U.S. Department 

of Transportation 

Federal Highway 

Administration 

1200 New Jersey Ave., SE 

Washington, D.C. 20590 

April 1, 2020 

In Reply Refer To: 

HSST-1/CC-160 

Mr. Michael J. Buehler 

Trinity Highway Products, LLC 

3617 Cincinnati Ave. 

Rocklin, California 95765 

Dear Mr. Buehler: 

This letter is in response to your December 12, 2019 request for the Federal Highway 

Administration (FHWA) to review a roadside safety device, hardware, or system for eligibility 

for reimbursement under the Federal-aid highway program. This FHWA letter of eligibility is 

assigned FHWA control number CC-160 and is valid until a subsequent letter is issued by 

FHWA that expressly references this device. 

Decision 

The following device is eligible, with details provided in the form which is attached as an 

integral part of this letter: 

• SMTTM 

Scope of this Letter 

To be found eligible for Federal-aid funding, new roadside safety devices should meet the crash 

test and evaluation criteria contained in the American Association of State Highway and 

Transportation Officials’(AASHTO) Manual for Assessing Safety Hardware (MASH). 

However, the FHWA, the Department of Transportation, and the United States Government do 

not regulate the manufacture of roadside safety devices. Eligibility for reimbursement under the 

Federal-aid highway program does not establish approval, certification or endorsement of the 

device for any particular purpose or use. 

This letter is not a determination by the FHWA, the Department of Transportation, or the United 

States Government that a vehicle crash involving the device will result in any particular 

outcome, nor is it a guarantee of the in-service performance of this device. Proper 

manufacturing, installation, and maintenance are required in order for this device to function as 

tested. 

This finding of eligibility is limited to the crashworthiness of the system and does not cover other 

structural features, nor conformity with the Manual on Uniform Traffic Control Devices. 
 

 

 

 

 

 

2 

Eligibility for Reimbursement 

Based solely on a review of crash test results and certifications submitted by the manufacturer, 

and the crash test laboratory, FHWA agrees that the device described herein meets the crash test 

and evaluation criteria of the AASHTO’s MASH. Therefore, the device is eligible for 

reimbursement under the Federal-aid highway program if installed under the range of tested 

conditions. 

Name of system: SMTTM 

Type of system: Truck-Trailer Mounted Attenuator (TTMA) 

Test Level: MASH Test Level 3 (TL3) 

Testing conducted by: KARCO 

Date of request: December 12, 2019 

FHWA concurs with the recommendation of the accredited crash testing laboratory on the 

attached form. 

Full Description of the Eligible Device 

The device and supporting documentation, including reports of the crash tests or other testing 

done, videos of any crash testing, and/or drawings of the device, are described in the attached 

form. 

Notice 

This eligibility letter is issued for the subject device as tested. Modifications made to the device 

are not covered by this letter. Any modifications to this device should be submitted to the user 

(i.e., state DOT) as per their requirements. 

You are expected to supply potential users with sufficient information on design, installation and 

maintenance requirements to ensure proper performance. 

You are expected to certify to potential users that the hardware furnished has the same chemistry, 

mechanical properties, and geometry as that submitted for review, and that it will meet the test 

and evaluation criteria of AASHTO’s MASH. 

Issuance of this letter does not convey property rights of any sort or any exclusive privilege. This 

letter is based on the premise that information and reports submitted by you are accurate and 

correct. We reserve the right to modify or revoke this letter if: (1) there are any inaccuracies in 

the information submitted in support of your request for this letter, (2) the qualification testing 

was flawed, (3) in-service performance or other information reveals safety problems, (4) the 

system is significantly different from the version that was crash tested, or (5) any other 

information indicates that the letter was issued in error or otherwise does not reflect full and 

complete information about the crashworthiness of the system. 

Standard Provisions 
3 

• To prevent misunderstanding by others, this letter ofeligibility designated as FHW A 

control number CC-160 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 upon request. 

