May 4, 2004
Refer to: HSA-10/WZ-178
Ronald K. Faller, PhD.
Midwest Roadside Safety Facility
1901 'Y' Street, Bldg. C
P.O. Box 880601
Lincoln, Nebraska 68588-0601
Dear Mr. Faller:
Thank you for your letter of March 17, 2004, requesting Federal Highway Administration (FHWA) acceptance of RooGuards, Incorporated's 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 Midwest Roadside Safety Facility (MwRSF) and video of the tests. You 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 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 "RGI Safety Barricade" is a roto-molded, linear low density polyethylene barricade section, with a density of 0.938 g/cm3, an Ultra Violet resistant rating of 8, and an environmental stress crack resistance of 1000. Each RGI Safety Barricade is 1,994 mm (78.5 inches) long, 927 mm (36.5 inches) tall, 546 mm (21.5 inches) wide at the base, and 140 mm (5.5 inches) wide at the top. The nominal base thickness is 8.9 mm (0.35 inch). The unit's bottom vertical face is 152 mm (6 in) in height.
One RGI Safety Barricade weighs 34.0 kg (75 pounds) empty. Water ballast was placed in the units to the bottom of the drain level locate approximately 38 mm (1.5 inches) above the base of the device which accounted for 16.8 kg (37 pounds) of water. An A-frame reflector was installed in the rectangular slot on the top of the RGI Safety Barricade.
Full-scale automobile testing was conducted on the RooGuards longitudinal channelizing barricade. An 885 kg (1950 pound) Geo Metro was accelerated into the line of barricade units at an angle of 22.6 degrees and a speed of 69.2 kph (43.0 mph), which was within the limits of test level 2.
Thirty-seven barricade units were connected together for a length of approximately 67.7 m (225 feet). The test vehicle impacted barricade unit number 13 (as counted from the beginning of the installation) and pushed through, displacing barricade units number 13 through 17. Units number 8 through 12, as well as number 18 through 23, also were displaced by the movement of adjacent units but they remained connected to the beginning and end sections of the barricade installation respectively. Only one unit, number 14, was fractured and leaked water.
The test vehicle penetrated over 20 feet behind the line of units, and traveled nearly 105 feet downstream from the point of impact. Exterior vehicle damage was minimal, with little or no occupant compartment deformation. Cosmetic damage, consisting of dents, scuff marks, and broken lenses, was concentrated on the right front corner of the vehicle. The drive shaft was pulled slightly out resulting in a leak of transmission fluid. No contact was made with the vehicle's glass. The occupant impact velocities and ride-down accelerations were well within the limits in the NCHRP Report 350.
The results of the testing met the FHWA requirements for longitudinal channelizing barricades. 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. As this device is not intended as a barrier, redirection of the test vehicle was not expected. It should be noted that the penetration of the Roo-Guards longitudinal channelizing barricade would be greater if the 2000P pick-up truck impacting at 25 degrees had been used. The test using the 820C automobile showed that a passenger vehicle can impact the device without undue risk to the vehicle occupants.
Please note the following standard provisions that apply to FHWA letters of acceptance:
/Original Signed by/
John R. Baxter, P.E.
Director, Office of Safety Design
Office of Safety