U.S.Department 1200 New Jersey Ave., SE 

of Transportation Washington, D.C. 20590 

Federal Highway 

Administration December 27, 2016 

In Reply Refer To: 

HSST-1 /CC-126C 

Mr. Kaddo Kothman 

Road Systems, Inc. 

36 161 Howard County Airport 

Big Spring, TX 79720 

Dear Mr. Kothman: 

This letter is in response to the, 2016, request from Balbino Beltran for the Federal Highway ' 

Administration (FHW A) 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 FHW A control number CC-126C and is valid until a subsequent letter is issued by 

FHW A that expressly references this device. 

Decision 

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

integral part of this letter: 

• 	 MSKT- SP-MGS (MASH Sequential Kinking Terminal, Standard Posts, Midwest 

Guardrail System) with Wood Posts. 

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' Manual for Assessing Safety Hardware (MASH). However, the 

FHWA, the Department ofTransportation, and the United States Government do not regulate the 

manufacture ofroadside 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 FHW A, 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. 
2 

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. 

Eligibility for Reimbursement 

FHWA previously issued an eligibility letter for the roadside safety system described in your 

pending request. Your pending request now identifies a modification to that roadside safety 

system. 

The original roadside safety device information is provided here: 

Name of system: MSKT- MASH Sequential Kinking Terminal 

Type of system: W-Beam Guardrail Terminal 

Date of original request: January 20, 2016 

Original FHW A eligibility letter: September 21 , 2016 

FHWA Control number: CC-126 

The pending modification(s) consists of the following changes: 

1. 	 Use of CRT wood posts in post locations 3 through 8. 

FHWA concurs with the recommendation of the accredited crash testing laboratory as stated 

within 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 

If a manufacturer makes any modification to any of their roadside safety hardware that has an 

existing eligibility letter from FHWA, the manufacturer must notify FHWA of such modification 

with a request for continued eligibility for reimbursement. The notice of all modifications to a 

device must be accompanied by: 

o 	 Significant modifications - For these modifications, crash test results must be submitted 

with accompanying documentation and videos. 

o 	 Non-signification modifications - For these modifications, a statement from the crash test 

laboratory on the potential effect of the modification on the ability of the device to meet 

the relevant crash test criteria. 

FHWA's determination of continued eligibility for the modified hardware will be based on 

whether the modified hardware will continue to meet the relevant crash test criteria. 

You are expected to supply potential users with sufficient information on design, installation and 
3 

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 the 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 crash worthiness of the system. 

Standard Provisions 

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

control numbers CC-126C 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 FHW A to use, 

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

• 	 Ifthe subject device is a patented product it may be considered to be proprietary. If 

proprietary systems are specified by a highway agency for use on Federal-aid 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 63 5 .411. 

Sincerely yours, 

Michael S. Griffith 

Director, Office of Safety Technologies 

Office of Safety 

Enclosures 
Version 10.0 (05/16) 

Page 1 of 11 

Request for Federal Aid Reimbursement Eligibility 

ofHighway Safety Hardware 

Date of Request: 

Name: 

September 6, 2016 

Balbi no A. Beltran 

I r. New r Resubmission 

.... 

Cll

....

.... ·e 

..Q 

::I 

"' 

Company: 

Address: 

Country: 

KARCO Engineering, LLC. 

9270 Holly Road Adelanto, CA 92301 

United States 

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 I Variant Testing Criterion Test 

Level 

'CC': Crash Cushions, 

Attenuators, & Terminals 

r Physical Crash Testing 

(e' Engineering Analysis 

MSKTTerminal 

AASHTOMASH TL3 

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: Kaddo Kothmann Same as Submitter D 

Company Name: Road Systems, Inc. Same as Submitter D 

Address: 3616 Howard County Airport, Big Spring TX 79720 Same as Submitter D 

Country: United States Same as Submitter D 

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

Eligibility Process for Safety Hardware Devices' document. 

Road Systems, Inc. is the manufacturer and marketer of device. 

