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
| Interpretations | Date |
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ID: nht92-7.34OpenDATE: April 21, 1992 FROM: Al Twyford TO: Associate Administrator for Safety, Federal Highway Administration TITLE: None ATTACHMT: Attached to letter dated 5/14/92 from Paul J. Rice to Al Twyford (A39; Std. 108) TEXT: I would like to voice a complaint about some makes of new cars that have two sets of headlights (4), which operate at the same time. When approaching these vehicles at night, going in the opposite direction, it has the same effect as a car approaching my vehicle with the high beam headlights on. I have had conversations with the California Highway Patrol and Department of Motor Vehicles, and they claim that these headlamps are approved for auto manufacturers by your department. They claim they can do nothing about the problem, without a change on the matter by your agency. If you are committed to Highway Safety, why would you approve these headlamps for automobiles? Night driving is bad enough, without adding more vehicles to the highway with these extra bright lights which have the effect of highbeam brightness. I would like to ask that you re-examine your approval of these extra headlamps, and do some further testing under night time driving conditions. I personally have responded to these automobiles with the four lights with a dose of my highbeams to get these drivers to turn off the extra set of headlights. This doesn't seem to work as they either don't realize what they are doing to oncoming traffic, or can't turn off the lower set of lights. I might add that from the rear of my vehicle, it's the same problem; the approaching vehicle has the effect on me of highbeam lights in my rear view mirror and side view mirror. I would appreciate some feedback on this problem, and what you propose to do about it. If you do nothing, I plan to take this matter up with Congressmen and U.S. Senators. Thank you. |
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ID: 1983-3.13OpenTYPE: INTERPRETATION-NHTSA DATE: 10/20/83 FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA TO: Liberty Square TITLE: FMVSS INTERPRETATION TEXT:
Mr. P. T. Miller 90 W. 79th Avenue Liberty Square P.O. Box G Merriville, Indiana 46410
Dear Mr. Miller:
The Department of Commerce has forwarded your letter of September 27, 1983, to Mr. Vinson of this office, for our reply. You have asked about Federal standards for motorcycle headlamps in connection with your investigation of an accident in Indiana involving a motorcycle reputedly equipped with "a custom light approximately 2 1/2" by 5"...smaller than a stock light." Indiana Law requires that motorcycles be equipped with headlamps meeting Federal standards. The principal Federal standard on motorcycle headlighting is SAE Standard J584a, incorporated by reference in 49 CFR 571.108, Motor Vehicle Safety Standard No. 108. The standards do not list permissible sizes for motorcycle headlamps that are not sealed beam, specifying only that the light emitted comply with requirements at various photometric test points. Thus, the small size of the lamp in question is not indicative that it failed to meet Federal motorcycle requirements.
However, we are not aware that motorcycle headlamps are available in rectangular sizes smaller than those used on passenger cars, i.e.,4" by 6". Perhaps the lamp in question was intended by its manufacturer for use as a driving lamp on passenger cars; its size is consistent with that type of lamp. But without further information I'm afraid we can be of no greater assistance. Sincerely,
Frank Berndt Chief Counsel
Reference # 3-1538 September 27, 1983
P. T. Miller 90 W. 79th Avenue Liberty Square P. 0. Box G Merriville, Indiana 46410
Dear Mr. Miller:
This is in response to your letter about standards for sizes of motorcycle headlights.
I was unable to locate information on Department of Commerce standards in this area. However, Mr. Taylor Vinson of the Chief Counsel's Office of the National Highway Traffic Safety Administration advised me that Federal transportation laws and standards have been under the jurisdiction of that agency since 1969. He asked me to send him a copy of your letter so that he could investigate your question and answer you directly.
