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: aiam1569OpenMr. 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 |
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ID: aiam0885OpenMr. Ray Brown, Pine Ridge Nursery, 14484 Cedar Avenue, Rosemount, MN 55068; Mr. Ray Brown Pine Ridge Nursery 14484 Cedar Avenue Rosemount MN 55068; Dear Mr. Brown: Thank you for your letter of October 11, 1972, regarding th installation of LP gas tanks in a small van to serve as a 'recreational vehicle.'; There is no Federal regulation regarding installation of LP gas tank on the exterior of recreational vehicles.; There is a voluntary standard on recreational vehicles issued by th National Fire Protection Association (NFPA), 60 Batterymarch Street, Boston, Massachusetts 02110, identified as NFPA Standard No. 501C. This standard includes requirements for fuel supply systems based on the use of LP gas. You may wish to refer to the standard for safety guidance in installing your system.; I appreciate you interest in motor vehicle safety.Sincerely, Robert L Carter, Associate Administrator, Motor Vehicle Programs; |
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ID: aiam3422OpenMs. Judith I. Robey, Executive Vice President, Devlin Associates, Inc., 1150 First Avenue, Suite 795, King of Prussia, PA 19406; Ms. Judith I. Robey Executive Vice President Devlin Associates Inc. 1150 First Avenue Suite 795 King of Prussia PA 19406; Dear Ms. Robey: This responds to your April 28, 1981, letter asking for informatio relating to the agency's recordkeeping requirements.; I have enclosed copies of the agency's major recordkeeping regulation and portions of one statute that requires the retention of information. This information describes the types of records to be retained and the periods that retention is required. The agency has not specified the form or location for record retention, but it has stated that records must be readily retrievable when necessary. The agency has not imposed a penalty for accidental loss of records. I can see no instance in which a penalty would be imposed for such an accidental loss.; Finally, you ask for any recommendations that we might have wit respect to record retention. We only suggest that records be maintained in an easily accessible manner so that they can be used effectively in removing dangerous vehicles or equipment from the highway. Other than this general recommendation, the actual recordkeeping techniques that a company should use would depend upon the size and sophistication of the company.; If you have any questions concerning any of the materials that I hav provided you, you may contact Roger Tilton of my staff (202-426-9511).; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1257OpenMr. C.C. King, Southwestern Transportation Company, P.O. Box 6187, Dallas, Texas 75222; Mr. C.C. King Southwestern Transportation Company P.O. Box 6187 Dallas Texas 75222; Dear Mr. King: This is in reply to your letter of July 18, 1973, requestin information on an NHTSA ruling that you understand prohibits tire companies from surrendering damaged tires to carriers for salvage purposes.; The NHTSA has not issued a ruling in the precise terms you describe However, a recent amendment (copy enclosed) to the Federal motor vehicle safety standard applicable to passenger car tires, Standard No. 109, could be viewed as having that effect. The amendment prohibits the sale, the offer for sale, or the introduction or delivery for introduction in interstate commerce of any tire designed for use on a passenger car that fails to meet the requirements of the standard, unless the tire is altered so that it cannot be used or repaired for use on a motor vehicle (including a trailer). Tire manufacturers may be understandably reluctant to claim that damaged tires will still conform to the safety standard, and when altered so that their use as motor vehicle equipment is prevented. This may reduce their value for salvage purposes. There is no specific prohibition to their surrender for use as salvage, however, and they may have salvage value if a purpose if a purpose, such as scrap, unrelated to motor vehicles is intended for them.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0934OpenMr. Arthur B. Chivvis, Executive Director, Urethane Safety Group, The Society of the Plastics Industry, Inc., 250 Park Avenue, New York, NY, 10017; Mr. Arthur B. Chivvis Executive Director Urethane Safety Group The Society of the Plastics Industry Inc. 250 Park Avenue New York NY 10017; Dear Mr. Chivvis: Thank you for your letter of December 6, 1972, to Mr. Douglas Toms regarding terminology used in flammability tests and your concern for usage of positive designations instead of description terms.; We concur in the need to use terminology that can be standardized an universally understood as a means for preventing ambiguities. In view of the many flammability performance qualities that are subject to evaluation by test methods covering a wide range of exposure conditions, it is not surprising that descriptive terminology has found wide range.; We would appreciate receiving any definitions that your group ha adopted for flammability testing to standardize on terminology.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam0045OpenMr. John A. Diehl, The Armstrong Rubber Company, 475 Elm Street, West Haven, Connecticut 06516; Mr. John A. Diehl The Armstrong Rubber Company 475 Elm Street West Haven Connecticut 06516; Dear Mr. Diehl: #In our telephone conversation of January 8, 1968, an your letter of January 9, 1968, your requested: #>>>'...an early reply whether labels are required, when the information already appears on *one sidewall*, except the basic label. (Basic Label Information - DOT-153) It is also our feeling that the labeling is not a serious requirement to meet minimum safety standards.'<<< #This letter confirms my statement in our telephone conversation that Motor Vehicle Safety Standard 109 may be met if the information required in S4.3 of this standard is molded on one or both sidewalls of the tire in lieu of a label until August 1, 1968, after which this information is required on each sidewall. #Sincerely, Roger H. Compton, Director, Office of Standards on Accident Avoidance, Motor Vehicle Safety Performance Service; |
