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 |
|---|---|
ID: aiam2473OpenMr. William H. Tucker, Tucker, Gray and Thigpen, 2728 Eighth Street, P. O. Box 2485, Tuscaloosa, AL 35401; Mr. William H. Tucker Tucker Gray and Thigpen 2728 Eighth Street P. O. Box 2485 Tuscaloosa AL 35401; Dear Mr. Tucker: This is in reply to your letter of October 4, 1976, requesting data o the Gateway Gumbo Wide Mudder tire involved in an automobile accident that you are investigating.; From your correspondence, you indicate that the tire was manufacture by the Denman Rubber Company and that Dunlap Kyle of Batesville, Mississippi owns the engineering specifications or blueprints. As this statement suggests a variation from usual tire industry practice, we did some investigating of our records. Our records indicate that there is a retreading plant operated by Dunlap and Kyle Company, P. O. Box 689, Batesville, Mississippi, for the retreading of light truck- type tires. Therefore, before we can answer your letter, we need some additional information.; Please forward to us the tire identification number of the tire as thi will help determine if, in fact, this is a retreaded tire. This number will be located near the symbol DOT, and if it is a retreaded tire, should be located near the shoulder of the tire and not near the bead.; Sincerely, E. T. Driver, Director, Office of Crash Avoidance, Moto Vehicle Program; |
|
ID: aiam1374OpenHonorable John W. Davis, House of Representatives, Washington, DC 20515; Honorable John W. Davis House of Representatives Washington DC 20515; Dear Mr. Davis: This is in reply to your letter of December 17, 1973, on behalf of Ms Judith Davis, who has suggested the incorporation of the Federal odometer form into the bill of sale as a means of reducing paperwork in motor vehicle transactions.; Although the Federal odometer disclosure regulation requires the selle to give the buyer several items of information that we consider essential to adequate disclosure, the regulation does not require the use of a separate form. If Ms. Davis is able to include the required information in the bill of sale used by the Rome Auto Auction, she may do so. Information items that are common to the bill of sale and the disclosure statement, such as the model and make of the vehicle, would not have to be stated twice.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam2896OpenMr. S. L. Terry, Chrysler Corporation, P.O. Box 1919, Detroit, MI 48231; Mr. S. L. Terry Chrysler Corporation P.O. Box 1919 Detroit MI 48231; Dear Mr. Terry:#This in (sic) response to your letter of July 21, 1978 requesting an interpretation of Federal Motor Vehicle Safety Standard No. 101, *Controls and Displays*. Please excuse the delay in responding.#You requested an interpretation that a single telltale which monitors both the oil pressure and coolant temperature gauges could be identified by the word 'Engine'. You indicated that it is industry practice to combine the monitoring of these two functions into a single telltale because the response by the driver to either malfunction is the same. It is the interpretation of the NHTSA that the multipurpose telltale which monitors the two functions specified above may be identified by the word 'Engine.' The standard does not require that any of the displays listed in S5.1 be provided or that two or more displays, if provided, be provided separately.#Sincerely, Joseph J. Levin, Jr., Chief Counsel; |
|
ID: aiam1334OpenMr. James M. Robertson, University Club Tower, Suite 2410, Tulsa, OK 74119; Mr. James M. Robertson University Club Tower Suite 2410 Tulsa OK 74119; Dear Mr. Robertson: I am enclosing a copy of Part 580, *Odometer Disclosure Requirements* 49 CFR 580, issued under the authority of S 408 of the Motor Vehicle Information and Cost Savings Act, which like all regulations of this and other Federal agencies is published in the Federal Register. This daily publication can be obtained at a price of $45.00 per year from : Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.; Interpretation of the regulation to date has established that th odometer disclosure statement can be made in any format which includes the required information. Commercially printed forms, handwritten forms, and forms included in the 'buyer's order form' used by dealers have all been approved. The government does not print forms, but the regulation includes an example of an acceptable format.; If you have further questions, please write again. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam2406OpenMr. Kenneth C. Ploeger, President, ACUTEK, 5th & Dryden, Odessa, MO, 64076; Mr. Kenneth C. Ploeger President ACUTEK 5th & Dryden Odessa MO 64076; Dear Mr. Ploeger: This is in reply to your letter of October 13, 1976, to Mr. Lewis C Owen, Safety Standards Engineer, concerning an interpretation of the words 'optically combined' as they apply to your Acutek 301 combination rear lamp.; In the Acutek lamp, the data you submitted indicate that when th taillamp bulb is activated independently from the clearance lamp bulb, and vice versa, there is no appreciable amount of incidental light emitted from the lens of the clearance lamp. The amount of light 'spill' appears to be so small that it would not be interpreted (by a driver following the vehicle on which it is installed) as illuminating the lens of the taillamp when operated in the clearance lamp mode, and vice versa.; Accordingly, the Acutek 301 combination rear lamp appears to meet th requirements of Federal Motor Vehicle Safety Standard No. 108, 'Lamps, Reflective Devices, and Associated Equipment.'; Sincerely, E. T. Driver, Director, Office of Crash Avoidance, Moto Vehicle Programs; |
|
