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FHWA Home / Safety / Roadway Departure / Safety Eligibility Letter

Safety Eligibility Letter B-176

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U.S. Department of Transportation
Federal Highway Administration

1200 New Jersey Ave. S.E.
Washington, D.C. 20590

June 27, 2008

In Reply Refer To: HSSD/B-176

Mr. John Addy
Hill & Smith
Springvale Business and Industrial Park
Bliston, Wolverhampton, West Midlands, UK, WV14 OQL

Dear Mr. Addy:

This letter is in response to your request for Federal Highway Administration (FHWA) acceptance of a roadside safety system for use on the National Highway System (NHS).

You requested that we find this system 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” for both the standard and minimum deflection arrangements of Zoneguard™.

Requirements
Roadside safety systems should meet the guidelines contained in the NCHRP Report 350, "Recommended Procedures for the Safety Performance Evaluation of Highway Features". FHWA Memorandum “ACTION: Identifying Acceptable Highway Safety Features” of July 25, 1997 provides further guidance on crash testing requirements of longitudinal barriers.

Description
The Zoneguard™ portable longitudinal barrier system is comprised of 8 gauge, 0.165 in (4.2 mm) thick, ASTM A36 pressed, galvanized steel panels assembled in 50 ft (15.24 m) long sections. Each section is 2.69 ft (820 mm) high with a base width of 2.3 ft (700 mm) and a top beam width of 0.52 ft (157 mm). The Zoneguard™ has a step 0.5 ft (150 mm) wide on each side just above surface level, which slopes upward to meet the upper beam section. Each section weighs approximately 3097 lb (1406 kg). The base of each 50 ft (15.24 m) long section has 12 rubber feet, 2.30 ft x 0.54 ft x 0.043 ft (700 mm x 165 mm x 13 mm), which are fixed using an adhesive compound.

Crash Testing
The complete barrier test installations were each nominally 2.69 ft (820 mm) high, 2.3 ft (700 mm) wide, and 250 ft (76.2 m) long. Tests were conducted for two different anchoring patterns: (1) the standard arrangement which includes anchoring at each end of the barrier and (2) the minimum deflection arrangement which includes anchoring every 33.3 ft (10.2 m) along the barrier. The standard arrangement is anchored at points 1.64 ft (500 mm) and 16.67 ft (5.1 m) from each end on both sides for a total of four anchors per end. These anchors were 1.5 in (38 mm) diameter ASTM 1018 smooth rod, 12 in (305 mm) long and installed 8 in (200 mm) deep into concrete. The minimum deflection Zoneguard™ arrangement is identical to the standard arrangement described above apart from the addition of the intermediate threaded resin anchors placed in both sides of the “foot” section on 33.3 ft (10.2 m) centers. Alternate anchor designs certified by the manufacturer may be used to provide equal or greater anchorage strength to that provided for the test installations.

The following table summarizes the six tests conducted on the Zoneguard systems. The tests in bold text apply to this acceptance.

Test # Test Criteria Vehicle Mass Standard or Min. Deflection Impact Speed Maximum Deflection*
ZG-USA-1 350 & MASH 1065 kg Min. Deflection 103.5 km/hr 0.20 m
ZG-USA-2 350 2118 kg Min. Deflection 99.3 km/hr 0.31 m
ZG-USA-3 MASH 2208 kg Min. Deflection 101.5 km/hr 0.41 m
ZG-USA-4 350 2118 kg Standard 100.9 km/hr 1.83 m
ZG-USA-5 MASH 2208 kg Standard 104.0 km/hr 1.93 m
ZG-USA-6 350 8165 kg Standard 80.5 km/hr 1.45 m

* This column shows the maximum dynamic deflection of the top of the barrier.