KARCO Engineering, LLC is an independent research and testing laboratory having no affiliation with any other 

entity. The company is solely-owned and operated by Mr. Frank D. Richardson and Ms. Jennifer W. Peng 

(husband and wife) and was established on September 2, 1994. KARCO is actively involved in data acquisition 

and compliance/certification testing for a variety of government agencies and equipment manufacturers. The 

principals and staff of KARCO Engineering have no past or present financial, contractual or organizational 

interest in any company or entity directly or indirectly related to the products that KARCO tests. If any financial 

interest should arise, other than receiving fees for testing, reporting, etc., with respect to any project, the 

company will provide, in writing, a full and immediate disclosure to the FHWA. 
Version 10.0 (05/16) 


Page 2 of 11 


PRODUCT DESCRIPTION 

(' New Hardware or 

Significant Modification 

(i' Modification to 

• Existing Hardware Non-Significant 

The MSKT-SP-MGS (MASH Sequential Kinking Terminal - Standard Post - Midwest Guardrail System) terminal, as 

approved in CC-126 dated June 10, 2016, is a W-beam guardrail terminal consisting of an impact head 

assembly, a breakaway cable anchorage system and a 12.5 ft (3.8 m) end section. The system requires use of 

37.5 ft (11.4 m) of standard guardrail downstream mounted on 8-in. (203-mm) deep wood or composite blocks 

and 6 ft (1 .8 m) long W6x9 (or W6x8.S) steel posts. A 9.4 ft (2.9 m) W-beam rail section is required downstream 

of Post 3 to transition the rail splices to mid-span. 

Some States specify the use of wood posts instead of steel posts for their guardrail systems. To accommodate 

the needs of these States, it is requested that the use of a wood-post version be approved for the MSKT 

terminal. From an impact standpoint, it is our opinion that the steel-post system is more critical than the woodpost system. Refer to the complete product description for the analysis and reasoning behind this conclusion. 

CRASH TESTING 

By signature below, the Engineer affiliated with the testing laboratory, agrees in support of this submission that 

the Modification to Existing Hardware is deemed Non-significant for the device listed above to meet the MASH 

criteria. 

Engineer Name: Balbino A. Beltran 

Balbino A. Beltran Digitally signed by Balbino A. Beltran 

Engineer Signature: ON: cn=Balbino A. Beltran, o=KARCO Engineering, LLC.. ou, 

email=abeltran@karco.com, c=US 

Date: 2016.09.06 18:23:00 -07'00' 

Address : 9270 Holly Road Adelanto, CA 92301 Same as Submitter [gl 

Country: United States Same as Submitter [gl 

A brief description of each crash test and its result: 
Version 10.0 (05/16) 

Page 3 of ll 

Required Test 

Number 

Narrative 

Description 

Evaluation 

Results 

3-30 (1100() 

KARCO Test No. P35125-01 . An 11 OOC (2,425 

lb) passenger car impacting the terminal 

end-on at a nominal impact speed and 

angle of 100 km/h (62.2 mph) and 0 

degrees, respectively, with the quarter point 

of the vehicle aligned with the center line of 

the nose of the terminal. This test is 

primarily intended to evaluate occupant risk 

and vehicle trajectory criteria. 

The test vehicle, a 2009 Kia Rio 4-door sedan 

weighing 2,390.9 lb (1,084.5 kg), impacted 

the MASH SKTterminal head on at impact 

speed and angle of 61.54 mph (99.05 km/ h) 

and 0.9 degree, respectively. The vehicle 

pushed the impact head down the length of 

the guardrail past the fifth post, at which 

point the rail began to buckle and the 

vehicle began to yaw counter-clockwise 

until it impacted the rail at the bend before 

coming to a stop next to the rail on the 

traffic side. The test vehicle sustained 

moderate damage to the front end with no 

occupant compartment deformation. The 

vehicle remained upright without excessive 

roll or pitch. The test article was extensively 

damage from Post 1 through Post 5 and the 

rail wrapped around Post 6. The Occupant 

Impact Velocities (OIV) and ridedown 

accelerations are within the recommended 

limits. The MSKT-SP-MGS terminal passed all 

evaluation criteria for Test 3-30. 

