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NHTSA Interpretation File Search

Overview

NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies. 

Understanding NHTSA’s Online Interpretation Files

NHTSA makes its letters of interpretation available to the public on this webpage. 

An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.

  • Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
  • Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
  • The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
  • Some combination of the above, or other, factors.

Searching NHTSA’s Online Interpretation Files

Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.

Single word search

 Example: car
 Result: Any document containing that word.

Multiple word search

 Example: car seat requirements
 Result: Any document containing any of these words.

Connector word search

 Example: car AND seat AND requirements
 Result: Any document containing all of these words.

 Note: Search operators such as AND or OR must be in all capital letters.

Phrase in double quotes

 Example: "headlamp function"
 Result: Any document with that phrase.

Conjunctive search

Example: functionally AND minima
Result: Any document with both of those words.

Wildcard

Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).

Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).

Not

Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”

Complex searches

You can combine search operators to write more targeted searches.

Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”). 

Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”

Search Tool

NHTSA's Interpretation Files Search



Displaying 13311 - 13320 of 16510
Interpretations Date
 search results table

ID: nht70-2.17

Open

DATE: 07/21/70

FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA

TO: Mr. James Deifster

TITLE: FMVSS INTERPRETATION

TEXT: Your request for information on requirements for camper manufacturers has been referred to this office for reply. The information we have received states that you are a manufacturer of campers, selling them to dealers, and also installing them on trucks.

The National Traffic and Motor Vehicle Safety Act of 1966, 15 U.S.C. @(Illegible Word) et seq., (copy enclosed) requires manufacturers of motor vehicles and motor vehicle equipment to manufacture their products so that they comply, and to "certify" that they comply, with applicable Federal motor vehicle safety standards. Camper bodies for both slide-in and chassis-mount camper installation are items of motor vehicle equipment and must comply with Federal Motor Vehicle Safety Standard No. 205, will be certified by their manufacturer that they comply with the standard. I enclose a copy of the standard and the regulations governing certification for your information, Standard No. 205 incorporates by reference the USA Standard(Illegible Words) "Safety Code for Safety Glazing Materials for Glazing Motor Vehicles Operating on Land Highways." This USAS standard can be obtained for a small fee from the USA Standards Institute, 10 East 40th Street, New York, N.Y. 10016.

If you install slide-in camper bodies on pick-up trucks only, you are not subject to additional requirements. However, if you install chassis-mount camper bodies onto truck chassis, you are in addition to being a manufacturer of motor vehicle equipment, a manufacturer of motor vehicles, specifically, multipurpose passenger vehicles, and are required to comply with regulations and standards applicable to manufacturers of multipurpose passenger vehicles. Copies of these requirements, which have been promulgated pursuant to the National Traffic and Motor Vehicle Safety Act of 1966 and codified in Chapter 5 (formerly Chapter 3) of Title 49, Code of Federal Regulations, are available from the Government Printing Office, Washington, D. C. 20402, under the title Federal Motor Vehicle Safety Standards. The price is $ 8.00, which includes a subscription for one year to receive copies of amendments.

Because of the relative length and complexity of these requirements, it is difficult to summarize them for you here. Many trade associations have familiarized themselves with them in order to assist their membership in complying with them. If after studying the materials you have specific questions concerning their application to you, we will be pleased to answer them.

I have also enclosed a mailing list questionnaire. If you will complete and return it to the address indicated thereon, you will receive future notices pertaining to those areas you have marked.

ENCLOSURES

ID: nht70-2.18

Open

DATE: 08/11/70

FROM: AUTHOR UNAVAILABLE; Rodolfo A. Diaz; NHTSA

TO: University of Michigan Law School

TITLE: FMVSR INTERPRETATION

TEXT: Your letter of June 22, 1970, concerning the Cyromatic Safety Control, together with a copy of the July 1, 1970, reply sent by Mr.(Illegible Word) Weinberger, Chairman of the Federal Trade Commission, has been referred to my office for reply.

The National Highway Safety Bureau does not have the facilities for testing or investigating specific devices or designs. However, the(Illegible Word) on Winter(Illegible Words) of the National Safety Council has completed an(Illegible Words) of the type mentioned in your letter. I am enclosing for your information a copy of the National Safety Council report on this evaluation.

In brief, the conclusion of the Committee were that there were no significant differences in the performance of the test vehicles whether the device was stated and operable, rendered inoperable, or removed from the vehicles. The only test results considered significant involved a high(Illegible Words) on dry pavement where the device increased(Illegible Words) of the test vehicles by a substantial amount, thus effecting their handling performance adversely.

