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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 4031 - 4040 of 6047
Interpretations Date

ID: nht68-2.38

Open

DATE: 10/03/68

FROM: AUTHOR UNAVAILABLE; Robert M. O'Mahoney; NHTSA

TO: State of New Jersey Division of Motor Vehicles

TITLE: FMVSS INTERPRETATION

TEXT: Your letter of September 3, 1968, to Mr. Sason of the National Highway Safety Bureau, discussing the Chrysler Corporation's Super Lite, has been referred to this office.

The State of Vermont has contacted us in regard to this question. We understand that in Vermont, and in other States, Chrysler has taken legal action to prevent state prohibition or regulation of the Super Lite on the basis of Federal preemption under @ 103(d) of the National Traffic and Motor Vehicle Safety Act, and Standard 108.

I enclose a copy of a letter, dated September 17, 1968, from Director Hadden to the Chrysler Corporation, in which he says:

"It should be noted, however, that, while the incorporation of this lamp in your 1969 automobiles would not be precluded by the Federal Standard, the various States may interpose restrictions as to the lamp."

In this office stated to the State of Vermont's Department of Motor Vehicles in response to an inquiry on the question: It is the opinion of the FH A that Federal lighting Standard No. 108 does not deal with the aspect of performance that relates to the Super Lite, and therefore there is no preemption of State regulations dealing with it.

We will be glad to give you whatever interpretive assistance you wish in this and other matters relating to the traffic safety laws, within the limits of our resources. We would also like to hear from you that legal developments are taking place in your state in this area.

ID: nht68-2.45

Open

DATE: 05/31/68

FROM: AUTHOR UNAVAILABLE; Joseph R. O'Gorman; NHTSA

TO: Oshkosh Truck Corporation

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letters of January 15 and March 25, 1958, to the National Highway Safety Bureau, concerning the applicability of Federal Motor Vehicle Safety Standard No. 108 to snow removal and heavy duty on-off highway vehicles manufactured by Oshkosh.

Standard No. 108 requires that headlamps be mounted not more than 54 inches above the road surface. Since your snow removal vehicles may be used in hauling operations as a secondary function, and since your heavy duty vehicles are used on the public roads, they are required to be equipped with headlamps located in accordance with Standard No. 108. Additional headlamps mounted on the cab roof or elsewhere on the front of the snow removal vehicle is permitted by the standard.

With reference to your heavy duty vehicles, headlamps located in the bumper, with adequate openings in front of the headlamps; or headlamps located below the bumpere, with protective shields around the headlamps would be permitted by Standard No. 108.

With respect to the requirements of Standard No. 108, we 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 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 standard. The certification information that you have provided us in your letter of January 15 is in accordance with our requirements.

We trust this information will be of assistance to you in your desire to comply with the existing safety standards.

ID: nht68-2.47

Open

DATE: 05/20/68

FROM: AUTHOR UNAVAILABLE; Joseph R. O'Gorman; NHTSA

TO: Department of California Highway Patrol

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of January 16, 1968, your reference 61.A218. A1115, to the National Highway Safety Bureau concerning applicability of Federal Motor Vehicle Safety Standards 108 and 205 to compers.

Your questions along with our corresponding answers are listed below: uestion: 1. Do Federal Standards Nos. 108 and 205 apply to Camper bodies which are not manufactured as a part of a vehicle but which may be purchased separately and later installed on a pickup truck by its owner? Answer: The enclosed Notice of Making Regarding Compare affirms the applicability of Federal Standard No. 205 to camper bodies. Federal Standard No.

108 is a standard applicable to chassis cabs and to complete motor vehicles. Question: 2. Do Federal Standards Nos. 108 and 205 apply to campers which are sold by the pickup truck dealer as part of a new vehicle even though the camper body itself is actually a load on the pickup and is designed to be recovered from the pickup when the owner decides to transport other types of loads? Answer: The applicability of Federal Standard No. 205 is covered in the enclosure. Federal Standard No.

108 is a requirement upon the dealer who sells a motor vehicle. If the vehicle is designed for more than one configuration in use, the dealer must provide that both configurations are in compliance with Federal Motor Vehicle Safety Standards.

The enclosed information on the National Traffic and Motor Vehicle Safety Act of 1966 are provided to further assist you.

ID: nht68-2.7

Open

DATE: 06/19/68

FROM: AUTHOR UNAVAILABLE; David A. Fay; NHTSA

TO: Robert Bosch Corporation

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of May 24, 1968, to Mr. J. E. Leysath of this Bureau, concerning the testing of automotive flasher devices.

