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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 11911 - 11920 of 16510
Interpretations Date
 search results table

ID: nht73-4.21

Open

DATE: 05/21/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Highway Aircraft Corporation

TITLE: FMVSR INTERPRETATION

TEXT: This is in reply to your letter of April 24, 1973, to Mr. Schneider asking for an interpretation that the Fascination vehicle your company proposes to manufacture is "an automobile." You state that you "are currently testing both a single wheel and a dual wheel arrangement on the front, and it is not clear yet which one will prevail."

If the final configuration of the Fascination were that of a four-wheeled vehicle it would be categorized as a "passenger car" under the Federal Motor Vehicle Safety Standards. Currently all three-wheeled vehicles are classified under our regulations as "motorcycles." Under a recent rule making proposal, a copy of which I enclose, the definition of a motorcycle with three wheels would be restricted to those lacking a full or partial enclosure for the driver, clearly excluding the Fascination. If the proposal is adopted, and you choose the three-wheel configuration for the Fascination, then the vehicle would probably be classified as a passenger car. It is possible that some adjustments would be made in the standards applied to three-wheeled or other lightweight vehicles, on petitions received from those interested.

ENC.

Highway Aircraft Corp.

April 24, 1973

Lawrence Schneider Office of Chief Counsel National Highway Traffic Safety Admin.

We are in final stages of development and testing on our new FASCINATION automobile. We have been in communication with Roger Compton and other members of the National Highway Traffic Safety Administration staff, and it has come to our attention that it is necessary for us to request a ruling as to the classification of our automobile. At least we feel it is an automobile; however, some of the regulations relating to three-wheel vehicles seem to confuse the issue.

We have no desire to side step any of the safety laws, which might be the case if our vehicle were called a motocycle. It has further come to our attention that several of the states have laws that classify a three-wheel vehicle as a motorcycle. It is therefore our desire to secure a ruling from your office that would clearly establish the FASCINATION as an automobile. This would make us subject to all the safety laws and would give us a sound basis upon which to approach the various states in which we will be licensing the car.

This is a four-passenger vehicle. The passenger compartment is 58" wide, the rear track width is 63", and the wheelbase is 130". The car will weigh something less than 2,000 pounds. We are currently testing both a single wheel and a dual wheel arrangement on the front, and it is not clear yet which one will prevail.

If any further details will be needed to clear up the situation, please contact us immediately. We will be waiting for your reply.

Doran Rhodes Assistant to the President

ID: nht73-4.22

Open

DATE: 05/23/73

FROM: AUTHOR UNAVAILABLE; Claude S. Brinegar; NHTSA

TO: National Motor Vehicle Safety Advisory Council

TITLE: FMVSS INTERPRETATION

TEXT: In response to the March 15 resolution of the National Motor Vehicle Safety Advisory Council urging removal of the legal barriers to the introduction of passive restraint systems, I can report that the Department has taken a major step in the direction the Council urges. The proposed test dummy regulation, published April 2, is intended to permit manufacturers to produce vehicles with passive restraint systems under either of the passive options available before passive restraints become mandatory. Upon adoption of the proposed regulation and of the corresponding amendment to Standard 208, the first barrier addressed in the Council's resolution will be removed.

The Council's second concern is with the seat belt installation laws of the States. It would be unfortunate if these laws interfere with the evaluation of fully passive restraint systems. The Department will take such steps as seem advisable to remove any legal obstruction to the manufacture and use of vehicles with fully passive systems. We expect to announce our position on this point shortly.

ID: nht73-4.23

Open

DATE: 05/30/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Volvo of America Corp.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of May 8, 1973, concerning the intent of Section S4.7 of the amendment of Motor Vehicle Safety Standard No. 201 proposed by the notice of September 25, 1970. Although we have recently issued a notice advising the public that we intend to issue a further proposal on this subject before adopting a final rule, we can provide a brief explanation of the intent of Section S4.7.

The principal portions of the "A" and "B" pillars to which S4.7 was directed, are those portions lying above the low line of the vehicle's window. However, the breadth of S4.7 is such that it would also include all contactable areas of the pillars lying below the window line.

You will have further opportunity to comment on the use of force distributing materials and response to the rulemaking of Standard 201.

