Safety Eligibility Letter B-152
Safety Eligibility Letter B-152
PDF [1.40 MB]
U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Ave. S.E.
Washington, D.C. 20590
March 27, 2008
In Reply Refer To: HSSD/B-151
Bryant L. Lowery, P.E.
Special Design Engineer
Location and Design Division
Virginia Department of TransportationM
1401 East Broad Street
Richmond, Virginia 23219
Dear Mr. Lowery:
This letter is in response to your request for Federal Highway Administration (FHWA) acceptance of a roadside safety device for use on the National Highway System (NHS).
Name of device: | Permatile Precast Concrete Barrier 10 foot length |
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Type of device: | Portable concrete barrier |
Test Level: | NCHRP Report 350 TL-3 |
Prior Testing conducted by: | Texas Transportation Institute (TTI) |
Date of request: | March 14, 2008 |
You requested that we find this device acceptable for use on the NHS under the provisions of National Cooperative Highway Research Program (NCHRP) Report 350 “Recommended Procedures for the Safety Performance Evaluation of Highway Features.”
Requirements
Roadside safety devices should meet the guidelines contained in the NCHRP Report 350, "Recommended Procedures for the Safety Performance Evaluation of Highway Features". FHWA Memorandum “Action: Identifying Acceptable Highway Safety Features” of July 25, 1997, provides further guidance on crash testing requirements of longitudinal barriers.
Description
You requested formal acceptance of the Virginia Department of Transportation (VDOT) 10 foot F-shape Concrete Barrier with the pin and loop positive connection. A 20 foot version of this design (Scan01.tif, enclosed for reference) was tested and accepted for use as a TL-3 NCHRP 350 temporary barrier in FHWA Acceptance Letter B-54 dated May 18, 1999. Permatile Concrete Products Company manufactured and supplied this barrier that was tested by TTI under NCHRP report 350 Test 3-11, Contract No. T99011 and Project No. 402041. The drawings “Scan02.tif” and “Scan03.tif” include the details of the 10' version and are enclosed for reference.
Crash Testing
The 20-foot long version of the VDOT barrier was successfully crash tested as noted above. Through the observation of crash testing of numerous portable concrete barrier segments of varying lengths over the years FHWA has learned that the length of the barrier plays little, if any, role in the successful performance. As long as the steel reinforcing and the integrity of the end connections are maintained, the shorter barrier length will be acceptable for use.
Findings
The 10-foot long VDOT barrier described above and detailed in the enclosed drawings is acceptable for use on the NHS under the range of conditions that the 20-foot barrier was tested, when proposed by a State.
Please note the following standard provisions that apply to FHWA letters of acceptance:
- This acceptance is limited to the crashworthiness characteristics of the devices and does not cover their structural features, nor conformity with the Manual on Uniform Traffic Control Devices.
- Any changes that may adversely influence the crashworthiness of the device will require a new acceptance letter.
- Should the FHWA discover that the qualification testing was flawed, that in-service performance reveals unacceptable safety problems, or that the device being marketed is 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.
- We expect you will wish to have suppliers of this device certify that the hardware furnished has essentially the same chemistry, mechanical properties, and geometry as that submitted for acceptance, and that it will meet the crashworthiness requirements of the FHWA and the NCHRP Report 350.
- To prevent misunderstanding by others, this letter of acceptance is designated as number B-151 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.
- 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. |
2 Enclosures