ID: aiam0988OpenSenator Herman E. Talmadge, Senate Office Building, Washington, DC 20510; Senator Herman E. Talmadge Senate Office Building Washington DC 20510; Dear Senator Talmadge: This is in reply to your inquiry of January 16, 1973, on behalf of you constituent, Mr. Ski Bashinski. As Executive Director of the Georgia Independent Auto Dealers Association, Mr. Bashinski was concerned that the Federal Odometer Disclosure Requirements might become effective at a date earlier than that suggested in the notice of proposed rulemaking on the subject.; The regulations to which Mr. Bashinski refers were proposed by th National Highway Traffic Safety Administration on December 2, 1973, (sic) pursuant to Title IV, Odometer Requirements, of the Motor Vehicle Information and Cost Savings Act, P.L. 92-513. The effective date proposed was six months after issuance of a rule.; After reviewing the comments to its proposal, the NHTSA issued th Odometer Disclosure Requirements as a final rule on January 31, 1973. In the light of comments indicating a need for a prompt effectiveness, the rule will go into effect March 1, 1973. The other provisions of Title IV went into effect by operation of law on January 18, 1973, and require the assistance of the disclosure statement if they are to be fully effective.; Sincerely, Lawrence R. Schneider, Chief Counsel |
|
ID: aiam2023OpenMr. C. J. Baker, Director of Engineering, Peerless Division - Royal Industries, P.O. Box 445, Tualatin, OR 97062; Mr. C. J. Baker Director of Engineering Peerless Division - Royal Industries P.O. Box 445 Tualatin OR 97062; Dear Mr. Baker: This responds to your July 15, 1975, question whether Standard No. 121 *Air Brake Systems*, requires 'hold back valves' on air brake system reservoirs to guard against loss of air pressure through auxiliary equipment installations.; The answer to your question is no. Standard No. 121 does not contain prohibition on the use of air pressure from the air brake system for powering auxiliary devices. The vehicle must, of course, conform to Standard No. 121 following installation of the devices, if the installation occurs prior to the first purchase in good faith for purposes other than resale. For example, the compressor build-up pressure must still meet S5.1 of the standard whether or not auxiliary equipment is installed.; Although not a requirement of the standard, the NHTSA does consider i appropriate that a pressure protective valve be placed in the line to the auxiliary device so that a rupture of an auxiliary line does not cause depletion of air pressure in the brake system.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
|
ID: aiam2411OpenMr. Byron A. Crampton, Manager of Engineering Services, Truck Body and Equipment Association, Inc., 5530 Wisconsin Avenue, Suite 1220, Washington, DC 20015; Mr. Byron A. Crampton Manager of Engineering Services Truck Body and Equipment Association Inc. 5530 Wisconsin Avenue Suite 1220 Washington DC 20015; Dear Mr. Crampton: This responds to the Truck Body and Equipment Association's letter o September 14, 1976, inquiring as to the effect of Standard No. 121, *Air Brake Systems*, on State laws relating to air brake performance. You ask whether the Commonwealth of Massachusetts can impose requirements pertaining to parking brake release on trucks and buses which differ from provisions contained in the Federal standard.; I believe that the question you raised is identical to a questio raised by the State of California, International Harvester Company, and White Motor Corporation in October 1974, prior to the effective dates of Standard No. 121. It was our opinion at that time that promulgation by a State of a more restrictive parking brake requirement providing for the installation of a release not specified in Standard No. 121 was prohibited by S 103(d) of the National Traffic and Motor Vehicle Safety Act. A copy of that letter is enclosed for your information.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
|
ID: aiam1048OpenMr. Normal E. Randall, Manager Quality Control, Joan Fabrics Corporation, 122 Western Avenue, Lowell, MA, 01853; Mr. Normal E. Randall Manager Quality Control Joan Fabrics Corporation 122 Western Avenue Lowell MA 01853; Dear Mr. Randall: This is in reply to your letter of February 28, 1973, and an attache copy of an earlier letter dated September 26, 1972, that you sent to Mr. Bobby A. Boaz in our Office of Consumer Affairs and Public Information but was evidently never received. You ask what types of vehicles are covered by Standard No. 302, 'Flammability of Interior Materials', and especially whether campers, motor homes, and mobile homes are covered.; The standard applies to passenger cars, multipurpose passenge vehicles, trucks, and buses. It does not apply to trailers, the vehicle category which includes mobile homes and other towed recreational vehicles, but it does apply to motor homes and to those campers that are constructed on new chassis.; You ask further for any available information regarding testin procedures, requirements, reporting procedures, and any other related information. There are no reporting requirements, and otherwise the information you seek is found in Standard No. 302 itself. Accordingly, a copy of that standard, as well as a copy of a proposed amendment, are enclosed for your consideration.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam1570OpenMr. James P. Coughlin, Vice President - Marketing, Bell Helmets Inc., 2850 East 29th Street, Long Beach, CA 90806; Mr. James P. Coughlin Vice President - Marketing Bell Helmets Inc. 2850 East 29th Street Long Beach CA 90806; Dear Mr. Coughlin: This is in reply to your letter of July 25, 1974, asking whether th statement 'Make no modifications' included in the labeling requirements of Standard 218, *Motorcycle Helmets*, would prohibit the after-market installation of a quick release device which may be attached to a helmet's retention strap. You included an illustration of such a device in your letter.; The answer is no. The statement does not restrict after-marke modifications by a first purchaser for purposes other than resale. It only serves to warn the consumer of the danger of making such modifications.; Yours truly, Richard B. Dyson, Acting 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.