October 6, 2004
Refer to: HSA-10/WZ-191
Mr. Barry D. Stephens
Senior Vice President, Engineering
Energy Absorption Systems, Incorporated
3617 Cincinnati Avenue
Rocklin, California 95765
Dear Mr. Stephens:
Thank you for your letter of June 28, 2004, requesting Federal Highway Administration (FHWA) acceptance of your company's Safe-Hit Barracudatm Longitudinal Channelizing Barricade as a Test Level 2 (TL-2) crashworthy traffic control device for use in work zones on National Highway System (NHS). Accompanying your letter were reports of crash testing conducted by E-TECH Testing Services and video of the tests. 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."
The FHWA guidance on crash testing of work zone traffic control devices is contained in two memoranda. The first, dated July 25, 1997, titled "INFORMATION: Identifying Acceptable Highway Safety Features," established four categories of work zone devices: Category I devices are those lightweight devices which are to be self-certified by the vendor, Category II devices are other lightweight devices which need individual crash testing but with reduced instrumentation, Category III devices are barriers and other fixed or heavy devices also needing crash testing with normal instrumentation, and Category IV devices are trailer mounted lighted signs, arrow panels, etc., for which crash testing requirements have not yet been established. The second guidance memorandum was issued on August 28, 1998, and is titled "INFORMATION: Crash Tested Work Zone Traffic Control Devices." This later memorandum lists devices that are acceptable under Categories I, II, and III.
A brief description of the devices follows:
The Safe-Hit Barracudatm Longitudinal Channelizing Barricade (LCB) is a rotation molded hollow, low-density polyethylene plastic section which can accept water ballast. From the outside, the segments are identical to your company's existing TRITON® Barrier, but the Barracuda segments are fabricated without an internal steel framework.
The Safe-Hit Barracudatm LCB is modular and can be used in various lengths for specific applications. A dimensioned drawing and material specifications are enclosed for reference. The height of each section is 828 mm, the length is 1984 mm, and the wall thickness is nominally 5 mm. The section shape is tapered from a base width of 495 mm to a top width of 546 mm. The test articles were installed according to the instructions supplied by the manufacturer. A total of 18 yellow colored sections were aligned end to end and interconnected with ABS connector pins to form the LCB installation. The installation was freestanding and unanchored on a flat, clean, and dry asphalt surface. Water ballast was added to bring the mass of each section to 586 kg.
Full-scale automobile testing was conducted on your company's LCB. Because LCBs are a unique category of barricade, the FHWA has recommended that they be tested with the 820 C vehicle at an impact angle of 20 degrees just like a redirective barrier. However, since LCBs are not designed to redirect the vehicle, controlled penetration is allowed. All other criteria, including occupant impact speed, ridedown acceleration, and occupant compartment penetration/intrusion, must be evaluated as if the device were a longitudinal barrier. The test is summarized in the table below.
|Test Number||01-4019-001 (TL-2)|
|Device Tested||Safe-Hit Barracudatm Longitudinal Channelizing Barricade|
|Weight of Ballasted Unit||584 kg|
|Mass of Test Vehicle||833 kg|
|Impact Speed||70.3 kmh|
|Occupant Risk Values:|
The vehicle penetrated directly through the installation losing most of its velocity and experiencing relatively minor roll and pitch. The vehicle then yawed clockwise traveling roughly parallel to the back side of the installation and came to rest 14.6 m downstream from the point of impact and 1.8 m behind the original face of the installation. The maximum dynamic and permanent lateral deflection of the test article was 3.0 m.
Damage was limited to minor deformation of the grill and hood. The headlights were broken out. The seatbelt broke loose during the impact and the dummy's head cracked the windshield. There was no measurable deformation of the vehicle interior.
The results of the testing met the FHWA requirements and, therefore, the device described above and detailed in the enclosed drawings and specifications are acceptable for use on the NHS under the range of conditions tested, when proposed by a State.
You also had two additional requests:
1) that we accept the TRITON barrier as a LCB, and
2) that TRITON barrier can be used with the BARRACUDA devices.
We concur in request 1), the TRITON barrier may be used in lieu of a row of channelizing devices or a LCB.
We also concur in request 2), but recommend that TRITON barrier follow the BARRACUDA LCB and that the respective units be ballasted so that they are the same approximate weight, considering the steel structure inside the TRITON units add weight.
Please note the following standard provisions that apply to FHWA letters of acceptance:
/Original Signed by/
John R. Baxter, P.E.
Director, Office of Safety Design
Office of Safety