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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 13241 - 13250 of 16510
Interpretations Date
 search results table

ID: nht69-2.45

Open

DATE: 12/11/69

FROM: AUTHOR UNAVAILABLE; Robert Brenner; NHTSA

TO: American Motors Corporation

COPYEE: CLAYBROOK; BOAZ; FULMER; NIELD; ARMSTRONG

TITLE: FMVSR INTERPRETATION

TEXT: We have received your submittal of consumer information in response to the requirements of 49 CFR Part 375. That regulation requires that manufacturers submit their information to the Administrator 30 days in advance of the time it is made available to prospective purchasers. Since we have not required that this advance submittal be in the same form as that given to prospective purchasers, the following comments are only advisory in nature. There are several respects, however, in which your information, if supplied in this form to prospective or actual purchasers, would not satisfy the requirements of the regulations.

1. The Stopping Distance information is presented as a "range of stopping distances," both in numerical and graphical form. The regulations clearly require a single stopping distance figure to be provided for a given group, that can be met or exceeded by all vehicles in the group. We do not know, and consumers surely would not know, the significance of the lower figure given. Even if it were clear, the provision of such additional, non-required information in close proximity to the required data would cause confusion in attempting to compare figures between various makes--the main purpose of the information.

2. The provision of four sets of data in respect to partial failure of the braking system, for "fronts operative" and "rears operative," and for lightly-loaded and maximum-loaded vehicles, is not in accordance with the regulation requirement that information be provided for the "most adverse combination" of weights and system failures. As stated in item 1. above, the inserting of this additional information, self-serving in every case since only the worst element should be included, would make comparisons difficult and be unfair to competing manufacturers who followed the regulations strictly.

3. The form of the Stopping Distance information would fail to satisfy the requirement that the information be presented "in effentially the form illustrated in Figure 1" of 49 CFR @ 375.101. In particular, we refer to the placing of two columns side by side instead of the single-axis graph depicted in that figure, and the inclusion of other varying between the required statements and warnings and the information itself. "The reference to shorter stopping distance with wheel lock-up and without restricting pedal effort, between the required information and the graphs, is especially objectionable, since the safety advantages of avoiding wheel skid were a particular concern in developing this regulation. Although the regulation do not prohibit the provision of other then required information in a Consumer Information booklet, they do require that it be connected in such a manner that the required information, both taxtual and cumulative, is presented in "essentially the form illustrated." 4. The Tire Reserve Load section of the regulations requires that "the table that is provided for a specific vehicle shall contain only information that is applicable to that vehicle." This requirement prohibits a large, all-purpose chart such as yours, with information for many vehicle included on it, at least as far as the information given to the actual purchaser of a vehicle is concerned. More generally, the information is not presented in "essentially the form illustrated in Figure 1" of 49 CFR @ 375.102.

5. The large, all-inclusive bar graph on Accleration and(Illegible Word) Ability does not present the information in "essentially the form illustrated in Figure 1" or 49 CFR @ 375.106, or recuired.

We will be glad to answer any questions that you may have with respect to the requirements of these or other motor vehicle safety regulations and standards.

ID: nht69-2.46

Open

DATE: 09/25/69

FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA

TO: Toyota Motor Company Ltd.

TITLE: FMVSR INTERPRETATION

TEXT: This is to confirm the information given to you by Mr. Richard Dyson of this office by telephone on September 19, 1969, concerning the consumer information regulations, in response to your telegram of September 15.

Your understanding of section 375.106, Acceleration and Passing is correct. The acceleration interval may be begun in any gear, and the gears may be shifted during the interval.

You also asked how long "manufacturers are responsible after the sale of a vehicle for the information they provide." The regulations apply to manufacturers, so that strictly speaking the information is only required to be correct for vehicles at the point of sale to a person for purposes other than resale -- as is the case with the Standards. In other words, there is no implied requirement in regard to vehicle degradation with use. If a vehicle in use were found not to perform in accordance with the consumer information, however, (or not to conform to standards) that fact might be strong evidence of a violation by the manufacturer in the design or production of the vehicle.