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

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

• This FHWA eligibility letter is not an expression ofany Agency view, position, or 

determination of validity, scope, or ownership ofany intellectual property rights to a 

specific device or design. Further, this letter does not impute any distribution or licensing 

rights to the requester. This FHWA eligibility letter determination is made based solely 

on the crash-testing information submitted by the requester. The FHWA reserves the 

right to review and revoke an earlier eligibility determination after receipt ofsubsequent 

information related to crash testing. 

Sincerely, 

Michael S. Griffith 

Director, Office ofSafety Technologies 

Office of Safety 

Enclosures 
SystemType SubmissionType DeviceName / Variant TestingCriterion Test 

Level 

'CC':Truck-Mounted Attenua r-

(' 

Physical CrashTesting 

Engineering Analysis SMTTM 

AASHTOMASH TL3 

I r- (' Resubmission 

I I I I 

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Page 1 of 7 

Request for Federal Aid Reimbursement Eligibility 

of Highway Safety Hardware 

r ettiSubm

Date of Request: December12,2019 New 

Name: BretR.Eckert,P.E. 

Company: Trinity Highway Products,LLC 

Address: 3617Cincinnati Ave.,RocklinCA 95765 

Country: USA 

To: Michael S. Griffith, Director 

FHWA, Office of Safety Technologies 

I request the following devices be considered eligible for reimbursement under the Federal-aid 

highway program. 

Device&TestingCriterion-Enter from right to left starting with TestLevel ! -! - ! ! -! -! 

By submitting this request for review and evaluation by the Federal Highway Administration, I certify 

that the product(s) was (were) tested in conformity with the AASHTO Manual for Assessing Safety 

Hardware and that the evaluation results meet the appropriate evaluation criteria in the MASH. 

Individual or Organization responsible for the product: 

Contact Name: MichaelJ.Buehler,P.E. SameasSubmitter 

CompanyName: Trinity Highway Products,LLC SameasSubmitter [SJ 

Address: 3617Cincinnati Ave.,RocklinCA 95765 SameasSubmitter [SJ 

Country: USA SameasSubmitter [SJ 

Enter below all disclosures of financial interests as required by the FHWA `Federal-Aid Reimbursement 

Eligibility Process for Safety Hardware Devices' document. 

TheSMTTMTrailerMounted Attenuator ("SMTTM")system technology is thecommercialembodiment of 

intellectual property that is protected by patentsowned byTrinity Highway Products,LLC("THP"). THPdoesnot 

pay royalties forsalesof theSMTTM. TheSMTTMsystem wasdesignedand developed byengineersandemployees 

at THP. Thepatent holders of record for theSMTTMsystem areMichaelJ.Buehler,P.E.,PatrickA.Leonhardt,P.E., 

and Sean Thompson; and all are employed by THP. The associated United States patent, number 9,399,845 

(DatedSept.11,2013),isassigned toTrinity HighwayProducts,LLC. 

ApplusIDIADAKarcoEngineering,LLC(KARCO)conducted thecertification testsof theSMTTMsystem. KARCOis 

an internationally accredited third party crash testing laboratory. Full-scale crash testing on the SMTTMsystem 

was performed in accordance with testing criteria, asset forth by the American Association of State Highway 

andTransportation Officials(AASHTO) in theManual for AssessingSafetyHardware("MASH") (2016). Other than 

fees paid to KARCOto conduct the testsand then analyze and report the test results, KARCOand THP do not 

share financialinterests. 
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I 

r- New Hardwareor 

Significant Modification r Modification to ExistingHardware 

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PRODUCT DESCRIPTION 

Help 

TheSMTTMisa mobilecrashcushionattached to the rear of asupport vehicle. It isa towablesystem designed to 

be used onshadow or advanced warning vehiclesupstream of moving operationsor asabarrier vehicle for 

stationary work zones. TheSMTTMisdesigned to be used onsupport vehicleswith a minimum weight of 12,000 

lb.anda maximum weight of 25,000lb. 