Modification has no effect on crashworthiness 
Version 10.0 (05/16) 

Page 4 of 11 

Required Test 

Number 

Narrative 

Description 

Evaluation 

Results 

3-31 (2270P) 

KARCO Test No. P34149-01 . A 2270P (5,000 

lb) pickup truck impacting the terminal endon at a nominal impact speed and angle of 

100 km/h (62.2 mph) and 0 degrees, 

respectively, with the center line of the 

vehicle aligned with the center line of the 

nose of the terminal. This test is primarily 

intended to evaluate occupant risk and 

vehicle trajectory criteria. 

The test vehicle, a 2008 Dodge Ram 4-door 

pickup truck, with a test inertial mass 

weighing 4,896.4 lb (2,221 kg). impacted the 

MASH SKT terminal head-on at impact 

speed and angle of 62.33 mph (100.31 km/ 

h) and 0.4 degrees, respectively. The vehicle 

pushed the impact head down the length of 

the guardrail past Post 8 and came to rest 

50.5 ft (15.4 m) from the point of initial 

impact The test vehicle sustained moderate 

damage to the front end with no occupant 

compartment deformation. The vehicle 

remained upright and stable. The test article 

was extensively damaged from Post 1 

through Post 8. The Occupant Impact 

Velocities (OIV) and ridedown accelerations 

are within the recommended limits. The 

MSKT-SP terminal passed all evaluation 

criteria for Test 3-31 . 

Modification has no effect on crashworthiness 
Version 10.0 (05/16) 

Page 5 of 11 

KARCO Test No. P35025-01 . An 11 OOC (2,425 

lb) passenger car impacting the terminal 

end-on at a nominal impact speed 

and angle of 100 km/h (62.2 mph) and 5 

degrees, respectively, with the center line of 

the vehicle aligned with the center line of 

the nose of the terminal. This test is 

primarily intended to evaluate occupant risk 

and vehicle trajectory criteria. 

The test vehicle, a 2010 Kia Rio 4-door sedan 

weighing 2,457.0 lb (1, 114.5 kg), impacted 

the MASH SKT terminal head-on at impact 

speed and angle of 61.47 mph (98.93 km/ h) 

and 4.4 degrees, respectively. The vehicle 

pushed the impact head down the length of 3-32 (1100() Modification has no effect on crashworthiness the guardrail past the fifth post, at which 

point the vehicle mounted the guardrail. 

Upon dismounting the rail, the vehicle 

proceeded forward and to the left and 

remained upright throughout the impact 

sequence. The test vehicle sustained 

moderate damage to the front and left side 

with no occupant compartment 

deformation. The vehicle remained upright 

and stable. The test article was extensively 

damaged from Post 1 through Post 5. The 

Occupant Impact Velocities (OIV) and 

ridedown accelerations are within the 

recommended limits. The MSKT-SP-MGS 

terminal passed all evaluation criteria for 

Test 3-32. 
Version 10.0 (05/16) 

Page 6 of 11 

3-33 (2270P) 

KARCO Test No. P34149-04 . A 2270P (5,000 

lb) pickup truck impacting the terminal endon at a nominal impact speed and angle of 

100 km/h (62.2 mph) and 5 degrees, 

respectively, with the center line of the 

vehicle aligned with the center line of the 

nose of the terminal. This test is primarily 

intended to evaluate occupant risk and 

vehicle trajectory criteria. 

The test vehicle, a 2008 Dodge Ram 4-door 

pickup truck weighing 4,895.3 lb (2,220.5 

kg), impacted the MASH SKT terminal headon at an impact speed and angle of 62.74 

mph (100.97 km/ h) and 5.7 degrees, 

respectively. The vehicle pushed the impact 

head down the guardrail past the fifth post 

at which point the vehicle mounted the 

guardrail in a controlled manner without 

excessive deceleration and proceeded 

forward. The vehicle then impacted Post 6 

before separating from the guardrail. The 

vehicle impacted the test article again 

between Posts 23 and 24. The vehicle 

sustained moderate damage at the front 

and left side and deformations to the 

occupant compartment were negligible. 

The vehicle remained upright and stable. 

