u.s. Deportment 

of Tronspor!O!iOn 

Federal HIghway 

Administration 

Memorandum 

SUbJect Action: IdentifYing Acceptable Highway Safety Features Dale JUL 25 1997 

f$: 

From Director, Office of Engineering 

Reply to 

Attn, Of. HNG-14 

TO 

Regional Administrators 

Federal Lands Highway Program Administrator 

Division Administrators 

Federal Lands Highway Division Engineers 

The Intennodal Surface Transportation Efficiency Act of 1991 (ISTEA) required the Secretary of 

Transportation to institute measures to enhance the crashworthy performance of roadside features 

to accommodate vans, mini-vans, pickup trucks, and 4-wheel drive vehicles. In recognition of 

this requirement, the 1993 National Cooperative Highway Research Program (NCHRP) Report 

350, Recommended Procedures for the Safety Performance Evaluation of Highway Features 

( NCHRP Report 350), contains guidance for testing highway features with pickup trucks to 

assess the safety performance of those features. The Federal Highway Administration (FHW A) 

believes the pickup truck is an acceptable surrogate for the other vehicles cited in the ISTEA. 

Through a formal rulemaking process that culminated in a final rule in a notice in Volume 58, 

No. 135, of the Federal Register, dated July 16, 1993, the FHWA added Report 350 at 

paragraph 625.S(a)(13) of Title 23, Code of Federal Regulations (23 CFR). Since that time the 

"Guides and references" section of23 CFR, Part 625, under which the NCHRP Report 350 was 

cited, has been removed. The NCHRP Report 350 is now cited in Section 16, Paragraph (a)(12) 

of the Non-Regulatory Supplement to the Federal-aid Policy Guide, Subchapter G, 

Part 625 (NS 23CFR 625). To further promulgate application of the guidelines in the NCHRP 

Report 350 a memorandum from the Office of Engineering, "Information: Procedures for 

Determining Acceptability of Highway Features," dated November 12, 1993, was sent to 

Regional Federal Highway Administrators and the Federal Lands Highway Program 

Administrator. 

The effect of both the Federal Register notice and the November 1993 memorandum was a 

strong indication that, after five years from the effective date of the final rule in the notice, the 

FHW A would require all new installations of highway features on the National Highway System 

(NHS) that are covered in the NCHRP Report 350 to have been tested and found acceptable 

according to the guidelines in that report. Thus, the resulting nominal deadline for full 

compliance with the recommended guidelines in the NCHRP Report 350 was set at August 16, 

1998. However, also in the Eederal Register notice was a statement that" ... the FHW A wants to 

assure all that during the scheduled transition period it will continually reassess its position." 
• 

In the spirit of that promise, an outline of the FHWA's current position follows: 

• Except as modified below, all new or replacement safety features on the NHS covered by 

the guidelines in the NCHRP Report 350 that are included in projects advertised for bids or 

are included in work done by force-account or by State forces on or after October I, 1998, 

are to have been tested and evaluated and found acceptable in accordance with the 

guidelines in the NCHRP Report 350. (The slight change from the previously implied 

deadline was made to take advantage of any benefit there might be in having the date 

coincide with the beginning of the Federal fiscal year. Citing the advertising date rather 

than the installation dated was done to minimize project timing problems that might lead to 

requiring the issuance of change orders to be in strict compliance with the cited deadline.) 

Note that breakaway support hardware previously found acceptable under the breakaway 

requirements of either the 1985 or 1994 editions of the AASHTO Standard Specifications 

for Structural Supports for Highway Signs. Luminaires and Traffic Signals are acceptable 

under the NCHRP Report 350 guidelines. 

• Exceptions: 

1. For some types of breakaway supports the FHW A will accept pendulum testing and the 

use of the test results to calculate an estimate of high-speed breakaway performance. 

The FHW A will place limits on the maximum masses and heights of acceptable 

breakaway luminaire supports. For additional discussion and guidance on these items 

see the attached "Background and Guidance on Requesting Federal Highway 

Administration Acceptance of Highway Safety Features" (Submission Guidelines). 

2. The testing and acceptance procedures for truck-mounted attenuators and certain workzone devices are modified in the guidance given in the Submission Guidelines. 

3. Bridge railings tested and found acceptable under other guidelines may be acceptable for 

use on the NHS. See the Submission Guidelines (attached) and Mr. Horne's May 30, 

1997, memorandum, "Action; Crash Testing of Bridge Railings," for additional 

guidance. 

4. For reasons cited in the attached Submission Guidelines, for work zone crash cushions, 

freestanding concrete work zone traffic barriers, and portable, usually trailer-mounted, 

work zone devices, such as lighting supports, flashing arrow panels, temporary traffic 

signals, and changeable message signs, the deadline for compliance with the guidelines 

in the NCHRP Report 350 is October 1,2002. 

5. For specific small, lightweight channelizing and delineating devices the Submission 

Guidelines provide for self certification by the developer on the basis of documented 

field experience or comparison with like acceptable devices. 

6. Traffic signal supports and utility poles are exempt from the crashworthiness 

requirements being addressed here. Actually, breakaway utility poles are expressly 
3 

covered in the NCHRP Report 350 and guidelines for testing breakaway sign and 

luminaire supports could reasonably be applied to traffic signal supports. Nevertheless. 

because of the structural requirements for utility poles and most traffic signal supports. 

the technical problems with making them breakaway, and the assumed net benefit to the 

public from allowing them, unshielded, within the clear zone, a requirement that they be 

made breakaway, historically, has not been imposed on them. On the other hand, they 

constitute real risks for motorists and all practicable measures should be taken through 

their location or a reduction in their numbers to reduce their risk to motorists. 

In addition, because of their low structural requirements, consideration should be given 

to making post-top-mounted traffic signal supports breakaway. 

• The FHW A dpes not intend that this requirement (that new highway safety features installed 

on the NHS be proven crashworthy in accordance with the guidelines in the NCHRP Report 

350) result in the replacement or upgrading of any existing installed features beyond what 

would normally occur with planned highway improvements. On the other hand, a State 

should have a rational, documented policy for determining when an existing non-standard 

feature should be upgraded. 

• To aid the States and the FHWA in the evaluation of the in-service performance of the work 

zone and roadside features and the formulation of rational policies on the deployment and 

upgrading of these features, it would be highly desirable ifthere were inventory and accident 

data bases of sufficient detail, accuracy, and precision that one could use them to evaluate 

the field performance of specific highway feature designs. Existing or emerging video log, 

GPS, GIS, data warehousing, and other technologies make this a reasonable goal. It is 

believed that significant steps have already been taken by some States that could lead to 

attainment of this goal. It is recommended that regional and division personnel working in 

the planning and safety areas work with their State counterparts to see what can be done to 

accelerate the improvement and application of these technologies and the dissemination of 

information on their application toward attainment of the goal. 

