Federal Highway Administration
April 18, 2008
In Reply Refer To: HSSD/CC26I
Barry D. Stephens, P.E.
Sr. Vice President Engineering
Energy Absorption Systems, Inc.
3617 Cincinnati Avenue
Rocklin, CA 95678
Dear Mr. Stephens:
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).
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.”
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.
The REACT 350® uses an array of different energy absorbing cylinders with varying wall thicknesses to dissipate impact energy. We have accepted variations in the REACT system in FHWA acceptance letters beginning with CC-26 dated March 3, 1995, and most recently with CC-26H dated November 2, 2002. In your current request you asked for FHWA review and acceptance of an optimized system which is a self-restoring, redirective, non-gating crash cushion that can be used in temporary or permanent installations for both uni- and bi-directional traffic applications when appropriately transitioned and anchored.
The optimized system modified the rear four cylinders by making them slightly thicker and more robust. To support your request, you supplied an NCHRP 350 compliance report prepared by E-TECH Testing Services, Inc. that describes the REACT 350® as well as the three full-scale crash tests you conducted on this attenuator.
The Energy Absorption Systems developed the optimized REACT to withstand at least three consecutive impacts without requiring maintenance or resetting between impacts. You evaluated the redesign by conducting three full-scale NCHRP 350 tests. The first test you completed was NCHRP 350 test 3-30 (820C/100KPH/0 deg/ w/offset) which you then followed with two consecutive NCHRP 350 tests 3-31 (2000P/100KPH/0 deg). Your test report stated that all three tests were conducted over a five day period and the system received no maintenance or resetting between tests. Your three TL-3 tests (100 km/h) verified that the impact performance for light cars (820kg) was acceptable and that heavier vehicles could also be brought to a safe and controlled stop without resetting the test article. You also analyzed the other Report 350 tests recommended for impact attenuators and documented why no further testing was warranted by the cylinder modification.
Based upon the successful completion of the aforementioned NCHRP 350 tests you provided, we agree that your 9 cylinder TL-3 model of the REACT 350® redirective, non-gating crash cushion can be used in temporary or permanent installations for both uni- and bi-directional traffic applications when appropriately transitioned and anchored. The system as described above may be used on the NHS when such use is acceptable to the contracting authority.
Please note the following standard provisions that apply to FHWA letters of acceptance:
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