1200 New Jersey Avenue, SE 

Washington, D.C. 20590

In Reply Refer To: 

HSSD/B-42B 

Mr. Michael Budd 

Rockingham Precast 

P.O. Box 1347 

Harrisonburg, VA 22801 

Dear Mr. Budd: 

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: 12-Foot T-LOC F-Shape Portable Concrete Barrier 

Type of device: Temporary Concrete Barrier 

Test Level: AASHTO Manual for Assessing Safety Hardware (MASH) Test Level-3 

Testing conducted by: Texas Transportation Institute (TTI) on May 5, 2009 

Date of request: February 10, 2009 

Initial response by email sent February 23, 2009 

You subsequently requested that we formally find this device acceptable for use on the NHS 

under the provisions of the AASHTO Manual for Assessing Safety Hardware (MASH) Test 

Level-3 (TL-3). 

Requirements 

Roadside safety devices should meet the guidelines contained in the AASHTO Manual for 

Assessing Safety Hardware (MASH). The FHWA Memorandum “ACTION: Identifying 

Acceptable Highway Safety Features” of July 25, 1997, provides further guidance on crash 

testing requirements of longitudinal barriers. 

Description 

The Rockingham Precast T-LOC barrier was originally accepted on October 20, 1997, in our 

Acceptance Letter B-42. The barrier tested was composed of 32-inch high, 12-foot long concrete 

F-Shape segments using a connection detail specifying 32-inch long slotted tube 

(4 inches x 4 inches x 1/2 inches) and mating fabricating ‘T’ made of 1/2-inch thick steel. 
2

Your present request is for formal acceptance of 32-inch high, 12-foot long concrete F-Shape 

barrier segments using a connection detail specifying 12-inch long slotted tube connection 

(HSS4 x 4 x 1/2) anchored to the end of barrier segments using four #6 dowel bars 24 inches in 

length welded to the sides of the slotted tube (two on each side). The width of the slot in the tube 

was 1 inch. The interlocking mating "T" connection was fabricated using 1/2-inch thick steel 

plate. The width and length of the "T" connection was 2 inches and 12 inches respectively. 

The "T" connection was anchored to the ends of the barrier units using three #6 bars, 36 inches in 

length, and welded to the "T" connection steel. These bars, along with the bars welded to the 

slotted tube connection, were cast within the barrier concrete for each unit. Both the slotted tube 

and the "T" connection were located 10 inches from the base of the barrier unit. Each barrier 

unit was reinforced using three #5 longitudinal reinforcing bars, 11 feet, 8 inches in length. 

These bars were lapped with the three bars anchoring the "T" connection. The longitudinal 

reinforcing bars were skewed to lap with the dowel bars used to anchor the slotted tube 

connection. 

The Office of Safety questioned the strength of the 12-inch long connection detail and requested 

that you conduct MASH Test 3-11, which you did. The vehicle was redirected and remained 

upright, and the occupant risk values were within the limits set by MASH. The test data 

summary sheet is attached for reference. 

Findings 

We concur in your request that the modified T-LOC concrete barrier segments that have been 

successfully crash tested to AASHTO MASH TL-3 conditions at a segment length of 12 feet will 

be considered acceptable for use on the NHS connection details when the segments are 

manufactured to a length of 12 feet. Please note the following standard provisions that apply to 

the 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 

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 AASHTO 

MASH. 

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

B-42B 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. 
3

• T-LOC concrete barriers 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 yours, 

 David A. Nicol, P.E. 

 Director, Office of Safety Design 

 Office of Safety 

FHWA:HSSD:WLongstreet:tb:x60087:6/24/09 

File: s://directory folder/WLongstreet/RockinghamPrecastT-LockF-ShapeBarrier.doc 

cc: HSSD (Reader, HSA; Chron File, HSSD; W.Longstreet, HSSD; NArtimovich, HSSD; 

 MMcDonough, HSSD) 
1200 New Jersey Avenue, SE 

Washington, D.C. 20590

July 17, 2009 

In Reply Refer To: 

HSSD/B-42B 

Mr. Michael Budd 

Rockingham Precast 

P.O. Box 1347 

Harrisonburg, VA 22801 

Dear Mr. Budd: 

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: 12-Foot T-LOC F-Shape Portable Concrete Barrier 

Type of device: Temporary Concrete Barrier 

Test Level: AASHTO Manual for Assessing Safety Hardware (MASH) Test Level-3 

Testing conducted by: Texas Transportation Institute (TTI) on May 5, 2009 

Date of request: February 10, 2009 

Initial response by email sent February 23, 2009 

You subsequently requested that we formally find this device acceptable for use on the NHS 

under the provisions of the AASHTO Manual for Assessing Safety Hardware (MASH) Test 

Level-3 (TL-3). 

Requirements 

Roadside safety devices should meet the guidelines contained in the AASHTO Manual for 

Assessing Safety Hardware (MASH). The FHWA Memorandum “ACTION: Identifying 

Acceptable Highway Safety Features” of July 25, 1997, provides further guidance on crash 

testing requirements of longitudinal barriers. 

