Refer to: HSA-10/WZ-160
Mr. Michael McCarty
Services & Materials Company
Div. Jackson Products, Incorporated
801 Corporate Centre Drive
St. Charles, MO 63304-8685
Dear Mr. McCarty:
This is in response to Dr. Ron Faller's letter of May 6, 2003, requesting Federal Highway Administration (FHWA) acceptance of Jackson Products TrailBlazer Vertical Panel with warning light, and the TrailBlazer Plus Directional Panel with warning light as crashworthy traffic control devices for use in work zones on the National Highway System (NHS). Accompanying the letter were reports of crash testing conducted by the Midwest Roadside Safety Facility (MwRSF) and footage of the tests on CD-Rom. It was requested that we find these devices 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 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 devices follows:
The TrailBlazer Vertical Panel is blow-molded of high density polyethylene (HDPE) with a density of 0.950 g/cm3 . The overall dimensions are 997 mm (39.25 inches) tall, 373 mm x 227 mm (14.69 x 8.93 inches) wide at the base, and 216 mm x 84 mm (8.5 x 3.29 inches) wide at the top with a nominal thickness of 2.0 mm (0.08 inches.) The overall height to the top of the warning light is 1245 mm (49 inches). The unit is ballasted with a recycled fitted rubber base.
One Flex-O-Lite Night Flasher was attached to the top center of the vertical panel. The 2 lantern battery light was attached with one standard 12.7 mm (0.5 inch) diameter x 95 mm (3.75 inch) long vandal resistant fastener.
The TrailBlazer Plus is blow-molded of the same HDPE material. The overall dimensions are 1003 mm (39.5 inches) tall, 833 mm x 299 mm (32.78 x 11.79 inches) wide at the base, and 673 mm x 136 mm (26.5 x 5.34 inches) wide at the top with a nominal thickness of 2.0 mm (0.08 inches). The overall height to the top of the warning light is 1257 mm (49.5 inches). The unit is ballasted with a recycled fitted rubber base. One Flex-O-Lite Night Flasher was attached to the top center of the vertical panel. The 2 lantern battery light was attached with one standard 12.7 mm (0.5 inch) diameter x 95 mm (3.75 inch) long vandal resistant fastener.
Individual bogie testing was conducted on the two Jackson Products devices. The tests are summarized in the table below.
|Device||TrailBlazer||Trail Blazer Plus|
|Orientation||Head On||90 Degrees||Head On||90 Degrees|
|Mass, in kg
|18.2 (40.16)||18.3 (40.3)||18.6 (41.1)||18.2 (40.2)|
|Flags? Lights?||Each device had a light attached as noted above|
|Mass of Test Vehicle||929 kg (2049 pounds)|
|Impact Speed||101.8 km/hr||100.7 km/hr||104.0 km/hr||102.5 km/hr|
|Velocity Change||0.28 m/s||0.97 m/s||1.6 m/s||1.6 m/s|
|Extent of contact||See discussion below|
|Windshield Contact||See discussion below|
This crash-testing program used a hard-nosed bogie vehicle of a mass larger than the standard 820C test vehicle. There are significant constraints involved in using such a non-standard testing device, some of which are:
In each impact, the device immediately flexed toward the hood of the bogie. Either the entire light/battery assembly detached, or the lens itself detached from the battery case upon impact with the hood. The loose debris remained airborne with no direct contact with the "windshield" of the bogie. In one case, the debris contacted the "roof line" and passed over the bogie. In none of the cases did it appear that the debris would contact the windshield glass had a real vehicle been used.
We concur that the results of the testing met the FHWA requirements and, therefore, the devices described in the various requests above and detailed in the enclosed drawings are acceptable for use on the NHS under the range of conditions tested, when proposed by a State. They may also be used without the warning lights attached.
Please note the following standard provisions that apply to FHWA letters of acceptance:
Michael S. Griffith
Acting Director, Office of Safety Design
Office of Safety