The test article was extensively damaged 

from Posts 1 through Post 6. Post 7 was not 

impacted, but separated from the guardrail 

as a result of the rail buckling. The Occupant 

Impact Velocities (OIV) and ridedown 

accelerations are within the recommended 

limits. The MSKT-SP terminal passed all 

evaluation criteria for Test 3-33. 

Modification has no effect on crashworthiness 
Version 10.0 (05/16) 

Page 7 of 11 

KARCO Test No. P35126-01 . An 1 lOOC (2,425 

lb) passenger car impacting the terminal at 

a nominal impact speed and angle of 62.2 

mph (100 km/ h) and 15 degrees, 

respectively, with the corner of the vehicle 

bumper aligned with the critical impact 

point (CIP) ofthe length of need (LON) of 

the terminal. This test is primarily intended 

to evaluate occupant risk and vehicle 

trajectory criteria. 

The test vehicle, a 2010 Kia Rio 4-door sedan 

weighing 2,436.1 lb (1,105.0 kg), impacted 

the downstream end of the impact head 

between Posts 1 and 2 at impact speed and 

angle of 61.37 mph (98.77 km/h) and 15.3 

3-34 (11 OOC) degrees, respectively. The vehicle was Modification has no effect on crashworthiness 

contained and redirected by the guardrail 

before separating from the test article near 

Post 6 at a velocity of 27.7 mph and an exit 

angle of 17.0 degrees and proceeded 

downstream adjacent to the guardrail. The 

vehicle remained upright and stable 

throughout the impact sequence. The test 

vehicle sustained moderate damage to the 

front right side with no occupant 

compartment deformation. The test article 

was extensively damaged from Post 1 

through Post 5. The Occupant Impact 

Velocities (OIV) and ridedown accelerations 

are within the recommended limits. The 

MSKT-SP-MGS terminal passed all 

evaluation criteria for Test 3-34. 
Version 10.0 (05/16) 

Page 8 of 11 

3-35 (2270P) 

KARCO Test No. P35103-01. A 2270P (5,000 

lb) pickup truck impacting the terminal at a 

nominal impact speed and angle of 100 km/ 

h (62.2 mph) and 25 degrees, respectively, 

with the corner of the vehicle bumper 

aligned with the beginning of the length-ofneed (LON) of the terminal. This test is 

primarily intended to evaluate structural 

adequacy and vehicle trajectory criteria. 

The test vehicle, a 2011 Dodge Ram 4-door 

pickup truck weighing 4,942.6 lb (2,242.0 

kg), impacted the guardrail at Post 3, the 

beginning of length-of-need, at impact 

speed and angle of 62.36 mph (100.36 km/ 

h) and 26 degrees, respectively. The vehicle 

was contained and redirected by the 

guardrail before separating from the test 

article near Post 9 at a velocity of 32.75 mph 

(52.71 km/ h) and an exit angle of 34.93 

degrees and proceeded downstream 

adjacent to the guardrail on the traffic side. 

The vehicle then veered back toward the 

guardrail and impacted Post 20 before 

coming to rest at Post 26. The vehicle 

remained upright and stable throughout 

the impact sequence. The test vehicle 

sustained moderate damage to the front 

right side with no occupant compartment 

deformation. The test article was extensively 

damaged from Post 1 through Post 9. The 

maximum static lateral deformation was 

30.2 in (768 mm) between Posts 5 and 6. 

The Occupant Impact Velocities (OIV) and 

ridedown accelerations are within the 

recommended limits. The MSKT-SP-MGS 

terminal passed all evaluation criteria for 

Test 3-35. 

Modification has no effect on crashworthiness 

3-36 (2270P) 

MASH Test Designation 3-36. A 2270P (5,000 

lb) pickup truck impacting the terminal at a 

nominal impact speed and angle of 100 km/ 

h (62 mph) and 25 degrees, respectively, 

with the corner of the vehicle bumper 

aligned with the critical impact point (CIP) 

with respect to the transition to the stiff 

barrier or backup structure. This test is 

primarily intended to evaluate the 

performance of the terminal when 

connected to a stiff barrier or a backup 

structure. 

As a W-beam guardrail terminal, the MSKTSP-MGS terminal is designed to attach to Wbeam barrier, transitions to alternative 

barriers downstream of the terminal will 

require case-by-case evaluation. 