You should also note that the consumer information regulations relating to braking and acceleration performance specify that a period of burnishing or breaking in shall be completed before the performance is measured.[Illegible Page)[Illegible Page)

ID: nht69-2.47

Open

DATE: 12/23/69

FROM: AUTHOR UNAVAILABLE; C. A. Baker; NHTSA

TO: Department of California Highway Patrol

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of December 8, 1969, concerning alternate flashing of side marker lamps with turn a signal lamps.

Alternate flashing sidemarker lamps are permitted in paragraph S3.5 of Motor Vehicle Safety Standard No. 108 for signaling purposed; however, they must not impair the effectiveness of the turn signal lamps as required in paragraph S3.1.2.

ID: nht69-2.48

Open

DATE: 10/16/69

FROM: AUTHOR UNAVAILABLE; C. A. Baker; NHTSA

TO: Seagrove Corporation

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of September 29, 1969, to Mr. Julien B. Leysath concerning the mounting location of lamps and reflectors on fire trucks.

The lamps and reflectors shown on your print of drawing number 2207 B 43.3 dated September 29, 1969, appear to meet the requirements of MVSS No. 108 with the following exception:

1. Front side marker lamps are not indicated on either the "F" or "S" cab. The front clearance lamps on the "F" cab may be combination clearance and side marker lamps, but are not so labeled.

2. The rear reflex reflectors on the 4 wheel aerial truck and the trailer do not appear to be located as far apart as practicable.

3. Backup lamps are not required on trailers.

Since no dimensions are specified on your drawing, we can only assume that the locations are otherwise as specified in MVSS No. 108.

With respect to the requirements of MVSS No. 108, I must point out that this Bureau does not issue approvals on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above consants are for your information only and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of Standard No. 108.

ID: nht69-2.49

Open

DATE: 08/18/69

FROM: AUTHOR UNAVAILABLE; S. K. Booth; NHTSA

TO: Cox Trailors Incorporated

COPYEE: CENTRAL FILE(2); ANDERS; COMPTON; LEYSATH; NIELD; 512 CHRON; 510A CHRON; INTERPRETATIONS: STD.108; DYSON (2); CC-2921

TITLE: FMVSS INTERPRETATION

TEXT: This is in response to your letter of August 6, 1969, concerning the location of the side marker lamp and reflector on boat trailers manufactured by your company, as discussed by your Mr. Oglesby with Mr. Tyson of this office.

Paragraph S3.2.1.4 of Standard 108 states: "On trailers, the amber front side reflex reflectors and amber front side marker lamps may be located as for forward as practicable exclusive of the trailer tongue." The forward location chosen will be satisfactory if you can provide reasonable justification for not placing it farther forward, that is, closer to the base of the trailer tongue.

We are pleased to be of assistance.

ID: nht69-2.5

Open

DATE: 01/24/69

FROM: AUTHOR UNAVAILABLE; Charles A. Baker; NHTSA

TO: Nissan Motor Corporation in U.S.A.

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of December 6, 1968, to Dr. William Haddon, Jr., Director, National Highway Safety Bureau, requesting a clarification of the requirements for a turn signal pilot indicator as specified in Motor Vehicle Safety Standard No. 108.

With respect to the turn signal pilot indicator only, you are correct in your interpretation that so long as the indicator is the color green, the diameter circle is more than 3/16 inches, and the driver has a clear and unmistakable indication, it is not necessary to apply other test procedures in order to meet the requirements of Standard No. 108.

The above provision in no way excepts turn signal lamps from meeting the requirements of SAR Standard J588d, June 1966.

ID: nht69-2.50

Open

DATE: 09/25/69

FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA

TO: Bennett's Truck Equipment

TITLE: FMVSR INTERPRETATION

TEXT: This is in reply to your letter of September 10, 1969, in which you asked whether you should certify the trucks that you assemble as a manufacturer or a distributor, and what are the safety standards to which your vehicles must comply.

The answer to your first question is that if you assemble the body to the chassis, you must certify as a manufacturer, regardless of by whom the body or chassis is fabricated. You should note that under the "chassis-cab ruling" (pages 43 and 369 of the enclosed regulations) the chassis-cab manufacturer is required to certify on a temporary label as to the standards to which the chassis-cab will comply when completed.

In response to your second question, I am enclosing a copy of the motor vehicle standards and regulations.