The SMTTMconsists of a frame, axle, energy absorbing cartridges, lighting, face plate, optional spare tire, and 

optionalarrow board / messageboard. Theframeisastructural tubesteel space frame that isbolted together 

in sectionsconsisting of an ImpactFrame,Rear Arms,CenterFrame,Forward Arms,andTongueSection. There 

isalso a flanged pintle lunette ring that bolts into location on the front of the system. This ring has two 

possible positions to provide thecustomer adjustability in hitch height on the rear of thesupport truck. The 

frameispowder coatedand hasfactory installed decals,name-plate,andVIN tag. 

TheSMTTMis242" long by 82" wide. Thesystem is44" high,including the nominal height above the ground of 

12" ± 1" at the rear of thesystem. Asystem without the optionalarrow board weighsapproximately 2620 lbs. 

The axle isa torsion axle with hubs containing 14” trailer wheels and tires. The axle is equipped with an 

emergency breakaway braking system. This axle fastens to the bottom of the center frame in four locations 

using 5/8-11 boltsand nuts. Thewheelsand tiresareshrouded by fenders. 

There are two energy absorbing cartridges, the rear cartridge “Cartridge A” and the forward cartridge 

“CartridgeB”. Bothcartridges consist of aluminum cellsseparated byaluminumsheet diaphragms. Thesides, 

top and bottom, and end are aluminum sheet. The rear of each cartridge isasteel sheet “strong-back” that 

contains features for attachment to the Center or Tongue sections. Standard lighting consists of LEDstop, 

turn, tail,and clearance lights. Thelighting may beLEDor incandescentand can be manufactured by different 

lighting supply vendors. Theunique design of theimpact faceand framearmsare designed to limit rotation of 

theSMTTMwithout the need for additional equipment connected to the tongueorsupport vehicle. 

Thealuminum faceplate isa light-weight assembly designed to cover the rear of thesystem and improve 

driver visibility. It isa 0.040” thickaluminumsheet with fabricated bends to fit theImpactFrame. 

The energy absorbing and structural portions of the SMTTMconsistof the frame, frame arms, and cartridges. 

Theotherancillary portions of thesystem,suchas theelectrical lighting do not absorbappreciable amountsof 

impact energy thereforechanges to thesecomponentswill not affect the performanceof theSMTTMduring an 

impact event. For instance,various vendors maysupply electroniccontrolsand electrical lighting components 

that perform the same function as the components that were present during testing. The spare tire, arrow 

board, and battery box were present during testing, however, these itemsare not required for proper 

performance of the SMTTM.The impact face may also be any color and striped with any reflective or nonreflective tape of any color,depending uponcustomer requirements. 

CRASH TESTING 

Bysignaturebelow, theEngineer affiliated with the testing laboratory, agreesin support of thissubmission that 

all of the critical and relevant crash tests for this device listed above were conducted to meet the MASH test 

criteria. The Engineer has determined that no other crash testsare necessary to determine the device meets 

theMASH criteria. 

Engineer Name: StevenMatsusaka 

EngineerSignature: Steven Matsusaka

Address: 9270HollyRoad,Adelanto,CA.92301 SameasSubmitter 

Country: USA SameasSubmitter ~ 
 

 

 

 

 

 

 

 

 

 

 

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A brief description of each crash test and its result: Help 

RequiredTest 

Number 

Narrative 

Description 

Evaluation 

Results 

3-50(1100C) 

ApplusIDIADAKARCOTestNo.P39122-03. 

TestDateJune5,2019. CrashTestReport 

No.TR-P39122-03_Dfor MASHTest3-50 

CrashTest ofTrinity Highway ProductsSMT. 

The Trailer Mounted Attenuator (TMA) was 

impacted by a 2009 KiaRio 4-door sedan. 

The test vehicle impacted theSMTTMAat a 

velocity of 62.78mph (101.03km/h)andan 

impact angle of 0.5°. The SMT brought the 

vehicle to acontrolled stop.Themaximum 

dynamic deflection of thesystem was6.4ft. 

(2.0 m). The impact wasabsorbed by the 

TMA and the support truck was pushed 

forward until it came to rest 2.8 ft. (0.9 m) 

downstream.Thevehiclecame to rest 7.3ft. 