Non-Relevant Test, not conducted 
Version 10.0 (05/16) 

Page 9 of 11 

3-37 (2270P) 

3-38 (1500A) 

3-40 ( 1100() 

3-41 (2270P) 

3-42 (1 lOOC) 

Test No. P35025-02. A 2270P (5,000 lb) 

pickup truck impacting the terminal at a 

nominal impact speed and angle of 62.2 

mph (100 km/h) and 25 degrees, 

respectively, midpoint between the nose 

and the end of the terminal in the reverse 

direction. This test is intended to evaluate 

the performance of a terminal for a 

"reverse" hit. Successful testing of other 

cable anchor systems with the 11 OOC 

indicates that the 2270P is more critical with 

the concern of override and interaction with 

the terminal head. 

The test vehicle, a 2009 Dodge Ram 4-door 

pickup truck weighing 4,964.7 lb (2,252.0 

kg), impacted the guardrail at Post 3 with an 

impact speed and angle of 63.13 mph (101 .6 

km/h) and 24.9 degrees, respectively. The 

vehicle impacted Post 2, the back side of the 

impact head, and then Post 1 before 

separating from the test article at an angle 

of 13.37 degrees clockwise from its original 

path. The vehicle sustained moderate front 

end damage with no deformation to the 

occupant compartment. The test article 

received extensive damage between Posts 1 

and 2. The impact head was forced off the 

rail element and the cable anchor assembly 

was separated from the guardrail. The 

Occupant Impact Velocities (OIV) and 

ridedown accelerations are within the 

recommended limits. The MSKT-SP-MGS 

terminal passed all evaluation criteria for 

Test 3-37. 

MASH Test Designation 3-38. A 1500A 

(3,307 lb) passenger car impacting the 

terminal end-on at a nominal impact speed 

and angle of 100 km/h (62.2 mph) and 0 

degree, respectively, with the center line of 

the vehicle aligned with the center line of 

the nose of the terminal. This test is 

primarily intended to evaluate the 

performance of the staged attenuator/ 

terminal when impacted by a mid-size 

vehicle. 

The MSKT-SP-MGS terminal is not a staged 

device, because the force required to move 

the impact head down the rail does not 

change. The 3-30 test with the 11 OOC 

vehicle makes this test unnecessary. 

Test for non-redirective crash cushion, not 

applicable for terminals 

Test for non-redirective crash cushion, not 

applicable for terminals 

Test for non-redirective crash cushion, not 

applicable for terminals 

Modification has no effect on crashworthiness 

Non-Relevant Test, not conducted 

Non-Relevant Test, not conducted 

Non-Relevant Test, not conducted 

Non-Relevant Test, not conducted 
Version 10.0 (05/16) 

Page lC of 11 

3-43 (2270P) Test for non-redirective crash cushion, not 

applicable for terminals Non-Relevant Test, not conducted 

3-44 (2270P) Test for non-redirective crash cushion, not 

applicable for terminals Non-Relevant Test, not conducted 

3-45 (1500A) Test for non-redirective crash cushion, not 

applicable for terminals Non-Relevant Test, not conducted 

Testing Laboratory's signature concurs that these modifications are considered Non-Significant. 

Laboratory Name: KARCO Engineering, INC 

Laboratory Signature: Balbino A. Beltran Digitally signed by Balbino A. Beltran 

ON: cn=-Balbino A. Beltran, o=KARCO Engineering, LLC., ou, 

email=abeltran@karco.com, c=US 

Date: 2016.09.06 18:23:26 -07'00' 

Address: 9270 Holly Road Adelanto, CA 92301 Same as Submitter [8J 

Country: United States Same as Submitter [8J 

Accreditation Certificate 

Number and Dates of current 

Accreditation period : 

TL-371 ; December 18, 2015 through December 18, 2017 

Oigtta~y signed by B.ilbmo A. Belt1an 

Submitter Signature*: Balbi no A. Beltran ~.=::·::t::'"'"~KARCo ~~-abeltran@ll< .trco .c om, c-US 

Date:2016.09.0618:2l:44-07'00' 

