1200 New Jersey Ave., SE

Washington, D.C. 20590

August 17, 2011

FHWA: HSST: WLongstreet: ms: x60087:6/24/11

File: h://directory folder/HSST/WPL_052011_Compressor#2.docx

cc: HSST Will Longstreet 

In Reply Refer To:

HSST/CC-95C

Mr. Felipe Almanza

Chief Design Engineer

TrafFix Devices, Inc.

160 Avenida La Pata

San Clemente, CA 92673

Dear Mr. Almanza:

This letter is in response to your request for the Federal Highway Administration (FHWA) 

acceptance of an alternative anchoring system for your Compressor Crash Cushion for use on the 

National Highway System (NHS).

Name of system: Compressor Crash Cushion 

Type of system: Non-Gating Self-Restoring Narrow Crash Cushion/Impact Attenuator

Test Level: NCHRP Report 350 Test Level 3 (TL-3)

Testing conducted by: KARCO Engineering, LLC

Date of request: December 21, 2010

Date initially acknowledged: December 28, 2010

Task Force 13 Designator: SCI28

You requested that we find an alternative anchoring system acceptable for use on the NHS under 

the provisions of the National Cooperative Highway Research Program (NCHRP) Report 350.

Requirements

Roadside safety devices should meet the guidelines contained in NCHRP Report 350. The 

FHWA memorandum “ACTION: Identifying Acceptable Highway Safety Features” of July 24, 

1997, provides further guidance on crash testing requirements of longitudinal barriers and crash 

cushions.

Decision

The following device was found acceptable, with details provided below:

• Compressor Crash Cushion anchored to an asphalt pad with a 30-point anchor rod system
2

Description

The Compressor Crash Cushion was originally accepted for use on the NHS for one-way traffic 

applications in FHWA Product Acceptance Letter CC-95 on February 26, 2007 and for two-way 

traffic applications in Acceptance Letter CC-95A, dated December 23, 2009. In both cases, the 

Compressor was mounted on a reinforced concrete pad using fourteen (14) anchor bolts for each 

of the crash tests conducted. For the present request, the Compressor itself remained unchanged 

from the previously accepted design. In short, the TrafFix Devices Inc. Compressor is a redirective, non-gating and self-restoring narrow crash cushion with a total length of 6.5 meters 

(255.25 inches). Its effective length is 4.98 meters (196 inches). The Compressor measures 1.24 

meters (48.66 inches) wide, and is 1.36 meters (53.5 inches) in height. Its main components 

include: a steel mounting base, six plastic energy absorbing modules, and twelve steel fender 

panels. The front and rear anchor plates remain unchanged from the previously accepted design, 

but eight (8) anchor clips have been added to each side of the base plate to accommodate the 

additional anchors needed to secure the Compressor to an asphalt pad. Thirty (30) 7/8-inch-9TPI 

threaded anchor rods with an overall length of 406 millimeters (16 inches) were used. These 

rods were set into 2.54 millimeters (1-inch) diameter holes drilled 355.6 millimeters (14 inches) 

deep through a 6-inch thick asphalt pad and into compacted sub base. All bolts were secured 

with an epoxy adhesive. The front and rear anchor rods are positioned in the same fourteen (14) 

locations as were the concrete anchor bolts used for Acceptance Letter CC-95 and CC-95A 

testing. Design details for anchoring the Compressor to an asphalt pad are provided as enclosure 

to this correspondence.

Crash Testing

Since the basic design of the Compressor was unchanged from the previously accepted version, 

required testing for the new anchoring system is to determine the adverse affects of the crash 

performance of the unit. After an initial consultation with FHWA, it was agreed that NCHRP 

Report 350 tests 3-33 and 3-38 were likely to place the greatest loadings on the new anchor 

design and that the remaining tests for a redirective crash cushion need not be rerun. 

Test 3-33 required a 100 km/h impact by a 2000-kg pickup truck at 15 degrees on the nose of the 

crash cushion. As reported in Karco Test Report Number TR-P30145-01-A, dated December 4, 

2010, a 2042 kg (4502 lb) pickup truck impacted the Compressor at 101.4 km/h (63 mph) and at 

14.8 degrees. Occupant Impact Velocity was 10.7 m/sec and the Ridedown Acceleration was 

14.6 g’s. Vehicular roll, pitch, and yaw were recorded as 43.9, 30.5, and 177.3 degrees, 

respectively. The truck came to rest 3.9 meters (12.8 feet) rearward and 8.4 meters (27.5 feet) to 

the left of the crash cushion. The Karco report indicated that some repairs would need to be 

made to the Compressor to return it to its fully functional condition.