Finally, a few words on the attached Submission Guidelines, they replace a similar document 

that was attached to the previously cited November 1993 memorandum. While the new 

document contains updated information and has been expanded to address more features, the 

principal reason for this new version is to better describe what must be submitted by those 

wishing to take advantage of the Headquarters service of passing judgement on the 

crashworthiness of a highway feature. These guidelines should be consulted early in the 

development of a qualification program for a highway safety feature. If it is likely that 

development tests will be used to document crashworthiness of a feature, the guidelines should 

be considered in setting up and conducting the development testing program for a new or revised 

feature. 
An extra copy of this memorandum is being furnished to each Division Administrator for 

submission to their associated State highway agency. 

Donald P. Steinke 

Attachment 
Background and Guidance on Requesting Federal Highway 

Administration Acceptance of Highway Safety Features 

Introduction 

Attachment 

Highway safety features, such as breakaway sign and lumina ire supports, longitudinal barriers. 

crash cushions, and work zone traffic control devices, must demonstrate acceptable crashworthy 

performance to be accepted by the Federal Highway Administration (FHWA) for use on the 

National Highway System (NHS) within the clear zone or, particularly for work zone devices, 

within the roadway. From 1981 to 1993 the FHW A reviewed roadside safety hardware that had 

been crash tested in accordance with the procedures in the National Cooperative Highway 

Research Program (NCHRP) Report 230, Recommended Procedures for the Safety Performance 

Evaluation of Highway Appunenances (Report 230). This document was never formally 

recognized by the FHWA. In May 1993 a revised testing procedures document, NCHRP Report 

350, Recommended Procedures for the Safety Performance Evaluation of Highway Features 

(Report 350), was published. By a final rule in Federal Register Vol. 58, No. 135, dated July 16, 

1993, the FHWA formally added Report 350 to 23 CFR under the "Guides and references" 

section, Part 625.5(a)(13). (This "Guides and references" section has since been removed from 

the CFR. The Report 350 citation has been transferred to Section 16, Guides and References, 

paragraph (a)(12), of the Non-Regulatory Supplement to the Federal-Aid Policy Guide, 

Subchapter G, Part 625, Design Standards for Highways (NS 23 CFR 625).) The FHW A will 

require, unless otherwise indicated, that all new installations of applicable highway features 

included in projects on the NHS advertised for bids or installed by state forces or under force 

account work on or after October 1, 1998, will have been found crashworthy according to the 

guidelines in Report 350, except as the guidelines may be modified in the guidance that follows. 

Acceptance Letters 

As a service to ~ A field offices, state and local highway agencies, and industry, the FHW A's 

Office of Engmeering reviews crash test reports and other supporting documentation and issues 

acceptance letters to developers of crashworthy hardware. (Note that the term "developer,". as 

used in these guidelines refers to individuals, companies, or organizations that invent, develop, 

modify, manufacture, sell, or promote highway safety hardware.) The FHWA does not, with rare 

exceptions, conduct crash testing for developers of safety hardware. Typically, the developer 

must contract with a testing agency that is recognized as capable of conducting full scale impact 

testing of highway hardware. Testing in compliance with FHWA accepted procedures is then 

performed on the feature. The reSUlts, in the form of a test report and related documentation, are 

submitted by the developer or, at the request of the developer, the testing agency to the Office of 

Engineering. If the testing and performance of the feature are acceptable and sufficient detail on 

the design and operation of the device are provided, the Office of Engineering will issue a letter 
• 

to the petitioner (the developer or other person requesting acceptance of a feature) indicating 

acceptability of the feature for use on the NHS and the Report 350 test level for which it qualifies. 

This letter may also cite limitations on the feature's acceptability, such as the maximum mass of 

pole that may be used with an accepted breakaway feature or other physical or installation 

requirements. Copies of acceptance letters are sent to the FHW A's regional offices so that they 

are kept informed of additions or changes to the list of acceptable hardware and, in turn. pass the 

information on to state highway agencies through FHWA division offices. Should the petitioner 

differ with the FHW A's finding on the crashworthiness of a feature the finding can be appealed 

in writing. The appeal should be directed to the Office of Engineering at the address given on the 

last page of this attachment and include a statement of the point(s) of difference with the FHWA. 

the action desired, and documentation supporting the claim(s) being made. 

There are some features that, by their nature, are nearly certain to be safe and others that are so 

similar to currently accepted features that there is little doubt that they would perform acceptably. 

For these features, the FHW A may, on a case-by-case basis, not require qualification testing or 

may accept abbreviated or unique qualification procedures as the basis for their acceptance. 

Flexible delineator posts are an example of hardware that is unlikely to require full-scale crash 

testing. Barriers or breakaway supports that are substantially the same as previously accepted 

crashworthy hardware may also be accepted under this provision, again, on a case-by-case basis. 

It should be noted that acceptance of a design by FHW A does not ensure acceptance or use by the 

various state highway agencies. They may reject a design or place limitations on its use for a 

variety of reasons-placing their own interpretation on test results, requiring additional testing, 

or requiring in-service evaluation. Also, should the FHW A discover subsequent to the issuance 

of an acceptance letter that the qualification testing was flawed, that in-service 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. 

The FHW A may also revoke an acceptance if a device is promoted as acceptable under conditions 

that are significantly divergent from the test conditions. Any deliberate misrepresentation or 

withholding of the conditions of FHW A's acceptance of a feature by the supplier of a feature will 

be cause for withdrawal of acceptance. 

Crashworthy hardware items other than those accepted by FHWA Headquarters, it should be 

noted, could be acceptable for use on the NHS. As already stated, the FHWA's Office of 

Engineering reviews test results and issues acceptance letters as a service to developers and users 

to help provide continuity and uniformity in evaluations. However, it is not a requirement that 

an acceptance letter be issued by the Office of Engineering for crashworthy devices to be used on 

the NHS. If, for a particular device, it can be demonstrated to the satisfaction of a state highway 

agency that a device has been tested and evaluated in accordance with acceptance procedures 

recognized by the FHW A, and the results are satisfactory, that device could be accepted by that 

state, with concurrence by its FHWA division office, for use on the NHS within that state. 

However, should this alternative course be followed, in the interest of technology transfer, the 

2 
division office. through its regional office. should submit the crash test reports and other 

documentation upon which its acceptance is based to the Office of Engineering for information and 

possible Headquarters concurrence and distribution. 

