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: aiam1469OpenMr. William A. Goichman, Rozner and Yorty, Suite 1808, 10960 Wilshire Boulevard, Los Angeles, CA 90024; Mr. William A. Goichman Rozner and Yorty Suite 1808 10960 Wilshire Boulevard Los Angeles CA 90024; Dear Mr. Goichman: This responds to your March 26, 1974, request for information on sea belt regulations as they concern reclining passenger seats.; Federal Motor Vehicle Safety Standard No. 208, *Occupant Cras Protection,* requires passenger cars to be equipped with seat belt assemblies, but it does not contain performance requirements to regulate the effectiveness of the belt assembly with the seating system in the reclining position.; Federal Motor Vehicle Safety Standard No. 207, *Seating Systems* specifies minimum safety requirements for motor vehicle seats. The requirements of the standard are based on conventional seat designs that normally incorporate a seat back angle of approximately 25 degrees rearward inclination from the vertical. Standard No. 207 requires that reclining seats be tested in their most upright position and does not require seats to be tested in the reclining position.; The National Traffic and Motor Vehicle Safety Act of 1966 preempt state motor vehicle safety regulations which are not identical to the Federal standards with regard to the same aspect of performance and therefore any state law would be identical to Standards Nos. 207 and 208 on these aspects of performance (15 U.S.C. S1392 (d)).; The engineering staff is not aware of any studies in the area of sea belts and reclining seats.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2622OpenMr. Jerry W. McNeil, Director of Engineering, American Trailers, Inc., Box 26568, Oklahoma City, Oklahoma 73126; Mr. Jerry W. McNeil Director of Engineering American Trailers Inc. Box 26568 Oklahoma City Oklahoma 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: aiam2225OpenMr. Clarence J. Baudhuin, 24040 Killion Street, Woodland Hills, CA 91364; Mr. Clarence J. Baudhuin 24040 Killion Street Woodland Hills CA 91364; Dear Mr. Baudhuin: This is in response to your January 29, 1976, letter to Secretar Coleman, concerning problems with your 22 foot Executive 'MINI' Motorhome.; SS 567.4(g)93) and 567.5(a)(5) of 49 CFR Part 567, *Certification* provide that a motor vehicle's Gross Vehicle Weight Rating (GVWR) shall; >>>not be less than the sum of the unloaded vehicle weight, rated carg load, and 150 pounds times the vehicle's designated seating capacity.<<<; Your letter and its enclosures indicate that your vehicle's weight i 9180 pounds, its designated seating capacity is six, and the GVWR specified by Executive is 9000 pounds. From this information, there appears to be a violation by Executive of Part 567. In addition, the possibility that the rear axle may be overloaded under normal conditions of use may constitute a defect related to motor vehicle safety. I have forwarded your letter to our Office of Standards Enforcement for such further action as may be appropriate.; Please note that a final-stage manufacturer is not automaticall prohibited from certifying a GVWR that differs from that specified by the chassis manufacturer. For the purposes of the Federal motor vehicle safety standards and regulations, Executive is free to certify a lower GVWR, provided the above-cited constraint is observed.; The remaining questions presented in your letter are not matters ove which we have jurisdiction, and probably are most appropriately handled by a private attorney.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam1580OpenMr. Raymond E. Jones, Project Engineer, Dura Corporation, Fords Mill Road, Paris, KY 40361; Mr. Raymond E. Jones Project Engineer Dura Corporation Fords Mill Road Paris KY 40361; Dear Mr. Jones: This responds to Dura Corporation's July 24, 1974, questions whethe S5.6 of Standard No. 121, *Air brake systems*, requires parking brakes on air suspension liftable axles, and whether the 'no lockup' requirements of the standard apply to a liftable axle on a 'tandem axle rig'.; The parking brake performance options of S5.6 do not require parkin brakes on an air suspension liftable axle such as you describe. S5.6.2 requires only that the parking brakes installed on a vehicle meet minimum performance levels. S5.6.1 requires parking brake retardation force on 'an axle other than a steerable front axle'. We do not consider this requirement to apply to an axle which is not on the ground when the parking brake system is activated.; The standard's 'no lockup' requirement (S5.3.1) applies to >>>'any wheel at speeds above 10 mph except for . . . (b) Lockup of wheels on nonsteerable axles other than the two rearmos nonliftable, nonsteerable axles on a vehicle with more than two nonsteerable axles.<<<; Under this provision, if a vehicle has two nonliftable, nonsteerabl axles at the rear which do not lock up (such as an antilock-equipped tandem axle rig) it may be equipped with a liftable nonsteerable axle which does not meet the 'no lockup' requirements.; Yours truly, Richard B. Dyson, Acting Chief Counsel. |