Test 3-38 also required a 100 km/h 2000-kg pickup truck test, but into the side of the 

Compressor at a 20-degree angle. Karco Test Report Number TR-P30144-01-A, dated 

December 3, 2010, reported a 2029.5-kg (4473-lb) truck struck the crash cushion at 100.2 km/h 

(62.3 km/h) and 20.1 degrees. Occupant Impact Velocity was 7.0 m/sec (lateral) and the 

Ridedown Acceleration was 12 g’s. Vehicular roll, pitch and yaw were recorded as 15.7, 18.4, 

and 26.7 degrees, respectively. The truck came to rest 61.5 m (201.8 ft) downstream and 21.3 m 

(69.9 ft) to the left of the Compressor. After this test, the Compressor appeared to remain 

functional without requiring repairs.

Crash Test summaries are provided as enclosure to this correspondence.
3

Findings

The Compressor as described above and in Acceptance Letters CC-95 and CC-95A is acceptable 

for use on the NHS as a Self Restoring/Low Maintenance, Narrow Crash Cushion as a permanent 

or temporary attenuator when such use is acceptable to a highway agency. It can be mounted on 

a concrete pad with fourteen (14) anchor bolts or on an asphalt pad using thirty (30) steel rod 

anchors. The Compressor can be used in bi-directional traffic flow applications when used with 

Karco’s tested transition design. 

Therefore, the system described in the requests above and detailed in the enclosed drawings is

acceptable for use on the NHS under the range of conditions tested, when such use is acceptable

to a highway agency.

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

• This acceptance provides a AASHTO/ARTBA/AGC Task Force 13 designator that 

should be used for the purpose of the creation of a new and/or the update of existing Task 

Force 13 drawing for posting on the on-line ‘Guide to Standardized Highway Barrier 

Hardware’ currently referenced in AASHTO ‘Roadside Design Guide’.

• This acceptance is limited to the crashworthiness characteristics of the systems and does 

not cover their structural features, nor conformity with the Manual on Uniform Traffic 

Control Devices (when applicable).

• Any changes that may adversely influence the crashworthiness of the system will require 

a new acceptance letter.

• Should the FHWA discover that the qualification testing was flawed, that in-service 

performance reveals unacceptable safety problems, or that the system being marketed is 

significantly different from the version that was crash tested, we reserve the right to 

modify or revoke our acceptance.

• You will be expected to supply potential users with sufficient information on design and 

installation requirements to ensure proper performance.

• You will be expected to certify to potential users that the hardware furnished has 

essentially the same chemistry, mechanical properties, and geometry as that submitted for 

acceptance, and that it will meet the crashworthiness requirements of the FHWA and 

NCHRP Report 350.

• To prevent misunderstanding by others, this letter of acceptance is designated as number 

CC-95C and shall not be reproduced except in full. This letter and the test documentation 

upon which it is based are public information. All such letters and documentation may be 

reviewed at our office upon request.

• The Compressor Crash Cushion is a patented product and considered proprietary. If 

proprietary devices are specified by a highway agency for use on Federal-aid projects, 

except exempt, non-NHS projects, (a) they must be supplied through competitive bidding 

with equally suitable unpatented items; (b) the highway agency must certify that they are 

essential for synchronization with the existing highway facilities or that no equally 

suitable alternative exists; or (c) they must be used for research or for a distinctive type of 

construction on relatively short sections of road for experimental purposes. Our 

regulations concerning proprietary products are contained in Title 23, Code of Federal 

Regulations, Section 635.411.

• This acceptance letter shall not be construed as authorization or consent by the FHWA to 

use, manufacture, or sell any patented system for which the applicant is not the patent 

holder.
4

The acceptance letter is limited to the crashworthiness characteristics of the candidate system, 

and the FHWA is neither prepared nor required to become involved in issues concerning patent 

law. Patent issues, if any, are to be resolved by the applicant.