Crash Testing' General 

Developers who are new to the field of highway safety hardware may fmd Appendix A useful. 

It contains a list of testing agencies that have experience in testing roadside safety hardware for 

state highway agencies. developers, and the Federal Government. This list is not meant to be allinclusive nor is it an endorsement of these organizations. It is intended to provide a starting point 

that developers can use in determining where they might have the appropriate tests performed. 

Other facilities in the U.S. or in other countries may also be qualified to satisfactorily perform the 

tests. FHW A reserves the right not to accept test results if the competence of the crash test 

laboratory that performed the test is uncertain or if non-standard test equipment or procedures . 

were used. FHW A may accept the competence of a foreign laboratory based on certification 

through an FHW A recognized procedure, governing agency, or standards review organization. 

Various test levels (combinations of vehicle size and impact angle and speed) have been included 

in the Report 350 crash test matrices to permit tailoring the performance and cost of highway 

safety features to meet specific site requirements. When developing a crash testing program for 

a particular device careful attention should be paid to selecting the appropriate test level. Selection 

procedures for the various test levels are yet to be developed. However. work on developing such 

procedures is currently (1997) underway under an NCHRP project. FHW A acceptance letters will 

acknowledge the test level to which a device has been crash tested and is acceptable. It will be 

assumed that until nationally recognized selection procedures exist user agencies will, by some 

consistent, rational means, determine where a feature of a demonstrated test level is appropriate 

for use. 

Devices intended to serve as permanent or temporary traffic barriers -(longitudinal barriers, 

terminals, or crash cushions) must, as a minimum, qUalify under Report 350 test level 1 test 

procedures and acceptance criteria to be accepted for such service. Devices that do not qualify 

as traffic barriers may fmd use as channelizing devices or for delineation provided they meet 

Report 350 guidelines for work zone devices and are consistent with the Manual on Uniform 

Traffic ConJrol Devices requirements. They will not, however, be acceptable for use where a 

longitudinal barrier is needed to shield a work area. 

All hardware that is to be used with a device in service must be in place during the crash test, 

whether it is a functional part of the system or an ancillary feature such as a warning sign-sign 

supports need signs. delineator posts need delineators, breakaway lurninaire supports need mast 

arms and the equivalent of luminaires, etc. Barriers that are to be used with glare screens, signs, 

luminaire supports, handrails, or other hardware mounted on top should be tested with these 

devices in place. An exception to this requirement may be a light-weight fabric or pliable 

membrane snow or debris cover if its effect on crash performance can be judged inconsequential. 

3 
• 

The intention to use such a cover with a device and a full description of the cover must be 

specifically covered in any request for acceptance. 

The developer should also carefully choose which version of a device is to be tested. If a number 

of different sizes are proposed for use, then the "worst case" conditions, if predictable, should be 

tested. It may be that "worst case" conditions are not obvious and more than one version of a 

device will need to be tested. The FHW A Office of Engineering is willing to review a proposed 

test program to assist in determining an adequate number of tests to fully qualify a device and its 

variants. 

To date (1997), most crash testing has been done on level or nearly level test sites. The terrain 

on which a feature is located or over which an impacting vehicle may traver5·c " either pre- or postimpact) can have significant effects on the outcome of a crash into a given ature. Therefore, a 

request for acceptance should include, preferably in the test report, a .:. ,cussion of the site 

conditions-foundation and topography-for which a feature is intended to be used and the 

limitations of the testing program to evaluate the range of expected service conditions. 

Below is a section containing comments on specific aspects of testing various types of highway 

features. These comments are followed by a section on "Submission Requirements", which 

describes what needs to be supplied to the Office of Engineering when requesting FHW A review 

and acceptance of a crashworthy highway feature. Appendix B is a checklist citing information 

that FHW A has found to be essential in its evaluation of the crashworthiness of hardware. It is 

recommended that this list be carefully reviewed in designing a testing program and in preparing 

a request to the FHW A for acceptance of a feature. 

Crash Testing' Specific Features 

Sign and Luminaire Supports 

Crashworthy sign and luminaire supports are designed to break away or yield when struck by a 

vehicle. When a proposed breakaway support design includes two or three posts within a 

2. I-meter span all supports must be struck by the test vehicle. Testing conditions and evaluation 

criteria for determining acceptable breakaway performance are found in the AASHTO Standard 

Spedjicarions for Structural Supports for Highway Signs, Luminaires and Traffic Signals, 1994, 

(Support SpeCifications) and in Report 350. Please note that soil conditions are critical when 

considering the crashworthiness of many breakaway supports. Supports qualified in "standard" 

soil may not work in "weak" soils and thus may not be acceptable in weak soils. The use of a 

concrete foundation or a soil plate will also affect the performance of the support and must be 

documented. 

Full-scale crash tests, with the prescribed Report 350 test vehicle, are applicable to all types of 

breakaway hardware. Tests with pendulums or reusable bogie vehicles are acceptable for most 

breakaway supports, exceptions being base bending or yielding supports. These supports must 

4 
be tested using an automobile because no surrogate test devices have been approved that replicate 

the interaction between the vehicle and the support. Pendulum testing of base bending or yielding 

supports may be permiued on a case-by-case basis to evaluate the relative performance of supports 

that have previously been qualified using automobiles. 

The support hardware must perform satisfactorily at impacts between 35 krnIh and 100 krnIh, per 

Report 350. Since the higher speed tests cannot be run on a pendulum test facility, FHWA has 

allowed high speed results to be estimated using a procedure previously detailed in the 

discontinued FHWA Notice N 5040.20, dated July 14, 1976. That procedure is described here 

in Appendix C. This extrapolation method, when checked, has nearly always been found to be 

conservative and could result in the rejection of breakaway features that would actually pass full 

scale high-speed tests. 

Testing parameters and acceptance criteria for breakaway supports are as follows: 

1. The key criterion for acceptable dynamic performance in the Support Specifications is 

a maximum change in velocity of 16.0 ftfsec (4.88 mlsec) in a 1,800-pound (818-kg) test 

vehicle. The velocity change to be compared to the maximum allowable in the standard 

is the occupant impact velocity. This is the calculated speed at which a hypothetical 

unrestrained occupant impacts the car's interior after traveling a distance of two feet (flailspace distance) relative to the vehicle after vehicle contact with the feature. Report 350 

calls for a maximum velocity change of 5.0 meters per second (16.4 feet per second) based 

on a 0.6-m (1.97-foot) flail space distance. In adopting Report 350, the FHWA 

recognized this higher occupant impact velocity as an acceptable upper limit and also 

recognized the 35-krnIh and lOO-krnIh (21.7-mph and 62. I-mph) test speed range and the 

820 kg (l808-pound) test vehicle. Because Report 350 acceptance criteria are slightly less 

demanding than were the criteria in the 1985 or 1994 Support Specifications or the Report 

230 guidelines, breakaway hardware meeting these earlier criteria do not have to be requalified to be accepted under Report 350 criteria. 