(2.2m) downstreamand 1.1ft.(0.3m) right 

from its initial position. The test vehicle 

sustained damage to its front end. The 

hood crushed and creased near its center; 

the front bumper, front fenders, and 

headlights were crushed; and the engine 

waspushedrearward toward thefirewall. 

The occupant compartment was not 

penetrated and the deformation limits were 

not exceeded. The Trinity Highway 

ProductsSMT MASH Trailer Attenuator met 

all therequirements for MASH2016Test 

3-50. 

PASS 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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RequiredTest 

Number 

Narrative 

Description 

Evaluation 

Results 

3-51(2270P) 

ApplusIDIADAKARCOTestNo.P39123-02. 

TestDateJune28,2019. CrashTestReport 

No.TR-P39123-02_Bfor MASHTest3-51 

CrashTest ofTrinity Highway ProductsSMT. 

TheTrailer-Mounted Attenuator (TMA) was 

impacted by a 2013 RAM 1500 4-door 

pickup truck. The test vehicle impacted the 

SMTTMAat a velocity of 63.64mph(102.42 

km/h)andan impactangle of 0.4°.TheSMT 

TMA brought the vehicle to a controlled 

stop. The maximum dynamic deflection of 

thesystem was13.0ft.(4.0m).Theimpact 

wasabsorbed by the TMA and the support 

truck was pushed forward 8.9 ft. (2.7 m) 

before coming to rest. The test vehicle 

sustaineddamage to its front end.Thefront 

bumper was crushed, the grill partially 

detached, and the left headlight detached 

from the vehicle. The left front tire was 

deflated. The occupant compartment was 

not penetrated and the deformation limits 

were not exceeded. The Trinity Highway 

ProductsSMTMASHTrailerAttenuator met 

all therequirements for MASH2016Test 

3-51. 

PASS 

3-52(2270P) 

ApplusIDIADAKARCOTestNo.P39124-01. 

TestDateJune06,2019. CrashTestReport 

No.TR-P39124-01_Bfor MASHTest3-52 

CrashTest ofTrinity HighwayProductsSMT. 

The Trailer Mounted Attenuator (TMA) was 

impacted bya2013Ram15004-door pickup truck. The test vehicle impacted theSMT 

TMAat a velocity of 62.58 mph (100.71km/ 

h) and an impact angle of 0.3°. The SMT 

brought the vehicle to a controlled stop. 

The maximum measured dynamic 

deflection of thesystem was12.2ft.(3.7m). 

Theroll ahead distanceof thesupport truck 

was8.2ft (2.5m). Thetest vehiclesustained 

damage to its front end.Thefront bumper, 

hood,and left and right quarter panelswere 

deformedasaresult of theimpact.Thegrill 

and both headlights detached from the 

vehicle.Theright front wheel wasflattened 

and itssuspension components were 

damaged.Theoccupant compartment was 

not penetrated and the deformation limits 

were not exceeded. The Trinity Highway 

ProductsSMT MASH Trailer Attenuator met 

all therequirements for MASH2016Test 

3-52. 

PASS 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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3-53(2270P) 

ApplusIDIADAKARCOTestNo.P39125-01. 

TestDateJuly 19,2019. CrashTestReport 

No.TR-P39125-01_Bfor MASHTest3-53 

CrashTest ofTrinity Highway ProductsSMT. 

The Trailer-Mounted Attenuator (TMA) was 

impacted by a 2013 RAM 1500 4-door 

pickup truck. The test vehicle impacted the 

SMTTMAat avelocity of 63.48mph (102.16 

km/h)andan impactangle of 9.5°. TheSMT 

absorbed the vehicle'senergy and deflected 

its trajectory, causing the vehicle to spin 

about itsyaw axisbeforecoming to 

rest 74.4 ft. (22.7 m) downstream and 37.0 

ft.(11.3 m) left from its position at its initial 

point of contact with theTMA.Thesupport 

truck rolled forward 22.9 ft. (7.0 m) before 

coming to rest. The test vehicle sustained 

damage to its front end, with most of the 

damage occurring on the right side. The 

front bumper,hood,and right front quarter 

panel werecrushed;thegrill and headlights 

detached from the vehicle; and the right 

wheel was flattened and itssuspension 

components damaged. The occupant 

compartment was not penetrated and the 

deformation limits were not exceeded. The 

Trinity Highway ProductsSMTMASHTrailer 

Attenuator met all the requirements for 

MASH2016Test3-53. 