Yours truly,

Volvo of America Corporation

May 8, 1973

Lawrence Schneider, Esq. General Counsel National Highway Traffic Safety Administration

Re: Request for clarification of Federal Motor Vehicle Safety Standard No. 201 49 CFR Part 571

Volvo of America Corporation hereby requests clarification of Federal Motor Vehicle Safety Standard No. 201 as it relates to the "A" and "B" pillars of a vehicle.

It is our understanding that the standard as currently in effect does not specify requirements for the "A" and "B" pillars. However, Docket No. 2-1, Notice 2 as published in the September 25, 1970 Federal Register (page 14936) proposed an upgrading of Standard 201 which would have required force-distributing material on these surfaces. Although this proposed amendment has never been adopted, it is the best indication that we have to date of N.H.T.S.A.'s thinking in regard to requirements for the "A" and "B" pillars and we are using the information for planning purposes.

It is in regard to paragraph S4.7. of Docket No. 2-1; Notice 3 that we require clarification as follows:

S4.7. Pillars.

(quote)

The contactable surface of each "A" and "B" pillar, with the doors and windows closed, shall -

(a) Be covered with force-distributing material having a thickness of at least 0.50 inch; and

(b) With the force-distributing material removed, have no rigid contactable edge with a radius less than 0.50 inch.

2

Paragraph S3. "Definitions" of Docket No. 2-1; Notice 3 defines the term "contactable" as follows:

"Contactable" means able to be contacted from any direction by a 6.5-inch diameter rigid head form under a 90-pound static force.

Question:

Is it N.H.T.S.A's intention in paragraph S4.7. of the proposal to require that the "A" and "B" pillars be covered with force-distributing material for their entire length, i.e. from the roof to the floor, providing that the entire length is "contactable" as defined in paragraph S3.?

Your consideration of and a reply to our inquiry is requested as soon as practical. Thank you in advance for your consideration.

Very truly yours,

Donald W. Taylor Engineering Liason Representative

cc: D. Jarman L. Larsen G. Nield C. Simerlein E. Skarin

ID: nht73-4.24

Open

DATE: 06/01/73

FROM: AUTHOR UNAVAILABLE; J. E. Wilson; NHTSA

TO: General Motors Corporation

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of May 11, 1973, asking for confirmation of your interpretation of paragraph S7.9 of Standard No. 105a in terms of General Motors' air vacuum power brake.

Your interpretation is correct. Your system with its "two separate and independent energy sources in the power head . . . is equivalent to two entirely duplicate systems", and disconnection of one source at a time would be the correct test procedure under S7.9, provided the requirements of S5.1.3 are satisfactorily met under both conditions.

ID: nht73-4.25

Open

DATE: 06/01/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Grove Manufacturing Company

TITLE: FMVSR INTERPRETATION

TEXT: This is in reply to your letter of April 23, 1973, requesting our confirmation of certain issues discussed by you, and Michael Peskoe and David Fay of NHTSA, in a meeting in Mr. Peskoe's office on April 19, 1973.

It is correct that the NHTSA does not presently employ safety inspectors to inspect vehicles in service. Such inspections are made by inspectors of the Bureau of Motor Carrier Safety in the Federal Highway Administration, and it is true that their primary interest is the enforcement of the Bureau of Motor Carrier Safety regulations (49 CFR Parts 301-398). But if these investigators note violations of NHTSA regulations, the information will be forwarded to NHTSA and appropriate action will be taken.

It is correct that components of a vehicle service may be added, removed, or relocated at the discretion of a vehicle owner without violating NHTSA regulations. However, gross vehicle and axle weight ratings established by the vehicle manufacturer must be based on configurations of the vehicle which the manufacturer expects will be utilized in service. It is also correct that the weight imposed on each axle should not exceed the certified weight rating for each axle, but may be less than the certified weight rating.

Finally, it is correct that gross axle weight ratings may be established with a view towards the weight limitations of States in which the vehicle will be used.

Gross axle and vehicle weight ratings, under NHTSA regulations, are manufacturers' figures, and may be set at any level as long as the figures are consistent with the limitations specified in the NHTSA certification regulations. However, the weight ratings must also, of course, be consistent with the vehicle's load-carrying capacity.

