December 9, 2002

Refer to: HSA-10/SS-91

Mr. Brian Bruce
Quckfix Sign Systems, Ltd.
9424-58 Avenue
Edmonton, Alberta, Canada T6E 0B6

Dear Mr. Bruce: Thank you for your letter of October 4 requesting Federal Highway Administration (FHWA) acceptance of your company's sign support couplings as components of breakaway sign supports for use on the National Highway System (NHS). You provided information I had requested from the original petitioner, the late Mr. Perry Ruptash. Mr. Ruptash had provided me with a report from E-TECH Testing Services, Inc., drawings of the device, and videos of the crash tests. You requested that we find your company's Quickfix Couplers QF-001, QF-002, QF-003, QF-004, and QF-007 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."


Testing of the supports was in compliance with the guidelines contained in the NCHRP Report 350, Recommended Procedures for the Safety Performance Evaluation of Highway Features. 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.

The Quickfix couplers are cast of 380 Aluminum Alloy, and are affixed to a stub post installed in the ground with the sign post mounted above. The narrow circumference of the coupler, which is molded during the casting process, allows it to act as a fuse, breaking when the sign post is struck. Different models of couplers are available to support either 64 mm (2.5 inch) diameter round pipe and 45 mm (1 3/4 inch) square tube posts. The QF-003 Coupler was tested as being representative of the entire Quckfix product line since it has the largest cross sectional area and resistance to bending during a crash. The QF-003 is designed to adapt to 44.45 mm (1 3/4 inch) perforated square steel tube (PSST) upright posts and 57 mm (2 1/4 inch) ground support anchors. This coupling is shown in the enclosed drawing.

A two-post sign support was tested as a "worst case" scenario. The ground anchors were a

914 mm long by 51 mm square PSST inner post and 457 mm long by 57 mm square outer sleeves. Type QF-003 couplers were attached to the ground anchors such that the center of the couplers were a nominal 76 mm above surrounding grade. The couplers were in turn attached to upright post which were 3048 mm long by 45 mm square PSST. The ground anchors and sign support were 2.7 mm wall (12 ga) PSST. An 1828 mm wide by 1524 mm high aluminum sign was affixed flush with the top of the support posts to represent the largest sign to be supported by Quickfix couplers. The test installations are shown in the drawing enclosed for reference.


Full-scale automobile testing was conducted on your company's devices. The crash tests are summarized in the table below:


Test Number 24-0105-002

Test Number 24-0105-001

NCHRP Repot 350 Test #



Test Article

QF-003 (dual post) using 45 mm PSST

Height to Bottom of Sign

1600 mm (5 ft, 3 in)

Height to Top of Sign

3124 mm (10 ft, 3 in)

Coupler Cross Section Area

1516 mm (2.35 in2 )

1516 mm (2.35 in2 )

Coupler Mass

1.25 kg (2.75 pounds)

1.25 kg (2.75 pounds)

Test Article Mass (each)

37.2 kg (81.9 pounds)

37.2 kg (81.9 pounds)

Vehicle Test Inertial Mass

831 kg

824 kg

Impact Speed, Head-on

99.0 km/hr


Impact Angle

20 degrees

Vehicle Velocity Change

4.6 km/hr, or 1.3 m/sec

3.1 km/hr or 0.9 m/sec

Occupant Impact Speed

1.2 m/sec

0.8 m/sec

Vehicle crush

Minor dents to bumper, roof

Cracked grill, hood dent

Occupant Compart. Intrusion



Windshield Damage

No contact

No Contact

Stub Height

76 mm

76 mm

There was slight bending of the posts before the couplings fractured. This behavior is expected, and may very well be necessary for the couplings to perform properly. Therefore, the manufacturer's recommendations for minimum and maximum post size should be followed to ensure that the posts to be used are of a similar stiffness to the tested posts.


Damage was limited to minor denting. The results of tests met the FHWA velocity change and stub height requirements and, therefore, the couplings described above and shown in the enclosed drawings for reference are acceptable for use in Test Level 3 breakaway sign support systems on the NHS under the range of conditions tested, when proposed by a State.

The enclosed chart summarizes the data on the various couplings accepted by this action, namely the following models, QF-001, QF-002, QF-003, QF-004, and the QF-007. English units are used in that table as the couplings are fabricated to these measurements.

Please note the following standard provisions, which apply to FHWA letters of acceptance:


Sincerely yours,

Harry W. Taylor
Acting Director, Office of Safety Design