U.S. Department 

of Transportation 

Federal Highway 

Administration 

August 14, 2020 

1200 New Jersey Ave., SE 

Washington, D.C. 20590 

In Reply Refer To: 

HSST-1/B-347 

Mr. James Fu 

State of Hawaii, Department of Transportation 

601 Kamokila Boulevard, Room 611, 

Kapolei, HI 96707 

USA 

Dear Mr. Fu: 

This letter is in response to your March 31, 2020 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 B-347 and is valid until a subsequent letter is issued by FHWA that expressly 

references this device. 

Decision 

The following device is eligible within the length-of-need, with details provided in the form 

which is attached as an integral part of this letter: 

• Modified Hawaii Thrie Beam Approach Guardrail Transition

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: Modified Hawaii Thrie Beam Approach Guardrail Transition 

Type of system: Longitudinal Barrier Transition 

Test Level: MASH Test Level 3 (TL3) 

Testing conducted by: Midwest Roadside Safety Facility 

Date of request: March 31, 2020 

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. 
3 

Standard Provisions 

• To prevent misunderstanding by others, this letter of eligibility designated as FHWA 

control number B-347 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 of any Agency view, position, or 

determination of validity, scope, or ownership of any 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 of subsequent 

information related to crash testing. 

Sincerely, 

Michael S. Griffith 

Director, Office of Safety Technologies 

Office of Safety 

Enclosures 
Version 10.0 (05/16) 

Page 1 of 5 

Request for Federal Aid Reimbursement Eligibility 

of Highway Safety Hardware 

Submitter 

Date of Request: March 31, 2020 New Resubmission 

Name: James Fu, S.E. 

Company: State of Hawaii, Department of Transportation 

Address: 601 Kamokila Boulevard, Room 611, Kapolei, HI 96707 

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 & Testing Criterion - Enter from right to left starting with Test Level 

System Type Submission Type Device Name / Variant Testing Criterion Test 

Level 

'B': Rigid/Semi-Rigid Barriers 

(Roadside, Median, Bridge 

Railings) 

Physical Crash Testing 

Engineering Analysis 

Modified Hawaii Thrie 

Beam Approach 

Guardrail Transition 

AASHTO MASH TL3 

! - ! - ! 

 

 

 

 

 

 

 

 

 

 

I r. r 

I I 

r. 

r 

~ 

~ 

~ 

~ 

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: James Fu, S.E. Same as Submitter 

Company Name: State of Hawaii, Department of Transportation Same as Submitter 

Address: 601 Kamokila Boulevard, Room 611, Kapolei, HI 96707 Same as Submitter 

Country: USA Same as Submitter 

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

Eligibility Process for Safety Hardware Devices' document. 

The Midwest Roadside Safety Facility (MwRSF) and its employees were asked to perform crash testing and 

evaluate the device named herein for the Hawaii Department of Transportation. 

MwRSF’s financial interests are as follows:

(i) No compensation, including wages, salaries, commissions, professional fees, or fees for business referrals; 

(ii) Consulting relationships consist of answering design and implementation questions; 

(iii) Research funding or other forms of research support include continued funding for roadside safety research 

projects with MwRSF; 

(iv) No patents, copyrights, or other intellectual property interests for this system; 

(v) No licenses or contractual relationships for this system; and 

(vi) No business ownership and investment interests for this system. 
 

 

 

 

 

 

 

 

(i' r 

Version 10.0 (05/16) 

Page 2 of 5 

PRODUCT DESCRIPTION 

New Hardware or Modification to 

Significant Modification Existing Hardware 

The modified Hawaii Department of Transportation (HDOT) Thrie Beam Approach Guardrail Transition (AGT) 

test installation was approximately 83 ft long and consisted of a concrete parapet, transition, a thrie beam AGT, 