2. The maximum stub height remaining after a support breaks away, measured above a 

1500-mm chord, as specified in the Support Specifications, shall not exceed 100 mm. 

(This is intended to prevent the vehicle undercarriage from snagging on the broken stub 

and to minimize vehicle instability if a wheel hits the stub.) 

3. The occupant compartment must not be penetrated nor seriously deformed. Maximum 

roof crush will be evaluated on a case-by-case basis. However, in no case when a 

breakaway pole falls onto a test vehicle will a roof crush greater than 150 mm (6 inches) 

be found acceptable. 

4. Features, primarily luminaire supports, that are expected to contain electrical wiring are 

to be tested with non-energized wiring of the size, structure, and configuration expected 

to be used with the feature. The objective of including wiring in the lest installation is to 

5 
• 

evaluate both the effect the wiring might have on a support's breakaway performance and 

the potential for the creation of an electrical hazard when the support might be knocked 

down. Where alternative wiring designs are likely to be used with a support, the design 

expected to most adversely affect breakaway performance is .to be used. (This criterion 

of testing with wiring in place has not been required in the past. The FHWA, however, 

will not require retesting of previously accepted supports tested without wiring. It should 

be noted that, while neither the current Support Specifications nor Report 350 call for 

testing supports with wiring in place, the requirement is expected to be included in the 

Support SpeCifications shortly.) 

Because pendulum and bogie testing of luminaire supports, which, as indicated, the FHWA will 

accept, do not reveal the consequences of a support falling on the roof of an impacting vehicle and 

even automobile testing does not investigate the full range of potential consequences from a 

support falling on a vehicle, based on test observations and engineering judgement, the FHW A 

has set upper limits on the support masses and heights it will fmd acceptable even where analysis 

or testing appear to indicate acceptability of greater mass or height supports. The maximum 

acceptable luminaire support mass is 450 kg (992 pounds) and the maximum luminaire support 

height is 18.50 m (60.7 feet). These values are up from the limits of 272 kg (600 pounds) and 

15.2 m (50 feet) cited a few years ago. Any further increase in these limits will have to be based 

on full-scale crash testing and an investigation of the range of vehicle roof crush characteristics 

that go beyond the recommended testing procedures in Report 350. 

Traffic Barriers (I.ongitudinal Barriers Transitions. and Crash Cushions and Terminals) 

Report 350 contains recommended testing procedures, reporting requirements, and criteria for 

determining and documenting the acceptable crashworthy performance of traffic barriers. The 

required number of tests, test speeds, impact angles and locations, and test vehicles vary, 

depending upon the test level and whether the article to be tested is a longitudinal barrier, barrier 

transition, or terminal or crash cushion. If there is any question concerning the total number or 

type of tests to be run, the developer may wish to discuss this issue with the FHW A Office of 

Engineering beforehand and reach a preliminary agreement on an appropriate test matrix . 

. The required strength-test (containment-test) vehicle for the first three of the six test levels 

suggested for longitudinal barriers is a 2000-kg (4,409-pound) * -ton pickup truck. The strengthtest vehicle for test level 4 is an 8000-kg (17,637-pound) single-unit truck. The strength-test 

vehicles for test levels 5 and 6 are 36 OOO-kg (77,366-pound) tractor semi-trailer combinations. 

The difference between the latter two test vehicles is that for test level 5 the trailer is a van-type 

and for test level 6 the trailer is a tanker. 

Bridge railings are longitudinal barriers and are treated as such in Report 350. However, because 

of some unique history connected with their testing and acceptance they are covered separately 

below. 

6 

," 
Bridge Railings 

Bridge railings, as stated, are longitudinal barriers and are to be tested as such with regard to the 

application of Report 350. Their design is covered in both the AASHTO' s Standard Specifications 

for Highway Bridges and the 1994 AASHfO LRFD Bridge Design Specifications (LRFD), which 

reflects the design approach in the 1989 AASHTO Guide Specifications for Bridge Railings (Guide 

Specifications). As can be inferred from comments below, the testing criteria in the LRFD have 

been effectively superseded by Report 350. 

The FHW A policy of requiring crash tested bridge railings was established by the memorandum 

"Bridge Rails", dated August 28,1986. Typically, individual states have sponsored the testing 

of their own bridge railings and implemented the new designs upon receipt of acceptable crash 

test results. 

The LRFD and the Guide Specifications contain guidance for testing bridge railings that differs 

from the guidance in Report 350 in that they recognize only three "Performance Levels." These 

performance levels approximately m~tch three test levels in Report 350, test levels 2, 4, and 5. 

The FHW A recommends that all bridge railing testing now be conducted in accordance with 

Report 350 and that Report 350 test levels 2, 4, and 5 be substituted for the 1994 LRFD 

performance levels 1,2, and 3, respectively. (The AASHTO is considering, and is likely to adopt 

in the near feature, a revision in the LRFD to incorporate the six tests levels cited in Report 350.) 

FHW A has issued two memoranda (the cited August 28, 1986, memorandum and one dated 

August 13, 1990) listing a total of 47 railing designs that met full scale test requirements at the 

time that they were tested and may be considered acceptable for use on the NHS at specified 

performance levels. A third memorandum dated May 30, 1997, updated these earlier listings. 

This new memorandum provides guidance on determining an acceptance test level equivalent to 

a Report 350 test level for bridge railings tested under the railing section of the LRFD, or it's 

predecessor, the AASHTO Guide Specifications for Bridge Railings, or other guidelines. It also 

identifies additional railings tested under the LRFD, Report 350, or other guidelines. 

Work-Zone Traffic Control Deyjces and Mjscellaneous FeahlIes 

In addition to truck. mounted attenuators (TMAs), which are covered separately below, Report 350 

provides guidance for crash testing other work zone features-work zone signs, barricades, 

channelizing devices, etc.-and insubstantial features such as delineator posts. Because of the 

nature of these features some of the test procedures are less rigorous than those for other features. 

For example, under some conditions, low-speed tests may not be required and for tests of freestanding objects with masses less than 45 kg, reduced instrumentation is permitted. (See 

Report 350 section 3.2.3.2.) For determining this 45-kg limit, Report 350 exempts ballast mass 

from the mass of the feature if " ... the ballast effectively does not contribute to the change in the 

vehicle's velocity upon impact with the device. ~ However, the ballast mass, its location, and its 

means of attachment must be clearly described in the drawings and specifications to be provided 

7 
• 

under section 6.1 of Report 350. 

