1200 New Jersey Avenue, SE

Washington, D.C. 20590

May 18, 2010

Mr. Pratip Lahiri

Specifications and Standards Section, POD 23

New York State Department of Transportation 

50 Wolf Road 

Albany, New York 12232

Dear Mr. Lahiri:

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

acceptance of a roadside safety system for use on the National Highway System (NHS).

Name of system: Type IIA Box Beam End Terminal 

Type of system: End Terminal

Test Level: Modified MASH TL-3

Testing conducted by: Midwest Roadside Safety Facility

Date of request: November 10, 2009

Date of completed package: April 13, 2010

Request initially acknowledged: November 19, 2009

You requested that we find this system acceptable for use on the NHS under the provisions of the 

American Association of State Highway and Transportation Officials (AASHTO) Manual for 

Assessing Safety hardware (MASH). 

Requirements

Roadside safety devices should meet the guidelines contained in the AASHTO MASH. The

FHWA Memorandum “Identifying Acceptable Highway Safety Features” of July 25, 1997, 

provides further guidance on crash testing requirements of longitudinal barriers. 

Description

The subject Type IIA End Terminal is a re-directive gating end terminal which is used with the 

New York State generic box beam guiderail (6 in. x 6 in. x 3/16 in. steel tube box beam). The 

cross section of the end terminal is identical to the generic box beam. The effective length of the 

Type IIA end terminal is 25 ft., 4 in., which includes a 17 ft., 11 7/8 in. shop-curved section and 

In Reply Refer To: 

HSSD/CC-107
2

8 ft., 3 1/16 in. straight section. The curved section has a radius of 35 ft. and 43 inches of the 

leading end of the straight section is turned down at a 1:2 slope. The end terminal requires

8 posts which are spaced approximately 3 ft. apart. Enclosure 1 shows the general layout of the 

New York State DOT Type IIA and details of each component. 

Crash Testing

According to MASH, test 3-30 through test 3-38 are to be conducted for end terminals. The 

point of impact in tests 3-30, 3-31, 3-32, and 3-33 are the face of the ramped part of the end 

terminal. However, New York State Department of Transportation’s (NYSDOT) intention is to 

utilize the Type IIA End Terminal at locations where the available clear zone is limited to less 

than 5 feet behind the leading end of the terminal (e.g., relatively tight radius driveways). Due to 

the flared design of the end terminal, it is unlikely that a vehicle can collide with the face of the 

ramped part of the system. Even if such a collision occurs and the vehicle is not contained, the 

vehicle will enter the hazard free area. Consequently, we agree that these four tests can be 

waived if the end terminal is properly installed and its use is confined to locations described. 

Different variations of the Type IIA end terminal were crash tested by the Midwest Roadside 

Safety Facility. The variation described above and shown in Enclosure 1 was crash tested 

according to MASH test 3-34. The test article passed the test. Enclosure 2 shows a summary of 

the test results. 

The point of impact for Test 3-34 is the Critical Impact Point (CIP). By definition, the CIP is 

where the behavior of the test article changes from redirecting the impacting vehicle to either 

capturing the vehicle or allowing it to gate through the system. Normally the CIP is determined 

through detailed analysis of the end terminal or use of relevant computer programs. However, in 

the test conducted, the CIP was assumed and then verified by a full scale crash test. 

Test 3-35 was conducted on a variation of the final Type IIA End Terminal and the test article 

passed the test (Enclosure 3). The difference between this test article and the final Type IIA end 

terminal is that post 2 and 4 were moved to the back side of the rail for the final Type IIA End 

Terminal. This change is not expected to have a significant effect on the performance of the 

terminal and we concur that the final design would also be expected to pass the test.

A modified version of test 3-35 was also conducted on the end terminal described above because 

the NYSDOT staff considered the modified test more critical than the test recommended in 

MASH due to the fact that the end terminal is flared back rather than straight. The difference 

between the modified 3-35 and MASH 3-35 is the point of impact. In the former, the point of 

impact was upstream of the beginning of Length of Need (LON) (the fifth post in Enclosure 1) 

and in the latter it was the beginning of LON. The test article passed the test and Enclosure 4 

summarizes the test results. 

Test 3-36 is required where the end terminal is attached to rigid barriers or other very stiff 

features. As long as the Type IIA End Terminal is used with the New York State generic box 

beam guiderail, this test is not applicable. 
3

Test 3-37 is to examine the behavior of the end terminal during reverse direction impact. This 

test was not performed. The reason for this is that the device is not intended to be utilized in a 

location that can result in a reverse direction impact. This acceptance letter is provided with 

recognition that the described Type IIA End Terminal cannot be installed in locations where 

there is a potential for reverse direction impacts to encounter the flared /curved portion of the end 

terminal, such as a median. 

 

Test 3-38 is not required because the subject end terminal does not possess significant 

attenuation capability. 

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 such use is acceptable to a highway agency, and 

when installed in a manner consistent with the following limitations:

1) The Type IIA End Terminal is limited to locations where the available clear zone is less than 

5 feet behind the leading end of the terminal (e.g., relatively tight radius driveways).

2) The Type IIA End Terminal cannot be extended beyond an abrupt shoulder break such as a 

ditch because there is a higher potential for underride in such circumstances. 

3) Because the Type IIA End Terminal was subjected to a reduced MASH test matrix, the use of 

these terminals should be supervised to ensure that they are not being placed in inappropriate 

locations. Also, installations shall be monitored to ensure that in-service performance results 

in improved crash behavior compared to box beam guiderail terminals currently in use.

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

• This acceptance is limited to the crashworthiness characteristics of the systems and does not 

cover their structural features, or conformity with the Manual on Uniform Traffic Control 

Devices.

• 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 the NCHRP Report 

350. 
4

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

CC-107 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. 

• 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. 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 yours,

David A. Nicol, P.E.

Director, Office of Safety Design

Office of Safety

FHWA:HSSD:NArtimovich:tb:x61331:5/4/10

File: s://directory folder/nartimovich/CC107NYSDOTBoxTerm.doc

cc: HSSD (Reader, HSA; Chron File, HSSD; N.Artimovich, HSSD; MMcDonough, HSSD;

DNicol, HSSD)