Midwest Guardrail System (MGS), and a guardrail anchorage system. At the downstream end of the test 

installation, there existed an 8-ft long version of HDOT’s Type D2 End Post. Since the downstream half of the

end post was not expected to interact with the test vehicles, the length of the end post was reduced from its 

standard 18-ft length to reduce installation costs. The test installation end post was 34 in. tall, 18 in. wide, and 

was reinforced with a combination of longitudinal and lateral steel rebar. The vertical steel bars of the end post 

were anchored directly to the non-reinforced existing concrete tarmac using a chemical epoxy with a 

minimum bond strength of 1,450 psi. The upstream end of the end post was sloped vertically with a 2-in. x 12-

in. taper. The face of the end post was recessed 4 in. at the location of the guardrail terminal connector so that 

the face of the thrie beam was nearly flush with the face of the end post concrete parapet. The concrete mix for 

the end post concrete parapet required a minimum 28-day compressive strength of 4,000 psi. 

HDOT’s AGT consisted of 12 ft - 6 in. of nested thrie beam rail supported by W6x15 posts at various post 

spacings. The upstream end of the AGT incorporated the previously MASH-tested MGS upstream stiffness 

transition to connect the AGT to the adjacent MGS. All guardrail segments had a top mounting height of 31 

inches. Blockouts within the AGT consisted of rectangular HSS steel tubes. The W6x15 posts were 7 ft long, 

while the W6x8.5/W6x9 posts were 6 ft long. To ensure the width of the blockouts matched the width of the 

posts, 6-in. wide blockouts were used with W6x15 posts, and 4-in. wide blockouts were used with W6x8.5/ 

W6x9 posts. 

A 6-in. tall concrete curb was placed below the AGT with its front face flush with the face of the guardrail. The 

curb began at the upstream end of the concrete end post and extended 1761⁄4 in. upstream. The curb was 

terminated with a vertical taper measuring 4 in. vertically by 36 in. longitudinally prior to extending below the 

asymmetrical W-to-thrie transition segment. A 4-in. x 12-in. vertical taper was applied to the downstream end 

of the curb adjacent to the concrete end post to mitigate wheel snag on the end post. 

Approximately 37 ft - 6 in. of MGS extended from the upstream end of the AGT. This MGS region of the test 

installation utilized plastic blockouts manufactured by Mondo Polymer Technologies. 

A guardrail anchorage system typically utilized as a trailing end terminal was utilized to anchor the upstream 

end of the test installation. The guardrail anchorage system was originally designed to simulate the strength of 

other crashworthy end terminals. The anchorage system consisted of timber posts, foundation tubes, anchor 

cables, bearing plates, rail brackets, and channel struts, which closely resembled the hardware used in the 

Modified Breakaway Cable Terminal (BCT) system. The guardrail anchorage system has been MASH TL-3 crash 

tested as a downstream trailing end terminal. 

CRASH TESTING 

By signature below, the Engineer affiliated with the testing laboratory, agrees in support of this submission 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 tests are necessary to determine the device meets 

the MASH criteria. 

Engineer Name: Ronald Faller Ronald K. Faller ou=Midwest Roadside Safety Facility, email=rfaller1@unl.edu, c=US 

Digitally signed by Ronald K. Faller 

DN: cn=Ronald K. Faller, o=University ofNebraska-Lincoln, Engineer Signature: Date: 2020.04.17 08:53:55 -05'00' 

Address: 130 Whittier Research Center, 2200 Vine Street, Lincoln, NE 68583-0853 Same as Submitter 

Country: USA Same as Submitter 
 

 

 

 

Version 10.0 (05/16) 

Page 3 of 5 

A brief description of each crash test and its result: 

Required Test 

Number 

Narrative 

Description 

Evaluation 

Results 

3-10 (1100C) Test no. 3-10 is not applicable for this type 

of system. Non-Relevant Test, not conducted 

3-11 (2270P) Test no. 3-11 is not applicable for this type 

of system. Non-Relevant Test, not conducted 

3-20 (1100C) 

Lab test no.: HWTT-1 

Date of test: July 1, 2019 

Crash test report no.: TRP-03-425-20 

A 2,407-lb passenger car with a simulated 

occupant seated in the drivers seat, 

impacted the modified HDOT thrie beam 

approach guardrail transition (AGT) a speed 

of 61.8 mph and angle of 25.2 degrees. 

