1200 New Jersey Ave., SE

Washington, D.C. 20590

April 20, 2011

In Reply Refer To:

HSST/CC-65F

Mr. Felipe Almanza

TrafFix Devices Inc. 

160 Avenida La Pata

San Clemente, CA 92673

Dear Mr. Almanza:

This letter is in response to your request for the Federal Highway Administration (FHWA) 

acceptance of a roadside safety device for use on the National Highway System (NHS).

Name of device: Scorpion Truck Mounted Attenuator 

on lightweight shadow vehicle

Type of device: Truck Mounted Attenuator 

Test Level: NCHRP Report 350 Test Level 2

Testing conducted by: Karco Engineering 

Date of request: November 29, 2010

Complete package Rec’d: December 1, 2010

Request acknowledged: December 12, 2010

You requested that we find this system acceptable for use on the NHS under the provisions of the 

National Cooperative Highway Research Program (NCHRP) Report 350 “Recommended 

Procedures for the Safety Performance Evaluation of Highway Features.” 

Requirements

Roadside safety devices should meet the guidelines contained in the NCHRP Report 350 or the

American Association of State Highway and Transportation Officials’ Manual for Assessing 

Safety Hardware (MASH). The FHWA memorandum “Identifying Acceptable Highway Safety 

Features” of July 25, 1997, provides further guidance on crash testing requirements of 

longitudinal barriers. 

Decision

The following device is found acceptable:

• Test Level 2 Scorpion Truck Mounted Attenuator (TMA) on 4500 kg (9920 lb) shadow 

vehicle.
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Description

The TrafFix Devices, Inc. Scorpion TMA is a crash cushion which mounts directly to a host 

vehicle’s rigid frame. It is comprised of three sections: (1) steel mounting section; (2) steel 

back-up section; and (3) aluminum cartridge section. 

The steel mounting section provides a rigid attachment for the interface between the TMA and 

the host vehicle. The steel back-up section provides a structural mounting frame for the pivot 

location for the TMA to rotate to the vertical stored position when needed for transport. The 

aluminum cartridge section is comprised of structural energy absorbing curved aluminum tube 

framework, and three aluminum crush modules. The device has an overall length of 2.885 m 

(113.6 in) and overall width of 2.406 m (94.7 in). Enclosures 1 through 3 show the above 

components. 

Crash Testing

The Scorpion TMA was crash tested by KARCO Engineering according to NCHRP 350 test 

designation 2-51 guidelines. Occupant impact velocities and occupant risk values were within 

allowable limits in this test. The test vehicle was not penetrated during the test. Enclosure 4 

summarizes the results of test 2-51. In this test a 4497 kg (9914 lb) medium duty truck. It 

should be noted that the support vehicle roll-ahead distance in test 2-51 was measured 4121 mm 

(162 in, or 13-1/2 ft). Enclosure 5 illustrates movement of the support truck and deformation of 

the test article. 

Findings

The Scorpion TMA described above was previously crash tested and accepted by FHWA for use 

on the NHS in acceptance letter CC-65 dated on July 14, 2000. In test 2-51 a 9000 kg 

(19,842 lb) dump truck was used. For this current request letter, a smaller truck (4497 kg) was 

used for test 2-51. Results of the testing indicate that satisfactory results were obtained. 

I concur with your request that the Scorpion TMA can be installed on vehicles weighing a 

minimum of 4500 kg (9920 lb). One element that highway agencies should be aware of when 

considering use of this product is the roll-ahead distance of 13-1/2 ft that was observed in the 

crash test. 

Therefore, the device described above and detailed in the enclosed drawings is acceptable for use 

on the NHS under the range of conditions tested, when such use is acceptable to a highway 

agency.

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

• This 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 
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significantly different from the version that was crash tested, we reserve the right to modify 

or revoke our 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 it will meet the crashworthiness requirements of the FHWA and the NCHRP 

Report 350.

• To prevent misunderstanding by others, this letter of acceptance is designated as number 

CC-65F and shall not be reproduced except in full. This letter and the test documentation 

upon which it is based are public information. All such letters and documentation may be 

reviewed at our office upon request. 

• Scorpion TMAs are patented products and considered proprietary. If proprietary devices are 

specified by a highway agency for use on Federal-aid projects, except exempt, non-NHS 

projects, (a) they must be supplied through competitive bidding with equally suitable 

unpatented items; (b) the highway agency must certify that they are essential for 

synchronization with the 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.

• This acceptance letter shall not be construed as authorization or consent by the FHWA to use, 

manufacture, or sell any patented device for which the applicant is not the patent holder. The 

acceptance letter is limited to the crashworthiness characteristics of the candidate device, and 

the FHWA is neither prepared nor required to become involved in issues concerning patent 

law. Patent issues, if any, are to be resolved by the applicant.

Sincerely,

Michael S. Griffith

Director, Office of Safety Technologies

Office of Safety

Enclosures