Sincerely,

Michael S. Griffith

Director, Office of Safety Technologies

Office of Safety

Enclosures 
 1200 New Jersey Ave., SE

Washington, D.C. 20590

August 17, 2011

In Reply Refer To:

HSST/CC-95C

Mr. Felipe Almanza

Chief Design Engineer

TrafFix Devices, Inc.

160 Avenida La Pata

San Clemente, CA 92673

Dear Mr. Almanza:

This letter is in response to your request for the Federal Highway Administration (FHWA) 

acceptance of an alternative anchoring system for your Compressor Crash Cushion for use on the 

National Highway System (NHS).

Name of system: Compressor Crash Cushion 

Type of system: Non-Gating Self-Restoring Narrow Crash Cushion/Impact Attenuator

Test Level: NCHRP Report 350 Test Level 3 (TL-3)

Testing conducted by: KARCO Engineering, LLC

Date of request: December 21, 2010

Date initially acknowledged: December 28, 2010

Task Force 13 Designator: SCI28

You requested that we find an alternative anchoring system acceptable for use on the NHS under 

the provisions of the National Cooperative Highway Research Program (NCHRP) Report 350.

Requirements

Roadside safety devices should meet the guidelines contained in NCHRP Report 350. The 

FHWA memorandum “ACTION: Identifying Acceptable Highway Safety Features” of July 24, 

1997, provides further guidance on crash testing requirements of longitudinal barriers and crash 

cushions.

Decision

The following device was found acceptable, with details provided below:

• Compressor Crash Cushion anchored to an asphalt pad with a 30-point anchor rod system
2

Description

The Compressor Crash Cushion was originally accepted for use on the NHS for one-way traffic 

applications in FHWA Product Acceptance Letter CC-95 on February 26, 2007 and for two-way 

traffic applications in Acceptance Letter CC-95A, dated December 23, 2009. In both cases, the 

Compressor was mounted on a reinforced concrete pad using fourteen (14) anchor bolts for each 

of the crash tests conducted. For the present request, the Compressor itself remained unchanged 

from the previously accepted design. In short, the TrafFix Devices Inc. Compressor is a redirective, non-gating and self-restoring narrow crash cushion with a total length of 6.5 meters 

(255.25 inches). Its effective length is 4.98 meters (196 inches). The Compressor measures 1.24 

meters (48.66 inches) wide, and is 1.36 meters (53.5 inches) in height. Its main components 

include: a steel mounting base, six plastic energy absorbing modules, and twelve steel fender 

panels. The front and rear anchor plates remain unchanged from the previously accepted design, 

but eight (8) anchor clips have been added to each side of the base plate to accommodate the 

additional anchors needed to secure the Compressor to an asphalt pad. Thirty (30) 7/8-inch-9TPI 

threaded anchor rods with an overall length of 406 millimeters (16 inches) were used. These 

rods were set into 2.54 millimeters (1-inch) diameter holes drilled 355.6 millimeters (14 inches) 

deep through a 6-inch thick asphalt pad and into compacted sub base. All bolts were secured 

with an epoxy adhesive. The front and rear anchor rods are positioned in the same fourteen (14) 

locations as were the concrete anchor bolts used for Acceptance Letter CC-95 and CC-95A 

testing. Design details for anchoring the Compressor to an asphalt pad are provided as enclosure 

to this correspondence.

Crash Testing

Since the basic design of the Compressor was unchanged from the previously accepted version, 

required testing for the new anchoring system is to determine the adverse affects of the crash 

performance of the unit. After an initial consultation with FHWA, it was agreed that NCHRP 

Report 350 tests 3-33 and 3-38 were likely to place the greatest loadings on the new anchor 

design and that the remaining tests for a redirective crash cushion need not be rerun. 

Test 3-33 required a 100 km/h impact by a 2000-kg pickup truck at 15 degrees on the nose of the 

crash cushion. As reported in Karco Test Report Number TR-P30145-01-A, dated December 4, 

2010, a 2042 kg (4502 lb) pickup truck impacted the Compressor at 101.4 km/h (63 mph) and at 

14.8 degrees. Occupant Impact Velocity was 10.7 m/sec and the Ridedown Acceleration was 

14.6 g’s. Vehicular roll, pitch, and yaw were recorded as 43.9, 30.5, and 177.3 degrees, 

respectively. The truck came to rest 3.9 meters (12.8 feet) rearward and 8.4 meters (27.5 feet) to 

the left of the crash cushion. The Karco report indicated that some repairs would need to be 

made to the Compressor to return it to its fully functional condition.