Any further requests on this matter should be sent to: Taylor Vinson Office of Chief Counsel, Room 5219 National Highway Traffic Safety Administration 400 7th Street, S.W. Washington, D. C. 20590 (202) 426-9511
Sincerely,
Christopher Benya Office of Consumer Affairs
cc: Taylor Vinson
September 9, 1983
Department of Commerce 14th St. East St. Northwest Room 5725 Washington D. C. 20230
Attention: Lee Gray Director of Consumer Affairs
RE: Our File No. 8-309072-1 Our Insured: Thomas Daniels Loss of: 8-12-83
Dear Mr. Gray:
I am investigating a serious accident involving an automobile and a motorcycle and the investigating police officer in his report stated that the light on the motorcycle was a custom light approximately 2 1/2" by 5" and was smaller that a stock light.
A check of the Indiana Statute regarding lamps or reflectors on motorcycles states that no motorcycles shall be operated on public streets or highways by a resident of this state that is not equipped with a lamp or reflectors meeting the standards of the US Dept. of Commerce as amended. You will note that they refer to the standards set by the Department of Commerce.
If you could forward to this office a copy of the directive showing the standards of headlights required on motorcycles that the Indiana Law refers to.
Your help will be greatly appreciated.
Very truly yours,
P. T. Miller Asst. Distr. Claim Manager
66 E. SOUTH WATER ST./CHICAGO, IL 60601/(312) 372-1818 |
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ID: 11660ZTVOpen Mr. Yoshiaki Matsui Dear Mr. Matsui: We have received your letter of March 13, 1996, asking for an interpretation of the word "replaceable" with respect to the replaceable light sources permitted by Motor Vehicle Safety Standard No. 108 for use in motor vehicle headlamps. This information will assist you in the development of HID headlamps. You ask whether "replaceable" as used in paragraph S7.7 means that access should be provided for convenient replacement without the use of special tools, which is a specific requirement of Standard No. 108 for light sources for the center highmounted stop lamp. The answer is no; there is no requirement that replaceable light sources be replaceable without the use of special tools. We recognize that HID light sources may be designed for the life of the vehicle on which they are installed, and, optimally, would require replacement only in the event of front end damage. However, NHTSA believes it is in the interest of safety that light sources that are not designed for such longevity should be replaceable in a simple manner. When the agency amended Standard No. 108 to permit replaceable light sources (48 FR 24690, June 2, 1983), the replaceable light sources that were initially produced had bayonet mountings, which provided positive one-way insertion of the bulb into the reflector assembly. This allowed owner-replacement of the light source, a safety benefit used in justification of the final rule: "The easy replacement of the bulb may result in faster replacement of burned out headlamps." Thirteen years later, headlighting systems have become more complicated in a way that the agency did not foresee then, but the principle of simplicity of replacement of the light source remains. If you have further questions you may refer them to Taylor Vinson of this Office (FAX 202-366-3820). Sincerely, Samuel J. Dubbin Chief Counsel ref:108 d:4/24/96
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1996 |
ID: 1985-01.38OpenTYPE: INTERPRETATION-NHTSA DATE: 02/27/85 FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA TO: Mr. H. Horiyoshi Mazda (North America), Inc. TITLE: FMVSS INTERPRETATION TEXT:
Mr. H. Horiyoshi Executive Vice President and General Manager Mazda (North America), Inc. 24402 Sinacola Court Farmington Hills, MI 48018
Dear Mr. Horiyoshi:
This is in reply to your letter of November 21, 1984, asking for an interpretation of Motor Vehicle Safety Standard No. 108 as it would apply to a contemplated parking lamp system.
Usually passenger cars are designed with two parking lamps, one on each side of the vehicle front. Mazda would have two such lamps on each vehicle side, each of the two lamps flanking the headlamp. You have asked whether, in determining the H-V axis, one takes the axis as the center of each lamp, or should one consider the pair a single device and place the H-V axis at the midpoint between them. Standard No. 108 requires passenger cars to be equipped with a minimum of two parking lamps, located "as far apart as practicable." Therefore, the outermost parking lamp, (the one located between the turn signal lamp and the headlamp) is the lamp that must meet the parking lamp requirements of Standard No. 108, and the H-V axis for purposes of compliance would be determined at the center of the lens of that lamp. Supplementary lighting equipment is permissible under Standard No. 108 and does not have to meet the standard's requirements, but it must not impair the effectiveness of the lighting equipment required by the standard (paragraph S4.1.3). Because of the difference in candela between parking lamps and headlamps, information available to us does not indicate that your supplementary parking lamp would have this effect, and consequently, the design would be permitted.
