Mr. Leo J. Yodock, III

623 NE 5 th 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 (TL­2) device under the provisions of

National Cooperative Highway Research Program (NCHRP) Report 350 “Recommended 

Procedures for the Safety Performance Evaluation of Highway Features.”

Introduction

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 self­certified 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 low­density 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

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

In Reply Refer To: 

HSA­10/WZ­220 

January 13, 2006
2 

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.

Testing

Full­scale 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 34­inch long 2 pound­per­foot u­channel and the 

other panel was mounted on a 43­inch long 2 inch I.D. Schedule 40 pipe.  Other appurtenances

installed and impacted included 44­inch 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 3­71 

Test Number  400001­YWC9 

Model  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

Findings

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 TL­2 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
3 

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:

· Our 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 in­service 

performance reveals unacceptable safety problems, or that the device being marketed is

significantly different from the version that was crash tested, it reserves the right to 

modify or revoke its 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 they will meet the crashworthiness requirements of the FHWA and 

the NCHRP Report 350.

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

WZ­220 shall not be reproduced except in full. This letter, and the test documentation 

upon which this letter is based, is public information. All such letters and documentation 

may be reviewed at our office upon request. · The Yodock Slimline LCB is a patented device and is considered "proprietary." The use 

of proprietary work zone traffic control devices in Federal­aid projects is generally of a 

temporary nature.  They are selected by the contractor for use as needed and removed 

upon completion of the project. Under such conditions they can be presumed to meet 

requirement "a" given below for the use of proprietary products on Federal­aid projects. On the other hand, if proprietary devices are specified by a highway agency for use on 

Federal­aid projects they: (a) must be supplied through competitive bidding with equally 

suitable unpatented items; (b) the highway agency must certify that they are essential for

synchronization with 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, a copy of which is enclosed.

· 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
4 

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,

John R. Baxter, P.E.

Director, Office of Safety Design 

Office of Safety 

Enclosures

FHWA:HSA­10:NArtimovich:tb:x61331:1/11/06 

File:  h://directory folder/artimovich/WZ220­YodockFIN.doc 

cc:  HSA­10 (Reader, HSA­1; Chron File, HSA­10; 

N.Artimovich, HSA­10)