Impact location was 64.9 in. upstream from 

the end of the Type D2 End Post. At 0.176 

sec after impact, the vehicle became parallel 

to the system with a speed of 39.0 mph. At 

0.344 sec, the vehicle exited the system with 

a speed of 37.2 mph and an angle of 12.8 

degrees. The vehicle was successfully 

contained and smoothly redirected. 

Exterior vehicle damage was moderate and 

the interior occupant compartment 

deformations were moderate, with a 

maximum of 3.5 in., consequently not 

violating the limits established in MASH 

2016. Damage to the barrier was minimal, 

consisting of contact marks and kinks of the 

thrie beam sections, contact marks on the 

front face of the concrete end post, and 

minor spalling of the concrete. The 

maximum lateral permanent set of the 

barrier system was 1.4 inches. The 

maximum lateral dynamic barrier deflection 

was 2.6 inches. at post no. 18. The working 

width of the system was 20.0 inches. All 

vehicle decelerations, occupant ridedown 

accelerations (ORAs), and occupant impact 

velocities (OIVs) fell within the 

recommended safety limits established in 

MASH 2016. The test vehicle showed no 

tendency for rollover and did not penetrate 

or ride over the barrier. 

PASS 
 

 

 

 

Version 10.0 (05/16) 

Page 4 of 5 

Required Test 

Number 

Narrative 

Description 

Evaluation 

Results 

3-21 (2270P) 

Lab test no.: HWTT-2 

Date of test: July 19, 2019 

Crash test report no.: TRP-03-425-20 

A 5,000-lb pickup truck with a simulated 

occupant seating in the driver's seat, 

impacted the system at a speed of 63.0 mph 

and an angle of 25.2 degrees. Impact 

location was 89.7 in. upstream from the end 

of the Type D2 End Post. At 0.184 sec after 

impact, the vehicle became parallel to the 

system with a speed of 42.4 mph. At 0.368 

sec, the vehicle exited the system with a 

speed of 41.0 mph and an angle of 11.1 

degrees. The vehicle was successfully 

contained and smoothly redirected. 

Exterior vehicle damage was moderate and 

the interior occupant compartment 

deformations were moderate, with a 

maximum interior occupant compartment 

deformation of 6.5 in., consequently not 

violating the limits established by MASH 

2016. Damage to the barrier was moderate, 

consisting of contact marks, post deflection, 

rail kinking, and gouging and spalling to the 

concrete parapet and curb. The maximum 

lateral permanent set of the barrier system 

was 6.2 in. The maximum lateral dynamic 

barrier deflection was 9 in. at post no. 18. 

The working width of the system was 23 

inches. All vehicle decelerations, occupant 

ridedown accelerations (ORAs), and 

occupant impact velocities (OIVs) fell within 

the recommended safety limits established 

in MASH 2016. The test vehicle showed no 

tendency for rollover and did not penetrate 

or ride over the barrier. 

PASS 

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.):
 

 

 

Version 10.0 (05/16) 

Page 5 of 5 

Laboratory Name: Midwest Roadside Safety Facility 

Laboratory Signature: Karla Lechtenberg DN: cn=Karla Lechtenberg, o=MwRSF, ou, email=kpolivka2@unl.edu, c=US Digitally signed by Karla Lechtenberg 

Date: 2020.04.17 10:01:04 -05'00' 

Address: 130 Whittier Research Center, 2200 Vine Street, 

Lincoln, NE 68583-0853 Same as Submitter 

Country: USA Same as Submitter 

Accreditation Certificate 

Number and Dates of current 

Accreditation period : 

A2LA Certificate Number: 2937.01, Valid to November 30, 2019 (Currently, 

valid to November 30, 2021) 

Submitter Signature*: 

Submit Form 

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 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
 

 

 

 

 

 

 
 

INTENDED USE

The Modified Hawaii Thrie Beam Approach Guardrail Transition is a non-proprietary system. It is 

intended to be used when the 31” [787] tall strong-post, W-beam guardrail such as Midwest

Guardrail System (SGR20) is placed adjacent to the Hawaii 34” [864] Aesthetic Concrete Bridge 