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 
TRAFFIC 

o--~~~~~~~~~~~~~~~~~~~~--:io· [15.24mo--~~~~~~~~~~~~~~~~~~~~-< 

·12'-6" [3.81m] MSKT-SP-MGS Terminal 

1--------L------1----37'-6" [11 .43m] (6' CRT Posts {UP671), 8" Wood Blocks and 12 gage W-Beom Required1-----1 

'-3" [1905~'-3" [1905 

Length of Need and 

End of Payment for Installation 

Soil Plate on Downstream 

Side 

A 

·-3• [1905' 

PLAN 

ELEVATION 

'-3" [1905 

9'-4 1/2" (G12025) Second Roil 

....... 

M~ 

'-3" [1905' '-3" [1905 

ITEM OlY BILL OF MATERIALS ITEM NO. 

A 1 IMPACT HEAD MSJOOO 

B 1 W-BEAM GUARDRAIL END SECTION, 12 Go. SF1303 

c 1 FlRST POST TOP (6X6x.1" Tube) MTPHP1A 

D 1 FlRST POST BOTTOM (6' W6X15} MTPHP1B 

E 1 SECOND POST ASSEMBLY TOP UHP2A 

F 1 SECOND POST ASSEMBLY BOTTOM HP2B 

G 1 BEARING PLATE E750 

H 1 CABLE ANCHOR BOX S760 

J 1 BCT CABLE ANCHOR ASSEMBLY E770 

K 1 STRUT MS7B5 

HARDWARE (All DIMENSIONS IN INCHES) 

a I 2 5/16 • 1 HEX BOLT GRD 5 B5160104A 

4 5/16 WASHER W0516 

c 2 5/16 HEX NUT N0516 

d 9 5/B Dia. • 1 1/4 SPLICE BOLT (POST f2) 8580122 

• 2 5/B Dia. • 9 HEX BOLT GRD 5 B580904A 

f 3 5/6 WASHER W050 

g 11 5/B Dia. H.G.R NUT N050 

h 1 J/• Dia. • e 1/2 HEX BOLT GRO M-411 B340854A 

j 1 3/4 Dia. HEX NUT NOJO 

k 2 1 ANCHOR CABLE HEX NUT NlOO 

2 1 ANCHOR CABLE WASHER WlOO 

m 8 1/2 RSI SHOULDER BOLT W/WASHER SB12A 

n 8 1/2 STRUCTURAL NUT N012A 

a 8 1/2 STRUCTURAL WASHER W012A 

p 1 BEARING PLATE RETAINER TIE CT-lOOST 

GENERAL NOTES: 

1. All bolts, nuts, cable assemblies, cable anchors and 

bearing plates shall be galvanized. 

2. The lower sections of the Posts 1 &2 shall not 

protrude more than 4 in [100] above the ground 

(measured along a 5' [1 .5m] cord). Site grading may be 

necessary to meet this requirement. 

3. The lower section of the hinged post should not be 

driven with the upper post attached. If the post is 

placed in a drilled hole, the backfill material must be 

satisfactorily compacted to prevent settlement. 

4. When competent rock is encountered, a 12" [300] 0 

post hole, 20 in. [500] deep cored into the rock surface 

may be used if approved by the engineer for Posts 1 

and/or 2. Granular material will be placed in the bottom 

of the hole, approximately 2.5" [60] deep to provide 

drainage. The first and/or second post can be field cut 

to length, placed in the hole and backfilled with suitable 

backfill. The soil plate may be trimmed if required. 

5. The breakaway cable assembly must be taut. A 

locking device (vice grips or channel lock pliers) should 

be used to prevent the cable from twisting when 

tightening nuts. 