Note that FHWA acceptance of a device as meeting crashworthiness requirements does not imply 

that it has been determined that the device is in conformance to the Manual on Uniform Traffic 

Control Devices (MUTCD). Acceptance letters for crashworthy traffic control devices will carry 

a disclaimer to that effect. However, if, in the opinion of the FHWA, a crash tested device 

submitted for acceptance is clearly out of conformity with the MUTCD the entire submission may 

be returned to the petitioner. 

There is a wide variety of devices used in work zones, some of which are not normallYiound on 

the roadside or in the traveled way outside of work zones. For purposes of determining the level 

of effort needed to demonstrate crashworthiness, work zones devices and miscellaneous features 

will be divided into four categories: 

1. The first category contains those small and lightweight channelizing and delineating 

devices that have been in common use for many years and are known to be crashworthy 

by crash testing of similar devices or years of demonstrably safe operational performance. 

These include plastic or rubber cones and tubular markers, flexible delineator posts, and 

plastic drums with 00 lights, batteries, signs, etc. added. If ballast is used, it must be 

located at ground level in accordance with the manufacturers instructions. For devices to 

be included in this category there must be virtually no potential that they will penetrate 

windshields, cause tire damage, or have a significant effect on the control or trajectory of 

an impacting vehicle. FHW A will not issue letters of acceptance nor maintain a list of the 

many individual devices in this category. These devices may be allowed based upon the 

developer's self-certification if the device: 

a. is built to a specification for a device for which the crashworthiness has been 

validated by crash or surrogate testing, or 

b. is a type of device that is being accepted as being crashworthy on the basis of 

crash test experience with similar devices or years of demonstrably safe operational 

performance. (Simplified crash testing showing that a device poses no risk to 

impacting vehicle occupants may be used to support the manufacturers certification. 

This simplified testing must, as a minimum, be documented by a written report, 

observed by an independent, impartial observer, recorded on videotape, and 

include a means, other than the test vehicle's speedometer, for determining the 

vehicle speed at time of impact.) 

Self-certification will be subject to approval by the individual highway agencies. 

Devices with a top-mounted warning light will only be included in this category if they 

satisfy condition l.a. 

8 

.-
2. The second category includes devices that are not expected to produce significant 

vehicular velocity change, but may otherwise be hazardous. All or parts of the device may 

be substantial enough to penetrate a windshield or injure a worker or they may cause 

vehicle instability when driven over or should they become lodged under a vehicle. 

Testing of devices in this category will be required. However, they may, as mentioned 

above for devices of 45 kg or less, qualify for the reduced testing requirements cited in 

section 3.2.3.2 of Report 350. Lesser instrumentation than required in Report 350 may 

be acceptable. Depending on the device, videotaping may be substituted for high-speed 

film photography in recording test results and instrumentation in the vehicle may be 

omitted. Examples of this class are barricades, portable sign supports, intrusion detectors 

and alarms, and drums, vertical panels, or. cones with lights. 

Devices in this category could merit an FHW A acceptance letter unless it is determined 

that a blanket acceptance (or prohibition) is warranted based on experience with or testing 

of like devices. In order to help highway agencies evaluate the potential hazards to 

workers (bystanders) from work zone devices and determine any limitations to be placed 

on their use or location, the masses and trajectories of elements of a device launched in its 

testing must be recorded and reported. 

If sufficient crash testing is done to indicate that a certain class of device, with any 

ancillary feature(s), is crashworthy, then this class may be moved to Category 1. FHWA 

will make the determination whether to move a class of devices to another category, 

although petitions from industry, documented by crash testing and design details, are 

welcome. 

3. The third category is for hardware that is expected to cause significant velocity changes 

or other potentially harmful reactions in impacting vehicles. Hardware in this category 

must be tested to the full requirements of Report 350. If requested, individual letters of 

acceptance will be issued by the FHW A for crashworthy devices in this category. 

Barriers, fixed sign supports, crash cushions, and other work zone devices not meeting the 

definitions of category 1 or 2 devices are examples from this category. 

Because of the large and expensive inventory, long life, and lack of alternative applications 

for work zone crash cushions and freestanding concrete work zone traffic barriers and the 

timing of the availability of Report 350 qualified hardware of these two types, the FHW A 

has concluded that it is appropriate to extend the deadline for requiring that these devices 

comply with the recommendations in Report 350. Therefore, until October I, 2002, the 

FHW A will accept the use of work zone crash cushions and freestanding concrete work 

zone traffic barriers on the NHS, provided they have been crash tested and found 

acceptable under procedures and criteria at least as stringent as those recommended in 

Report 230, assuming the small test vehicle had a mass of 820 kg (1800 pounds). 

(Actually. there are many concrete work zone barriers that do not meet these criteria and 

that should be phased out of service as soon as possible.) To be used on projects on the 

9 
NHS advertised for bids or constructed with state forces or through force account work on 

or after October I, 2002, work zone crash cushions and freestanding concrete traffic 

barriers must be shown to be crashworthy under the guidelines in Report 350. 

4. The last category, which is actually a subset of category 3, includes portable, usually 

trailer-mounted, devices such as area lighting supports, flashing arrow panels, temporary 

traffic signals, and changeable message signs which are often used in or adjacent to the 

traveled way. While they have significant value in the work zone by contributing to safer 

traffic operation, these devices may cause great harm to occupants of impacting vehicles. 

Even though accident experience to date shows that crashes with these devices are rare, 

it is believed that they should be made crashworthy and meet the recommended acceptance 

guidelines in Report 350 if they are to be used, unshielded, in the clear zone on the NHS. 

However, in the belief that, as currently configured and deployed, these devices provide 

a net benefit to motorists and that it is unlikely that crashworthy versions can be developed 

in time to reasonably meet the October I, 1998, compliance deadline cited above, the 

FHW A is setting October I, 2002, as the date at which it will no longer accept the 

unshielded use of devices in this category on roadways or within clear zones on the NHS 

unless they have been proven crashworthy. (In the interim, as should be done with these 

devices even if proven crashworthy, they should be positioned and operated in as safe a 

manner as practical. This would mean, where reasonable, placing them behind 

crashworthy barriers or shielding them with a TMA or crash cushion. For those devices 

that it is decided appropriate to operate unshielded within the clear zone, they should be 

highly visible, both in and out of service, and be removed from the clear zone as soon as 

practicable after they are no longer needed.) 