Crash tests performed included tests 3-10U (“U” refers to tests run in compliance with the update to the NCHRP Report 350, now known as MASH-08) and 3-11 for the minimum deflection arrangement and tests 3-11 and 4-12 for the standard arrangement. Prior to crash testing we concurred in your request that the MASH-08 small passenger vehicle be considered a “worst case scenario” and a proper substitute for the 820C vehicle called for in Report 350. Enclosed with this acceptance letter are drawings of the test article and test summary sheets. The tests and the results met the FHWA requirements.

Findings
The system described above and detailed in the enclosed drawings is acceptable for use on the NHS under the range of conditions tested, when acceptable to a State. When used across a bridge joint it should be noted that the Zoneguard™ can accommodate approximately 10 inches of movement.

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

 

Sincerely yours,

Signature of David A. Nicol

David A. Nicol, P.E.
Director, Office of Safety Design
Office of Safety


Zoneguard Assy.-Temporary

Table 4.1 - Summary of Test Results and Conditions

Table 4.1 – Summary of Test Results and Conditions
General Information
Test Agency Southwest Research Institute
Test Number ZG-USA-6
Test Date 10/01/2007
Test Category 3-10 Update
Test Article
Type Longitudinal Barrier
Installation Length 76.2 m (250 ft)
Nom. Barrier Height 0.82 m (2.69 ft)
Type of Primary Barrier Portable Steel Barrier
Soil NA - Installed on Concrete
Test Vehicle
Type Small Car
Designation 1100C
Model 2002 Kia Rio
Mass (kg) 1065
Inertial Mass (kg) 1065
Dummy Mass (kg) 73
Gross Static Mass (kg) 1138
Impact Conditions
Speed (km/hr) 103.4
Angle (degrees) 23.7
Exit Conditions
Speed (km/hr) 84 (calculated)
Angle (degrees) 12
Occupant Risk Values
Impact Velocity (m/s)
x-direction 5.0
y-direction -7.2
Ridedown Accelerations (g's)
x-direction -3.3
y-direction 12.8
Test Article Deflection
Dynamic (top of rail) 0.20 m (8 in)
Dynamic (base of rail) 0.10 m (4 in)
Permanent (top of rail) 0.09 m (3.5 in)
Permanent (base of rail) 0 m (0 in)
Vehicle Damage
Exterior
CDC 11LFEW0
VDS 11-LFQ-3
Interior
OCDI LF0000000
Max. Deform (mm) 0
Post Impact Vehicle Behavior
Maximum Roll Angle (degrees) -20.4 @ 0.420 sec.
Maximum Pitch Angle (degrees) -9.9 @ 0.724 sec.
Maximum Yaw Angle (degrees) 123.6 @ 2.767sec.

Table 4.1 - Summary of Test Results and Conditions

Table 4.1 – Summary of Test Results and Conditions
General Information
Test Agency Southwest Research Institute
Test Number ZG-USA2
Test Date 10/01/2007
Test Category 3-11
Test Article
Type Longitudinal Barrier
Installation Length 76.2 m (250 ft)
Nom. Barrier Height 0.82 m (2.69 ft)
Type of Primary Barrier Portable Steel Barrier
Soil NA - Installed on Concrete
Test Vehicle
Type ¾-ton pickup
Designation 2000P
Model 2000 Chevrolet 2500
Mass (kg) 2118
Inertial Mass (kg) 2118
Dummy Mass (kg) NA
Gross Static Mass (kg) 2118
Impact Conditions
Speed (km/hr) 99.3
Angle (degrees) 24.2
Exit Conditions
Speed (km/hr) 79 (calculated)
Angle (degrees) 8.5
Occupant Risk Values
Impact Velocity (m/s)
x-direction 4.9
y-direction -5.6
Ridedown Accelerations (g's)
x-direction 9.0
y-direction 12.2
Test Article Deflection
Dynamic (top of barrier) 0.31 m (12 in)
Dynamic (base of barrier) 0.05 m (2 in)
Permanent (top of barrier) 0.17 m (6.5 in)
Permanent (base of barrier) 0 m (0 in)
Vehicle Damage
Exterior
CDC 11LFEW5
VDS 11-LFQ-3
Interior
OCDI LF0000000
Max. Deform (mm) 0
Post Impact Vehicle Behavior
Maximum Roll Angle (degrees) 10.0 @ 0.082 sec.
Maximum Pitch Angle (degrees) -16.0 @ 0.680 sec.
Maximum Yaw Angle (degrees) 62.2 @ 1.069sec.