It is felt that sufficient date is available in the National Safety Council Committee on(Illegible Words) evaluation to warrant investigation on the(Illegible Words) on the Federal Trade Commission, concerning possible misleading advertising on the part of manufacturers of this type of device. Consequently, we have contacted, Mr. Weinberger directly concerning the(Illegible Words).

ID: nht70-2.19

Open

DATE: 05/26/70

FROM: AUTHOR UNAVAILABLE; Rodolfo A. Diaz; NHTSA

TO: Oliver and Sons Inc.

TITLE: FMVSR INTERPRETATION

TEXT: This is in reply to your letter of February 25, 1970, to the National Highway Safety Bureau, that has been referred to this office, in which you enclose certification labels you are(Illegible Word) using to fulfill the requirement of Section 118 of the National Traffic and Motor Vehicle Safety Act of 1966. Your letter did not reach me until now, and I apologize for delay in responding.

You really did not comply enough information for us to properly evaluate your situation. You state that you are a distributor of truck bodies, but you as not say whether you install the bodies yourself.

If you do, in fact assemble a truck body to a chassis-cab, you are considered to be a manufacturer under the Act. As the statutory manufacturer of the vehicle, you are required to certify that the completed assemblage meets all the standards in effect on the date of manufacture of the chassis-cab.

The primary responsibility for conformity of the chassis-cab, however, falls on the manufacturer of it (generally a major automotive manufacturer and under the regulations, that manufacturer is required to affix a label to the chassis-cab listing the standards to which it conforms. Under Section 108(b)(2) of the Act, such a certification protects subsequent persons in the chain of distribution from liability for nonconformity of which they have no knowledge. Thus, they body assembler to directly responsible for comformity of the finished vehicle with (1) any applicable standards to which the chassis-cab manufacturer was not certified, and (2) any other standards conformity to which is affected by what the(Illegible Word) door to the vehicle, his certification must be for all standards, in the language specified in the certification regulations;(Illegible Word) he can rely on the chassis-cab manufacturer's label for the standard it covers, as(Illegible Word) as he does not know of any nonconformity.

The(Illegible Word) being used on your labels does not fulfill the requirements of the certification regulations that becomes effective as to(Illegible Word)(Illegible Word) after August 11, 1969 (49 C.F.R. 367).

A truck body is not a motor vehicle within the meaning of the Act and the regulations, and therefore is not covered by the present certification regulations. Although it is motor vehicle equipment such equipment is only required by the Act to be certified where there is a safety standard applicable to it or to equipment, such as glazing, that is part of it. When the body is assembled to the chassis, the completed vehicle must be certified in accordance with the certification regulations, as explained above.

It is not clear what you mean by the phrase "modification label." You may be referring to Section 367.6 of the certification regulations, which is intended for the use of distributors who alter a previously certified vehicle that has been completed by another manufacturer. In any event, the nonenclosure does not meet the requirements of the section.

We are enclosing the following publications:

The National Traffic and Motor Vehicle Safety Act of 1966.

The Certification Regulations (49 C.F.R. Part 367).

A sample certification label.

A publication having to do with the availability of the latest edition of Federal Motor Vehicle Safety Standards and Regulations.

Mailing List Questionnaire.

A new proposal having to do with vehicles manufactured in two or more stages (35 F.R. 4639 through 4641).

Please cobalt a copy of your label that has been revised to fulfill the requirements.

We trust this will clarify the situation for you. We will be pleased to answer any additional questions that you might have.

ENCLOSURES

ID: nht70-2.2

Open

DATE: 04/09/70

FROM: AUTHOR UNAVAILABLE; R. A. Diaz; NHTSA

TO: Toyo Kogyo Company, Ltd.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of March 2, 1979, to Mr. Clue D. Ferguson, concerning an interpretation of Federal Motor Vehicle Safety Standard No. 111.

In your letter you indicated that the mirror, as mounted in the vehicle, cannot be hit at a 45 degrees angle by a 6.5 inch head form because of the geometric arrangement in your automobile. In this case we would accept the maximum(Illegible Words) Form. We must point out, however, that the test also includes any other angle from the one you describe down to a 45 degrees angle under this horizontal(Illegible Word) S3.1.2.3 of standard No. 111).

Please note that this interpretation is intended to provide(Illegible Line)(Illegible Line)(Illegible Words) a given item of equipment meets applicable Federal motor vehicle safety standards and he must certify to that effect.

