Federal Highway Administration
1200 New Jersey Avenue S.E.
Washington, D.C. 20590
June 14, 2007
In Reply Refer To: HSSD/SS-149
Ms. Shubha Hosalli
Quality Assurance Test Specialist
Carmanah Technologies Corp.
Building 300, 770 Enterprise Crs.
Victoria, British Columbia V9A 3S2
Dear Ms. Hosalli:
Thank you for your mail correspondence of March 5, 2007, requesting the Federal Highway Administration (FHWA) acceptance of your company's Roadway Beacon mounted on the previously accepted breakaway sign post coupling, the "Kleen Break" (model 425) by Xcessories Squared Inc., for use on the National Highway System (NHS) under the provisions of the National Cooperative Highway Research Program (NCHRP) Report 350 "Recommended Procedures for the Safety Performance Evaluation of Highway Features". Accompanying your letter were the details of the Kleen Break breakaway coupling and a drawing of the Carmanah Roadway Beacon, both of which are enclosed with this letter.
The Carmanah Roadway Beacon is a compact solar flashing beacon referred to as a "Single Beacon Sign Post Square." It consists of a solar engine, the engine housing, a signal head with LED signal module, and a mount for the 1-3/4 inch and 2 inch (51 mm) solid or perforated square steel tube (PSST). The weight of the device is approximately 50 lb (23 kg).
Testing of the Kleen Break was in compliance with the guidelines contained in the NCHRP Report 350, Recommended Procedures for the Safety Performance Evaluation of Highway Features and was documented in the FHWA acceptance letter SS-131 dated December 2, 2005. Requirements for breakaway supports are those in the American Association of State Highway and Transportation Officials' Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals.
Because the previously accepted Kleen Break breakaway coupling uses a rigid perforated or solid square steel tube post with the frangible coupling, I agree that the maximum change in vehicle velocity and overall breakaway performance of the frangible coupling will not be affected by the addition of the 50 lb (23 kg) Carmanah Roadway Beacon installed above the sign. The maximum change in velocity in the low-speed pendulum tests conducted on the Kleen Break coupling was 0.29 m/s and is therefore likely to pass this test with the 50 lb (23 kg) Carmanah Roadway Beacon installed. Further, the normal rotation of the sign assembly about the center of gravity will likely allow the test vehicle to pass under it with minimal contact. Since the maximum weight for luminaire poles is limited to 1000 pounds (454 kg) to reduce roof deformation in the low speed impact, it is likely that the extra 50 lbs (23 kg) of the Carmanah Roadway Beacon added to the approximate 66 lb (30 kg) Kleen Break coupler with PSST post would not cause a roof deformation in excess of the acceptable limits of 6 inches.
When the Carmanah Roadway Beacon is installed on a 1-3/4 inch or a 2 inch solid or PSST sign post and utilizes the previously FHWA accepted breakaway sign post coupler as mentioned above, it is acceptable for use at all appropriate locations on the NHS as a Test Level 3 device under the provisions of NCHRP Report 350 when selected by the contracting authority.
Please note the following standard provisions that apply to FHWA letters of acceptance:
SS-149, 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.
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