PASS 

3-54(1500A) Per MASH,this test is optional. Non-Relevant Test,not conducted 

Full Scale Crash Testing was done in compliance with MASH by the following accredited crash test 

laboratory (cite the laboratory’s accreditation status as noted in the crash test reports.): 

Laboratory Name: KARCOEngineering, INC 

LaboratorySignature: 

Address: 9270HollyRoad,Adelanto,CA92301 SameasSubmitter 

Country: USA SameasSubmitter 

Accreditation Certificate 

Number and Dates of current 

Accreditation period : 

International AccreditationServices(IAS) 

ISO17025Accreditation Certificate #TL-371 

Cert.1: ExpiresJuly1,2019 

Cert.2: ExpiresJuly1,2022 

Submit Form 
 

 

 

 

 

 

 

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Page 7 of 7 

ATTACHMENTS 

Attach to this form: 

1) Additional disclosures of related financial interest as indicated above. 

2) A copy of the full test report, video, and a Test Data Summary Sheet for each test conducted in 

support of this request. 

3) A drawing or drawings of the device(s) that conform to the Task Force-13 Drawing Specifications 

[Hardware Guide Drawing Standards]. For proprietary products, a single isometric line drawing is 

usually acceptable to illustrate the product, with detailed specifications, intended use, and contact 

information provided on the reverse. Additional drawings (not in TF-13 format) showing details that 

are relevant to understanding the dimensions and performance of the device should also be submitted 

to facilitate our review. 

FHWA Official Business Only: 

Eligibility Letter 

Number Date Key Words 
 

 

 

 

  

 

 

 

 

      

      

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TRINITY 

HIGHWAY 

INTENDED USE 

The SMTTM is a mobile crash cushion attached to the rear of a support vehicle. It is a towable

system designed to be used on shadow or advanced warning vehicles upstream of moving

operations or as a barrier vehicle for stationary work zones. The SMTTM is designed to be used

on support vehicles with a minimum weight of 12,000 lb. and a maximum weight of 25,000 lb. 

FEATURES 

The SMTTM consists of a frame, axle, energy absorbing cartridges, lighting, face plate, optional

spare tire, and optional arrow board / message board. The frame is a structural tube steel

space frame that is bolted together in sections consisting of an Impact Frame, Rear Arms,

Center Frame, Forward Arms, and Tongue Section. There is also a flanged pintle lunette ring

that bolts into location on the front of the system. This ring has two possible positions to

provide the customer adjustability in hitch height on the rear of the support truck.

SPECIFICATIONS 

• The SMTTM is 242" long.

• Width is 82" wide.

• Height is 44" high, including the nominal height above the ground of 12" ± 1" at the rear

of the system.

• A system without the optional arrow board weighs approximately 2620 lbs.

ELIGIBILITY 

The SMTTM TMA has been tested in conformance to MASH 2016 Test Level 3 and is determined

eligible for Federal‐aid reimbursement by FHWA.

FHWA Eligibility Letter(s): CC‐#### dated __________________ for MASH 2016 Test Level 3

REFERENCES 

Manual for Assessing Safety Hardware (MASH), American Association of State Highway and

Transportation Officials (AASHTO), 2016

CONTACT INFORMATION

 2525 North Stemmons Freeway

Dallas, TX 75207 

Telephone: (888) 323-6374

Fax: (800) 770-6755

http://www.trinityhighway.com 

SMT TRAILER MOUNTED ATTENUATOR 

SWT## 

SHEET NO. DATE 

2 of 2 12/4/2019 

THP-FE-051 Rev E, 8/31/18