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: aiam1802OpenMr. Fred W. Cords, Minnesota Automotive, Inc., Box 2074, North Mankato, MN 56001; Mr. Fred W. Cords Minnesota Automotive Inc. Box 2074 North Mankato MN 56001; Dear Mr. Cords: This is in reply to your letter of January 6, 1975, requesting a opinion on whether a person who installs a Mico Brake Lock device on a new vehicle before its sale to the first purchaser is required to affix an alterer label in accordance with 49 CFR SS 567.7 and 568.8. You state that you believe the device, which serves as a hydraulic parking brake, is readily attachable because it can be installed in a minimum amount of time and does not in any way alter the operation of the vehicle's original brake system.; The NHTSA will generally abide by a good faith determination on th part of a manufacturer that a device is readily attachable. Such a decision should be based primarily on the intricacy of the installation of the device. Simple tools, a relatively short installation time, and the ability to install the device without extensively modifying the vehicle would all be factors pointing to a decision that a component is readily attachable. You should note that section 567.7 of the Certification regulations also requires an alterer label when the installation of a component invalidates a vehicle's existing weight ratings, whether or not the component is readily attachable. On the basis of your letter, however, it appears to us that this would not occur as a result of installation of the Mico Brake Lock device.; If your device meets these criteria, no additional labeling will b required.; Yours truly, James C. Schultz, Acting Chief Counsel |
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ID: aiam4006OpenWarren F. B. Lindsley, Esq., Camel Square Suite 200E, 4350 East Camelback Road, Phoenix, AZ 85018; Warren F. B. Lindsley Esq. Camel Square Suite 200E 4350 East Camelback Road Phoenix AZ 85018; Dear Mr. Lindsley: This is in reply to your letter of July 3, 1985, to Mr. Vinson of m staff, with reference to the center high-mounted stop lamp, in which you have asked 'whether a light which pulsates a few times and then assumes a steady state meets the requirements of the code.'; As Mr. Vinson explained to you, a center high-mounted stop lam installed as original equipment on a passenger car manufactured before September 1, 1986, must be steady-burning in use, but is permitted to flash automatically with the hazard warning system. As of September 1, 1986, original equipment lamps must only be activated upon application of the service brakes, and can only be steady-burning. A 'light that pulsates a few times then assumes a steady state' would not fulfill this requirement.; The standard does not cover aftermarket equipment for vehicles no originally manufactured with the center high-mounted stop lamp. For this application, the law of each State where a retrofitted car would be operated would determine the legality of a pulsating/steady state lamp. The agency, of course, would prefer that aftermarket equipment conform as closely as possible to original vehicle equipment specifications. We believe that standardization of rear signals minimizes the possibility of creating confusion to following drivers in situations where immediate action is essential to avoid a rear end collision.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam2608OpenMr. Chester J. Barecki, Vice President - Sales Engineering, American Seating Company, 901 Broadway Avenue, N. W., Grand Rapids, MI 49504; Mr. Chester J. Barecki Vice President - Sales Engineering American Seating Company 901 Broadway Avenue N. W. Grand Rapids MI 49504; Dear Mr. Barecki: This responds to your March 24, 1977, letter asking for a interpretation of the requirements for knee contact area in Standard No. 222, *School Bus Passenger Seating and Crash Protection*, which state that, when impacted, 'the resisting force of the impacted material shall not exceed 600 pounds and the contact area on the knee form surface shall not be less than 3 square inches.' You ask whether this requirement can be interpreted as meaning that, when impacted, the resisting force of the impacted material shall not exceed 200 pounds per square inch rather than 600 pounds over 3 square inches.; The 600 pound maximum force and the 3 square inch minimum contact are are two distinct requirements. The first specifies an upper bound on the load that will be applied to the upper leg while the latter specifies a lower bound on the knee area over which an impact load must be distributed. To combine the two requirements, as you suggest, tends to relax the contact area requirement for a load which is less than 600 pounds. Such an interpretation would not ensure the level of safety the agency demands for knee contact area. The suggested combination of the two requirements may not provide an adequate distribution of forces over the knee. Accordingly, the agency declines to accept the suggested interpretation of the standard.