ID: nht70-2.20

Open

DATE: 08/11/70

FROM: AUTHOR UNAVAILABLE; Francis Armstrong; NHTSA

TO: Bruce Duncan Company Inc.

TITLE: FMVSR INTERPRETATION

TEXT: This is in reply to your letter of July 20, 1970, in which you request a ruling as to whether the Honda ATV is subject to the Federal Motor Vehicle Safety Standards and Regulations promulgated as a result of the National Traffic and Motor Vehicle Safety Act of 1966 (the Act).

The descriptive literature furnished with your letter states that, "the machine looks to be street legal," and shows that the vehicle has lighting equipment. Therefore, the Honds ATV, as described, appears to be a "motor vehicle" within the meaning of Section 102(3) of the Act, and specifically a "motorcycle" as defined in 49 CFR 571.3(b). Motorcycle means a motor vehicle with motive power having a seat or saddle for the use of the rider and designed to travel on not more than three wheels in contact with the ground.

We trust this will clarify the situation for you. We will be pleased to answer any additional questions that you might have.

ID: nht70-2.21

Open

DATE: 08/11/70

FROM: AUTHOR UNAVAILABLE; Rodolfo A. Diaz; NHTSA

TO: Recreational Vehicle Institute Inc.

TITLE: FMVSR INTERPRETATION

TEXT: This is in response to your letter of July 23, 1970, in which you asked for the Bureau's interpretation of the phrase, "designated seating position that includes the windshield header within the head impact area."

The phrases "designated seating position" and "head impact area" are both defined in the general Definitions section of the standards, 49 CFR 571.3. The remaining substantive phrase, "windshield header," is not defined in the standards. It is intended to refer to the portion of the interior of the vehicle immediately above the top of the windshield, usually but not necessarily a strip of molding separating the glass from the interior roof.

ID: nht70-2.22

Open

DATE: 08/26/70

FROM: AUTHOR UNAVAILABLE; R. A. Diaz; NHTSA

TO: International Manufacturing Company

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of August 12 to Mr. Toms requesting an interpretation of Federal Motor Vehicle Safety Standard No. 211 (Wheel Discs, Wheel Nuts, and Hub Caps).

This standard does not prohibit projections per see on wheel equipment items; it prohibits winged projections. Thus there is no limitation on how far a cylindrical projection, for example, may extend beyond the outer edge of the tire. On the other hand, any winged projection is prohibited, even if recessed.

I hope this answers your question.

ID: nht70-2.23

Open

DATE: 08/27/70

FROM: AUTHOR UNAVAILABLE; R.A. Diaz; NHTSA

TO: Lanes Auto Sales

TITLE: FMVSR INTERPRETATION

TEXT: This is in reply to your letter in which you asked about the requirements of the Federal motor vehicle safety standards in regard to combination of new and used components.

In your first group of questions, you asked whether you could put a used fifth wheel or a used dump body on a new truck. The answer is yes, but the finished vehicle must conforms to all the motor vehicle safety standards applicable to that type of vehicle at the time it is completed. At this time, probably the only standard that would require action on your part would be Standard 108 on lighting systems, Other Standards applicable to trucks have been proposed, however, which will require you to take further action or observe certain limits in the future, and you should take stops to keep informed of the applicable requirements. I an enclosing a copy of current standards and regulations, and if you will fill out the enclosed form you will be put on a smailing list for notices that apply to your operations.

Also in reference to this group of questions, the requirements on persons who complete vehicles are the same whether they own the trucks or do the work for a dealer or for the ultimate user.

You also asked about building "a trailer out of new frames using old axles, brakes, and wheels, with parts made before 1966". In such a case, the vehicle that you build must conform to current applicable safety standards, unless it is a repair job done on a presently registered used vehicle that will continue to be registered as a used vehicle. Whether you call the trailer a used or new one depends on the State requirements - you may do whatever is permitted by your State licensing authorities in this regard.

Finally, you asked whether, when you build a trailer with used wheels, axles, bearings, brake drums, and springs, you may put on used tires. At present you certainly may do so, since there is no Federal safety standard for truck tires. It is probable that one will be issued in the future, however, and if and when such a standard becomes effective, any tires you use must meet the requirements of that standard.

Please let us know if we can be of further assistance.

Enclosures

ID: nht70-2.24

Open

DATE: 09/03/70

FROM: AUTHOR UNAVAILABLE; Douglas W. Toms; NHTSA

TO: General Motors Corporation

TITLE: FMVSR INTERPRETATION

TEXT: On August 13, 1970, you petitioned, on behalf of General Motors Corporation, for reconsideration of the amendment of 49 CFR 571.3, published on July 14, 1970 (35 F. R. 11242), which established a definition of "fixed collision barrier". The views presented in your petition have been carefully considered. For the reasons stated below, your petition is denied.

