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FHWA Home / Safety / Roadway Departure / Safety Eligibility Letter

Safety Eligibility Letter B-226

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U.S. Department of Transportation
Federal Highway Administration

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

November 18, 2011

In Reply Refer To:
HSST/B-226

Hemal Shah, PE
Conti Enterprises, Inc
2045, Lincoln Highway
Edison, NJ 08817

Dear Mr. Shah:

This letter is in response to your request for the Federal Highway Administration (FHWA) to review a roadside safety system for eligibility for reimbursement under the Federal-aid highway program.

Name of system:

Conti Half Shape Concrete Bridge Rail

Type of system: Temporary bridge railing
Test Level: MASH Test Level 3
Testing conducted by: Pennsylvania Transportation Institute
Date of request: October 28, 2011
Date of request: December 17, 2010
Date initially acknowledged:

October 28, 2011

You certify that the device described herein meets the crashworthiness criteria of the American Association of State Highway and Transportation Association"s (AASHTO) Manual on Assessing Safety Hardware (MASH). Based on your testing, you asked that we find the device(s) eligible for reimbursement under the Federal-aid highway program.  Eligibility for reimbursement under the Federal-aid highway program does not establish approval or endorsement by the FHWA for any particular purpose or use.

Decision:
The following device is eligible, with details provided below:

Requirements
Roadside safety devices should meet the guidelines contained in the American Association of State Highway and Transportation Officials' Manual for Assessing Safety Hardware (MASH). The FHWA Memorandum "Identifying Acceptable Highway Safety Features" of July 25, 1997 provides further guidance on crash testing requirements of longitudinal barriers.

This Conti designed half section concrete barrier is a pre-cast steel reinforced concrete barrier with following critical dimensions

Please refer to the enclosed drawing, "Exhibit-A" for the detailed fabrication shop drawing. This shop drawing provides all necessary details to fabricate and to inspect and verify the barrier being used during application.  Concrete within the pre-cast barrier is 4000-psi design strength (28-days).

During the preparation of the crash test it was determined that the HS-l barrier system needed to be tested according to the MASH guidance at TL-3. The TL-3 test level is designed to document the safety system's capability to safely contain and redirect vehicles traveling at high speeds. The MASH 3-11 test uses a pickup truck designated as vehicle 2270P (2270 kg). The vehicle impacts the determined critical impact point of the length of need barrier at a designated impact speed of 100 km/h at a nominal angle of 25 degrees.

The length of need (LON) of the constructed barrier system at the crash testing facility was 98 ft, consisting of 5 consecutive HS-l barrier sections pinned together and each section was bolted onto a simulated 9-inch concrete bridge deck constructed at the test facility. The critical impact point (CIP) on the constructed barrier system was determined to be 4.3 ft downstream of the joint between the third (middle) and fourth barrier sections. The approach angle of the vehicle was set at 25 degrees. The test vehicle was a 2002 Dodge RAM 1500 Quad Cab 2WD, meeting the MASH criteria for the 2270P vehicle.

The test vehicle impacted the barrier system at a speed of 98.2 km/h (61 mi/h) and a 24.08-degree angle 5.1 ft from the joint of the third and fourth barrier. The test vehicle was safely redirected by the barrier system with an exit angle of 4.8 degrees well within the designated exit box. The test vehicle suffered minor damage throughout the impact. No measurable deformation of the passenger compartment was detected. No penetration of any kind or obstruction of view of the driver was detected. The test article had suffered minor damage and very small deformation. The impacted barrier segment developed a crack in the lower left comer of the barrier at the joint between the impacted (third) and adjacent upstream (fourth) barrier. Maximum permanent and dynamic penetrations occurred at the same location and were measured at 0.012 m (0.47 in).

Findings
Therefore, the system described and detailed in the attached form is eligible for reimbursement and should be installed 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 eligibility letters:

 

Sincerely yours,

/* Signature of Michael S. Griffith */

Michael S. Griffith
Director, Office of Safety Technologies
Office of Safety

Enclosures

Page last modified on June 24, 2011.
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