Post #1 Connection Detail Impact Head Connection Detail SECTION A-A 

Post #2 

SECTION 8-8 

Anchor Brocket 

-~S-I=- MSKT-MGS-W 

Terminal 

Test Level 3 

Sheet: 

Date: 

08/05/16 

Road Systems, Inc. 

l 1 0 "w'""MsKT-MGS-W l'"'1 N one I"" O .. ­ S»-Ml-G'llll 

By: 

JRR 
Wood-Post MSKT System Product Description 

The MSKT-SP-MGS (MASH Sequential Kinking Terminal - Standard Post - Midwest Guardrail System) 

terminal, as approved in CC-126 dated June 10, 2016, is a W-beam guardrail terminal consisting of an 

impact head assembly, a breakaway cable anchorage system and a 12.5 ft (3 .8 m) end section. The system 

requires use of 37.5 ft (11.4 m) of standard guardrail downstream mounted on 8-in. (203-mm) deep wood 

or composite blocks and 6 ft (1 .8 m) long W6x9 (or W6x8.5) steel posts. A 9.4 ft (2.9 m) W-beam rail 

section is required downstream of Post 3 to transition the rail splices to mid-span. 

Some States specify the use of wood posts instead of steel posts for their guardrail systems. To 

accommodate the needs of these States, it is requested that the use of a wood-post version be approved for 

the MSKT terminal. 

Figure 1 shows a schematic drawing of the wood-post MSKT terminal. The wood-post system uses the 

same SP anchorage system, i.e., the same steel posts 1 and 2 with a ground strut, as the steel-post system. 

Posts 3 through 8 are CRT (Controlled Release Terminal) wood posts, and standard wood line posts are 

used from post 9 and beyond. Other than the posts, the other components of both MSKT systems are the 

same. 

Both wood-post and steel-post systems have been successfully used in the field over the years and there 

has not been any problems identified with either system. For example, both steel-post and wood-post SKT 

and FLEA T terminals have been deployed in the field with excellent in-service records. Actually, from an 

impact standpoint, it is our opinion that the steel-post system is more critical than the wood-post system. 

The analysis and reasoning for this conclusion is presented as follows. 

For head-on impacts (Test Designation 30, 31 , 32, and 33), both steel-post and wood-post systems should 

perform the same from the initial point of impact up to post 3 since both systems use the same steel Posts 

I and 2 with a ground strut anchorage system. From Post 3 through Post 8, the wood-post system is, in 

our opinion, more consistent and predictable than the steel-post system. The wooden CRT posts are 

designed to break away at a given force level when impacted in a longitudinal direction. In comparison, 

the standard steel line posts are simply pushed down when impacted in a longitudinal direction to allow 

for vehicle to pass over the bent posts. Thus, there is more debris on the ground in the path of the vehicle 

for the steel-post system, which could potentially cause the vehicle to roll and yaw. Thus, we believe that 

the wood-post system would perform in a more consistent and predictable manner than the steel-post 

system for head-on and shallow angle impacts. 

Two similar small-car, head-on tests (Test 3-30) were conducted on a NCHRP 350 SKT terminal with a 

MSKT impact head, one for a steel-post system (KARCO Test Report no. TR-P35127-01) and one for a 

wood-post system (KARCO Test Report no. TR-P35226-01) to demonstrate that the MSKT impact head 

can be used interchangeably on a NCHRP 350 SKT terminal. These test results were submitted 

previously to FHW A for review. While the tests were conducted under NCHRP 350 guidelines and not 

MASH guidelines, they nonetheless provide a direct comparison in the impact performance of steel-post 

versus wood-post systems. Videos of these two crash tests show that the vehicle kinematics are similar for 

both systems initially through Posts 1 and 2, which are breakaway posts. However, from Post 3 on, the 

wood-post system, with the wood CRT posts, has a smoother and more controlled vehicle kinematics than 

the steel-post system, with standard steel line posts. This observation is supported by the test results as 
summarized in the following table. Note that the occupant risk factors, i.e., flail space velocities and 

ridedown accelerations, are similar for both systems. The most significant differences are that the steelpost system has significantly higher maximum roll angle (25 .3 deg. v. 13 .3 deg.) and maximum pitch 

angle (49.7 deg. v. 9.7 deg.) than the wood-post system. In summary, under almost identical test 

conditions, the wood-post system has smoother and more controlled vehicle kinematics than the steel-post 

system using the MSKT impact head while exhibiting similar occupant impact severity in terms of flail 

space velocity and ridedown acceleration. 

