March 10, 2006 

Mr. Alex F. Talbott 

LifeNet SoftWalls, LLC

8311 Shelbyville Road 

Louisville, KY  40222 

Dear Mr. Talbott: 

In your February 2 letter, you requested the Federal Highway Administration (FHWA)

acceptance of a barrier system comprised of used automobile tires called the LifeNet SoftWalls

Median Barrier System. You also sent me copies of test reports prepared by the Transportation 

Research Center in East Liberty, Ohio, that documented the results of the National Cooperative 

Highway Research Program (NCHRP) Report 350 tests 3­10 and 3­11. Initial staff review of

these reports revealed some errors and inconsistencies that needed to be addressed. Corrected 

copies of these reports were received electronically on March 3.

The tested LifeNet Softwalls barrier system consisted of approximately 400 used automobile 

tires with diameters ranging from 23 inches to 31 inches. These tires were arranged in stacks

seven tires high and connected together with tire treads from other tires. Enclosure 1 shows the 

component parts and the layout of the test installation. As can be seen, the installation was set 

in a 4.5 foot offset zigzag pattern with each individual segment consisting of 6 interlocking 

stacks of tires. The barrier height was 4.5 feet and its overall length was 105 feet. The test 

installation was freestanding on a flat concrete surface and was unanchored.  Tennis balls were 

used under the tread strap sets to simulate drainage risers. 

In test 3­10, the small car impacted the barrier at 100.7 kmh and an impact angle of 20 degrees

approximately 80 feet downstream from the beginning of the installation. The vehicle was

effectively “captured” (rather than redirected) by the barrier, which straightened out during the 

impact and slid along the ground approximately 17 feet longitudinally and 12 feet laterally. Occupant impact velocity was 11.6 m/s and the ridedown acceleration was 9.3 G’s. In test 

3­11, the pickup truck impacted at 100.3 kmh and at an impact angle of 25 degrees, also 

approximately 80 feet from the upstream end of the test installation. Again, the vehicle was

captured upright by the barrier as it was straightened out from its original zigzag alignment. The barrier moved approximately 40 feet longitudinally and 16 feet laterally. Occupant impact 

velocity was 9.7 m/s and the ridedown acceleration was 5.7 G’s. In both tests, the selected 

400 Seventh St., S.W. Washington, D.C. 20590

In Reply Refer To: 

HSA­10/B­144
2 

impact point was 80 feet from the upstream end of the test installation thus establishing the 

design length of need point. Enclosure 2 shows the summary sheets for the two tests that were 

run.

Based on the reported results of these tests, the LifeNet SoftWalls Median Barrier System 

meets the evaluation criteria in the NCHRP Report 350 for a test level 3 longitudinal barrier 

and may be used on the National Highway System if selected for use by a transportation 

authority. In both tests, acceptable crash performance was contingent upon the test vehicles

being stable immediately prior to impact (i.e., the vehicles’ suspensions were neither 

compressed nor extended) and upon the LifeNet Softwalls installation being free to translate 

both longitudinally and laterally along the ground. End users may require additional testing if

your barrier is installed on sloping terrain or on a surface that may prevent or restrict its free

movement when struck by a vehicle. 

Please note the following standard provisions that apply to this acceptance letter:

· This acceptance is based on the reported crash performance of the LifeNet SoftWalls

barrier under the conditions in which it was tested. It is not intended to address its

structural or maintenance characteristics or its long term durability. · Should the FHWA discover that the qualification testing was flawed, that in­service 

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

significantly different from the version that was crash tested, it reserves the right to 

modify or revoke its 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 mechanical properties and geometry as that submitted for

acceptance. · To prevent misunderstanding by others, this letter of acceptance, designated as number 

B­144 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.

· If the LifeNet SoftWalls barrier is patented it is considered "proprietary." If proprietary 

devices are specified by a highway agency for use on Federal­aid projects they: (a) must 

be supplied through competitive bidding with equally suitable unpatented items; (b) the 

highway agency must certify that they are essential for synchronization with 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, a copy of which is

enclosed.

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

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

holder. The acceptance letter is limited to the crashworthiness characteristics of the
3 

candidate device, 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 yours,

/original signed by John R. Baxter/

John R. Baxter, P.E.

