Skip to main content

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 11871 - 11880 of 16510
Interpretations Date
 search results table

ID: nht73-3.30

Open

DATE: 02/20/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Canadian Pittsburgh Industries, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of December 22, 1972, which was forwarded to us by the Department of Transport of Canada, requesting assignment of a manufacturer's code number for glazing materials you manufacturer.

In your letter you indicate that the glazing in question is purchased in stock sheets, and then out to the customer's requirements. The assignment of Code number is limited to what NHTSA has called "prime glazing material manufacturers" and this group includes only those who "fabricate, lauinate, or tamper the glazing material." As your function appears to be only that of cutting the material to size, we would not consider you, at least with respect to this material, to be a prime glazing material manufacturer. Consequently, a code number assignment would be improper. The labeling requirements which you would be subject to, if this glazing as cut by you is to be imported into the United States, are those requirements specified in S6.4 and S6.5 of Motor Vehicle Safety Standard No. 203, copy enclosed.

ID: nht73-3.31

Open

DATE: 02/20/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Lectron Products, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of January 29, 1973, concerning your safety belt interlock system.

Paragraph S7.4.1 of Federal Motor Vehicle Safety Standard No. 208, Occupant Crash Protection, requires that the belt system at each occupied seating position be operated after the occupant is seated in order to start the engine. It is our opinion that a system such as yours, which senses whether the safety belt is properly buckled around the occupant before allowing the engine to start, would meet the above requirements and could be used under the option described in S4.1.2.3.

ID: nht73-3.32

Open

DATE: 02/20/73

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

TO: Truck Body and Equipment Assoc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of January 8, 1973, concerning the application of Standard No. 124, "Accelerator Control Systems", to auxiliary throttles mounted inside or outside of the cab and used exclusively while the vehicle is in a stationary position to insure proper engine speed for the operation of pumps, elevating platforms, and similar equipment. Since the definition of "idle position" was amended to provide for the use of throttle positioners in 37 F.R. 20035 (September 23, 1972), the auxiliary throttles described are not subject to the requirements of the standard.

ID: nht73-3.33

Open

DATE: 02/22/73

FROM: AUTHOR UNAVAILABLE; C. A. Baker for E. T. Driver; NHTSA

TO: Morino and Moore

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of February 1 to Mr. B.M. Crittenden, Regional Administrator, concerning emergency flashers.

Effective January 1, 1969, all new automobiles were required to meet Federal Motor Vehicle Safety Standard No. 108, "Lamps, Reflective Devices and Associated Equipment," which in turn required the vehicular hazard warning signal operating unit to meet Society of Automotive Engineers Standard J910, January 1966. Prior to January 1, 1969, automobile were required to meet the standards and regulations of the individual States. Since New York required hazard warning signals (4-way flashers) in 1966, most automobiles manufactured for sale throughout the United States were similarly equipped.

SAE J910 did not contain requirements relating the activation of the signal to the position or rotation of the steering wheel. Several States prohibited the operation of the subject signal on a moving vehicle; therefore, on many cars, this signal was cancelled by the rotation of the steering wheel, and consequently could not be activated even with the vehicle stopped with the steering wheel in certain positions.

We are unaware of similar complaints on the activation of the hazard warning signals.

ID: nht73-3.34

Open

DATE: 02/27/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Fildew; Gilbridge; Miller & Todd

TITLE: FMVSR INTERPRETATION

TEXT: This is in response to your letter of February 14, 1973, in which you asked about the responsibilities with respect to the motor vehicle safety standards of an automobile dealer who sends a new vehicle to a specialty manufacturer for modifications. You asked whether the dealer must file reports as a final-stage manufacturer, or ascertain whether the specialty manufacturer has filed reports or certified the vehicle.

The final-stage manufacturer in the case you describe is the specialty manufacturer, and all the responsibilities that pertain to that category lie with him, not the dealer. There is also no obligation for the dealer to ascertain that the specialty manufacturer has filed reports.

The answer with respect to the dealer ascertaining that the final-stage manufacturer has certified the vehicle is somewhat less clear. There is no direct responsibility for this; a failure of the final-stage manufacturer to certify would not itself bring down any penalties on the dealer. However, the certification is designed to protect the dealer, in cases of nonconformity with the standards of which the dealer does not have actual knowledge. (See sections 108(b)(2) and 114 of the National Traffic and Motor Vehicle Safety Act, 15 U.S.C. 1397(b)(2), 1403.) To put it negatively, if the vehicle were completed in violation of applicable standards and it were not certified, a dealer might be considered to have sold a nonconforming vehicle without the exercise of due care, in violation of the Act. The question is further complicated by the fact that not all alterations would rise to the level of manufacturing (addition of trailer hitches probably would not, for example), and these minor

changes would not require additional certification by anyone. In sum, although there is no direct legal obligation for the dealer to see that there is a certification where there are major alterations, it is a very good idea, for his own protection.

The regulations on this subject are codified in Parts 567 and 568 of Title 49, Code of Federal Regulations. The October 1, 1972 edition of that title is current with respect to those parts. We do have a proposal outstanding to make some amendments regarding the certification of altered vehicles (37 FR 22800, October 25, 1972), and an amended rule may be issued in the near future.

ID: nht73-3.35

Open

DATE: 03/01/73

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

TO: E.T.R.T.O.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your submission No. 65/109 of January 23, 1973, petitioning that temporary exemption from Motor Vehicle Safety Standard No. 109 be provided for European tire manufacturers who manufacture high speed tires. Your petition points out that Standard No. 109 does not allow the manufacture of high speed tires designed to be inflated to relatively high inflation pressures, but which do not have commensurate load-carrying ability at those pressures. You indicate that such tires are commonly used in Europe for high speed passenger cars, and have not produced safety problems.

