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: aiam1250OpenMr. Ray Hartman, Vice President, Engineering, Crown Coach Corporation, 2500 East Twelfth Street, Los Angeles, CA 90021; Mr. Ray Hartman Vice President Engineering Crown Coach Corporation 2500 East Twelfth Street Los Angeles CA 90021; Dear Mr. Hartman: This is in reply to your letter of August 28, 1973, concerning th effective date of Motor Vehicle Safety Standard No. 121. Your direct question is whether the effective date is the starting or completion date for the vehicle's components or the starting date for the vehicle.; Standard No. 121 applies to the vehicle and its effective dat therefore relates to the vehicle, rather than to any of its components. A vehicle completed after the effective date will have to meet the standard, even though it is equipped with a foundation brake system that was manufactured before the effective date.; The vehicle's completion date, rather than its starting date, is th date that determines whether it must conform to the standard. If your company manufactures its vehicles from the ground up, rather than installing a body on a vehicle built by another manufacturer, the relevant completion date is the date you complete your manufacturing operation. However, if you buy an incomplete vehicle, as defined in our regulation on vehicles manufactured in two or more stages (49 CFR Part 568), and complete that vehicle, you may choose as the completion date for purposes of Standard No. 121 the date on which the manufacturer of the incomplete vehicle finished his work, the date on which you completed the vehicle or any date in between.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3877OpenMr. Jerry D. Williams, Senior Vice President, American Transportation Committee, Highway 65 South, Conway, AR 72032; Mr. Jerry D. Williams Senior Vice President American Transportation Committee Highway 65 South Conway AR 72032; Dear Mr. Williams: This is in further response to your December 12, 1984 letter to th National Highway Traffic Safety Administration (NHTSA) concerning our definition of a school bus. Your specific question asked, 'Are vehicles which are built to carry ten school aged passengers or less, and which are used for school or related functions, considered by NHTSA to be school buses or multipurpose passenger vehicles?' As explained below, a vehicle carrying 11 or more persons (i.e., 10 children and a driver) to and from school or related events would be considered a school bus. A vehicle carrying 10 or less persons would be a multipurpose passenger vehicle.; Under the definitions section of our Federal Motor Vehicle Safet Standards (49 CFR Part 571.3), vehicles carrying 11 or more persons which are sold for purposes that include carrying students to and from school or related events are 'school buses.' Under our regulations, a vehicle which is designed to carry less than 11 persons would be considered a multipurpose passenger vehicle. Such a vehicle would be certified as complying with the safety standards applicable to multipurpose passenger vehicles.; Ms. Deirdre Hom of my staff informed your associate, Mr. Joe Clark, o the above in a telephone call on December 14, 1985. This letter confirms the information given to Mr. Clark in that conversation.; If you have any further questions, do not hesitate to contact m office.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1040OpenMr. Norman E. Salzman, General Manager, The Fairmount Press, P.O. Box 3, Bronx, NY 10453; Mr. Norman E. Salzman General Manager The Fairmount Press P.O. Box 3 Bronx NY 10453; Dear Mr. Salzman: This is in response to your letter to Mr. Paris of February 28, 1973 concerning the Federal odometer Disclosure Requirements.; You ask, first, whether provision has been made for resale by wholesaler. By this you appear to suggest that wholesalers are not, or should not be, required to give a statement upon each resale. Our reply is that a wholesaler is on the same footing as any other transferor. If he owns the vehicle, however briefly, and resells it, he must disclose the mileage upon resale.; Your second question concerns the penalty for not issuing the require mileage statement. Our reply is that a failure to disclose is a violation of the requirements of the Act and is therefore subject to injunction under section 410. Furthermore, in the event that there are problems with an odometer, your failure to submit a statement would seriously undermine your defense in an action brought under section 409.; Your last question is whether both the New York form and the Federa form are necessary. Although we do not have a copy of the New York form, it is our understanding that it contains the greater part of the information required by our regulations. If the balance of the information can be added, we would not object to the use of the New York form to satisfy the Federal requirements.