Rail or the Hawaii 42” [1067] Aesthetic Concrete Bridge Rail. A 6-in. [152] tall concrete curb was

placed below the AGT with its front face flush with the face of the guardrail. The curb began at the

upstream end of the Type D2 End Post and extended 1761⁄4 in. [4477] upstream. The curb was 

terminated with a vertical taper measuring 4 in. [102] vertically by 36 in. [914] longitudinally prior

to extending below the asymmetrical W-to-thrie transition segment. A 4-in. x 12-in. [102 x 305]

vertical taper was applied to the downstream end of the curb adjacent to the concrete end post to 

mitigate wheel snag on the Type D2 End Post.

The Modified Hawaii Thrie Beam Approach Guardrail Transition should be used in locations where

a maximum dynamic deflection of 9.0 in. [229] or less is acceptable and where a working width of 

23.0 in. [584] is provided. The Hawaii Thrie Beam AGT to Bridge Rail has been crash tested under 

Test Level 3 (TL-3) conditions and deemed crashworthy according to the Manual for Assessing

Safety Hardware, Second Edition (MASH 2016) performance criteria.

COMPONENTS 

Unit Length = 35’-5” [10795] 

DESIGNATOR COMPONENT NUMBER

FBB01 5/8”-11 UNC [M16x2], 1.25” [32] Long Guardrail Bolt 20 

FBB02 5/8”-11 UNC [M16x2], 2” [51] Long Guardrail Bolt 24 

FBB03 5/8”-11 UNC [M16x2], 10” [254] Long Guardrail Bolt 8 

FBB06 5/8”-11 UNC [M16x2], 14” [356] Long Guardrail bolt 13 

FBX22b 7/8”-9 UNC [M22x2.5], 16” [406] Long Heavy Hex Bolt 5

FNX16b 5/8”-11 UNC [M16x2] Heavy Hex Nut 64 

FNX22b 7/8”-9 UNC [M22x2.5] Heavy Hex Nut 5

FWC16a 5/8” [16] Dia. Plain USS Washer 24 

FWR10 3”x3”x1/4” [76x76x6] Square Washer Plate 5 

PPB02 Composite Recycled Blockout 2 

PWBxx 17.5” [445] Long, 12”x4”x0.25” [305x102x6] Steel Blockout 6

PWBxx 17.5” [445] Long, 8”x6”x0.25” [203x152x6] Steel Blockout 4 

PWE06 W6x8.5 or W6x9 [W152x12.6 or 13.4], 72” [1,829] Long Steel Post 8

PWExx W6x15 [W152x22.5], 78” [1,981] Long Steel Post 4

RET01b Thrie Beam Terminal Connector 1 

RTM08a 12’-6” [3,810] Thrie Beam Section 2

RTM19a 6’-3” [1,905] Thrie Beam Section 1 

RWM04a 12’-6” [3,810] W-Beam Section 1

RWT02 6’-3” [1,905] Asymmetrical W- to Thrie Beam Transition 1 

--- Concrete, Minimum 4,000 psi f’c -

--- See Bill of Bars -

ELIGIBILITY

Eligibility will be pursued.

MODIFIED HAWAII THRIE-BEAM APPROACH GUARDRAIL TRANSITION 

XXX##

SHEET NO. DATE:

2 of 7 4/22/2020
REFERENCES 

Rosenbaugh, S. K., Hovde, S. E., Faller, R. K., and Urbank, E. L., Crash Testing and Evaluation of the 

Hawaii Thrie Beam Approach Guardrail Transition: MASH Test Nos. 3-20 and 3-21, Report to Hawaii 

Department of Transportation, Transportation Report No. TRP-03-425-20, Midwest Roadside Safety

Facility, University of Nebraska-Lincoln, March 2020. 

CONTACT INFORMATION

Hawaii Department of Transportation

Aliiaimoku Building

869 Punchbowl St.

Honolulu, HI 96813 

MODIFIED HAWAII THRIE-BEAM APPROACH GUARDRAIL TRANSITION 

XXX##

SHEET NO. DATE:

3 of 7 4/22/2020