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: aiam3767OpenMr. Lee Jay Mandell, President, LJM Associates, Inc., 22030 Lanark Street, Canoga Park, CA 91034; Mr. Lee Jay Mandell President LJM Associates Inc. 22030 Lanark Street Canoga Park CA 91034; Dear Mr. Mandell: This is in response to your letter of October 19, 1983, discussing lighting product that you have developed and asking for 'the approval of the DOT or at least to insure that no active disapproval would be forthcoming.'; Your device utilizes the body panel between the left and right rea lights to emphasize braking, right and left turns, hazard flashing, and backing up. Roughly, your device operates by lights spreading from the center of the panel outward, in either or both directions.; We think that there is great potential for confusion that this devic could create since it is so unlike anything seen before on a motor vehicle. In the stopping mode the driver following will see the steady light of the stop lamp at the edge of the vehicle, but also the dynamic lights of your device spreading out from the center. The same dynamic light spread is seen but is meant to indicate something entirely different when both turn signal lamps are operating simultaneously in the hazard warning mode. Thus, the potential for impairment of the required lighting equipment exists.; Generally, we do not favor any lights on the rear of a vehicle that ar not required by the Federal lighting standard.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2875OpenMr. Ken Yoneyama, Chief Engineer, Bridgestone Research Inc., 350 Fifth Ave., Suite 4202, New York, New York 10001; Mr. Ken Yoneyama Chief Engineer Bridgestone Research Inc. 350 Fifth Ave. Suite 4202 New York New York 10001; Dear Mr. Yoneyama: This is in response to your letter of September 22, 1978, askin whether tires listed in Table 1-A of Appendix A, Federal Motor Vehicle Safety Standard No. 109, *New Pneumatic Tires - Passenger Cars*, must comply with Part 575.104, *Uniform Tire Quality Grading Standards*, (UTQGS), if the tires are installed as original equipment on multi-purpose passenger vehicles. You also inquire as to the effective dates for the provision of UTQGS information to first purchasers of new motor vehicles under Part 575.104(d) (1) (iii).; UTQGS applies to a tire type whose predominant contemplated use is o passenger cars, even if the manufacturer knows the tire type is also used as original equipment on multi-purpose passenger vehicles. A manufacturer's determination to certify a tire as conforming to Standard No. 109, will also determine the tire's classification for purposes of UTQGS. Thus, UTQGS would apply to any tire labeled with a size designation listed in Appendix A of Standard no.l 109, other than a deep tread, winter-type snow tire or space-saver or temporary use spare tire, regardless of the tire's actual use.; On October 23, 1978, NHTSA issued a *Federal Register* notice (cop enclosed) granting the petition of American Motors Corporation to revise the effective dates for Part 575.105(d) (1) (iii) to September 1, 1979 for bias-ply tires and March 1, 1980 for bias-belted tires. On the basis of this change, your statement regarding effective dates is correct.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam0848OpenMr. Gorou Utsunomiya, Chief, Liaison Engineer in U.S., 23777 Greenfield Road, Suite 462, Southfield, MI 48075; Mr. Gorou Utsunomiya Chief Liaison Engineer in U.S. 23777 Greenfield Road Suite 462 Southfield MI 48075; Dear Mr. Utsunomiya: This is in reply to your letter of August 8, 1972, enclosing sketche of motor vehicles and asking into which vehicle category under the motor vehicle safety standards they fall. The numbered paragraphs below correspond to those in your letter.; >>>1. Figures 1, 2, and 3 illustrate trailers under the standards Trailers are presently subject only to Motor Vehicle Safety Standard No. 108, 'Lamps, Reflective Devices, and Associated Equipment.' Trailers equipped with air brakes and manufactured after September 1, 1974, will be required to conform to Standard No. 121, 'Air Brake Systems.' It is unlikely that many camping or recreational trailers will be subject to these requirements.; 2. Figure 4 illustrates two pickup trucks equipped with slide-i campers. Pickup trucks must conform to all standards applicable to trucks. The campers must conform, as you state, to Motor Vehicle Safety Standard No. 205, 'Glazing Materials.' Both pickup trucks and slide-in campers will be required to conform to a new Standard No. 126, 'Truck- Camper Loading,' when that standard becomes effective. A copy of the standard is enclosed.; 3. In referring to the illustrations of the pickup trucks equipped wit slide-in campers, you ask whether the requirements applicable to the trucks when combined with a camper are different from those applicable when the truck is not so equipped. The answer is no. The standards applicable to pickup trucks (those that are applicable to 'trucks') are the same whether or not the pickup is equipped with a camper.; 4. The requirements for pickup trucks and slide-in campers do no differ if both components are manufactured by the same company.; 5. Wagon campers and motor homes are considered to be multi-purpos passenger vehicles when constructed on truck chassis. The illustrations you enclose appear to us to represent vehicles manufactured on truck chassis.