Test 3-38 also required a 100 km/h 2000-kg pickup truck test, but into the side of the 

Compressor at a 20-degree angle. Karco Test Report Number TR-P30144-01-A, dated 

December 3, 2010, reported a 2029.5-kg (4473-lb) truck struck the crash cushion at 100.2 km/h 

(62.3 km/h) and 20.1 degrees. Occupant Impact Velocity was 7.0 m/sec (lateral) and the 

Ridedown Acceleration was 12 g’s. Vehicular roll, pitch and yaw were recorded as 15.7, 18.4, 

and 26.7 degrees, respectively. The truck came to rest 61.5 m (201.8 ft) downstream and 21.3 m 

(69.9 ft) to the left of the Compressor. After this test, the Compressor appeared to remain 

functional without requiring repairs.

Crash Test summaries are provided as enclosure to this correspondence.
3

Findings

The Compressor as described above and in Acceptance Letters CC-95 and CC-95A is acceptable 

for use on the NHS as a Self Restoring/Low Maintenance, Narrow Crash Cushion as a permanent 

or temporary attenuator when such use is acceptable to a highway agency. It can be mounted on 

a concrete pad with fourteen (14) anchor bolts or on an asphalt pad using thirty (30) steel rod 

anchors. The Compressor can be used in bi-directional traffic flow applications when used with 

Karco’s tested transition design. 

Therefore, the system described in the requests above and detailed in the enclosed drawings is

acceptable for use on the NHS under the range of conditions tested, when such use is acceptable

to a highway agency.

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

• This acceptance provides a AASHTO/ARTBA/AGC Task Force 13 designator that 

should be used for the purpose of the creation of a new and/or the update of existing Task 

Force 13 drawing for posting on the on-line ‘Guide to Standardized Highway Barrier 

Hardware’ currently referenced in AASHTO ‘Roadside Design Guide’.

• This acceptance is limited to the crashworthiness characteristics of the systems and does 

not cover their structural features, nor conformity with the Manual on Uniform Traffic 

Control Devices (when applicable).

• Any changes that may adversely influence the crashworthiness of the system will require 

a new acceptance letter.

• Should the FHWA discover that the qualification testing was flawed, that in-service 

performance reveals unacceptable safety problems, or that the system being marketed is 

significantly different from the version that was crash tested, we reserve the right to 

modify or revoke our acceptance.

• You will be expected to supply potential users with sufficient information on design and 

installation requirements to ensure proper performance.

• You will be expected to certify to potential users that the hardware furnished has 

essentially the same chemistry, mechanical properties, and geometry as that submitted for 

acceptance, and that it will meet the crashworthiness requirements of the FHWA and 

NCHRP Report 350.

• To prevent misunderstanding by others, this letter of acceptance is designated as number 

CC-95C and shall not be reproduced except in full. This letter and the test documentation 

upon which it is based are public information. All such letters and documentation may be 

reviewed at our office upon request.

• The Compressor Crash Cushion is a patented product and considered proprietary. If 

proprietary devices are specified by a highway agency for use on Federal-aid projects, 

except exempt, non-NHS projects, (a) they must be supplied through competitive bidding 

with equally suitable unpatented items; (b) the highway agency must certify that they are 

essential for synchronization with the existing highway facilities or that no equally 

suitable alternative exists; or (c) they must be used for research or for a distinctive type of 

construction on relatively short sections of road for experimental purposes. Our 

regulations concerning proprietary products are contained in Title 23, Code of Federal 

Regulations, Section 635.411.

• This acceptance letter shall not be construed as authorization or consent by the FHWA to 

use, manufacture, or sell any patented system for which the applicant is not the patent 

holder.
4

The acceptance letter is limited to the crashworthiness characteristics of the candidate system, 

and the FHWA is neither prepared nor required to become involved in issues concerning patent 

law. Patent issues, if any, are to be resolved by the applicant.

Sincerely,

Michael S. Griffith

Director, Office of Safety Technologies

Office of Safety

Enclosures