ID: nht73-4.26

Open

DATE: 06/08/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Truck Equipment & Body Distributors Association

TITLE: FMVSR INTERPRETATION

TEXT: This is in reply to your letter of May 11, 1973, in which you ask about the certification responsibilities for consecutive manufacturers of certain multi-stage vehicles that are intended for use by utilities. The facts as you present them are that a chassis-cab is purchased by a customer and delivered to a utility distributor, who installs a sub-base and a digger-derrick. The truck is then sent to a body-builder who installs a body consisting essentially of storage compartments, which are used to carry personal tools. The compartments are installed to the floor installed by the utility distributor. The unit is then returned to the utility distributor, who installs clearance and other lamps, reflectors, and other accessories, and hooks up hydraulic lines. Smaller vehicles are described as being manufactured in essentially the same manner.

It appears to us that the manufacturing operations you have described fit quite readily into the manufacturing categories established by Parts 567 and 568. The utility equipment distributor is an intermediate manufacturer; he performs manufacturing operations, but does not complete the vehicle, as further manufacturing operations, the installation of the body, are clearly contemplated for the vehicle to perform its intended function. The body-builder is the final-stage manufacturer. When he completes his work the vehicle is ready to perform its intended function, except for the addition of the lighting equipment and the other operations performed by the utility equipment distributor. These latter operations appear to involve "readily-attachable components" and if so the party performing them would not be a final-stage manufacturer.

The certification requirements do not operate differently because; in the case you describe, the utility equipment distributor performs operations on the vehicle at two separate times (installing the derrick, and later the lighting). His responsibilities each time are governed by the operation he then performs. However, inasmuch as the utility distributor appears to perform much of the heavy manufacturing, and because he is also the last person to modify the vehicle, he may wish to assume the responsibility for certification under section 568.7(b), in order that he may affix his name as the manufacturer to the certification label.

ID: nht73-4.27

Open

DATE: 06/14/73

FROM: AUTOR UNAVAILABLE; Lawrence R. Schneider; NHTSA

TO: Hayden; Smith; Ford & Hays

TITLE: FMVSR INTERPRETATION

TEXT: This is in reply to your letter of May 21, 1973, forwarding to us your second attempt to compose a letter that will conform to Part 577, Defect Notification, for a defect involving the lighting in boat trailers manufactured by V/M Custom Boat Trailers. We responded to an earlier letter from you on May 16, 1973.

Section 577.6 prohibits the making of any statement in the notification that either states or implies that the problem discussed is not a defect, or that it does not relate to motor vehicle safety. As we indicated to you in our letter of May 16, we considered your statement, "The defect on those trailers . . . does not affect the mechanical operation of said trailer except insofar as the lighting is inefficient as installed according to the U.S. Department of Transportation" to be prohibited by section 577.6. The additional phrase, "This statement is one of fact only and is not intended to be a disclaimer which is prohibited by section 577.6 of the Act", which you have now inserted, does not remedy that deficiency. The regulation states that such a statement may not be made at all; it does not allow it to be made and denied.

Our objection to the statement is with your description of the defect as an "inefficiency" according to the Department of Transportation. This safety related defect results, rather, from violations of law which require your client's products to meet minimim safe levels of performance. We recommend that rather than attempt once again to rewrite your statement, and risk violation of the regulation, you delete it entirely, and send the notification to purchasers forthwith.

In other respects your notification appears to conform to Part 577.

ID: nht73-4.28

Open

DATE: 06/26/73

FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA

TO: Peterbilt Motor Truck Co.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of May 22, 1973, in which you state you are a distributor of Peterbilt trucks and ask whether certain operations you perform subject you to Federal requirements. These operations are modifications to air brake systems and the installation of used bodies on new truck chassis.

A company whose business includes the installation of used bodies on new truck chassis is a manufacturer under the National Traffic and Motor Vehicle Safety Act and, as such, has certain responsibilities under the Act and regulations issued by this agency. In response to your question regarding registration, you are required pursuant to NHTSA "Manufacturers' Identification" regulations (49 CFR Part 566) to submit to the agency information regarding the manufacturing operations of your company and the types of vehicles that it manufactures.

A manufacturer is also required, pursuant to NHTSA "Certification" regulations (49 CFR Part 567, 568) to ascertain and certify the conformity of each vehicle he manufacturers to applicable motor vehicle safety standards. Under these regulations the person who completes the vehicles (the "final-stage manufacturer") is required to affix to the vehicle a label that contains the certification that the vehicle conforms to applicable standards, as well as other information. Our experience has been that most manufacturers who install truck bodies onto new chassis are final-stage manufacturers, who must affix this label. Persons whose manufacturing operations precede that of the final-stage manufacturer are required to provide documentation with the vehicle that indicates what steps will be necessary in order to bring the vehicle into conformity with applicable standards.