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam2624OpenMr. Jerry W. McNeil, Director of Engineering, American Trailers, Inc., Box 26568, Oklahoma City, OK 73126; Mr. Jerry W. McNeil Director of Engineering American Trailers Inc. Box 26568 Oklahoma City OK 73126; Dear Mr. McNeil: This responds to your May 25, 1977, letter asking whether two sampl certification labels you submitted comply with the requirements of Part 567, *Certification*, and Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars*.; The National Highway Traffic Safety Administration (NHTSA) does no issue advance approvals of compliance with Federal safety standards or regulations. The agency will, however, give you an informal opinion as to whether your labels appear to comply with the requirements. The two labels you submitted do not follow the format required by Part 567 for certification labels. Therefore, they do not appear to comply with the requirements. Your method of stating tire and rim sizes differs from that required in Part 567 and Standard No. 120. For example, you state your tire and rim information as follows: '10-20-F-Tires-7.5 Rims at 75 PSI Cold Dual.' By the requirements of Part 567 and Standard No. 120 as they apply to certification labels, this information should read: '10.00-20(F) tires, 20x7.5 rims, at 75 psi cold dual.' Further, the statement after GAWR 'maximum with minimum size tire-rims shown below' should be deleted from the certification label. I am enclosing a copy of Part 567 and Standard No. 120 for your information.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam0989OpenMr. Orin D. Miner, P.O. Box 138, Palmyra, Wisconsin 53156; Mr. Orin D. Miner P.O. Box 138 Palmyra Wisconsin 53156; Dear Mr. Miner: Contact 6 of Milwaukee, Wisconsin has sent us a copy of your lette asking that we respond to your questions.; In your letter you inquire as to the distribution of fines collecte from tire manufacturers as a result of their manufacturing tires that do not comply with the requirements of the Federal standard for passenger car tires (Standard No. 109).; Monies collected as settlement offers are transmitted to the genera funds of the United States Treasury.; The Federal Motor Vehicle Safety Standard, including the passenger ca tire standard, are minimum standards vehicle manufacturers and equipment manufacturers are required to meet. They are issued to give assurance that if the product in question meets the standards the public will have some protection against unreasonable risk of death or injury.; In addition to the question of civil penalties, manufacturers o non-conforming vehicles or tires are usually required to issue a defect notification and are urged to replace the defective equipment. Your complaint does not appear to be concerned with a safety related problem but rather with tires that you believe have not given you adequate treadwear. This is not area covered by existing standards, however, this agency has under consideration a quality grading regulation which would include grading requirements for the treadwear life of each tire manufactured after a given date.; Concerning your recommendation that Federal inspectors be placed i tire manufacturers' plants, has been considered at various times and the agency's present thinking is that the cost and manpower involved would not warrant this course of action.; Thank you for your interest in auto safety and your view in this area. Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam0147OpenMr. Eugene D. Prahst, Chief Product Engineer, Dump Trailer Division, The Heil Company, 3000 W. Montana Street, Milwaukee, WI 53201; Mr. Eugene D. Prahst Chief Product Engineer Dump Trailer Division The Heil Company 3000 W. Montana Street Milwaukee WI 53201; Dear Mr. Prahst: Thank you for your letter of February 24, 1969, to the Office o Standards Preparation, concerning the proposed lighting equipment on your dump trailers.; The lamps and reflectors shown on your drawing 701B1907 dated Februar 20, 1969, appear to be in conformance with the requirements of Standard No. 108 with the following exceptions:; >>>1. The required license plate lamp is not shown. 2. The minimum mounting height for reflectors is 15 inches. 3. With respect to maximum mounting zones for lamps and reflectors, th limiting dimensions of 16, 30, and 24 inches indicated on your drawing appear to be too liberal for a trailer with essentially square corners.; 4. With reference to Notes 2 and 3 on your drawing, certai restrictions as specified in paragraph S3.3 of Standard No. 108 are applicable for combination lamps.<<<; With respect to the requirements of Standard No. 108, I must point ou 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 Standard No. 108.; Sincerely, Charles A. Baker, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service; |
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ID: aiam3139OpenMr. M. S. Keshav, Manager - Research & Development, Bajaj Auto Limited, Bombay Poona Road, Akurdi - Poona - 411 035, India; Mr. M. S. Keshav Manager - Research & Development Bajaj Auto Limited Bombay Poona Road Akurdi - Poona - 411 035 India; Dear Mr. Keshav: This is in reply to your letter of September 2, 1979, to Franci Armstrong asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108. SAE Standard J588e August 1970 is the referenced standard for turn signal lamps. Paragraph 4.2 of J588e requires that as mounted on the vehicle 'The optical axis (filament center) of the front turn signal lamp shall be at least 4 inches from the inside diameter of the retaining ring of the headlamp unit providing the lower beam'. You mentioned that on some motorcycles sold in the United States this requirement is satisfied only with the handlebar in the straight ahead position but not when turned to the full lock position. You asked whether this complies with Standard No. 108.; Table IV specifies that the minimum edge to edge separation between th headlamp and turn signal lamp on motorcycles is 4 inches. Most manufacturers have interpreted this requirement to mean that the separation is permanent, and have supplied turn signals that are mounted stationary with the headlamp, and that turn with it so that the separation distance is maintained. Therefore, the configuration you describe would not comply with Standard No. 108 because Federal requirements for location and mounting of lighting equipment are intended to apply to a vehicle under all its operating conditions.