The temporary exemption regulations (49 CFR 555, copy enclosed), in accordance with the statutory authority under which they were issued (P.L. 92-548), apply only to manufacturers of motor vehicles. They do not apply to manufacturers of motor vehicle equipment, and the relief which they provide is accordingly not available to tire manufacturers.

The NHTSA is of the opinion that the requirements of Standard No. 109, emphasizing the load-carrying as well as the high speed capability of passenger car tires, should be suited to driving conditions which predominate in the United States. Despite the facts, as you mention, that it is possible for motorists to exceed posted speed limits, and that areas do exist where speed limits are not posted, the NHTSA believes the high speed requirements of Standard No. 109 are sufficient to guard against tire failures under these conditions. At the same time, the NHTSA will consider petitions to amend Standard No. 109, submitted pursuant to NHTSA procedural rules (49 CFR 553.31, .33), and E.T.R.T.O. is free to petition to amend the standard to include requirements for European-type high speed tires. Your petition should contain full supporting data for the amendments requested. We would expect you as well to include possible performance requirements for such tires.

You refer briefly in your letter to the performance of these tires when tested pursuant to the planned Uniform Tire Quality Grading regulation. The NHTSA plans to publish in the very near future a revised notice of proposed rulemaking regarding this regulation, and we will be pleased to receive your comments to that proposal when it is published.

ID: nht73-3.36

Open

DATE: 03/02/73

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

TO: Semperit of America, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of January 25, 1973, inquiring whether size designations "225/70SR14 replaces G70SR14", and "215/70SR15 replaces F70SR15" etc., may be used under Federal Motor Vehicle Safety Standard No. 109.

Paragraph S4.3(a) of Standard No. 109 provides for the labeling of "one size designation, except that equivalent inch and metric size designations may be used." The NHTSA has taken the position that this requirement does not prohibit the labeling of replacement sizes when the replaced size is in fact being superseded by the replacement size.

Because your proposed label contains both a metric and an inch size designation, however, it is not clear whether these size designations are intended as "equivalent" or "replacement" sizes. If you intend the former size to supersede the latter, your use of "replaces" between the two size designations is consistent with Standard No. 109. If your intention is to label equivalent size designations, however, the use of "replaces" is inappropriate One way in which equivalency may be appropriately shown is to place the inch size designation in a parenthesis () immediately following the metric size designation.

One last point is that the size designations listed in the Appendix of Standard No. 109 for 70 Series radial ply tires differ from those specified in your letter. Table I-G, which lists this tire type, specifies size designations in which the second letter is an "R". Thus, the size designations which you submit should have read GR70SR14 and FR70SR15. Other size designations of this tire type should be identified accordingly.

ID: nht73-3.37

Open

DATE: 03/02/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Chesapeake Maring Products

TITLE: FMVSR INTERPRETATION

TEXT: This is in response to your letter of February 5, 1973, in which you suggested, with reference to a previous interpretation, that boat trailer assemblers be allowed to use the "altering distributor" certification of 49 CFR @ 567.6, rather than certifying the vehicle as the manufacturer under @ 567.4.

The altering distributor label was not designed to deal with assemblers of vehicles, but with persons who alter vehicles that have already been completed and assembled. A basic prerequisite to its use is that there be a vehicle that already has been certified. I take it that your suggestion really amounts to requiring the supplier of the unassembled parts to certify the vehicle.

We are unwilling to do this on the basis of our present information. It is true that a boat trailer is among the simplest vehicles on the road, but considering vehicles generally, we must consider a vehicle as a functioning whole, not as a group of parts. There may easily be problems caused by the way in which it is assembled, and we do not consider it reasonable to require a manufacturer of parts, against his will, to take responsibility for the final assembly. Although it is conceivable that such a scheme could work with very simple vehicles, it certainly could cause large problems with more complex ones.

We permit the unassembled parts manufacturer to certify if he wishes. Furthermore, the person who assembles the vehicle can require a written commercial warrantly that

the vehicle will conform if properly assembled, which will protect him in certifying the vehicle. I recommend one of these courses of action as a matter of good business practice.

If the unassembled parts manufacturer does certify the package in accordance with @ 567.4 (g)(1)(ii), then it would be permissible for a distributor to use @ 567.6 where he deviates from the certifier's instructions.

ID: nht73-3.38

Open

DATE: 03/05/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Volkswagen of America, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in response to your letter of February 26, 1973, in which you asked a question concerning the relationship of the seat belt interlock and warning system required by Standard No. 208.

You asked whether the informative warning system, required by S7.3.5.4 to operate when the driver turned the ignition to "start" position and "the operation of the seatbelt systems required by S7.4.1 to start the engine has not been performed", is required to operate when the driver turn the ignition to start under the "free start" provisions of S7.4.3.

The answer is no. The "start" warning of S7.3.5.4 is only required to operate when a seatbelt operation "required to start the engine" has not been performed. When the engine is free to start under S7.4.3, the warning is not required. Of course, if the driver puts the vehicle in gear, the warning must sound under the provisions of S7.3.1 if the required seatbelt operations have not been performed.

ID: nht73-3.39

Open

DATE: 03/08/73

FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA

TO: Physicians for Automotive Safety

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of February 2, 1973, to Mr. Medlin of my staff, informing us of an infant car hammock made by(Illegible Word) Lamb.

Since the present child restraint standards do not cover infant restraints, we are limited in the action we can take on such a device. The Notice of Proposed Rule Making on the Child Restraint Systems Standard will be issued in the near future. This will inform all such manufacturers and the public of the new requirements for devices used to position or restrain an infant in a motor vehicle. We feel that this is the most appropriate action in this specific situation due to the limited market(Illegible Word) and availability of this device.

We appreciate your forwarding us this information and your continued support of child restraint safety.

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.