Refer to: HSA-10/WZ-107

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 letters of September 4, 2001, requesting Federal Highway Administration 

(FHWA) acceptance of your company’s Energy Dispersement Cell Barricade (EDCB) 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 3 (TL-3) devices, respectively, 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 of the device follows: 

Energy Dispersement Cell Barricade - TL-3

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

water-filled containers. Overall dimensions on these 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. The bottom vertical face of the 
2

device is 230 mm in height. For this test, water ballast was placed in the units to the maximum 

capacity. The approximate full mass of each unit is 1025 kg (1650 pounds.) A total of three 

units were placed adjacent to each other and coupled with Polyethylene couplers. The total 

length of the installation was 5.5 m (18 ft.) 

The Type III barricade atop each water filled unit was fabricated with two 50 mm (2 inch) 

schedule 80 PVC pipes, 2.59 m long (102 inch) supports. The center of the support pipes are 

placed 330 mm (13 in) from each end of the units. Hollow plastic lumber measuring 20 mm 

(3/4 inch) thick, 195 mm (7.7 inches) tall, by 1840 mm (72.4 inches) long was attached to the 

PVC pipe with 6 mm (1/4 inch) “U” bolts. The top of the middle horizontal panel was 1940 mm 

(76.4 inches) above the ground. The top of the upper horizontal panel was mounted 2440 mm 

(96 inches) above grade. In addition, a 1220 mm x 1220 mm x 12 mm (4 foot x 4 foot x 7/6 inch) 

plywood sign panel was bolted to the middle Type III barricade. The top of the sign panel was 

3250 mm (128 inches) above grade. Four battery powered warning lights were attached to the 

top of the pipe supports. 

This device was evaluated as a road-closure system to be placed perpendicular to the centerline 

of the roadway. A similar Yodock system was successfully crash tested earlier and accepted by 

FHWA Acceptance Letter WZ-34 dated March 23, 2000. It consisted of a single unit with type 

III apparatus with no water ballast added. Because the vehicle velocity change for that device 

was 3.9 m/s it was known that an impact into a similar barricade system filled with water would 

cause unacceptable decelerations. It was decided to run such a test anyway to determine the 

worst possible performance of this system. One reason for this ultimate test was the proposed 

use for such a system: it is intended to be placed at right angles to the roadway to deter vehicles 

from proceeding beyond that point. It was expected that the water-filled barricade would keep 

vehicles from filtering through, be very difficult for unauthorized persons to move, yet still be 

somewhat forgiving in the event of a crash. Please note that, as a result of this testing, it has 

been determined that these units may not be completely filled with water when deployed. 

For this device, a single Report 350 test 3-71 was conducted with an 820 kg passenger car 

impacting the center barricade of the array head-on at a speed of 100 km/hr. 

Testing 

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

summarized in the following table. 

Test Number 400001-YWC2 

NCHRP Report 350 Test # 3-71 

Test Article Type III Barricade 

Height to Bottom of Sign 1535 mm 

Height to Top of Sign 3260 mm 

Flags or lights 4 Type A/C Beacons 

Test Article Mass (one cell) 1056 kg 
3

Vehicle Inertial Mass 820 kg 

Impact Speed 96.3 km/hr 

Occupant Risk Values: 

 Occupant Impact Velocity 8.5 m/s 

 Ridedown x-direction -2.0 g’s 

 Ridedown y-direction 2.0 g’s 

 Max 0.050-s accel x-dir -16.2 g’s 

 Max 0.050-s accel y-dir -1.4 g’s 

 Max 0.050-s accel z-dir -3.2 g’s 

Vehicle crush 280 mm max 

Occupant Compartment 

Intrusion 

95 mm (crush) 

Windshield Damage Hole caused by hood 

The mass of the middle cell was 60 kg (cell unit) + 965 kg (water) + 20 kg (barricade posts and 

panels) + 11 kg (sign on middle cell only) 

In the EDCB test, the vehicle broke through the middle barricade, pulling those to the right and 

to the left along with it for a short distance. The impact forced the hood back into the 

windshield, causing a hole in the glass. Even though the test resulted in a hole in the windshield, 

parts of the device itself did not show potential for penetrating the occupant compartment. 

Because of the mass of the water in the filled cells, Occupant Impact Velocity exceeded that for a 

breakaway work zone traffic control device. However, it was within the desirable limit for a 

crash cushion impact and is considered survivable. 

Findings 

The Model 2001 Type III EDCB tested full of water, exceeded the velocity change requirements 

for a work zone traffic control device. However, its intended use is to hinder access to an area 

and be difficult to move. The researchers calculated that the occupant impact velocity of 5 

meters per second would not be exceeded if the volume of water was reduced by half in these 

units. Therefore, we conclude that the Model 2001 Type III barricade will be acceptable for road 

closures in if the cell units are used half filled with water (482 kg of water). The fill mark or 

other method of regulating the maximum water line must be permanently incorporated into the 

EDCB units. An additional condition is that they not be placed in a location where traffic 

running perpendicular to the closed road cannot impact the end of a EDCB installation as they 

have not been crash tested at the 90 degree orientation. 
4

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

the device described above and shown in the enclosed drawings for reference is 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 EDCB, the base unit of which 

is 812 mm tall, will also be acceptable subject to the same conditions and restrictions as the 

crash-tested Model 2001 EDCB. 

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. 

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

WZ-107 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 
5

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:x61331:2/01/02 

File: WZ107Yodock.wpd 

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

 N. Artimovich, HSA-10) 

Sec. 635.411 Material or product selection. 

(a) Federal funds shall not participate, directly or indirectly, in payment for any premium or royalty on 

any patented or proprietary material, specification, or process specifically set forth in the plans and 

specifications for a project, unless: 

(1) Such patented or proprietary item is purchased or obtained through competitive bidding with equally 

suitable unpatented items; or 

(2) The State highway agency certifies either that such patented or proprietary item is essential for 

synchronization with existing highway facilities, or that no equally suitable alternate exists; or 

(3) Such patented or proprietary item is used for research or for a distinctive type of construction on 

relatively short sections of road for experimental purposes. 

(b) When there is available for purchase more than one nonpatented, nonproprietary material, 

semifinished or finished article or product that will fulfill the requirements for an item of work of a 

project and these available materials or products are judged to be of satisfactory quality and equally 

acceptable on the basis of engineering analysis and the anticipated prices for the related item(s) of work 

are estimated to be approximately the same, the PS&E for the project shall either contain or include by 

reference the specifications for each such material or product that is considered acceptable for 

incorporation in the work. If the State highway agency wishes to substitute some other acceptable 

material or product for the material or product designated by the successful bidder or bid as the lowest 

alternate, and such substitution results in an increase in costs, there will not be Federal-aid participation in 

any increase in costs. 

(c) A State highway agency may require a specific material or product when there are other acceptable 

materials and products, when such specific choice is approved by the Division Administrator as being in 

the public interest. When the Division Administrator's approval is not obtained, the item will be 

nonparticipating unless bidding procedures are used that establish the unit price of each acceptable 

alternative. In this case Federal-aid participation will be based on the lowest price so established. 

(d) Appendix A sets forth the FHWA requirements regarding (1) the specification of alternative types of 

culvert pipes, and (2) the number and types of such alternatives which must be set forth in the 

specifications for various types of drainage installations. 

(e) Reference in specifications and on plans to single trade name materials will not be approved on 

Federal-aid contracts. 

ENCLOSURE 2