You argued that the phrase "absorb no significant portion of the vehicle's Kinetic energy" was subjective, and therefore not in accord with the statutory requirement that standards be stated in objective terms. This argument is without merit. It appears to be based on the misconception that the purpose of the definition is to describe, or prescribe standards for, a manufacturer's test barrier, as evidenced by your statement that it "gives manufacturer no guidelines for determing whether or not he has built a barrier which complies with the definition." The Bureau does not intend that manufacturers should build barriers to "comply with the definition." As stated in the notice,

"this is not intended to be a description of an actual test barrier. It is a device used in various standards to establish required quantitative performance levels of a vehicle in a crash situation, and means simply that the vehicle must meet the requirement no matter how small an amount of energy is absorbed by the barrier."

Far from being subjective, the definition is mathematically precise. As the energy absorption of the barrier approaches zero as a limit, the performance characteristic being measured must remain at or above the minimum stated in the standard.

From a practical standpoint, the definition is an important aid in regulation, and is a help to all parties in that a potential source of controversy concerning compliance with the standards is removed. It simply means that when the Bureau crash-tests a vehicle, the vehicle must meet the requirement no matter what the energy-absorption properties of the barrier, and therefore there is no room for argument on the differing properties of the Bureau's and the manufacturer's test barriers. The purpose of the standards is to regulate vehicles and equipment, not test barriers; manufacturers may use whatever barriers or tests they wish to ensure compliance It is a reasonably simple matter to erect a barrier that absorbs only a minute fraction of an impacting vehicle's energy. A conscientious manufacturer should therefore have no difficulty in determining whether a particular design will meet a standard.

Your petition also argued that the definition was impracticable because

"there is no known method of measuring the amount of energy absorbed by a barrier. Therefore, there is no way that the manufacturer could even attempt to determine whether or not his barrier complied with the definition, and, more importantly, whether or not his vehicle when tested complied with the performance requirements of the standards."

The energy absorption of a barrier is a direct function of the movement of the barrier during the impact. To be sure, there are other properties, such as its effective mass and elasticity, that also are factors in energy absorption. But it is clear that as the barrier movement approaches zero, the energy absorption also approaches zero; and the barrier movement can be measured, as you indicated by your recommendation that a specified amount of movement be allowed. In all cases where the vehicle has a tangible margin of safety performance over the required minimum, therefor, a manufacturer will have no difficulty in determining that his vehicle complies,

If our standards "allowed" barrier movement, it would be far more difficult to establish conclusively that a given vehicle did not meet the standard, since it would always be open to the manufacturer to argue that the Bureau's barrier did not move as far, and consequently did not absorb as much energy, as the standard allowed. To the extent that there may be a small degree of uncertainty as to the variance is the vehicle test performance caused by the variance of a barrier from zero absorption, that uncertainty must rest with the manufacturer, who is free to design into his vehicles whatever margin of performance he desires.

This matter was thoroughly considered by the Bureau, and the opinions of knowledgeable members of the public were sought and carefully evaluated. For these reasons, your petition for reconsideration must be denied.

We appreciate your cooperation in the field of motor vehicle safety.

ID: nht75-1.31

Open

DATE: 06/10/75

FROM: AUTHOR UNAVAILABLE; R. L. Carter; NHTSA

TO: Mercedes-Benz

TITLE: FMVSS INTERPRETATION

TEXT: Please forgive the delay in responding to your letter of December 12, 1974, requesting an interpretation of the definition of "permanently attached end fitting" appearing in Federal Motor Vehicle Safety Standard No. 106-74, Brake Hoses.

You have described a process of heat shrinking plastic vacuum booster hose over short corrugated metal connecting tubes, the ends of which are flared to retain threaded hex fittings. You have submitted sample hose assemblies and requested confirmation of your interpretation that the end fittings are permanently attached. While these fittings may meet the common understanding of the words "permanently attached," Standard No. 106-74 defines "Permanently attached end fitting" as:

an end fitting that is attached by deformation of the fitting about the hose by crimping or swaging, or an end fitting that is attached by use of a sacrificial sleeve or ferrule that requires replacement each time a hose assembly is rebuilt.

