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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 12161 - 12170 of 16505
Interpretations Date
 

ID: nht72-3.32

Open

DATE: 05/08/72

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Stylar Industries Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of March 22, 1972, on the subject of the application of Motor Vehicle Safety Standard No. 207 to the type of swivelling seat manufactured by your company.

We understand from your letter that you are concerned about the type of swivelling seat that is not continuously fastened to its base and that can therefore come loose in a rollover accident. To avoid this problem, you have designed your seat with a stud bolt that links the seat to its base regardless of the amount of rotation. Your question to us is whether removal of the stud bolt would cause the seat not to conform to Standard 207.

The answer to your question depends in part on whether the seat without the bolt would be able to meet the applicable strength requirements of the standard. Removal of the stud belt would not, in itself, cause the seat not to conform to the standard. The seat would conform to S4.3 if the seat were to lock itself by means other than the bolt when returned to the forward facing position.

ID: nht72-3.33

Open

DATE: 03/15/72

FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA

TO: Society of Automotive Engineers, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of February 7, 1972, to the Administrator, in which you requested "clarification" of two requirements of Standard 207 that impose forces on rearward facing seats.

We do not believe that the requirements are unclear. S4.2(b) requires a rearward facing seat to withstand a force of 20 times its weight applied in a rearward direction, while S4.3.2.2 requires the restraining device not to release or fail under an acceleration of 20 g's in the direction opposite to that in which the seat folds.

You suggest that these forces and accelerations are equivalent to those in a 30 mph barrier impact, and point out that none of the existing standards provides for a 30 mph rear impact. The intent of the cited sections is to require rear facing seats to withstand the force of rear and collisions, which occur frequently and are often of considerable severity. We have some doubt that the 20 g acceleration is equivalent to a 30 mph rear barrier impact; frontal 30 mph impacts typically produce accelerations of 30 to 40 g's. Whether it is not is irrelevant, however, to the validity of the standard. The standard is clear in its own terms, and in our judgement its requirements are appropriate and feasible.

ID: nht72-3.34

Open

DATE: 05/03/72

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Volkswagen of American, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of April 10, 1972, on the subject of the label required by Standard 207 to be affixed to a seat that is not intended for use while the vehicle is in motion.

Although S4.4 of Standard 207 does not require the warning to be verbal, it is our impression that the concept is difficult to convey by nonverbal symbols. A quick review of personnel in the NHTSA revealed that most of them were familiar enough with the international sign system to know that something was being forbidden, but were unsure as to what the forbidden act was. Of the two symbols, the one showing the vehicle in motion appeared to be more understandable, but not by much.

It is our conclusion that neither of the symbols is adequate to give the warning intended by S4.4. This is not to say that the symbols would not be adequate in other countries whose citizens are more familiar with symbolic labeling. I might add that the label need not contain the exact words of the standard. It would be acceptable, for example, to say "Do not ride in this seat," if you find that shortening the phrase would make the label less cumbersome.

ID: nht72-3.35

Open

DATE: 05/05/72

FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA

TO: Resources Applications, Designs & Controls, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of April 12, 1972, on the subject of the test procedures of Motor Vehicle Safety Standards 207 and 210.

Your first question is whether the center of gravity referred to in S5.1.2 of Standard 207 is the center of gravity of the seat bench alone or the center of gravity of the seat bench in combination with the supporting structure. It is often a close question in recreational vehicle seating where the seating system ends and the vehicle structure begins. In cases such as the one depicted in Attachment 1 to your letter, where the supporting structure consists of a storage cabinet that is integrated into the interior structure of the vehicle, it is our opinion that the storage cabinet should not be considered in determining the weight and center of gravity of the seat bench under S5.1.2.

Your second question asks us to concur in your opinion that separate tests are not required under Standards 207 and 210 when identical seats are installed in different vehicles. Our reply is that the number of tests you perform is a matter for you to decide; we do not, as a rule, comment on the adequacy of a test program. The standards do not require a manufacturer to test his product in a specific manner or with a specific frequency, so that failure to test is not, in itself, a violation. If our Office of Standard Enforcement should happen to test one of the vehicles in question, however, and it fails when tested in accordance with the standard, the manufacturer may be subject to civil penalties unless he can establish that he exercised due care in the design and manufacturer of the vehicle. Whatever your decision on the subject of testing, it should be carefully made.

Our reply to your third question follows the reasoning set forth above. If we conduct a test in accordance with S4.2(d) and the seat fails, the manufacturer will have to establish that he exercised due care in making that seat. Without a set of specific facts before us, we cannot say what the result of our inquiry would be.

The label proposed for the rotating seat to indicate that it is not to be used while the vehicle is in motion except in the forward facing position would be an acceptable label under Standard 207.

ID: nht72-3.36

Open

DATE: 08/23/72

FROM: LAWRENCE R. SCHNEIDER FOR RICHARD B. DYSON -- NHTSA

TO: Automotive Trade Association

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of July 18, 1972, to Miss Nancy Brownell concerning the placement of additional seats in a "van" by a dealer.

