Refer to: HSA-10/WZ-106

Mr. Leo J. Yodock, III 

Yodock Wall Co., Inc. 

3000 S.W. 4th Avenue 

Ft. Lauderdale, FL 33315 

 

Dear Mr. Yodock: 

Thank you for your letter of September 4, 2001, requesting Federal Highway Administration 

(FHWA) acceptance of your company’s Energy Dispersement Cell Channelizer (EDCC) as a 

crashworthy traffic control device for use in work zones on the National Highway System 

(NHS). Accompanying your letter was a report of crash testing conducted by the Texas 

Transportation Institute and videos of the tests. You requested that we find this device acceptable 

as a Test Level 2 (TL-2) device 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.” 

On December 13, 2001, you met with members of the Office of Safety Design staff to discuss 

the crash-testing program, the results, and the proposed uses associated with these devices. On 

January 9,2002, you submitted additional information as discussed at our meeting. 

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 

were those lightweight devices which could be self-certified by the vendor, Category II devices 

were other lightweight devices which needed individual crash testing, Category III devices were 

barriers and other fixed or massive devices also needing crash testing, and Category IV devices 

were trailer mounted lighted signs, arrow panels, etc. 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 follows: 

Energy Dispersement Cell Channelizer - TL-2 

The Yodock Barrier Model 2001 EDCC units are rotomolded, low-density polyethylene, 

containers that can be partially filled with water as ballast. Overall dimensions on the units are 

1830 mm long, 1170 mm tall, 610 mm width at the base, and 280 mm wide at the top. There are 

two forklift holes at 530 mm above ground level that nominally measure 150 mm x 280 mm. 
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The bottom vertical face of the device is 230 mm in height. Water ballast was placed in the units 

to the top of the vertical face located approximately 495 mm from the base of the device. The 

approximate measured volume of water in each unit was 170 L (45 U.S. Gallons.) A total of 40 

units were placed adjacent to each other and coupled with Polyethylene couplers. Total length of 

the installation was 73.2 m (240 feet.) An internal flashing beacon and solar battery, weighing 

4.0 kg, was installed on segments 13 and 14. Details of the EDCC units and couplers are shown 

in the enclosed drawings for reference. 

This device was evaluated as a longitudinal channelizing barricade. This is a subcategory of 

barricades now being considered for inclusion in the Manual on Uniform Traffic Control 

Devices (MUTCD). They can be used singly as Type I, II or III barricades, or connected so they 

are highly visible and have good target value. The interlocking units of a longitudinal 

channelizing barricade can be used to delineate or channelize traffic flow including pedestrian 

traffic. The interlocking barricade does not have gaps through which pedestrians, bicyclists, or 

motor vehicles can filter. However, it is not designed to prevent penetration by vehicles under 

minimum crash test performance conditions. After discussions with my staff, it was determined 

that NCHRP Report 350 test 2-10 (820 kg passenger car impacting at 70 kmh at an angle of 20 

degrees) would be appropriate; however, when evaluating its performance as a longitudinal 

channelizer barricade during this test, occupant risk and vehicle stability should be the 

determining criteria, and not structural adequacy. In other words, when the EDCC are used for 

channelizing, it would be acceptable for the vehicle to penetrate the longitudinal channelizer 

barricade in a safe manner. 

Testing 

Full-scale automobile testing was conducted on your company’s device. The test results are 

summarized in the following table. 

Test Number 400001-YWC1 

NCHRP Report 350 Test # 2-10 

Test Article Longitudinal Channelizer 

Height to Bottom of Sign n/a 

Height to Top of Sign n/a 

Flags or lights None 

Test Article Mass (each) 60 kg + 200 kg water 

Vehicle Inertial Mass 820 kg 

Impact Speed 68.3 km/hr 

Occupant Risk Values 

 Occupant Impact Velocity 7.0 m/s 

 Ridedown x-direction -4.9 g’s 
3

 Ridedown y-direction -4.3 g’s 

 Max 0.050-s accel x-dir -5.9 g’s 

 Max 0.050-s accel y-dir -3.6 g’s 

 Max 0.050-s accel z-dir -2.5 g’s 

Vehicle crush 100 mm 

Occupant Compartment 

Intrusion 

92 mm (crush) 

Windshield Damage none 

In the test of the EDCC the vehicle penetrated the channelizer and yawed sharply. The side of 

the car then struck the exposed blunt end, causing minor deformation of the passenger 

compartment at the door. The resulting deformation has a low potential to cause serious injury 

to occupants of the impacting vehicle. The vehicle traveled 6.1 m behind the channelizer before 

coming to rest 

Findings 

The EDCC does not meet the redirective requirements for a barrier. However, as a longitudinal 

channelizer it can provide an unbroken line of units that warn motorists from crossing into the 

protected area. 

Because this device has been tested and met the unique requirements that have been set for them, 

the device described above and shown in the enclosed drawings for reference are acceptable for 

use on the NHS under the range of conditions tested and the additional conditions discussed 

above, when proposed by a State. In addition, the Model 2001m EDCC, which is 812 mm tall, 

will also be acceptable subject to the same conditions and restrictions as the crash-tested Model 

2001 EDCC. 

Please note the following standard provisions that apply to 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 MUTCD. 

• 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, 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 the will meet the crashworthiness requirements of FHWA and NCHRP Report 350. 
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• To prevent misunderstanding by others, this letter of acceptance, designated as number 

WZ-106 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 Wall plastic safety shape units are patented and considered “proprietary.” The 

use of proprietary work zone traffic control devices in Federal-aid 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 Federal-aid projects. On the other 

hand, if proprietary devices are specified for use on Federal-aid projects, except exempt, nonNHS projects, they: (a) must be supplied through competitive bidding with equally suitable 

unpatented items; (b) the highway agency must certify that the 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 types 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. 

Sincerely yours, 

Michael L. Halladay 

 Acting Program Manager, Safety 

Enclosure 

FHWA:HSA-10:NArtimovich:tb:x61331:2/06/02 

File: WZ106-Yodock.wpd 

cc: HSA-10 (Reader, HSA-1; Chron File, HSA-10; 

 N. Artimovich, HSA-10)