Motor Vehicle Safety Standard No. 108 specifies that turn signal flashers and vehicular hazard warning signal flashers conform to SAE Standards J590b and J945, respectively. These SAE standards, in turn, require that the test circuitry and test instrumentation conform to SAE Standard J823a. As you noted, the distribution of the 0.10+/-0.01 ohm series resistance in the standard test circuit (Figure 1 of J823a) is not specified in SAE Standard J823a. Therefore, your recommended distribution, namely, 0.025+/-0.005 ohms resistance between the power supply (positive terminal) and flasher input terminal, and 0.075+/-0.005 ohms resistance between the flasher output terminal and the flasher bulbs, would be permitted by SAE Standard J823a.

Flasher units having a ground terminal that is connected with the negative terminal of the power supply may be tested in the standard test circuit of SAE Standard J823a, provided the ground circuitry does not change the required resistance of 0.10+/-0.01 ohm looking into terminals A-B with the removable shunts in place (see note for Figure 1, SAE J823a).

The above-stated test provisions in no way except the flasher units from meeting all performance requirements specified in Standard No. 108, including those specified in basically referenced SAE Standards J590b, "Automotive Turn Signal Flashers," and J945, "Vehicular Hazard Warning Signal Flasher."

ID: nht68-3.13

Open

DATE: 02/09/68

FROM: AUTHOR UNAVAILABLE; Joseph R. O'Gorman; NHTSA

TO: Electrographic Corporation

TITLE: FMVSS INTERPRETATION

TEXT: In your letter of December 18, 1967, to Mr. Lowell K. Bridwell, you describe the procedure initiated by you for identifying and marking light hit containers. You ask for our acknowledgement of the procedure. It is not clear from your letter, but we gather that you manufacture truck bodies and ship light kits in a separate box, either to accompany or separate from the truck bodies.

The so-called "lighting Standard," Standard 103 of the initial Federal Motor Vehicle Safety Standards, to entitled "Lamps, Reflective Devices, and Associated Equipment." The standard applies to multipurpose passenger vehicles, trucks, trailers and buses, that are 80 or more inches wide overall, except pole trailers and converter dollies. It is the manufacturer of the completed vehicle who must certify that the vehicle conforms to all applicable Federal motor vehicle safety standards, including Standard No. 103. Unless the manufacturer of the lighting equipment and the completed vehicle are the same, the manufacturer of lighting equipment is not required to certify that such equipment conforms to Standard No. 103. It would seem logical to expect that the manufacturer of the completed vehicle would require from the manufacturer of the lighting equipment some indication that the lighting equipment is in conformity, but that is a matter to be settled between the two persons involved. Thus, while we have no objection to the procedure described in your letter, we do wish to emphasize that it does not relieve the vehicle manufacturer of insuring compliance and certifying to such compliance where appropriate.

Thank you for your interest. If further information is needed, please feel free to contact this office.

ID: nht68-3.14

Open

DATE: 05/24/68

FROM: AUTHOR UNAVAILABLE; David A. Fay; NHTSA

TO: Department of California Highway Patrol

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of April 5, 1968, (Reference 61.A218.A1115) addressed to Dr. William Haddon, Jr., concerning the location of clearance lamps on several styles of truck bodies manufactured by the Utility Body Company.

Rear clearance lamps mounted at the top corners of the sleeper cab of the vehicle in Figure 1 of the drawing attached to your letter would not be in conformance with the requirements of Federal Motor Vehicle Safety Standard No. 108. On this same vehicle, the required location of the front clearance lamps is at the top corners of the sleeper cab. The additional set of front clearance lamps on the truck cab would not be required or prohibited by Standard No. 103. Locations of rear clearance lamps on the vehicles shown in Figure 2 and Figure 3 of the drawing are in accordance with the requirements of Standard No. 108.

Our records do not indicate that we have furnished any evidence to the Utility Body Company regarding location of rear clearance lamps as shown in Figure 1. Under their letter of March 11, 1968, this company submitted to us a print of their drawing, which is identical to the drawing enclosed with your letter, and requested our comments on the proposed locations of their lighting equipment. The above information will be furnished to the Utility Body Company in reply to their March 11 letter and should serve as clarification of the requirements of Standard No. 108. This clarification also indicates that no conflict exists between the requirements of Standard No. 108 and the requirements of the California Vehicle Code with respect to location of your clearance lamps.

ID: nht68-3.44

Open

DATE: 07/26/68

FROM: AUTHOR UNAVAILABLE; David A. Fay; NHTSA

TO: Toyota Motor Company

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of June 27, 1968, in which you requested clarification of the term "optically combined" as applied to motor vehicle lights.

"Optically combined" in this context means that the same lens area is used for more than one function such as tail and stop lights or stop and turn signal lights or tail, stop and turn signal lights. The normal means used to accomplish this "optically combined" lamp has been to incorporate a single dual-filament bulb with a reflector and lens.