I hope that this answers your questions.
Sincerely,
Original Signed By Frank Berndt Chief Counsel |
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ID: 77-1.5OpenTYPE: INTERPRETATION-NHTSA DATE: 01/18/77 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Marchal America TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of December 17, 1976, asking whether 15 U.S.C. 1392(d) permits the installation of quartz halogen headlamps on State-owned vehicles. It is understood that these headlamps are manufactured in France, and are not of sealed beam construction. Thus they do not conform to Motor Vehicle Safety Standard No. 108. Your letter also commented that certain "state highway and law enforcement agencies . . . have indicated . . . that they prefer the quartz halogen units but are reluctant to install these units in their state vehicles because they are not of an approved type." Importation and sale of nonconforming motor vehicle equipment is expressly forbidden by Section 108(a)(1)(A) of the National Traffic and Motor Vehicle Safety Act. A civil penalty of up to $ 1,000 may be imposed for each violation. Therefore, quartz halogen headlamps that do not conform to Standard No. 108 may not be imported into the United States and sold to State agencies. Your inquiry appears premised that such may be allowable pursuant to Section 1392(d) which reads in pertinent part: Nothing in the section shall be construed to prevent . . . the government of any State or political subdivision thereof from establishing a safety requirement applicable to motor vehicle or motor vehicle equipment procured for its own use if such requirement establishes a higher standard of performance than that required to comply with the otherwise applicable federal standard. Section 1392(d) reflects a primary purpose of the National Traffic and Motor Vehicle Safety Act that there be uniform national safety standards for the manufacture of motor vehicles, and that the flow of interstate commerce not be burdened by differing requirements among the States. An exception is made, however, that allows the States to set higher standards for vehicles manufactured for State use. Section 1392(d) would be inapplicable to your fact situation which, as we understand it, involves a conversion after purchase, and does not involve a procurement specification affecting the vehicle manufacturer. |
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ID: 2401yOpen Mr. George B. Maday Dear Mr. Maday: This is in reply to your letter with respect to the automatic light switching device whose potential for the U.S. market you are assessing. The device automatically activates the headlamps at a pre-determined (but adjustable) level of darkness. There is a manual override for the operator. I regret the delay in responding. You have asked two questions: "l. What legislation is in force or pending regarding the mandatory utilization of such daytime running lights for vehicles?" None. The agency once proposed that motor vehicles be equipped with daytime running lamps as an option, but it terminated rulemaking on this subject without taking action. "2. What regulations, standards, forms, etc. have to be submitted to you or the appropriate agency to ensure that the product meets any U.S. specifications or standards prior to importation. None. There are no Federal motor vehicle safety standards that apply to this item of motor vehicle equipment. However, if you intend it to be installed as an item of original equipment, it must not create a noncompliance with Motor Vehicle Safety Standard No. l08 Lamps, Reflective Devices, and Associated Equipment, or result in an impairment of the effectiveness of the lighting equipment that the standard requires. For example, the standard requires the taillamps to be activated when the headlamps are activated. Therefore, when your device activates the headlamps, the taillamps must also be activated. Though expressed in somewhat different terms, the acceptability of your device in the aftermarket is governed by a similar consideration: it may not be installed by a motor vehicle manufacturer, distributor, dealer or repair business if the installation would render inoperative any element of design or device installed in accordance with Standard No. l08. The device would remain subject to the laws of any State in which it is sold or operated. We are unable to advise you as to its acceptability under State laws, and recommend that you consult the American Association of Motor Vehicle Administrators (AAMVA), 4600 Wilson Boulevard, Arlington, Va. 22203. Sincerely, Stephen P. Wood Acting Chief Counsel ref:l08 d:4/8/90 |
1990 |