System Wood-Post System Steel-Post System 

Impact Speed [km/h (mph)] 97.42 (60.54) 97.59 (60.64) 

Impact Angle (

0 

) 0.2 0.5 

Impact Severity (kJ) 298.2 303.3 

Flail Space Velocity (m/s) - X Direction 7.9 7.8 

- Y Direction 0.2 0.0 

Ridedown Acceleration (g) - X Direction -7.8 -8.9 

- Y Direction -3 .7 -3.7 

Maximum Roll Angle (

0 

) -13.3 25.3 

Maximum Pitch Angle (

0 

) -9.7 -49.7 

Maximum Yaw Angle (

0 

) 158.2 143.9 

For redirectional impacts (Test Designation 34 and 35), both steel-post and wood-post systems use the 

same anchorage system, so the anchorage capacity for both systems would be similar. Thus, any 

difference in the performance of the two systems in redirectional impacts would be in the lateral 

resistance of the posts and the interactions between the posts and the rail. The lateral resistance of wood 

and steel posts have been found to be fairly comparable in various studies over the years based on 

dynamic testing results. For example, in a recent study by Midwest Roadside Safety Facility rn, a series of 

bogie tests were conducted on wood and steel posts and the researchers concluded that "standard steel 

posts would also provide similar post-soil resistance to 6-in x 8-in. (152-mm x 203-mm) wood posts when 

installed in level terrain and using 6-ft (1. 8-m) long sections." In terms of interactions between the posts 

and the rail, the wood posts also perform better. Steel posts tend to bend and twist while breakaway wood 

CRT posts would break and split. There is also a potential for the rail to contact the edge or comer of the 

steel post flanges, resulting in a tear and even rupture to the rail. This would not be a problem for the 

wood-post system since the wood posts do not present any sharp edges. Also, wheel snagging may be 

more of a concern for steel-post systems given the bending and twisting of the posts. The satisfactory 

performance of wood-post guardrail systems in redirectional impacts (Tests 3-10 and 3-1 I) under MASH 

guidelines was demonstrated in two series of crash tests conducted on the Midwest Guardrail System 

(MGS) with Southern yellow pine wood posts and white pine wood posts. <£,lJ 

For the reverse direction impact (Test Designation 37), there should not be any difference between the 

wood-post and steel-post systems, given the point of impact and that Posts I and 2 and the ground strut 

are the same for both systems. 
In a September 9, 2015 correspondence between Road Systems, Inc. and FHW A, it was noted that 

"Review ofthe MASH tests ofthe SKT submitted so far show a significant vehicle lifting and rolling that 

was not observed in the original SKT testing of1997. This does not give us confidence that the wood and 

steel post versions will both meet MASH criteria." Interesting enough, this observation actually supports 

our opinion that the steel-post system is more critical than the wood-post system from an impact 

performance standpoint. The original testing of the SKT terminal in 1997 used a wood-post system, 

which seemingly performed better than the current MSKT terminal tested with a steel-post system. While 

these two series of tests are not directly comparable since one was tested under NCH RP 350 guidelines 

and the other under MASH guidelines and there are differences between the two systems, it nonetheless 

provides some interesting observations. 

In summary, we believe that the steel-post system is actually more critical than the wood-post system for 

reasons explained above. Since the MSKT steel-post system successfully passed all MASH evaluation 

criteria, it is our opinion that the MSKT wood-post system would also satisfy all of the MASH 

requirements with no problem. Thus, it is requested that the wood-post MSKT terminal be approved. 

REFERENCES 

1. 	 Homan, D. M., et al, "Investigation and Dynamic Testing of Wood and Steel Posts for MGS on a 

Wired-Faced MSE Wall," Report TRP-03-231-11, Midwest Roadside Safety Facility, conducted 

for the Central Federal Lands Highway Division, Lincoln, NE, February 2012. 

2. 	 Gutierrez, D.A., et al, "Midwest Guardrail System (MGS) with Southern Yellow Pine Posts," 

Report TRP-03-272-13, Midwest Roadside Safety Facility, Lincoln, NE, September 2013 . 

3. 	 Stolle, C.J., et al, "Evaluation of the Midwest Guardrail System (MGS) with White Pine Wood 

Posts," Report TRP-03-241-11 , Midwest Roadside Safety Facility, Lincoln, NE, March 2011.