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2526OpenMr. R. M. Premo, Director, Vehicle Safety Activities, Sheller- Globe Corporation, 355 St. Johns Road, Lima, OH 45804; Mr. R. M. Premo Director Vehicle Safety Activities Sheller- Globe Corporation 355 St. Johns Road Lima OH 45804; Dear Mr. Premo: This responds to your February 8, 1977, question whether the use of front-row two-passenger bench seat with a three-passenger seat back requires a forward restraining barrier for two or three designated seating positions according to the requirements of Standard No. 222, *School Bus Passenger Seating and Crash Protection*.; The NHTSA answered this question on February 22, 1977, in response to request for an interpretation from Blue Bird Body Company. I am enclosing a copy of that interpretation for your information. You will note that Blue Bird accomplished the modification of the front-row seat by the installation of a two-passenger bench seat. As the interpretation indicates, the NHTSA requires a restraining barrier only in front of designated seating positions.; You also ask what procedure is required to obtain approval from th NHTSA for a particular Front-row seat design. Although the agency does not give formal 'approval' of designs, it is willing to give an opinion as to whether your design appears to satisfy the requirements of the standard. We require that you submit full detail (including pictures if possible) of the proposed design. In particular, we would like to know how you intend to render the excess 13 inches of frame permanently inoperative as a seating position. We would also be interested to know why you cannot install a two-passenger bench seat to obviate the problem of excess seat frame.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam5349OpenMr. Richard Kreutziger Executive Director New York State Bus Distributors Ass'n 102 Grace Street Penn Yan NY 14527; Mr. Richard Kreutziger Executive Director New York State Bus Distributors Ass'n 102 Grace Street Penn Yan NY 14527; Dear Mr. Kreutziger: This responds to your request of April 13, 1994 for an interpretation of Motor Vehicle Safety Standard No. 108. You reference paragraphs S5.5.7(a) and (b) which apply to vehicles of less than 80 inches overall width and ask whether there are similar requirements for wider vehicles. Paragraph S5.5.7(a) requires that ' w hen the parking lamps are activated, the tail lamps, license plate lamps, and side marker lamps shall also be activated.' There is no similar requirement for vehicles whose overall width is 80 inches or more because these vehicles are not required to have parking lamps (see Table I of Standard No. 108). Paragraph S5.5.7(b) requires that ' w hen the headlamps are activated in a steady-burning state, the tail lamps, parking lamps, license plate lamps and side marker lamps shall also be activated.' Paragraph S5.5.3 requires tail lamps on all vehicles, regardless of width, to be activated when the headlamps are activated in a steady burning state. As noted in the preceding paragraph, wide vehicles are not required to have parking lamps. This leaves the question of license plate lamps and side marker lamps. As you have surmised, there is no specific requirement in Standard No. 108 that these lamps be simultaneously activated with the headlamps on vehicles whose overall width is 80 inches or greater. However, we understand that it is industry practice to wire its large vehicles in this manner. We also believe that those who do not wire the side marker lamps to operate with the headlamps include them in the separate switch that activates the clearance and identification lamps. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam2176OpenMr. Jack Gromer, Timpte, Inc., 5990 N. Washington Street, Denver, CO 80216; Mr. Jack Gromer Timpte Inc. 5990 N. Washington Street Denver CO 80216; Dear Mr. Gromer: This responds to Timpte's December 10, 1975, question whethe modification of a certified trailer prior to retail sale constitutes the manufacture of a vehicle subject to applicable safety standards such as Standard No. 121, *Air Brake Systems*.; The answer to your question is no. From your description, it appear that the proposed modification would be an alteration of a certified vehicle subject to S 567.7 of NHTSA certification regulations (49 CFR S 567.7) (copy enclosed). Under that section, conformity of the vehicle as altered need only be to standards in effect at the time the originally certified trailer was manufactured.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2463OpenMr. Dudley E. DeWitt, Manager/R & D, Great Dane Trailers, Inc., Lathrop Avenue, P.O. Box 67, Savannah, GA 31402; Mr. Dudley E. DeWitt Manager/R & D Great Dane Trailers Inc. Lathrop Avenue P.O. Box 67 Savannah GA 31402; Dear Mr. DeWitt: This responds to Great Dane Trailer's November 4, 1976, questio whether the 'controlled lockup' exception in S5.3.2 of Standard No. 121, *Air Brake Systems*, is available to a manufacturer who equips a 'tri-axle' trailer suspension with one set of wheel speed sensors on the center axle (or, alternatively, on the front axle) and one antilock valve and logic module that meters air pressure to the two rearmost axles.; Your question appears to be similar to questions about tandem-axl suspensions that prompted an interpretation of the 'controlled lockup' exception to the 'no lockup' requirements of S5.3.1 and S5.3.2. A copy is enclosed for your information. You will note that the closing statement in the interpretation states that '. . .the controlled lockup exception is not dependent on the number or location of sensors used in an antilock installation.' It is left to the manufacturer to decide what placement of the sensors will provide the best performance.; Sincerely, Frank A. Berndt |