ID: nht69-2.51

Open

DATE: 02/20/69

FROM: AUTHOR UNAVAILABLE; H.M. Jacklin, Jr.; NHTSA

TO: Toyo Kogyo Company, Limited

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of November 30, 1968 (your reference No. GSAE-26) requesting information to a number of questions related to the Federal Motor Vehicle Safety Standards. I regret that we did not receive your October 5, 1968 letter and that the pressure of work has delayed my answer to your most recent letter.

I am glad to send you the following information:

a. MVSS No. 112 - Headlight Concealment Devices.

1. It is stipulated in S.4.6 that "each headlamp concealment device shall, within an ambient temperature range of -20 to +120 degrees F., be capable of being fully opened in not more than three seconds after actuation of the mechanism described in S.4.3." With regard to the temperature condition at the time of a test, if only the ambient temperature satisfies the cold temperature conditions, is it all right to pay no regard to other conditions, such as the sticking of frost, ice, etc.?

ANSWER: It is only necessary that the ambient temperature conditions (-20 to +120 degrees F.) be satisfied at the time of the test.

b. MVSS No. 114 - Theft Protection.

1. With regard to the stipulation in S.4.2 that "The prime means for deactivating the car's engine or other main source of motive power shall not activate the deterrent required by S.4.1.(b)," we have provided the ignition switch with four stages as shown in the sketch below: our key-locking system is of the mechanism that the system does not activate at the stage "Off", activates only at the stage, "Lock" and satisfies S.4.4. Does this mechanism conform to S.4.2.7

ANSWER: The system as you describe it appears to conform to S4.2; however, the Bureau does not issue approvals of any specific system, and the development of equipment to comply with this requirement is the responsibility of the individual manufacturer.

2. With reference to the stipulation in S.4.1. "Each passenger car shall have a key-locking system that, whenever the key is removed, will prevent ----.", we would like to know whether or not we must provide such a mechanism as the key can be removed only at the stage "Lock" and cannot at the stage "Off".

ANSWER: A locking system having such a position that the key may be removed without activating either the cars' steering lock or its self-mobility lock would not conform to the standard in its present form, since paragraph S4.1 of the standard requires each car to have a key locking system that, whenever the key it removed, will prevent either steering or self-mobility of the car, or both.

c. MVSS No. 201 - Occupant Protection in Interior Impact

1. With regard to the interpretation of the stipulation in S.3.1 " , the deceleration of the head form shall not exceed 80 g for more than 3 milliseconds," when the deceleration wave -- shown in the chart below -- is obtained.

in case DELTA t[1] < 3 milliseconds, we interpret that the standard is satisfied even when delta t[1] +="SIGMA" t[2] t[3] t;> 3 milliseconds.

Is our interpretation correct? (Illustration omitted)

ANSWER: Your interpretation is correct. The standard permits more than one peak that exceed 80g which, cumulatively, may add to more than 3 milliseconds. No single peak may continuously exceed 80g for more than a 3 millisecond duration.

2. When the areas stipulated in S.3.1.1.(d) -- "Areas outboard of any point of tangency on the instrument panel of a 6.5 inch diameter head form tangent to an inboard of vertical longitudinal plane tangent to the inboard edge of the steering wheel," -- are illustrated, which of the following hatched portions in the figures below is in conformity to the stipulation? (Illustration omitted)

ANSWER: Figure (a) is correct for the inboard side. Present requirements do not apply to the area outboard of the steering wheel on the instrument panel.

d. MVSS No. 207 - Anchorage of Seats.

S.3.3 Folding and hinged seats. Except for folding auxiliary seats and seats with backs which are adjustable for occupant comfort only.

1. Is it correct to interpret that the underlined part is referring to seats with backs of reclining mechanism enabling to adjust the angle of the back?

ANSWER: Yes.

2. Or, should we interpret that the seats with reclinable backs come under the hinged seats?

ANSWER: No.

3. a. In the case of car with four doors, if the front seats are those with reclinable backs, these are presumed to be the ones corresponding to (1). Is this interpretation correct?

ANSWER: Yes.

b. In the case of a car with two doors, we would like to interpret that only the reclinable seat backs with folding mechanism enabling the passengers on the rear seat to get in and out are in conformity to (2). Is our interpretation correct?

