cracking

Findings

Windshield damage was limited to an area of moderate cracking at the impact point of the sign on the head-on barricade, and minor cracking radiating from that point. No potential for passenger compartment intrusion was evident.

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. We also concur that the following TDI Barricade Product Series are acceptable with a 48 x 48 corrugated sign, 3/8 (10 mm) thick, or lighter:

ProductDescriptionWeight each
35000 Series12ga steel legs with injection molded plastic panels17.4 lbs

 

14ga steel legs with injection molded plastic panels14.9 lbs
36000 SeriesBlow molded plastic legs w/injection molded plastic panels12.0 lbs
37000 SeriesBlow molded plastic legs and blow molded plastic panels12.0 lbs
39000 SeriesInjection molded plastic legs w/injection molded plastic panels10.2 lbs

Please note the following standard provisions that apply to the FHWA letters of acceptance:

Sincerely yours,

John R. Baxter, P.E.
Director, Office of Safety Design
Office of Safety

Enclosure


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