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ID: aiam2199OpenMr. Jackson Decker, Chief Product Engineer, E. D. Etnyre & Co., 200 Jefferson Street, Oregon, IL 61061; Mr. Jackson Decker Chief Product Engineer E. D. Etnyre & Co. 200 Jefferson Street Oregon IL 61061; Dear Mr. Decker: This responds to your letter of January 5, 1976, requesting informatio as to the criteria used to distinguish between a 'new' or a 'used' chassis, in regard to the certification requirements of 49 CFR Part 567 and 49 CFR Part 568.; You described a situation in which a chassis-cab comes to you 'from th field,' lacking both a certification label and an incomplete vehicle manual, under the claim that it is used, with the absence of a certification label explained by a statement that 'a previous body was mounted and removed by the customer and the vehicle was not presented for resale by a distributor or dealer.' You also add that 'the vehicle reportedly has had extremely limited or no use.'; It seems to us that the facts you are describing constitute a fairl obvious misrepresentation by your customer in order to circumvent the requirements of the standards. Even if the implausible allegation that the customer 'mounted and removed' a body were true, it would not remove the requirement for the vehicle to bear a certification label. Our regulations do not limit the labeling requirement to the narrow language of section 114, any vehicle upon completion must be permanently labeled.; Furthermore, for a vehicle to be 'used' today, it must be titled an registered under the laws of some State. Your letter does not discuss this, but we would assume that any vehicle whose owner cannot produce title and registration as a completed vehicle was never completed and used within the meaning of our regulations.; For these reasons, we would expect you as a final-stage manufacturer t treat as new a chassis-cab brought to you for completion under the conditions you described. If the chassis-cab were properly certified in a manner that evidenced prior use, or the customer were able to produce legitimate title/registration documentation showing significant previous use as a completed vehicle, the answer would of course be different.; Please let us know if we can be of further assistance. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2033OpenMr. Hidekimi Inoue, Bridgestone Tire Co., Ltd., 350 Fifth Avenue, New York 10001; Mr. Hidekimi Inoue Bridgestone Tire Co. Ltd. 350 Fifth Avenue New York 10001; Dear Mr. Inoue: This responds to your letter of July 14, 1975, concerning th permissibility of placing arrow-shaped markings on tire sidewalls to show the location of the treadwear indicators.; Federal Motor Vehicle Safety Standard No. 109 specifies certai labeling requirements for passenger car tires. Standard No. 119 specifies similar labeling for tires designed for use on vehicles other than passenger cars. Although the arrows which you have described are not required by either of these standards, the National Highway Traffic Safety Administration has no objection to such markings provided that none of the required label information is omitted.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam3272OpenMr. Robert Fondiller, President, WOW! Corporation, 200 West 58th Street, New York, NY 10019; Mr. Robert Fondiller President WOW! Corporation 200 West 58th Street New York NY 10019; Dear Mr. Fondiller: This responds to your March 18, 1980, letter to this agency in whic you posed some questions about a 3-wheeled vehicle your company plans to produce. First, you wanted to know if a 3-wheeled vehicle would be classified as a car, a motorcycle, or some other vehicle. Second, you asked if the vehicle could be licensed for street and/or highway use. Third, you asked if replacing the single rear wheel with a double rear wheel would result in the vehicle being classified as a 3- wheel or 4-wheel vehicle, and what effect, if any, classification as a 4-wheel vehicle would have on the answers given to the first two questions.; This agency classifies all 3-wheeled motor vehicles as motorcycles pursuant to the definition of 'motorcycle' given in 49 CFR S 571.3. The pertinent part of that section reads:; >>>'Motorcycle' means a motor vehicle with motive power having a sea or saddle for the use of the rider and designed to travel on not more than three wheels in contact with the ground.<<<; We determine the number of wheels on a vehicle simply by counting thos wheels. Hence, if you were to replace the single rear wheel with a double rear wheel, the vehicle would then be a 4-wheeled vehicle and could not be classified as a motorcycle. Such a vehicle would be classified as a passenger car.; The classification of a vehicle is important since it affects th Federal motor vehicle safety standards with which the vehicle must comply If a vehicle is a motorcycle, it must comply with the following safety standards: 108, 111, 112, 115, 120, 122, 123, and 127. If, on the other hand, a vehicle is a passenger car, it must comply with the following standards: 101, 103, 104, 107, 108, 110, 111, 112, 113, 114, 115, 118, 124, 127, 201, 202, 203, 204, 206, 207, 208, 209, 210, 211, 212, 214, 216, 219, and 302. As you see, the requirements for passenger cars are more stringent than for motorcycles.; I have enclosed a pamphlet prepared by this agency which gives a brie summary of the requirements of each of the Federal motor vehicle safety standards. However, because of the volume of these standards, we do not provide copies directly. I have also enclosed an information sheet which explains how you can obtain copies of our standards and other regulations.; This agency does not license any vehicles for street or highway use. W specify performance requirements, and any motor vehicle must be certified by its manufacturer as being in compliance with all applicable safety standards as of the date of its manufacture. If the vehicle complies with these requirements, we specify no further steps which must be taken.; If you have any further questions concerning motor vehicle safety o need further information, please do not hesitate to contact me.; Sincerely, Frank Berndt, Chief Counsel |
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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.