Section 108 of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397) prohibits, among other things, the sale, offer for sale, or the introduction in interstate commerce of motor vehicles that do not conform to applicable motor vehicle safety standards in effect on the day of the vehicle's manufacture. This prohibition applies until after the sale of the vehicle to a purchaser for a purpose other than resale (15 U.S.C. 1397(b)(1)).

This provision prohibits all persons, including dealers, from altering a new vehicle before its sale to a user in such a way that the vehicle no longer conforms to the standards. A person who performs such alterations would be required to ensure that the vehicle conformed to all applicable standards after the alterations have been made. It appears that merely adding seats to a van without making additional alterations would cause it to fail to conform to Motor Vehicle Safety Standard No. 208, "Occupant Crash Protection", (49 CFR 571.208), and possibly other standards as well. The failure of the vehicle to conform could result in the imposition of civil penalties against the person making the alteration or selling the vehicle of up to $ 1,000 for each violation (15 U.S.C. 1398), and other sanctions (15 U.S.C. 1399).

You are right in your opinion that the vehicle may be modified without regard to the standards after its first purchase for a purpose other than sale.

ID: nht72-3.37

Open

DATE: 03/22/72

FROM: AUTHOR UNAVAILABLE; E.T. Driver; NHTSA

TO: Fiat Motor Company, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of March 3, 1972, concerning multiple audible warning requirements.

The audible warning requirements of Federal Motor Vehicle Safety Standards 114 and 208 can be met with the use of one system rather than two separate ones.

ID: nht72-3.38

Open

DATE: 09/25/72

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Renault, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of September 12, 1972, concerning the automatic adjustment of seat belts required by S7.1.1 of Standard No. 208.

The belt system that Renault is considering for use after August 15, 1973, employs a continuous length of webbing that runs from a floor-mounted emergency-locking retractor up through a metal ring mounted high on the B-pillar, then downward across the occupant's chest to the buckle, where it passes around a knurl bar and back across the occupant's lap to an outboard floor anchorage. Your question concerns the amount of friction that may be produced by the knurl bar before the lap belt would be considered to have lost the automatic adjustment capacity required by S7.1.1.

After examining the buckle enclosed with your letter, we have concluded that in its present (Illegible Word) the (Illegible Word) produced by the knurl bar is such that the belt would probably not adjust automatically as required by S7.1.1.

In evaluating belts of similar design, we have not attempted to quantify the amount of allowable buckle friction. The characteristic to be avoided is the tendency of the buckle to trap an excessive amount of webbing on the lap belt side of the buckle. This tendency is overcome if the friction in the buckle is low enough that the normal motion of the occupant against the shoulder belt cinches up the lap belt, or if the buckle slides down of its own weight while the assembly is stored on the B-pillar so that the next occupant must lengthen the lap belt as he fastens the buckle.

In the case of the Renault buckle, a person using the assembly after its use by a larger person would find the buckle in the position appropriate for the larger occupant. After buckling it, he would have a slack lap belt. It appears that the friction in the buckle is great enough that the occupant's normal motion would not tighten the lap belt and that he would have to adjust it manually in order to have it fit him properly. We do not consider this to be satisfactory.

If you have further questions, please advise us.

ID: nht72-3.39

Open

DATE: 03/02/72

FROM: ELWOOD DRIVER FOR ROBERT L. CARTER -- NHTSA

TO: Lindburg Cadillac

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of February 16, 1972, to Secretary John Volpe, concerning the length of seat belts in a 1972 Cadillac automobile.

Federal Motor Vehicle Safety Standard No. 203, Occupant Crash Protection, copy enclosed, specifies requirements for occupant restaint systems. Effective January 1, 1972, car manufacturers are required to provide Type 2 belt assemblies (lap-shoulder belts) at the front outboard seating positions and lap belts at other positions. The Type 2 belt assemblies may have either integral or detachable shoulder belts, but the distance between the intersection of the lap-shoulder belt and the vertical counterline of a 50th-percentile adult male occupant must be at least six inches when the seat is in its rearmost position. The purpose of this requirement is to reduce the possibility of the shoulder belt pulling the lap belt up onto the occupant's abdomen where it could cause serious injury in a crash.

We have examined several 1972 model cars and have found that some manufacturers have chosen belt designs that provide distances of ten inches or more between the lap-shoulder belt intersection and the centerline of the occupant. The (Illegible Word) not prohibit distances greater than six inches, but it is obvious that the greater this distance, the closer the inboard end of the belt is to the seat and the more difficult it is to buckle the belt. I am happy to inform you that we have already initiated rule making action to amend Standard No. 208 that would prohibit such excessive distances.

Under the requirements of the National Motor Vehicle and Traffic Safety Act, copy enclosed, it is a violation of the law to sell a vehicle that does not conform to an applicable standard. Although the Act does not prevent the purchaser of a vehicle from altering or removing a safety device, after he has completed the purchase, we strongly advise him against such action. A dealer who perform such services after he has sold the vehicle does not violate the law, but he does his customer a disservice.