Some work zone traffic control devices are normally used in a series to channelize traffic. There 

is the potential that singly some of these devices may have little effect on an impacting vehicle 

but, when struck in mUltiples, may cause vehicle instability or occupant compartment intrusion. 

Also, because of the nature of their configurations, many of these devices can be easily turned or 

upset under normal operating conditions. To address both of these possibilities, when testing 

devices that are typically installed in series, it is recommended that crash tests include two of these 

devices placed in a row aligned with the path of the test vehicle. For a lOO-km/h test the devices 

should be spaced 6 meters apart and the second device should be either turned 90 degrees relative 

to the first or laid on the ground, whichever is judged the .. worst case" orientation for the device 

in question. 

Truck Mounted Attenuators 

The guidelines in Report 350 for assessing the crashworthiness of truck mounted attenuators 

(TMAs) are to be followed except that, until state-of-the-art developments indicate that practical 

and economical TMAs can fully meet the guidelines in Report 350 under test 3-50, the FHW A will 

accept a modified test 3-50, provided an unmodified test 2-50 (70 kmlh, small-car test with the 

host vehicle blocked to prevent movement) is run and passed. The modified 3-50 test the FHWA 

10 
.. • 

will accept for qualifying a test level 3 TMA is a 100-km/h small-car test where the host vehicle 

only has its brakes set and is in' second gear. This assumes all other Report 350 test level 3 

requirements are met. (For information and comparison with other TMAs, the FHW A suggests 

that the optional tests 2-52 and 2-53 or 3-52 and 3-53, as appropriate, be run and reported on all 

TMAs, even though TMAs may be accepted without passing these tests.) 

A recommended mass for the TMA host vehicle, which will affect a TMA's performance in an 

unblocked test, is given in Report 350. The mass of the host vehicle, the mass of any ballast in 

the host vehicle, and the manner in which the ballast is secured in the host vehicle are to be 

reported in the test report. Also, any structural features or modifications required in the host 

vehicle to receive the tested TMA are to be reported. 

Submission Requirements 

Items submitted with a request for an FHW A finding that a feature is crashworthy and acceptable 

for use on the NHS must fully identify: a) the feature(s) tested; b) the conditions and results of the 

testing; and, if acceptance is being sought for any variations in design or construction details or 

procedures from those covered in the documentation of the testing of the feature, c) the complete 

design, construction, and installation details and specifications for the version(s) of the feature for 

which acceptance is being sought. It will be the responsibility of the petitioner to provide 

documentation of the applicability of the testing actually done to assess the acceptability of a 

feature or features differing from the tested article(s). This documentation is to be included with 

the request for acceptance and be sufficiently complete and detailed to fully support the conclusion 

of applicability . 

Because the acceptance letter from the FHW A Headquarters is copied to FHW A field offices to 

notify those offices of Headquarters action, information is included with the acceptance letter that 

might otherwise not be necessary to include. One such item is a copy of a letter-sized (8.5"xll" 

or I.S.0. A4)(216 riun x 279 mm or 210 mm x 297 mm) engineering drawing or set of engineering 

drawings describing the accepted feature in sufficient detail and specificity that an observer in the 

field could use the drawing(s) to confirm that a purported installation of the accepted feature is in 

substantial conformance with what was found acceptable. Thus, two separate copies of a highquality, reproducible, letter-size, engineering drawing or set of drawings showing all pertinent 

details and installation requirements of the version(s) of the feature for which acceptance is being 

sought are to be included with the request for acceptance. (These can often simply be copies or 

reductions of a drawing or drawings included with the documentation of the crashworthiness of 

the feature.) Additional guidance on items to be included with a request for acceptance of a 

feature is given below. 

Report 350 contains rather complete guidance on the acquisition, reporting, and analysis of data 

on the testing of highway features. Appendix D at the end of this attachment is a table containing 

suggested evaluation factors and terminology that the FHW A suggests using as a supplement to 

Report 350 to provide a standard evaluation format for the visual assessment of test results. 

11 
• 

A submission requesting FHW A acceptance of a highway feature must include two copies of a test 

repon prepared according to the guidance in Chapter 6 of Repon 350 showing, except as modified 

in these guidelines, that Repon 350 testing procedures were followed and that Report 350 

acceptance criteria were met. Note that it is not sufficient to report the nominal test conditions, 

design details, or specifications. The tolerances and ranges in these must be evaluated against the 

actual test conditions and the details of the tested device to determine the relevance of the testing 

and the acceptability of the device and the proposed tolerances and specifications related to it. 

Therefore, in setting up and conducting tests and reporting test results, particular attention shOUld 

be given to the discussions concerning test articles covered in Chapters 2, 4, and 6 of Report 350. 

The objective is to accurately report the as-built foundation conditions, test article geometry, and 

material characteristics of what was actually tested, not just the nominal design dimensions and 

specifications for the feature, which, as indicated below, should also be reported: Ideally, all 

materials for a test installation should be examined before they are installed to ensure that they are 

representative of what will actually be supplied in service, with special vigilance for elements that, 

while within specifications, might falsely represent performance under service conditions. This 

process may require obtaining mill certification reports or actually rumting physical material tests 

on critical components of a feature. All materials used in appurtenances shall be declared, using 

chemical rather than proprietary names to describe synthetic materials. Descriptions and material 

specificatiOns for all components, including fastener hardware, should be included or referenced. 

In addition to two copies of test reports and a VHS cassette video of the full sequence of tests, the 

following must also be supplied: 

• The previously cited two sets of a reproducible letter-size drawing or set of drawings 

showing the feature and its installation in sufficient detail to be used to make dimensional 

checks of service installations, . 

• If not included in the test report, two complete sets of material and installation 

specifications for the proposed production model of the feature, including copies of any 

cited specifications (except for AASHTO or ASTM specifications frequently used in the 

highway field) . 

• Because of FHW A's regulation regarding the use of proprietary products on Federal-aid 

projects, the request for acceptance must identify any patent or proprietary rights held on 

the feature or elements of the feature for which acceptance is sought. If the feature is 

proprietary a statement will be included in the acceptance letter indicating the regulations 

that must be meet if the feature is to be specified on Federal-aid projects. 

12 
• 

The following additional documentation is desirable and may be required: 

• Two sets of prints of photos included in the test report. These will be required unless 

the reproductions in the test report are near photo-print quality. (Experience has shown 

that half tone and xerographic reproductions of photos are often not adequate for review 

of before and after conditions or failure details.) 

• One set of 16-mm film coverage of tests. This will be required if the video copy of this 

coverage is not of sufficient quality to be used in interpreting the test results. 