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2505OpenLt. C.R. Townsend, Director Motor Vehicle Inspection Division, Oklahoma Department of Public Safety, 3600 north Eastern, P.O. Box 11415, Oklahoma City, Oklahoma 73111; Lt. C.R. Townsend Director Motor Vehicle Inspection Division Oklahoma Department of Public Safety 3600 north Eastern P.O. Box 11415 Oklahoma City Oklahoma 73111; Dear Lt. Townsend: This is in response to your December 16, 1976, letter concerning tire marked 'Reno Farm Tire--Farm Use Only' that are appearing on some passenger cars in Oklahoma. I understand that the DOT symbol is also marked on the sidewalls of these tires, as a certification of conformity to Federal Motor Vehicle Safety Standard No. 109, *New Pneumatic Tires--Passenger Cars*.; Paragraph S6 of the standard precludes the manufacture of farm tires i passenger car tire sizes unless those tires conform to and are certified as conforming to all aspects of the standard. There is not, however, any provision in Standard No. 109 that prohibits the additional marking that you have described on a tire that is manufactured and sold for passenger car use. No safety issue appears to be presented by this situation.; You have also asked who is responsible for compliance with the Tir Identification and Recordkeeping regulation (49 CFR Part 574, copy enclosed). That regulation creates various obligations for tire manufacturers, motor vehicle manufacturers, motor vehicle dealers, and others. Where(sic) a tire manufacturer sells tires to a trailer manufacturer, the presence of the 'Farm Use Only' marking has no effect on those obligations.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam3060OpenMr. Donald Beyer, National Service Manager, Vespa of America Corporation, 355 Valley Drive, Brisbane, CA 94005; Mr. Donald Beyer National Service Manager Vespa of America Corporation 355 Valley Drive Brisbane CA 94005; Dear Mr. Beyer: This is in reply to your letter of June 20, 1979, asking for a interpretation of Federal Motor Vehicle Safety Standard No. 108 as it relates to operation of turn signal lamps by alternating current. You have informed us that Vespa wishes to use such a system on its 1980 motor driven cycles, and you have asked what SAE Standard or method must be followed by the lamps to comply.; Table III of Standard No. 108 requires that any motor driven cycles whose speed attainable in 1 mile exceeds 30 mph, be equipped with a turn signal flasher meeting SAE Standard J590b, *Turn Signal Flasher*, October 1965. The scope of this SAE Standard is that the specifications 'are for nominal 12 or 6 v - dc circuits ....' We construe this to mean that the typical electrical system of a motorcycle is designed to utilize direct current (dc), so that the alternate current (ac) flow from the alternator must be rectified (changed) to dc.; We would have no objections, however, to a turn signal system fed b alternating current if Vespa could demonstrate that such turn signal flashers and lamps would meet all performance requirements of SAE Standard J590b, *Turn Signal Flashers*, as well as the other requirements set forth in Standard No. 108.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1291OpenMr. William G. Mathews III, National Sales Manager, Marchal America, 14622 Southlawn Lane, Rockville, MD 20850; Mr. William G. Mathews III National Sales Manager Marchal America 14622 Southlawn Lane Rockville MD 20850; Dear Mr. Mathews: This responds to your letter No. 8495, dated October 5, 1973, to th National Highway Traffic Safety Administration concerning the legality of an automotive headlamp having a sealed metal reflector, glass lens arrangement. It is understood from your letter that such a headlamp would meet all requirements of Federal Motor Vehicle Safety Standard No. 108, including photometric and electrical performance, interchangeability and mechanical aiming.; Specifically your question is: 'Would a hermetically sealed metal an glass headlamp, (one in every way interchangeable with existing approved sealed beams except that the reflector would be metal instead of glass), be acceptable under current federal regulations?'; The answer to your question is 'yes.' Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam1207OpenMr. Robert B. Hirsch, Adams Rite Products, Inc., 540 West Chevy Chase Drive, Glendale, CA 91209; Mr. Robert B. Hirsch Adams Rite Products Inc. 540 West Chevy Chase Drive Glendale CA 91209; Dear Mr. Hirsch: This is in response to your July 25, 1973, request for copies of th Federal regulations concerning door locks and latches.; Federal Standard 206, *Door Locks and Door Retention Components*, i enclosed. It regulates passenger cars, multipurpose passenger vehicles, and trucks. These categories include ambulances and 'motor homes', which are self-propelled units with sleeping accommodations, generally constructed on a light truck chassis. Most other 'mobile homes' are not self- propelled and they qualify as trailers, which are not subject to this standard.; For your information, paragraph 9.1.2 of *Ambulance Design Criteria has also been enclosed. This publication specifies the criteria which an ambulance must meet to qualify for Federal funding under the Highway Safety Program S 402.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0489OpenMr. James Eckstein, 3025 St. Paul Street, Baltimore, Maryland 21218; Mr. James Eckstein 3025 St. Paul Street Baltimore Maryland 21218; Dear Mr. Eckstein: This is in reply to your letter of August 27, 1971, which was forwarde to this office October 20, 1971, by the Federal Trade Commission, regarding Government specifications for retreaded tires. You refer to problems you believe result from 'out of roundness,' specifically, abnormal wear and blowouts at normal boulevard and highway speeds. You wish to determine whether this problem results from 'too lenient' Government requirements, or whether 'manufacturers are negligent.'; Out-of-roundness can occur in a retreaded tire for numerous reasons and its presence does not necessarily indicate negligence on the part of the manufacturer. Moreover, while an out-of-round tire may affect vehicle handling it generally does not blow out at normal boulevard or even highway speeds, as result of the out-of-round condition. Thus, a blow out in an out-of-round tire could have resulted from other factors. Many tire dealers, in addition, have machines that can eliminate out-of-roundness by cutting of excess tread.; With reference to Federal regulations of retreaded tires, the firs such regulation will become effective January 1, 1972. This regulation, Motor Vehicle Safety Standard No. 117, 'Retreaded Pneumatic Tires,' specifies size and performance requirements for retreaded tires for use on passenger cars. There requirements are similar to those that have been applicable to new passenger car tires since January 1, 1968. None of these requirements specifically concern 'out-of-roundness.' We do not have evidence that this characteristic, by itself, is a safety problem.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1717OpenMr. Ronnie H. Walker, Howell, Kirby, Montgomery, D'Aiuto, Dean and Hallowes, Attorneys at Law, P.O. Box 273, Orlando, FL 32802; Mr. Ronnie H. Walker Howell Kirby Montgomery D'Aiuto Dean and Hallowes Attorneys at Law P.O. Box 273 Orlando FL 32802; Dear Mr. Walker: This responds to your November 18, 1974, request for copies of an Federal braking standards for horse trailers.; The National Highway Traffic Safety Administration has responsibilit for the issuance of Federal motor vehicle safety standards, and we have issued only one standard in this area. The standard applies to trailers that are equipped with air brakes (Standard No. 121, *Air brake systems*, 49 CFR 571.121). This standard becomes effective for trailers which are manufactured after January 1, 1975.; Therefore there are no Federal brake standards which apply to the hors trailer you describe.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3688OpenMr. James E. Forrester, Manager of Engineering Services, Truck Body & Equipment Association, P.O. Box 70409, Washington, D.C. 20088-0409; Mr. James E. Forrester Manager of Engineering Services Truck Body & Equipment Association P.O. Box 70409 Washington D.C. 20088-0409; Dear Mr. Forrester: This responds to your March 15, 1983, letter asking whether emergenc doors in school buses may be marked as 'emergency exits' and still comply with Standard No. 217, *Bus Window Retention and Release*.; Paragraph S5.5.3 states that each school bus exit shall have th designation 'Emergency door' or 'Emergency exit' as appropriate. The agency has previously determined that emergency doors are considered to be emergency exits and thus can be marked as either doors or exits. Emergency windows must be marked only as emergency exits.; 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.