You also ask if there are requirements for the making of periodic reports. NHTSA "Defect Reports" regulations (49 CFR @ 573.5(b)) do require manufacturers to furnish the NHTSA with quarterly production figures.

The other operation you describe is the modification of vehicle air brake systems, including changes in valves, lines, spring brakes, air tanks, etc. If you merely modify an existing air brake system, there are presently no certification or reporting requirements applicable to you. The NHTSA has just issued certification requirements for persons who alter completed vehicles, and depending on the extent of the modification you perform, these requirements may apply to you. They are effective February 1, 1974. All trucks manufactured after September 1, 1974, that are manufactured with air brakes will be required to conform to requirements specified in Federal Motor Vehicle Safety Standard No. 121. The law would not allow you to modify the air brake system of any truck manufactured on or after that date, before the sale of the truck to a purchaser for a purpose other than resale (a user), if the modification you performed would cause the vehicle to no longer comply with the standard.

I have only summarized the requirements that, based on the facts you have provided, would be applicable to you. Your responsibilities are stated specifically in the regulations we have referred to, and you may obtain copies of these requirements as indicated on the enclosed, "Where to Obtain Motor Vehicle Safety Standards and Regulations."

ENC.

May 22, 1973

Mr. Larry Schneider, Chief Counsel NHTSA

We are distributors of Peterbilt trucks and, in addition to the sales and services of Peterbilt trucks, we operate a service and repair shop which, in addition to the repair of used trucks, we intend to perform, occasionally, the following services both on new Peterbilts that we sell and other makes of new trucks sold by other dealers.

1) Modifications to air brake systems including, but not limited to, changes in valves, lines, spring brakes, air tanks, etc. $2) Removal of bodies from used trucks and installation of these bodies on new chassis.

Services described in 1) and 2) above are done on order to us from the owners of vehicles involved.

Can you advise us regarding our responibilities in the following areas.

a) Are we required to register? If yes, how do we do this?

b) Are we required to make periodic reports? If so, to whom and when?

c) Are we required to "certify" what we do? If so, how, when, to whom, etc.?

Thank you for your assistance.

ENGS MOTOR TRUCK CO.

R. W. Harvey

ID: nht73-4.29

Open

DATE: 06/26/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: The Southern Connecticut Gas Co.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter to Mr. David Snyder of this agency regarding information on tests performed on recapped tires, specifically, data comparing failure characteristics of retreaded tires with those of new tires.

The NHTSA does not presently have test data of the specific type you request. We are attempting to obtain that data through research contracts with outside parties, and results of that research, when they are received, will be placed in the rulemaking docket regarding retreaded tires. Other test data for retreaded tires have been placed in this docket (Docket No. 1-8), which is open for public inspection at NHTSA headquarters, 400 7th Street, S.W., Washington, D.C.

Certain studies have been conducted on the failure rates of tires, and some comparative data have been compiled. One volume with which we are familiar summarizes studies which provided information of this type. It is, Brenner and Harvey, Tire Use Survey, The Physical Condition, Use and Performance of Passenger Car Tires in the United States of America, NBS Technical Note 528, (National Bureau of Standards U.S. Department of Commerce). Copies are available from the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. It should be ordered by SD Catalog No. C13.46:528, prepaid, at 60 cents a copy.

Yours Truly

May 29, 1973

David Synder DOT/NHT SA

Mr. Litant suggested I write to you for information on tests performed on recapped tires.

(Illegible Words) interested in the safety-failure characteristics of recaps vs. standard tread(Illegible Word) tires. Any information in this area would be appreciated. The size of your sampling is pertinent and this figure would be helpful.

I wish to thank you in advance for your cooperation.

James W. Livsey Supervisor, Claims, Safety & Security

ID: nht73-4.3

Open

DATE: 04/05/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Michelin Tire Corporation

TITLE: FMVSR INTERPRETATION

TEXT: This is to confirm your conversation with Mr. Schmeltzer of this office in which he informed you that the Regrooved Tire regulation (49 CFR Part 569) does not prohibit the use of branding to meet its labeling requirements. The language in section 569.9 which requires the word "regroovable" to be "molded into or onto" tires designed for regrooving was intended to include any method, such as branding, that would leave the required information sunk into or raised upon the tire surface.

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.