ID: nht90-2.1OpenTYPE: INTERPRETATION-NHTSA DATE: APRIL 8, 1990 FROM: STEPHEN P. WOOD -- ACTING CHIEF COUNSEL, NHTSA TO: GEORGE B. MADAY -- PRES., NETWORK USA INC. TITLE: NONE ATTACHMT: LETTER DATED 11-19-89 TO ADMINISTRATOR, NHTSA, FROM GEORGE B. MADAY ATTACHED. TEXT: This is in reply to your letter with respect to the automatic light switching device whose potential for the U.S. market you are assessing. The device automatically activates the headlamps at a pre-detetmined (but adjustable) level of darkness. There is a manual override for the operator. I regret the delay in responding. You have asked two questions: 1. What legislation is in force or pending regarding the mandatory utilization of such daytime running lights for vehicles?" None. The agency once proposed that motor vehicles be equipped with daytime running lamps as an option, but it terminated rulemaking on this subject without taking action. 2. What regulations, standards, forms, etc. have to be submitted to you or the appropriate agency to ensure that the product meets any U.S. specifications or standards prior to importation. None. There are no Federal motor vehicle safety standards that apply to this item of motor vehicle equipment. However, if you intend it to be installed as an item of original equipment, it must not create a noncompliance with Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices, and Associated Equipment, or result in an impairment of the effectiveness of the lighting equipment that the standard requires. For example, the standard requires the taillamps to be activated when the headlamps are activated. Therefore, when your device activates the headlamps, the taillamps must also be activated. Though expressed in somewhat different terms, the acceptability of your device in the aftermarket is governed by a similar consideration: it may not be installed by a motor vehicle manufacturer, distributor, dealer or repair business if the installation would render inoperative any element of design or device installed in accordance with Standard No. 108. The device would remain subject to the laws of any State in which it is sold or operated. We are unable to advise you as to its acceptability under state laws, and recommend that you consult the American Association of Motor Vehicle Administrators (AAMVA), 4600 Wilson Boulevard, Arlington, Va. 22203. |
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ID: 11371Open Mr. Richard L. Russell Dear Mr. Russell: This responds to your FAX of November 15, 1995, to Blane Laubis of this agency, asking for an interpretation of Federal lighting regulations as they may affect your plans to modify your 1956 Jeep. You wish to add two additional auxiliary lights to supplement your upper beams, and you ask whether these lights are "required to be DOT approved." The answer is no; the DOT regulation on motor vehicle lighting (Federal Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices, and Associated Equipment does not prescribe requirements for lamps intended to supplement the headlamps, and thus the lamps of which you speak do not have to be certified as meeting Standard No. 108. As a matter of information, your use of the words "DOT approved" reflects a common misconception. We have no authority to approve or disapprove lighting equipment. Under our statute, a lighting (or vehicle) manufacturer is required to certify that its equipment (or vehicle) meets Standard No. 108 (if it is replacement equipment included in the standard), and the use of the DOT symbol on the item is the most frequently used method of certification. This means that the "DOT approved" headlamps on your 1956 Jeep are probably replacement sealed beams with DOT markings on them. You ask whether there is any limitation to bulb wattage for auxiliary lamps used to supplement the headlamps when used on the upper beam. There is no wattage limitation; however, if auxiliary lamps were installed by the dealer on a new vehicle before its first sale, we would regard the vehicle manufacturer's certification as negated if the brightness and location of the auxiliary lamps were such as to affect an oncoming driver's ability to perceive the front turn signals. Although your Jeep was manufactured long before the effective date of Standard No. 108 (January 1, 1969), we ask you to consider this safety concern when adding auxiliary lamps. We do not know the local laws on this subject, and recommend that you seek advice from the Department of California Highway Patrol. If you have any further questions, Taylor Vinson of this Office will answer them for you (phone 202-366- 5263). Sincerely,
Samuel J. Dubbin Chief Counsel ref:108 d:12/22/95
|
1995 |