Confidentiality of Submitted Items 

The FHW A recognizes that some of the items and information it needs to evaluate the crash 

worthiness of a feature may be proprietary and as such a petitioner may want them to be held in 

confidence. Within the limits of law and the guidance below, the FHWA will honor written 

requests for confidentiality. However, in the interest of advancing technOlogy, if a feature is 

found acceptable, unless the petitioner requests otherwise, the submitted films and video tapes 

may be sent to the FHW A/National Highway Traffic Safety Administration National Crash 

Analysis Center (NCAC), which makes such items available to the public without restriction. If 

the petitioner requests that these items not be sent to the NCAC or if the items are copyrighted, 

the information will be retained in the Office of Engineering and, upon request, will be available 

for viewing by interested individuals. The FHW A will not consider the test results or related 

photographic documentation or test data as confidential. However, it will respect restrictions on 

copying any copyrighted items, except that the letter sized drawings to be submitted for FHW A 

use in preparation and distribution of an acceptance letter must not be copyrighted. Items, such 

as detailed design drawings or specificatiOns needed to document the testing of a feature or 

features as well as the exact character of the feature or features for which acceptance is sought, 

that the petitioner wishes to declare proprietary and confidential must be so marked and physically 

separated from the body of the test report or reports. 

Addressing Requests for Acceptance 

Submissions requesting acceptance of features should be mailed to: 

HNG-14 

25 Jul97 

DIRECTOR, OFFICE OF ENGINEERING 

FEDERAL HIGHWAY ADMINISTRA nON (HNG-l) 

400 7TH ST. SW 

WASHINGTON, DC 20590 

13 
, , • 

APPENDIX A 

Testing Agencies with Significant Experience in Testing Roadside Safety Features* 

California Department of Transportation •• 

BOl< 19128 

5900 Folsom Boulevard 

Sacramento, CA 95819 

Contact: Mr. Richard Peter 

(916)227-7257 FAX: (916)227-7117 

CaIspan Transportation Sciences Center 

P.O. Box 400 

4455 Genesee Street 

Buffalo, NY 14225 

Contact: Mr. Saverio Pugliese 

(716) 631-6839 FAX: (716)631-6843 

E-Tecb Testing Services 

3617-B Cincinnati Avenue 

Rocklin, CA 95765 

Contact: Mr, John LaTumer 

(916) 645-8188 FAX: (916) 645-3653 

ENSCO, Inc. 

5400 Port Royal Road 

Springfield. VA 22151 

Contact: Mr. Dale Stout 

(703) 321-9000 FAX: (703) 321-7863 

Southwest Research Institute 

P.O. Box 28510 

San Antonio, TX 78284 

Contact: Mr. John W. Strybos 

(210) 522-2449 FAX: (210) 522-3042 

Texas Transportation Institute 

Texas A&M University 

College Station, TX 77843 

Contact: Dr. C. Eugene Buth 

(409) 845-6375 FAX: (409) 845-6107 

15 

University of Nebraska - Lincoln 

Civil Engineering Department 

W350 NEB HaIl 

Lincoln, NE 68588-0531 

Contact: Dr. Dean L. Sicking 

(402) 472-9332 FAX: (402)472-8934 

Transportation Researcb Center Inc_ 

10820 State Route 347 

East Liberty, Ohio 43319-0367 

Contact: John C. Stultz 

(937)666-2011 FAX: (937) 666-5705 

Crash Sorety Research Center 

Pennsylvania Transportation Institute 

Pennsylvania State University 

201 Research Office Building 

University Park, PA 16802 

Contact: Robert J. Wollyung 

(814) 865-7931 FAX: (814) 865-3039 

Federal Outdoor Impact Laboratory··· 

Tumer Fairbank Highway Research Center 

6300 Georgetown Pike 

McLean, V A 22101 

Contact: Mr. Richard E. King 

(703) 285-2468 FAX: (703) 285-2679 

• Some agencies may not have the capability to 

conduct all Report 350 tests. 

•• Services usually limited to State-sponsored 

research. 

••• Testing usually limited to State- or FHW Asponsored research. 
• 

APPENDIX B 

Crashworthy Features - FHW A Acceptance Request Submission Checklist 

Following is a listing (not necessarily complete) of items to be included with a request for FHW A 

review and acceptance of a crashworthy highway feature. Failure to supply these items, if 

applicable to the feature, or the submission of listed items that are incomplete or inaccurate or of 

poor graphic or visual quality, will delay processing a request for a feature's acceptance. To 

reduce the potential for problems caused by insufficient information at submission time or 

undesired restrictions being placed on the acceptability of a feature, it would be prudent to consult 

this checklist when developing the testing plan and procedures for demonstrating the acceptability 

of a feature. 

1. Two copies of acceptance qualification test report(s) and related supporting 

documentation, such as films, videos, photographs, etc., prepared in accordance 

with guidelines in NCHRP Report 350 and containing the following: 

A. Information to be included on article(s) tested: 

1.) Complete engineering drawings of as-tested feature(s) showing actual 

dimensions of all critical elements and their locations. Note that ancillary 

hardware, such as signs mast arms, lights, electrical wiring, glare 

screens, handrails ,etc., that are to be used with a feature is to be tested 

with it and needs to be fully described. In addition, any items, such as 

snow or debris covers, that are to be used with a device but are omitted 

from tests are to be identified and fully described. Further, for work 

zone features that are to be tested in pairs, the locations of the individual 

features are to be given, along with a discussion of the basis .for selecting 

the tested orientation. 

2.) Complete descriptions of the material properties of all critical elements 

of the tested features( s). 

3.) Description of installation or erection procedures. 

4.) Complete description and characterization of foundation or mounting 

conditions, including special test mounting structures, support pavement, 

soil types(s), soil placement and compaction, soil moisture content, etc. 

5.) Documentary video (VHS preferred) and or photographs of test 

installation( s). 

17 
• 

B. Infonnation to be included on testis) conducted: 

1.) Complete detailed information on relevant features of the test vehicle(s) 

or testing device. 

2.) Complete. precise infonnation on testis): 

a.) Names of principals responsible for conducting test(s) 

b.) Date(s) and time(s) 

c.) Location( s) 

d.) Current (at test time) and antecedent (10 days ±) weather and 

groundwater conditions-particularly, anything that might affect 

material properties or foundation conditions. 

e.) Complete infonnation on test instrumentation and test procedures, 

including identification of and justification for any deviations from 

Report 350 guidelines. 

f.) Complete infonnation on actual impact conditions (impact location, 

speed, angle, etc.) and a showing that the actual conditions were 

within allowable tolerances. 

g.) Complete report on test results as recommended in Report 350, plus 

documentation for any inferences or extrapolations, such as estimating 

high-speed breakaway performance of a device on the basis of 

performance in a low-speed pendulum test. 

