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U.S. Department of Transportation

Federal Highway Administration

400 Seventh St., S.W.
Washington, D.C. 20590

January 13, 2006

Refer to: HSA-10/WZ-220

Mr. Leo J. Yodock, III
623 NE 5th Terrace
Ft. Lauderdale, Florida 33304

Dear Mr. Yodock :

Thank you for your letter of September 15, 2005, requesting Federal Highway Administration (FHWA) acceptance of your company's "Slimline Channelizer"; model 2001SL Longitudinal Channelizing Barricade as a crashworthy traffic control device for use in work zones on the National Highway System (NHS). Accompanying your letter were reports of crash testing conducted by the Texas Transportation Institute and video of the tests. You requested that we find it acceptable for use on the NHS as a test level 2 (TL-2) device 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 Slimline Channelizer is a low-density polyethylene water filled unit that is 18 inches tall. It is rotationally molded and has a nominal wall thickness of 1/4 inch. The overall length of an individual unit is 78 inches and when interconnected with adjacent units, the nominal segment length is 72 inches. The top width of the unit is 6 inches and the bottom measures 12 inches wide. Flanges extend an additional 14 inches on each side at the base of each unit. Empty weight of the unit is 38 pounds, and 330 pounds when filled with 35 gallons of water. A drawing of a single unit is enclosed for reference.

Full-scale automobile testing was conducted on your company' devices. Each unit was anchored to the unreinforced concrete apron with six 3/8 inch x 4 inch Hilt Coil Anchors. Two 20x30 inch sign panels were installed on the channelizer installation in the vicinity of the impact; one sign panel was mounted on a 34-inch long 2 pound-per-foot u-channel and the other panel was mounted on a 43-inch long 2 inch I.D. Schedule 40 pipe. Other appurtenances installed and impacted included 44-inch long 2 3/8 inch O.C. plastic delineators and reflectors. Individual units link to form a longitudinal channelizing barricade by interlocking the male/female connectors on the end of each unit. The overall length of the 20 units was
120 feet.

The tests are summarized in the table below.

NCHRP Report 350 Test 3-71

Test Number



2001SL Slimline Longitudinal Channelizing Barricade (LCB)

Flags? Lights?

Yes, two sign panels and warning lights

Mass of Test Vehicle

820 kg

Impact Speed

71.0 km/hr

Impact Angle

19.1 degrees

Velocity Change

5.28 m/s

Occupant Impact Speed

4.3 m/s (longitudinal)

Extent of contact

Cosmetic damage to bumper

Windshield Damage

No contact with windshield

Other notes

Auxiliary devices showed no potential for windshield damage


The vehicle overrode the Slimline LCB with no tendency towards instability. Damage was limited to scrapes to the bumper. The auxiliary signs, lights, and road tubes had no adverse effect on the impact. There was no occupant compartment deformation.

The results of the testing met the FHWA requirements and, therefore, the device described in the request above and detailed in the enclosed drawing are acceptable for use as a TL-2 LCB on the NHS under the range of conditions tested, when proposed by a State.

You also requested that we accept the Slimline LCB with or without water ballast, fastened to the pavement with as little as two anchors, or free standing, and with or without the use of the delineator posts, signs, and lights. In brief, we concur with these requests.

The vehicle traversal of the LCB will be very different when the ballast is omitted and/or when the attachment to the pavement is reduced. However, based on prior testing of larger LCBs that are freestanding with little or no ballast, the test vehicle simply breaks through the LCB and knocks the individual units aside. Although we considered the possibility that a vehicle could "capture"; individual units if they deform and ride under the vehicle, we have seen no such behavior in any temporary work zone device over the last five years of crash testing.

The Slimline LCB can also be expected to perform in a satisfactory manner if impacted without delineator posts, light or signs present.

Please note the following standard provisions that apply to the FHWA letters of acceptance:

Sincerely yours,

/original signed by /

John R. Baxter, P.E.
Director, Office of Safety Design
Office of Safety


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