ID: nht95-5.10OpenTYPE: INTERPRETATION-NHTSA DATE: December 22, 1995 FROM: Samuel J. Dubbin -- Chief Counsel, NHTSA TO: Richard L. Russell TITLE: NONE ATTACHMT: 11/15/95 letter from Rick Russell to Blane Laubis TEXT: This responds to your FAX of November 15, 1995, to Blane Laubis of this agency, asking for an interpretation of Federal lighting regulations as they may affect your plans to modify your 1956 Jeep. You wish to add two additional auxiliary lights to supplement your upper beams, and you ask whether these lights are "required to be DOT approved." The answer is no; the DOT regulation on motor vehicle lighting (Federal Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices, and Associated Equipment does not prescribe requirements for lamps intended to supplement the headlamps, and thus the lamps of which you speak do not have to be certified as meeting Standard No. 108. As a matter of informa tion, your use of the words "DOT approved" reflects a common misconception. We have no authority to approve or disapprove lighting equipment. Under our statute, a lighting (or vehicle) manufacturer is required to certify that its equipment (or vehicle) meets Standard No. 108 (if it is replacement equipment included in the standard), and the use of the DOT symbol on the item is the most frequently used method of certification. This means that the "DOT approved" headlamps on your 1956 Jeep are probably replacement sealed beams with DOT markings on them. You ask whether there is any limitation to bulb wattage for auxiliary lamps used to supplement the headlamps when used on the upper beam. There is no wattage limitation; however, if auxiliary lamps were installed by the dealer on a new vehicle before it s first sale, we would regard the vehicle manufacturer's certification as negated if the brightness and location of the auxiliary lamps were such as to affect an oncoming driver's ability to perceive the front turn signals. Although your Jeep was manufactured long before the effective date of Standard No. 108 (January 1, 1969), we ask you to consider this safety concern when adding auxiliary lamps. We do not know the local laws on this subject, and recommend that you seek advice from the Department of California Highway Patrol. If you have any further questions, Taylor Vinson of this Office will answer them for you (phone 202-366-5263). |
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ID: nht95-7.65OpenTYPE: INTERPRETATION-NHTSA DATE: December 22, 1995 FROM: Samuel J. Dubbin -- Chief Counsel, NHTSA TO: Richard L. Russell TITLE: NONE ATTACHMT: 11/15/95 letter from Rick Russell to Blane Laubis TEXT: This responds to your FAX of November 15, 1995, to Blane Laubis of this agency, asking for an interpretation of Federal lighting regulations as they may affect your plans to modify your 1956 Jeep. You wish to add two additional auxiliary lights to supplement your upper beams, and you ask whether these lights are "required to be DOT approved." The answer is no; the DOT regulation on motor vehicle lighting (Federal Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices, and Associated Equipment does not prescribe requirements for lamps intended to supplement the headlamps, and thus the lamps of which you speak do not have to be certified as meeting Standard No. 108. As a matter of information, your use of the words "DOT approved" reflects a common misconception. We have no authority to approve or disapprove lighting equipment. Under our statute, a lighting (or vehicle) manufacturer is required to certify that its equipment (or vehicle) meets Standard No. 108 (if it is replacement equipment included in the standard), and the use of the DOT symbol on the item is the most frequently used method of certification. This means that the "DOT approved" headlamps on your 1956 Jeep are probably replacement sealed beams with DOT markings on them. You ask whether there is any limitation to bulb wattage for auxiliary lamps used to supplement the headlamps when used on the upper beam. There is no wattage limitation; however, if auxiliary lamps were installed by the dealer on a new vehicle before its first sale, we would regard the vehicle manufacturer's certification as negated if the brightness and location of the auxiliary lamps were such as to affect an oncoming driver's ability to perceive the front turn signals. Although your Jeep was manufactured long before the effective date of Standard No. 108 (January 1, 1969), we ask you to consider this safety concern when adding auxiliary lamps. We do not know the local laws on this subject, and recommend that you seek advice from the Department of California Highway Patrol. If you have any further questions, Taylor Vinson of this Office will answer them for you (phone 202-366-5263). |
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.