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2175OpenMr. R. D. Coughlin, Vice President, Rol'on America, Inc., Melbourne, FL 32901; Mr. R. D. Coughlin Vice President Rol'on America Inc. Melbourne FL 32901; Dear Mr. Coughlin: This is in response to your letter of December 10, 1975, regarding th applicability of existing Federal regulations to the manufacture of 'Helmate.'; At the present time, there is no regulation pertaining directly to th type of helmet accessory your corporation produces. The general regulation concerning motorcycle helmets is 49 CFR S 571.218, Motor Vehicle Safety Standard No. 218, *Motorcycle Helmets*. This standard establishes minimum performance requirements for helmets designed for use by motorcyclists and other motor vehicle users.; If a manufacturer, distributor, dealer, or motor vehicle repai business were to install 'Helmates' on helmets, the helmets would have to remain in conformity with the requirements of Standard 218. However, persons other than manufacturers, distributors, dealers, and repair businesses may modify products, after purchase by a user, without regard to the requirements of a Federal safety regulation. Thus, if 'Helmate' is mounted on the helmet by an ordinary consumer, safety Standard 218 is inapplicable.; There is some question as to whether motorcycle helmets will still mee the performance requirements of Standard 218, after the 3/8 inch hole required to mount the 'Helmate' is drilled. If it becomes apparent that installing 'Helmate' type helmet accessories causes the performance level of helmets to drop below the requirements of Standard 218, the NHTSA might find it necessary to enact regulations to rectify the situation. Our main concern is to assure that motorcycle helmets afford riders the protection and safety needed.; If I can be of any further assistance, please feel free to write. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0559OpenMr. L. M. Preziosi, Division Engineering Manager, Westinghouse Specialty Lamp Division, Westinghouse Electric Corporation, One Westinghouse Plaza, Bloomfield, NJ 07003; Mr. L. M. Preziosi Division Engineering Manager Westinghouse Specialty Lamp Division Westinghouse Electric Corporation One Westinghouse Plaza Bloomfield NJ 07003; Dear Mr. Preziosi: In your letter of December 22, 1971 to Lawrence R. Schneider you as for a clarification of the relationship between 49 CFR Part 566 - *Manufacturer Identification*, and 49 CFR S 571.108, Motor Vehicle Safety Standard No. 108, *Lamps, Reflective Devices, and Associated Equipment*. Specifically you ask whether identifying information is required for miniature bulbs.; Standard No. 108 establishes performance requirements for items o motor vehicle lighting equipment, and incorporates by reference certain SAE standards that specify requirements lamps must meet in laboratory tests when assembled. The SAE standard that applies to bulbs, J573d, *Lamp Bulbs and Sealed Units*, is not incorporated by reference, and Standard No. 108 contains no requirements for the output of bulbs furnished with a lamp assembly. When a lamp is tested for conformity, the production bulb is removed and a calibrated bulb substituted, in accordance with Paragraph C of SAE Standard J575d, *Tests for Motor Vehicle Lighting Devices and Components*, the test bulb is to be 'representative of standard bulbs in regular production' and must be 'selected for accuracy in accordance with specifications listed in . . . SAE J573.'; In summary, Standard No. 108 does not specify performance requirement for lamp bulbs, and production bulbs are not used in lamp testing. Therefore, Standard No. 108 does not apply to bulbs and bulb manufacturers are not required to certify conformance to Federal standards, or to submit information pursuant to the *Manufacturer Identification* regulations.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3585OpenMr. Ron Gustafson, Furudals Buruks Kursinternat, 790 70 FURUDUAL Sweden; Mr. Ron Gustafson Furudals Buruks Kursinternat 790 70 FURUDUAL Sweden; Dear Mr. Gustafson: This responds to your letter of June 28, 1982, asking abou requirements applicable to child restraints sold in the United States as well as any necessary permits or licenses. You also asked about any U.S. testing organizations, procedures or standards for child restraints.; All child restraints sold in the U.S. must conform with the minimu performance requirements of Federal Motor Vehicle Safety Standard No. 213, *Child Restraint Systems*. The standard also sets out the test procedures that are used to measure the performance of child restraints. There are no other performance requirements or test procedures applicable to child restraints. I am enclosing a copy of the standard.; You are not required to obtain a permit or license from this agenc prior to selling a child restraint in the U.S., nor are you required to obtain approval from any U.S. testing organization. As a manufacturer of motor vehicle equipment, you are required by Part 566, *Manufacturer Identification*, of our regulation to submit certain identifying information to the agency. I have enclosed a copy of Part 566.; In addition, you would be required by the National Traffic and Moto Vehicle Safety Act (15 U.S.C. S1392 *et seq*.) to certify that your child restraint complies with all applicable Federal Motor Vehicle Safety Standards. Under the Act, you would also be responsible for conducting a notification and remedy campaign for any safety-related defect in your product. I am enclosing a copy of the Act, which defines your responsibilities as a manufacturer.; If you have any further questions, please let me know. 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.