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ID: aiam1223OpenMr. Jerry M. Schneider, 5475 Northwest highway, Chicago, Illinois 60630; Mr. Jerry M. Schneider 5475 Northwest highway Chicago Illinois 60630; Dear Mr. Schneider: This is in response to your letter of August 21, 1973, asking whethe Standard 125 Warning devices are required to be installed as original equipment in motor homes by the manufacturer.; Standard 125 is an equipment standard, not a vehicle standard. Thi means that it is directed at the manufacturer of the devices, not vehicle manufacturers. Therefore the standard doesnot(sic) make installation of the device mandatory in any motor vehicle. The Bureau of Motor Carrier Safety, however, has made the use of the device mandatory by interstate carries subject to its regulation.; For your information, future requests for information should b directed to the Administrator, National Highway Traffic Safety Administration, 400 Seventh Street, S.W., Washington, D.C. 20590, and not the Docket Section, which essentially is a repository of comments which do not receive a reply.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2717OpenMr. Paul Bennett, Utility Trailer Manufacturing Co., P.O. Box 1299, City of Industry, CA 91749; Mr. Paul Bennett Utility Trailer Manufacturing Co. P.O. Box 1299 City of Industry CA 91749; Dear Mr. Bennett: This responds to Utility Trailer Manufacturing Company's October 6 1977, request for confirmation that the criteria for a bulk agricultural commodity trailer contained in S5.6 and S5.8 of Standard No. 121, *Air Brake Systems*, can be met by a trailer that does not accommodate 'slip-in bottom dump' bulk harvest tubs as well as the 'deck type' harvest tubs used for tomatoe (sic) harvesting. From your description, it is assumed for the purposes of this interpretation that the trailers in question do conform to the criteria in the standard for maximum length and an air line and reservoir arrangement that minimize field damage.; The criterion of 'skeletal construction that accommodates harves containers' can be met by a design that accommodates mounting of deck type bulk harvest tubs by means of removable flooring, whether or not the removal of flooring also permits the mounting of 'slip-in bottom' bulk harvest tubs.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1422OpenMr. C. W. Mohr, Vice President-Marketing, Certain-Teed Products Corporation, 2901 Lakeview Road, P.O. Box 366, Lawrence, KS 66044; Mr. C. W. Mohr Vice President-Marketing Certain-Teed Products Corporation 2901 Lakeview Road P.O. Box 366 Lawrence KS 66044; Dear Mr. Mohr: This responds to your January 25, 1974, question whether failure of 'common' clampband assembly on the 'Camtite' emergency and parking spring brake, which would cause complete loss of air to the service brake system and failure of the emergency/parking brake portion of one unit, would be in violation of paragraph S5.7.2.2 of Standard 121.; The answer is no. S5.7.2.2 requires that failure of components commo to the service and emergency braking systems shall not result in a loss of air that causes the parking brake to be inoperable. We interpret 'parking brake' to mean the entire parking brake system. The failure you describe would not render the entire system inoperable, because all parking brakes other than the affected unit would remain operable.; This letter will be placed in the public file for the information o other interested persons.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1518OpenMr. W. G. Milby, Project Engineer, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA, 81035; Mr. W. G. Milby Project Engineer Blue Bird Body Company P.O. Box 937 Fort Valley GA 81035; Dear Mr. Milby: In your letter of May 30, 1974, you ask whether a rear lightin configuration intended for your 1975 vehicles, based upon a proposal in Docket No. 69-19, would meet the current requirement that stop lamps be 'as far apart as possible.'; The photographs you enclose show that the intent of the proposed S8.1 has been met by providing a separation distance between turn signal and stop lamps that is 5 inches or more, and by placing the stop lamp so that its optical axis is inboard of a vertical longitudinal plane passing through the optical axis of the taillamps. Although it is obviously 'practicable' for you to retain the stop lamps in their present location, we consider that the reasons you wish to introduce the change support a determination of practicability under the current requirements, even though the proposal remains under consideration and may not be adopted.; Yours truly, Richard B. Dyson, Assistant 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.