Director, Office of Safety Design 

Office of Safety 

2 Enclosures
 2-5 

Figure 1. Details of the LifeNet SoftWalls Median Barrier System (continued) 
 2-7 

Figure 1. Details of the LifeNet SoftWalls Median Barrier System (continued) 
 2-8 

Figure 1. Details of the LifeNet SoftWalls Median Barrier System (continued) 
1 Since the test article moved out of the field of view of the widest overhead camera, dynamic deflection could not be 

2 Measured perpendicular from the line created by the rearmost pre-test tangent points of the barrier. 

0.000 s 0.060 s 0.120 s 0.200 s 

6.38 m

OriginalImpactPoint

OriginalImpactPoint 1.25 m

OriginalImpactPositionsPost-TestPositions

32.0 m

General Information Test Agency Transportation Research  Center Inc. (TRC Inc.)  Test No. 051229  Date December 29, 2005 Test Article  Type Longitudinal median barrier system  Manufacturer LifeNet SoftWalls, LLC  Size and/or dimension 32.0 meters long, consisting of  and material of key 396 used 23 to 31 inch tires,  elements 240 tire treads, and metal plates with 

self-tapping screws. 

Soil Type and Condition N/A Test Vehicle  Type Production Model  Designation 820C  Model 1995 Chevrolet Metro  Mass (kg)  Curb 917.8  Test Inertial 841.3  Dummy(s) 75.3  Gross Static 916.6 

Impact Conditions  Speed (km/h) 100.7  Angle (deg) 20 Exit Conditions  Speed (km/h) N/A  Angle (deg) N/A Occupant Risk Values  Impact Velocity (m/s)  x-direction 11.6  y-direction 0.4  THIV (optional) N/A  Ridedown Acceleration (g’s)  x-direction 9.3  y-direction 3.8  PHD (optional) N/A  ASI (optional) N/A Max. 0.050 –s Average (g’s)  x-direction N/A  y-direction N/A  z-direction N/A 

Test Article Deflections (m)  Dynamic N/A1 

 Permanent2 3.6 

Vehicle Damage  Exterior  VDS N/A  CDC 12FZEW2  Interior  OCDI FS0000000  Maximum Exterior  Vehicle Crush (mm) 100  Max. Occ. Compart.  Deformation (mm) 32 Post-Impact Vehicular Behavior  Maximum Roll Angle (deg) 6.1  Maximum Pitch Angle (deg) -3.6  Maximum Yaw Angle (deg) 64.4 

Veh

Figure 9. Summary of results for test 051229 
1 Since the test article moved out of the field of view of the widest overhead camera, dynamic deflection could not be 

2 Measured perpendicular from the line created by the rearmost pre-test tangent points of the tire barrier. 

0.000 s 0.120 s 0.240 s 0.360 s 

13.39 m

OriginalImpactPoint

OriginalImpactPoint 1.59 m

OriginalImpactPositionsPost-TestPositions

32.0 m

General Information Test Agency Transportation Research  Center Inc. (TRC Inc.)  Test No. 051230  Date December 30, 2005 Test Article  Type Longitudinal median barrier system  Manufacturer LifeNet SoftWalls, LLC  Size and/or dimension 32.0 meters long, consisting of  and material of key 396 used 23 to 31 inch tires,  elements 240 tire treads, and metal plates with 

self-tapping screws. 

Soil Type and Condition N/A Test Vehicle  Type Production Model  Designation 2000P  Model 1988 Ford F-250  Mass (kg)  Curb 1950.2  Test Inertial 1956.8  Dummy(s) 0.0  Gross Static 1956.8 

Impact Conditions  Speed (km/h) 100.3  Angle (deg) 25 Exit Conditions  Speed (km/h) N/A  Angle (deg) N/A Occupant Risk Values  Impact Velocity (m/s)  x-direction 9.7  y-direction 2.8  THIV (optional) N/A  Ridedown Acceleration (g’s)  x-direction 5.7  y-direction 0.6  PHD (optional) N/A  ASI (optional) N/A Max. 0.050 –s Average (g’s)  x-direction N/A  y-direction N/A  z-direction N/A 

Test Article Deflections (m)  Dynamic N/A1

 Permanent2 4.9 

Vehicle Damage  Exterior  VDS N/A  CDC 12FZEW2  Interior  OCDI FS0000000  Maximum Exterior  Vehicle Crush (mm) 152  Max. Occ. Compart.  Deformation (mm) 32 Post-Impact Vehicular Behavior  Maximum Roll Angle (deg) -15.6  Maximum Pitch Angle (deg) -4.3  Maximum Yaw Angle (deg) 71.3 

Veh

Figure 9. Summary of results for test 051230