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ID: aiam3371OpenMr. Stephen E. Mulligan, International Harvester, 401 North Michigan Avenue, Chicago, IL 60611; Mr. Stephen E. Mulligan International Harvester 401 North Michigan Avenue Chicago IL 60611; Dear Mr. Mulligan: This is in response to your letter of October 1, 1980, in which you as whether compliance with 49 CFR 567, Certification, will satisfy the requirements of S4.3 of Federal Motor Vehicle Safety Standard No. 115, 49 CFR 571.115.; Section 4.3 of Federal Motor Vehicle Safety Standard No. 115 require that the vehicle identification number (VIN) 'appear clearly and indelibly upon either a part of the vehicle other than the glazing that is not designed to be removed except for repair or upon a separate plate or label which is permanently affixed to such a part.' S4.3.1 requires each character to appear in a capital, sans serif typeface. In the case of passenger cars and trucks of 10,000 pounds or less GVWR, each character must have a minimum height of 4 mm. S4.4 specifies that the VIN for passenger cars and trucks of 10,000 pounds or less GVWR shall be located within the passenger compartment.; Section 567.4 of Part 567, Certification (49 CFR 567), requires tha the certification label be permanently affixed to the vehicle, and display the vehicle identification number. Consequently, for all vehicles except passenger cars and trucks of 10,000 pounds or less GVWR, compliance with S 567.4 of Part 567 would also effect compliance with S4.3 of Standard No. 115 so long as capital, sans serif typeface was used.; Sincerely, Frank Berndt, Chief Counsel |
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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: aiam3369OpenMr. Stephen E. Mulligan, International Harvester, 401 North Michigan Avenue, Chicago, Il 60611; Mr. Stephen E. Mulligan International Harvester 401 North Michigan Avenue Chicago Il 60611; Dear Mr. Mulligan: This is in response to your letter of October 1, 1980, in which you as whether compliance with 49 CFR 567, Certification, will satisfy the requirements of S4.3 of Federal Motor Vehicle Safety Standard No. 115, 49 CFR 571.115.; Section 4.3 of Federal Motor Vehicle Safety Standard No. 115 require that the vehicle identification number (VIN) 'appear clearly and indelibly upon either a part of the vehicle other than the glazing that is not designed to be removed except for repair or upon a separate plate or label which is permanently affixed to such a part.' S4.3.1 requires each character to appear in a capital, sans serif typeface. In the case of passenger cars and trucks of 10,000 pounds or less GVWR, each character must have a minimum height of 4 mm. S4.4 specifies that the VIN for passenger cars and trucks of 10,000 pounds or less GVWR shall be located within to passenger compartment.; Section 567.4 of Part 567, Certification (49 CFR 567), requires tha the certification label be permanently affixed to the vehicle, and display the vehicle identification number. Consequently, for all vehicles except passenger cars and trucks of 10,000 pounds or less GVWR, compliance with S 567.4 of Part 567 would also effect compliance with S4.3 of Standard No. 115 so long as capital, sans serif typeface was used.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3105OpenMr. Lourdes M. Delgado, 3000 Kennedy Boulevard, Room 307, Jersey City, NJ 07306; Mr. Lourdes M. Delgado 3000 Kennedy Boulevard Room 307 Jersey City NJ 07306; Dear Mr. Delgado: This responds to your recent letter requesting information concernin Federal and State laws applicable to the manufacture of van seats.; The National Highway Traffic Safety Administration issues safet standards and regulations governing the manufacture of motor vehicles and motor vehicle equipment. Safety Standard No. 207, *Seating Systems* (49 CFR 571.207), specifies performance requirements for seats, their attachment assemblies and their installation to minimize the possibility of seat failure resulting from crash forces. This standard is applicable to seats as installed in vehicles, including vans, but is not applicable to seats as individual pieces of motor vehicle equipment. Therefore, the vehicle manufacturer, not the seat manufacturer, would be responsible for compliance with Standard No. 207. However, under section 151, *et seq*., of the National Traffic and Motor Vehicle Safety Act, a manufacturer of vehicle seats would be responsible for any safety related defects in his products and would be required to notify owners and remedy the defects.; I am enclosing a copy of Safety Standard No. 207 for your information as well as an information sheet that explains where you can obtain copies of all our standards and regulations. You will have to contact the individual States in which you are interested to find out if there are any State or local laws applicable to your business.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3372OpenMr. Stephen E. Mulligan, International Harvester, 401 North Michigan Avenue, Chicago, IL 60611; Mr. Stephen E. Mulligan International Harvester 401 North Michigan Avenue Chicago IL 60611; Dear Mr. Mulligan: This is in response to your letter of October 1, 1980, in which you as whether compliance with 49 CFR 567, Certification, will satisfy the requirements of S4.3 of Federal Motor Vehicle Safety Standard No. 115, 49 CFR 571.115.; Section 4.3 of Federal Motor Vehicle Safety Standard No. 115 require that the vehicle identification number (VIN) 'appear clearly and indelibly upon either a part of the vehicle other than the glazing that is not designed to be removed except for repair or upon a separate plate or label which is permanently affixed to such a part.' S4.3.1 requires each character to appear in a capital, sans serif typeface. In the case of passenger cars and trucks of 10,000 pounds or less GVWR, each character must have a minimum height of 4 mm. S4.4 specifies that the VIN for passenger cars and trucks of 10,000 pounds or less GVWR shall be located within the passenger compartment.; Section 567.4 of Part 567, Certification (49 CFR 567), requires tha the certification label be permanently affixed to the vehicle, and display the vehicle identification number. Consequently, for all vehicles except passenger cars and trucks of 10,000 pounds or less GVWR, compliance with S 567.4 of Part 567 would also effect compliance with S4.3 of Standard No. 115 so long as capital, sans serif typeface was used.; Sincerely, Frank Berndt, Chief Counsel |
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.