Description 

The Rockingham Precast T-LOC barrier was originally accepted on October 20, 1997, in our 

Acceptance Letter B-42. The barrier tested was composed of 32-inch high, 12-foot long concrete 

F-Shape segments using a connection detail specifying 32-inch long slotted tube 

(4 inches x 4 inches x 1/2 inches) and mating fabricating ‘T’ made of 1/2-inch thick steel. 
2

Your present request is for formal acceptance of 32-inch high, 12-foot long concrete F-Shape 

barrier segments using a connection detail specifying 12-inch long slotted tube connection 

(HSS4 x 4 x 1/2) anchored to the end of barrier segments using four #6 dowel bars 24 inches in 

length welded to the sides of the slotted tube (two on each side). The width of the slot in the tube 

was 1 inch. The interlocking mating "T" connection was fabricated using 1/2-inch thick steel 

plate. The width and length of the "T" connection was 2 inches and 12 inches respectively. 

The "T" connection was anchored to the ends of the barrier units using three #6 bars, 36 inches in 

length, and welded to the "T" connection steel. These bars, along with the bars welded to the 

slotted tube connection, were cast within the barrier concrete for each unit. Both the slotted tube 

and the "T" connection were located 10 inches from the base of the barrier unit. Each barrier 

unit was reinforced using three #5 longitudinal reinforcing bars, 11 feet, 8 inches in length. 

These bars were lapped with the three bars anchoring the "T" connection. The longitudinal 

reinforcing bars were skewed to lap with the dowel bars used to anchor the slotted tube 

connection. 

The Office of Safety questioned the strength of the 12-inch long connection detail and requested 

that you conduct MASH Test 3-11, which you did. The vehicle was redirected and remained 

upright, and the occupant risk values were within the limits set by MASH. The test data 

summary sheet is attached for reference. 

Findings 

We concur in your request that the modified T-LOC concrete barrier segments that have been 

successfully crash tested to AASHTO MASH TL-3 conditions at a segment length of 12 feet will 

be considered acceptable for use on the NHS connection details when the segments are 

manufactured to a length of 12 feet. Please note the following standard provisions that apply to 

the 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 

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 AASHTO 

MASH. 

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

B-42B 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. 
3

• T-LOC concrete barriers 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 yours, 

 David A. Nicol, P.E. 

 Director, Office of Safety Design 

 Office of Safety 

FHWA:HSSD:WLongstreet:tb:x60087:6/24/09 

File: s://directory folder/WLongstreet/RockinghamPrecastT-LockF-ShapeBarrier.doc 

cc: HSSD (Reader, HSA; Chron File, HSSD; W.Longstreet, HSSD; NArtimovich, HSSD; 

 MMcDonough, HSSD) 
N 

VJ 

0.090 s 

General Information 

Test Agency ........................... Texas Transportation Institute 

Test No. ·································· 400001-RPC4 

Date ......................................... 2009-05-05 

Test Article 

Type ......................................... Portable Concrete Median Barrier 

Name ....................................... Rockingham Precast Barrier 

Installation Length ................... 192 ft 

Material or Key Elements ........ 12 ft segments of F-shaped portable 

concrete median barriers with T-LOK 

connection 

Soll Type and Condition ........... Concrete surface. dry 

Test Vehicle 

Type/Designation ..................... 2270P 

Make and Model ... .. ...... .. .. .. . . ... 2003 Dodge Ram Quad-Cab 

Curb ......................................... 4782 

Test Inertial. ......•...................... 4986 

Dummy .................................... No dummy 

Gross Static ............................. 4986 

Impact Conditions 

Speed ................................... 62.8 milh 

Angle .................................... 25.4 degrees 

Location/Orienlation .............. 4 ft upstream 

Exit Conditions of Joint 6-7 

Speed .................................... N/A 

Angle .................................... .N/A 

Occupant Risk Values 

Impact Velocity 

Longitudinal ........................ 10.2 fVs 

Lateral ............................... 22.3 IVs 

Ridedown Accelerations 

Longitudinal ........................ -4.0 G 

Lateral ............................... 15.9 G 

THIV .................................... 26.3 km/h 

PHD ....................................... 15.9 G 

Max. 0.050-s Average 

Longitudinal ........................ -4.6 G 

Lateral ............................... 10.6 G 

Vertical ............................... -3.2 G 

Post-Impact Trajectory 

Stopping Distance ......................... 182 ft dwnstnm 

21 ft twd traffic 

Vehicle Stability 

Maximum Yaw Angle ..................... 48 degrees 

Maximum Pitch Angle .................... -12 degrees 

Maximum Roll Angle ......... : ............ -33 degrees 

Vehicle Snagging ........................... No 

Vehicle Pocketing .......................... No 

Test Article Dofloctions 

Dynamic ......................................... 50.0 inches 

Permanent ..................................... 49.4 inches 

Working Width ............................... 71 . 7 inches 

Vehicle Damage 

VOS .............................................. 11LFQ4 

CDC ............................................... 11FLEW4 

Max. Exterior Deformation ............. 16.0 inches 

Max. Occupant Compartment 

Deformation ............................. 0.38 inches 

Figure 5.7. Summary of results for MASH08 test 3-11 on Rockingham prccast concrete median barrier.