In regard to the belts in the Cadillac you sold to Mr. and Mrs. T. Albert McCulley, we do not have the authority to grant or deny you permission to lengthen the inboard end of the belt. We can only suggest that perhaps you could lengthen the belt only to the extent that is necessary to provide a distance of not less than six inches between the interraction of the lap-shoulder belt and the centerline of a 50th-percencile adult (Illegible Word) occupant measured in accordance with paragraph s7.1.2 of Standard No. 206.

Thank you for your interest in motor vehicle safety. If we can be of further assistance, please do not hesitate to contact us.

Sincerely, LINDBURG CADILLAC

February 16, 1972

Honorable John Volpe Secretary of Transportation U. S. Dept. of Transportation

Dear Mr. Volpe:

Recently we delivered a new 1972 Cadillac S/N6D47R2Q-194774 to Mr. and Mrs, T. Albert McCulley, 434 Sherwood Forest, Belleville, Illinois 02225 fitted with the new seat belt warning system.

The center buckle section is so short that Mr. and Mrs. McCulley experienced difficulty in fastening the outside section to the center section. We have inquired from Cadillac the possibilities of lengthening the center buckle sections approximately eight inches which would still leave the warning system in operation and would greatly facilitate the fastening, put Cadillac informs us that the installation is strictly according to federal regulations and cannot be changed.

Would you grant us permission to add eight inches to the center buckle section for this particular vehicle?

VERY TRULY YOURS,

George A. Maty Vice President and Sales Manager.

CC: MR. AND MRS. T. ALBERT MCCULLEY; SEN. STUART SYMINGTON; SEN.THOMAS EAGLETON; REP. MELVIN PRICE

ID: nht72-3.4

Open

DATE: 02/16/72

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Alabama Tire Dealers and Retreaders Association

TITLE: FMVSS INTERPRETATION

TEXT: This is in response to your three letters, dated December 1, 1971, December 27, 1971, and January 11, 1972, concerning Motor Vehicle Safety Standard No. 117.

In your letter of December 1, 1971, you enclose a booklet that you have recently made available which contains your interpretation of Standard No. 117, and ask us to review it. As your letter was written before the amendment of December 23, 1971 (36 F.R. 24814), and the suit in Chicago, it does not, and our reply will not, deal with the changes made by that amendment or the "stay" ordered by the Court of Appeals. We believe your summary of the standard is correct, but we would recommend that you include in the requirements of paragraph S5.1.1 of Standard No. 117 the treadwear indicator requirements found in S4.2.1(d) of Standard No. 109. This fact is apparently being overlooked by some retreaders, and you may wish to point it out more clearly.

Your letter of December 27 asks whether exposure of cord that has occurred on casings because of "chipping" would prevent the casing from being retreaded under S5.2.1. As presently written, S5.2.1 would preclude the retreading of such a casing if what is exposed is ply cord. However, if it is actually "chafer" fabric, which is a special fabric placed only around the bead, then exposure is permitted.

Finally, with regard to your letter of January 11, I regret that, as you have been told, Mike will not be able to attend the Missalaga Conference. He has told me that your organization has done a very responsible job with regard to not only Standard No. 117 but other areas of tire safety as well, and we appreciate your efforts.

ID: nht72-3.40

Open

DATE: 08/04/72

FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA

TO: General Motors Technical Center

TITLE: FMVSS INTERPRETATION

TEXT: Your letter of July 11, 1972, raises two substantive questions concerning the belt system requirements of Motor Vehicle Safety Standard No. 208.

The first question concerns S7.4.1, which provides that the engine starting system shall not be operable "unless the belt system at each occupied front position is operated after the occupant is seated". You ask whether a system that you submitted for our inspection, which does not use electronic logic circuits, would conform to this requirement.

The belt system in question is designed to make it quite difficult to enter the vehicle if the belt system is fastened. The occupant is thus forced to unfasten the belt (if it has been left fastened) to enter the vehicle, then to fasten it in order to start the engine. The system employs an inboard-mounted shoulder belt with the outboard attachment point for the lap and shoulder belts mounted in the door. The ignition system employs a buckle switch, so that the belt must be buckled for the engine to start. Upon entering the vehicle, an occupant may find that the belt is either buckled or unbuckled, depending on the action of the previous occupant, but if it is buckled, he will find entry difficult if he does not first unbuckle it. After evaluating the system, we have concluded that the occupant is essentially compelled to operate the belt system after being seated in order to start the car. The system therefore conforms to the requirements of S7.4.1.

In view of the lack of logic circuits, we urge that the design of the buckle be given careful attention, to prevent defeat of the system by the insertion of objects into the buckle.

Your second question concerns the acceptability of belts which require "some action during normal vehicle entry or egress" under the requirements for passive belts. As presently drafted, S4.5.3 does not permit such belts to be classified as passive belts. We will treat your request for amendment of this requirement as a petition for rulemaking and give it prompt consideration.

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.