Table 4.1 - Summary of Test Results and Conditions

Table 4.1 – Summary of Test Results and Conditions
General Information
Test Agency Southwest Research Institute
Test Number ZG-USA-4
Test Date 10/01/2007
Test Category 3-11
Test Article
Type Longitudinal Barrier
Installation Length 76.2 m (250 ft)
Nom. Barrier Height 0.82 m (2.69 ft)
Type of Primary Barrier Portable Steel Barrier
Soil NA - Installed on Concrete
Test Vehicle
Type ¾-ton pickup
Designation 2000P
Model 2000 Chevrolet 2500
Mass (kg) 2118
Inertial Mass (kg) 2118
Dummy Mass (kg) NA
Gross Static Mass (kg) 2118
Impact Conditions
Speed (km/hr) 100.9
Angle (degrees) 25.1
Exit Conditions
Speed (km/hr) 79 (calculated)
Angle (degrees) 0
Occupant Risk Values
Impact Velocity (m/s)
x-direction 3.5
y-direction -3.8
Ridedown Accelerations (g's)
x-direction -4.3
y-direction 14.7
Test Article Deflection
Dynamic (top of barrier) 1.83 m (72 in)
Dynamic (base of barrier) 1.65 m (65 in)
Permanent (base of barrier) 1.57 m (62 in)
Vehicle Damage
Exterior
CDC 11LFEW5
VDS 11-LFQ-3
Interior
OCDI LF0000000
Max. Deform (mm) 0
Post Impact Vehicle Behavior
Maximum Roll Angle (degrees) 7.9 @ 0.269 sec.
Maximum Pitch Angle (degrees) -6.7 @ 0.571sec.
Maximum Yaw Angle (degrees) 30.9 @ 1.864sec.
Table 4.1 - Summary of Test Results and Conditions
Images and drawing of Single Unit Truck crashing into guardreail
General Information
Test AgencySouthwest Research Institute
Test NumberZG-USA-6
Test Date10/03/2007
Test Category4-12
Test Article
TypeLongitudinal Barrier
Installation Length76.2 m (250 ft)
Nom. Barrier Height0.82 m (2.69 ft)
Type of Primary BarrierPortable Steel Barrier
SoilNA - Installed on Concrete
Test Vehicle
TypeSingle Unit Truck
Designation8000S
Model1997 International 4700/DT466E
Mass (kg)8165
Inertial Mass (kg)8165
Dummy Mass (kg)NA
Gross Static Mass (kg)8165
Impact Conditions
Speed (km/hr)80.5
Angle (degrees)14.6
Exit Conditions
Speed (km/hr)76 (calculated)
Angle (degrees)0
Occupant Risk Values
Impact Velocity (m/s)
x-direction0.9
y-direction-1.4
Ridedown Accelerations (g's)
x-direction-2.7
y-direction12.2
Test Article Deflection
Dynamic (top of rail)1.45 m (4.75 ft)
Dynamic (base of rail)1.27 m (4.17 ft)
Permanent (base of rail)1.14 m (3.75 ft)
Vehicle Damage
Exterior
CDC11LFWW2
VDS11-LFQ-1
Interior
OCDILF0000000
Max. Deform (mm)0
Post Impact Vehicle Behavior
Maximum Roll Angle (degrees)-6.1 @ 0.888 sec.
Maximum Pitch Angle (degrees)4.4 @ 0.412 sec.
Maximum Yaw Angle (degrees)30.9 @ 1.864 sec.
Page last modified on June 24, 2011.
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