ANSWER: Yes.

S.3.3.1 The release control shall be readily accessible to the occupant of that seat and to the occupant of any seat immediately behind that seat.

1. The above stipulation is presumed to be laid down for the egress of the passengers on the rear seat. Therefore, when the reclining seats are installed in a four-door car, we would like to consider it unnecessary to pay regard to the underlined part. Is this interpretation correct?

ANSWER: Yes.

2. In the case of a two-door car, if the control which can be easily operated by passengers on the rear seat is installed only on one side (the right side), the passengers on the rear seat can operate the control by moving to the right side. Consequently, we consider it sufficient to install only on the right side the control which is easily accessible to the passengers on the rear seat. Is this interpretation correct?

ANSWER: In the case of a two-door car, for a split back or bucket seat arrangement, where both seat backs fold, a release control should be provided on the outboard side of each folding seat back. If the seat back is split and only one seat back folds, only one release control is required on the outboard side.

e. MVSS No. 210 - Seat Belt Assembly Anchorages

1. We judge that the fastening strength of the seat belt anchorage will change, depending on the shape of the eye bolt attaching the seat belt to the seat belt anchorage point.

If an anchorage is tested by using our designed seat belt assembly and the strength of the anchorage can be assured, we understand that the anchorage fully conforms to the standard, and also understand that it is not necessary to guarantee the owners of Mazda vehicles if they attach a test bolt assembly other than the one designated by us. Is our interpretation correct?

We, of course, will specify in our Operation Manual that the seat belt assembly designated by our company must be used.

ANSWER: Under Paragraph S.5.1 of Federal Motor Vehicle Safety Standard No. 210, anchorages are to be tested by using a Type 1 or Type 2 seat bolt assembly as defined in FMVSS No. 209. If you follow this procedure, using a belt which complies to No. 209, and your anchorages meet the requirements of Standard No. 210, then you are in compliance with this standard.

I must point out that this Bureau does not issue approvals on items of equipment or on vehicle designs. Therefore, the above comments are for your information only and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of the Standards.

ID: nht69-2.6

Open

DATE: 01/16/69

FROM: AUTHOR UNAVAILABLE; William Haddon, Jr., M.D.; NHTSA

TO: Rolls-Royce Limited Motor Car Division

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of November 8, 1968, requesting a clarification of the 30g horizontal inertia load direction specified in Standard No. 201, as published in the Federal Register on October 25, 1968.

In section S3.3.1(c), "Subject the interior compartment door latch system to a horizontal inertia load of 30g in a longitudinal direction....." means both forward and rearward directions. In addition, the loads specified in S3.3.1(a) are applied in both the inboard and outboard and the up and down directions. This is consistent with similar type requirements in Standard No. 206.

You state that a forward and rearward 30g inertia load requirement is more stringent than the alternative procedure of S3.3.1(b), the barrier test. The Bureau believes, and one large manufacturer so stated in his comments, that the most meaningful test of the ability of an interior compartment door to remain closed is one which considers the distortion and deformation loads that occur in a collision. A barrier or equivalent dynamic test is the best way of realistically evaluating the ability of these doors to remain closed. The Bureau, therefore, believes that the barrier test is as stringent a requirement as S3.3.1(c).

ID: nht69-2.7

Open

DATE: 01/13/69

FROM: AUTHOR UNAVAILABLE; Clue D. Ferguson; NHTSA

TO: Baycraft

TITLE: FMVSS INTERPRETATION

TEXT: Your letter of December 2, 1968, to Mr. William L. Hall, concerning safety glazing in canopies, has been referred to me for reply.

FHWA Ruling 68-1 clarified the requirement that slide-in campers must comply with Standard 205 since they are items of motor vehicle equipment for use in motor vehicles. A copy of FHWA Ruling 68-1 is enclosed.

The same rationale applies to your canopies. Forward facing windows must be laminated safety glass meeting the requirements of Test No. 26 of ASA Standard Z26.1-1966, July 15, 1966. Other windows may be AS1, 2, 3, 4, 5, 6, 7, 10, 11, 2-26, or 3-26.

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.