Since the design of your Toyota Crown combination stop, tail and turn signal lamp is such that a different part of the lamp area is used for the turn signal lamp, we do not interpret it to be optically combined with the tail and stop lamp.

The concurrence of the above interpretation with yours and that of the California Highway Patrol should not be construed to be an approval of your design. The results of recent research on lighting and signaling reviewed by this Bureau indicate that signal lights should be separated 4 1/2 to 5 inches minimum (centerline to centerline separation.) Although no dimensions are specified on your drawing it appears to be approximately full scale with a separation distance of 2 1/2 inches between the stop and turn signal lamps. The steady-burning stop lamp may therefore "wash out" or significantly reduce the effectiveness on the turn signal lamp. Federal Motor Vehicle Safety Standard No. 108 does not require a minimum separation distance between signal lights; however, upon completion of our present research contracts on rear lighting and signaling, we may consider such a requirement in the future.

ID: nht68-4.2

Open

DATE: 08/20/68

FROM: AUTHOR UNAVAILABLE; Charles A. Baker; NHTSA

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of July 24, 1968, to Mr. George C. Nield, concerning the method of operating school bus signal lamps as required by Motor Vehicle Safety Standard No. 108.

Paragraph S3.1.3.2(b)(2) of Standard No. 108 requires that the system of red and amber signal lamps shall be wired so that the red signal lamps are automatically energized, and the amber signal lamps are automatically de-energized, when the bus entrance door is opened. Paragraph S3.1.2 of the standard does not permit the installation of an additional lamp, reflective device or associated equipment if it impairs the effectiveness of the required equipment.

Therefore, the criteria for determining the compliance of an additional manual switch for controlling operation of the signal lamps is whether or not the manual switch would impair the effectiveness of the required automatic entrance door switch. A manual switch which overrides the entrance door switch only while the entrance door is closed does not appear to impair the effectiveness of the required automatic switch. However, a manual switch which controls operation of the signal lamps while the entrance door is open would definitely impair the effectiveness of the automatic switch.

With respect to the requirements of Standard 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 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 standard.

Thank you for writing.

ID: nht70-2.7

Open

DATE: 05/01/70

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

TO: Pullman Incorporated

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of April 14, in which you question the legality of the State of California's enforcement of a State motor vehicle safety standard which is reportedly not identical to the Federal standard (No. 108) concerning the same aspect of performance. Your question arises from the failure, thus far, of the California Highway Patrol to approve as a clearance lamp a light installed on the rear of a Pullman flat bed trailer that is certified as complying with Federal Standard No. 108; Lamps, Reflective Devices and Associated Equipment.

Once a Federal motor vehicle safety standard has become effective, section 103(d) of the National Traffic and Motor Vehicle Safety Act of 1966 ("the Act") prohibits any State from having

"With respect to any motor vehicle or item of motor vehicle equipment any safety standard applicable to the same aspect of performance of such vehicle or item of equipment which is not identical to the Federal standard."

While the Act thus limits the nature of the standards which a State may issue, it does not preempt the authority of a State to enforce, by reasonable procedures, standards not prohibited by that section.

It is not clear from your letter and its enclosures whether you are objecting to the State requirement of submitting the lamp in question for approval, or are claiming that the State has unjustifies refused to approve the lamp. If you will clarify this question, we will be pleased to give the matter further consideration.

ID: nht71-1.17

Open

DATE: 09/20/71

FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA

TO: Phillips Petroleum Company

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to a request made on behalf of Phillips Petroleum Company by Veigh J. Nielson for an assigned identification mark for two of Phillips' plants which manufacture tires for research purposes.

As I informed you in my letter of September 20, 1971, if Phillips purchases a new tire, removes the trend material and then applies its own experimental trend containing various rubber compounds, Phillips is considered to be a new tire manufacturer. If Phillips applies its experimental tread to a used tire, it is considered a retreader of tires.

As a new tire manufacturer you are required to certify the tire as conforming to the new passenger car tire standard (No. 109) and comply with Part 574 - Tire Identification and Record Keeping (49 CFR 574). Accordingly, you are assigned the identification mark of "J1" for tires made in your (Illegible Word), Oklahoma plant and "K1" for tires manufactured in your Stow, Ohio plant.

If you act as a retreader then Part 574 would not be applicable for the tires you retread because they are retreaded for your own use. (Enclosed is a copy of Docket No. 70-12, Notice No. 8 which makes the regulation inapplicable to retreaders who retread for their own use). As explained in my letter of September 20, you are, of course, required to certify that your new tires and your retreaded tires comply with the respective standards for new and retreaded tires if they are to be used on the public highways, by placing the symbol DOT on the tires in the prescribed location.

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.

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