Deformation of the hose about the fitting by heat shrinking is not "deformation of the fitting about the hose by crimping or swaging." The latter part of the definition is inapplicable because the assemblies are not subject to being rebuilt. Therefore, to classify these end fittings as permanently attached would require an amendment of the standard. Such an amendment is being considered.

Your January 7, 1975, petition for reconsideration, requesting exclusion of the above described vacuum hose from the coverage of Standard No. 106-74, was received more than 30 days after the most recent amendment of the definition of "brake hose". Therefore, it has been treated as a petition for rulemaking. The Standard defines "brake hose" as:

a flexible conduit manufactured for use in a brake system to transmit or contain the fluid pressure or vacuum used to apply force to a vehicle's brakes.

The conduit between the vacuum booster and vacuum pump in your brake booster circuit clearly falls within this definition, and hence is subject to the Standard's requirements. The NHTSA has concluded that, because of its flexibility, this hose is exposed to the same hazards as the more traditional types of vacuum brake hose and so should be subject to the same performance requirements. Accordingly, your petition to amend the definition is denied. The conduit between the vacuum pump and the intake manifold, however, falls outside the definition of "brake hose" because, as described by Mr. Craig Jones in a conversation with Mr. Howard Dugoff of this agency on March 17, 1975, the booster system produces full vacuum even when this conduit fails. Therefore, this conduit need not comply with the requirements of Standard No. 106-74.

Sincerely,

ATTACH.

MERCEDES-BENZ OF NORTH AMERICA, INC.

December 12, 1974

Office of Chief Counsel National Highway Traffic Safety Administration

Subject: Brake Hoses

Gentlemen:

Federal Motor Vehicle Safety Standard 106; Brake Hoses, defines under Section S4 a "permanently attached end fitting" as being a fitting that is attached by deformation of the fitting about the hose by crimping or swaging or an end fitting that is attached by use of a sacrificial sleeve or ferrule that requires replacement each time a hose assembly is rebuilt.

Vacuum booster circuit conduit can be constructed with materials and techniques so as to satisfy, what we believe to be, the intent of this definition. Specifically, thermoset plastic materials can be heat shrunk over corrugated connections at end fittings and mid-circuit devices such as check valves. Additionally, threaded hex fittings can be secured to metal end pipes by means of flaring. These construction techniques not only provide satisfactory performance but result in an assembly that cannot be disassembled without the disstruction of one or all of the various components. Examples of these construction techniques have been forwarded to the Docket Room.

These assemblies as used on Mercedes-Benz vehicles are completely and finally assembled by our suppliers. Installation of these assemblies into our vehicles entails only the threading of the fittings into the various parts of the vacuum cricuit. There is no final construction of these hose assemblies in our manufacturing facilities. Additionally, these assemblies are offered for spare parts usage only as complete assemblies.

We hereby request clarification as to whether or not this type of vacuum conduit assembly construction satisfies the intent of the definition of permanently attached end fittings as used in this Standard and thereby permit banded identification of the complete assembly rather than a separate identification of each component.

Should you require additional information or material to clarify this request, do not hesitate in contacting this office.

Very truly yours,

Heinz W. Gerth Assistant Vice President Engineering

MERCEDES-BENZ OF NORTH AMERICA, INC.

January 7, 1975

Office of The Chief Council National Highway Traffic Safety Administration Subject: Petition for Reconsideration FMVSS 106, Brake Hose

Gentlemen:

Pursuant to discussions with Mr. Driver in Washington on July 26, 1974 and with Mr. Dugoff on November 4, 1974 during his visit to Germany, we would like to restate our position that the flexible vacuum conduit used in Mercedes-Benz passenger vehicles in the brake boost circuit does not fall within the definition of brake hose as outlined in Standard 106.

While this particular conduit may not satisfy the hose flexibility requirements of paragraphs S9.2.2, S9.2.3, S9.2.7 and S9.2.10, it does offer the important advantages of being resistant to high temperature and ageing.

Additionally, the installation in Mercedes-Benz vehicles is such that it is subject to very little vibration between the intake manifold and booster. The material was specifically chosen because its limited flexibility permits safer, simpler installation requiring fewer mounting brackets. The complete assembly, when installed, is still sufficiently rigid so as to prevent any abrasion, and in appearance is similar to tubing so that a mechanic will not be tempted to push it aside to gain more workspace.

A sample of this assembly has been forwarded to the Docket Section for review. Should you request additional material or information for this Petition for Reconsideration, please do not hesitate in contacting this office.

Very truly yours,

Heinz W. Gerth Assistant Vice President Engineering

Request an Interpretation

You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:

The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590

If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.

Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.