3.) Composite video copy (VHS preferred) oftest films. (The copies of the 

test films to be available if requested.) 

4.) Documentary video and photographs and measurements of post-crash 

conditions of feature(s) and test vehicle(s) or test device(s). The 

infonnation submitted with the initial acceptance request should be 

sufficient to clearly illustrate the after-test conditions of the tested feature 

and the test vehicle or device. However, all the information gathered, 

which should be sufficient to permit a detailed postmortem analysis of the 

crash results, need not be submitted initially but should be available to 

clarify any questions that might arise during FHW A's evaluation of the 

acceptability of a feature. 

18 
• 

• 

C. Certification of the capability of the testing organization may be required. 

(Currently no formal certification procedures have been adopted in the U.S.) 

2. Two sets of documentation describing the feature(s) and service conditions 

(including test level and site and terrain and foundation conditions) for which 

acceptance is requested (preferably to be included as part of the test report and 

related documentary materials and supported by evaluations by the testing agency). 

A. Complete, accurate, and legible engineering drawings and specifications 

covering manufacture and installation of the feature(s), including material and 

dimensional tolerances and any required installation limitations or procedures. 

In addition to the drawings just cited, unless they meet the following criteria, 

a drawing or drawings suitable for reproducing by photo copying and that 

show sufficient details and dimensions to p,ermit one to confidently identified 

the feature for which acceptance is requested are to be supplied. Desirably, 

these drawings will be 8.5" x 11" (216 mm x 279 mm). However, I.S.O. A4 

or 8.5" x 14" (210 mm x 297 mm or 216 mm x 356 mm) will be accepted. 

Tbese drawings are intended for attachment to the acceptance letter, if issued, 

copies of which will be distributed to FHWA field offices. 

B. Complete description and chronology of any deviation(s) between the tested 

feature(s) and test installation conditions and the service design and installation 

conditions for which FHW A acceptance is sought, which would include the 

range in sizes or details of a feature for which tests of one, or at least less than 

all variations, are presented to show acceptability of the full rang. Alo.ng with 

this information, an independent assessment by a qualified organization, 

preferably the testing agency, of the significance these deviations might have 

on the in-service performance of the feature. Deviations to be evaluated will, 

of course, include differences between the test site terrain, which is to be 

described in detail, and expected service site terrains. 

3. The request for acceptance must identify any patent or proprietary rights held on 

the feature or elements of the feature for which acceptance is sought. 

4. Proprietary information submitted that the petitioner wishes the FHW A to treat as 

confidential should be so marked and physically separated from information on the 

conduct and the results of tests on the feature for which acceptance is requested, 

which the FHW A will make available for public inspection. Items that the FHW A 

will hold open for public inspection that the petitioner does not wish reproduced 

should be copyrighted. However, a non-copyrighted summary of test results 

should be included in the submission, along with the letter-sized drawings cited in 

. 2.A., which must not be copyrighted. 

19 
• 

APPENDIX C 

Estimating High-Speed Breakaway Performance from Low-Speed Test Results 

The following paraphrased and annotated excerpt from the discontinued FHWA Notice N 5040.20, 

"AASHTO Standard SpeCifications for Strucrural Supports for Highway Signs, Luminaires and 

Traffic Signals," dated July 14, 1976, presents formulas for estimating the high speed (60 mph or 

100 kmlh) breakaway performance of a signpost, luminaire support, or other breakaway device 

tested at low speed (20 mph or 35 kmlh). These formulas were developed under the FHW A 

srudy, "Safer Sign and Luminaire Supports." The srudy results are contained in reports 

FHWA-RD-76-32, -33, -34, and -35, dated from February to October 1976. 

From: 

V v 2 

(lIMV) H= _L (lIMV) + b (V __ L ) 

v

H 

L H v

H 

we obtain, in customary U.S. units [NCHRP Report 230 test speeds (29.3 to 88 fils)]: 

(lIMV) H = ~ (lIMV) L + b (78.2 ft / s) 

3 

or, in SI units [NCHRP Report 350 test speeds (9.72 to 28.78 mls)]: 

where: 

( lIMV) H = O. 35 (lIMV) L + b ( 2 4 • 3 B m / s ) 

t.MV = vehicle momenrum change 

= vehicle mass (M) x vehicle velocity change (V(L 0' H) - V x) 

(t.MV)L = measured vehicle momenrum change in the low speed test 

(t.MV)H = computed vehicle momenrum change at the higher speed 

V L = measured impact vehicle velocity during low speed test 

b = 

2 

1. 1M ( R 

p R 2 +0 2 

o 

V H = extrapolated vehicle velocity at the higher speed 

~ = mass of support 

Do = distance from support impact point to support c.m. 

R = radius of gyration of support about its c.m. 

This formula is considered acceptable for supports that break free with little or no bending in the 

support. It has not been tested and therefore should not be used with base bending (yielding) 

supports. 

21 
I , • 

APPENTI[X D 

Suggested Evaluation Factors 

passenger Compartment Intrusion 

I. Windshield intrusion 

a. No windshield contact 

b. Windshield contact, no damage 

c. Windshield contact, no intrusion 

d. Device embedded in windshield, no significant intrusion 

e. Partial intrusion into passenger compartment 

f. Complete intrusion into passenger compartment 

2. Body Panel Intrusion (Yes or No) 

Vebicle Control and Threat to Bystanders Of Otber Vebicles 

1. Physical loss of Control 

2. Loss of Windshield Visibility 

3. Perceived Threat to Otber Vehicles from Debris or Vebicle Trajectory 

4. Debris on Pavement 

5. Mass, Size, Shape of Significant Debris 

6. Trajectories ofVebicle and Significant Debris 

Vehicle and Device Condition 

1. Vehicle Damage 

a. None 

b. Minor scrapes, scratches, or dents 

c. Significant cosmetic dents 

d. Major dents to grill and body panels 

e. Major structural damage 

23 
2. Windshield Damage 

a. None 

b. Minor chip or crack 

c. Broken, no interference with visibility 

d. Broken and shattered, visibility restricted but remained intact 

e. Shattered, remained intact but partially dislodged 

f. Large portion removed 

g. Completely removed 

3. Device Damage 

a. None 

b. Superficial 

c. Substantial, but can be straightened 

d. Substantial, replacement parts needed for repair. 

e. Cannot be repaired 

24 

' .. 

• •