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: aiam2649OpenMr. Jac H. Karlan, 37-A Haddon Road, Cranbury, NJ 08512; Mr. Jac H. Karlan 37-A Haddon Road Cranbury NJ 08512; Dear Mr. Karlan: This is in response to your letter of June 10, 1977, requesting advic as to how your bumper-attachable energy absorber can be tested in order to establish its efficacy.; As you probably know, the National Highway Traffic Safet Administration (NHTSA) has promulgated a bumper standard (49 CFR Part 581, *Bumper Standard*) that will, beginning September 1, 1978, prohibit damage to vehicle surfaces, other than the bumper, during 5 mph test impacts. Phase II of the standard, which goes into effect September 1, 1979, will prohibit any damage to the bumper that exceeds 3/8 inch dent and 3/4 inch set. Since manufacturers will be required to meet these levels of bumper performance, shock absorbers such as yours may be greatly needed.; The NHTSA does not specify any design characteristics in its standards Thus, manufacturers are permitted to choose whatever design they wish, as long as their vehicles are capable of meeting the performance criteria provided in the standard. Thus, I suggest that you communicate with the automobile manufacturers regarding use of your shock absorber.; The contracts to which you refer in your letter were for th development of total vehicles. I suggest you contact an independent laboratory for testing your energy absorber.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3011OpenMr. Harvey Schock, Jr., Management Consulting in Product Assurances, P. O. Box 430, Haddonfield, NJ 08033; Mr. Harvey Schock Jr. Management Consulting in Product Assurances P. O. Box 430 Haddonfield NJ 08033; Dear Mr. Schock: This responds to your April 9, 1979, letter asking how the agency wil apply the reporting requirements of Part 573, *Defect and Noncompliance Reports*, to equipment manufacturers.; As the agency indicated in the preamble to the final rule, replacemen equipment manufacturers that are required to notify owners and to remedy defective or noncomplying equipment would do so to the best of their abilities. The reporting requirement does not require them to manufacture their equipment so that it is easily identifiable nor does it require them to maintain lists of persons to whom equipment has been sold. Some equipment manufacturers may wish to upgrade their recordkeeping and identification systems to facilitate their statutory obligations to recall and remedy, but the reporting regulation does not require this.; With respect to the 'flasher' incident to which you refer in you letter, if a vehicle manufacturer authorizes the use of incorrect flashers in its vehicles, problems resulting from the use of those flashers would be the responsibility of the vehicle manufacturer not the equipment manufacturer. The problem that you describe is one of incorrect use of properly functioning equipment. It is not a problem of defective equipment.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam1737OpenMr. Richard FitzMaurice, Senior Engineer, FMC Corporation, 1180 Coleman Avenue, Box 580, Santa Clara, CA 95052; Mr. Richard FitzMaurice Senior Engineer FMC Corporation 1180 Coleman Avenue Box 580 Santa Clara CA 95052; Dear Mr. FitzMaurice: This responds to your December 17, 1974, request for confirmation tha FMC Corporation's air-braked tilt-bed trailer, which has a primary cargo-carrying surface less than 40 inches from the ground, qualifies as a 'Heavy hauler trailer' and, as such, is not required to meet the requirements of Standard No. 121, *Air brake systems*, until September 1, 1976.; 'Heavy hauler trailer' is defined in the standard as follows: >>>'Heavy hauler trailer' means a trailer with one or more of th following characteristics:; (1) Its brake lines are designed to adapt to separation or extension o the vehicle frame, or; (2) Its body consists only of a platform whose primary cargo-carryin surface is not more than 40 inches above the ground in an unloaded condition, except that it may include sides that are designed to be easily removable and a permanent 'front- end structure' as that term is used in S 393.106 of this title.<<<; The tilt-bed trailer, which you describe in detail in your November 14 1974, letter, has a bed height of less than 40 inches and therefore qualifies for exemption until September 1, 1976.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam1409OpenMr. J.C. Eckhold, Director, Automotive Safety Office, Ford Motor Company, The American Road, Detroit, MI, 48121; Mr. J.C. Eckhold Director Automotive Safety Office Ford Motor Company The American Road Detroit MI 48121; Dear Mr. Eckhold: This is in reply to your letter of January 24, 1974, asking for a interpretation as to whether a rear lamp assembly design that Ford demonstrated to NHTSA representatives conforms to the location requirements of Standard No. 108. The assembly consists of three units which, from outboard to inboard, as a rear lighting assembly, comprise the tail lamp/stop lamp, backup lamp, and turn signal lamp.; Standard No. 108 specifies that stop lamps, tail lamps, and turn signa lamps be 'as far apart as practicable.' The standard does not specify a minimum separation distance of lamps, a maximum permissible location inboard, or location of one system relative to another. The determination of practicability in lamp spacing is to be made by the vehicle manufacturer, and the agency has generally afforded manufacturers some latitude in this interpretation.; Therefore, the configuration you have described and demonstrated woul not violate Standard No. 108. It should be noted, however, that it would be in conflict with the requirements for rear turn signals and stop lamps as proposed in Docket 69-19, Notice 3.; Sincerely, James B. Gregory, Administrator |
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ID: aiam3485OpenMr. Richard F. Gordon, President, IPD Co. Inc., 2762 N.E. Broadway, Portland, OR 97232; Mr. Richard F. Gordon President IPD Co. Inc. 2762 N.E. Broadway Portland OR 97232; Dear Mr. Gordon: Secretary Lewis has referred your letter of October 6, 1981, to thi office for reply. You have requested, in essence, a 'waiver' pursuant to the Regulatory Flexibility Act of the requirements of Motor Vehicle Safety Standard No. 108 that vehicle headlamps be of sealed beam construction.; There is no legal way such a request could be implemented through th Regulatory Flexibility Act itself. That Act urges regulatory agencies to use their existing statutory authority to accommodate small businesses where appropriate to do so. Modifications of regulations issued pursuant to the National Traffic and Motor Vehicle Safety Act occur through normal rulemaking procedures conducted in accordance with the Administrative Procedure Act. This agency has no current plan to engage in rulemaking allowing importation and sale in the aftermarket of European-type unsealed headlamps, and has consistently denied petitions for such rulemaking over the last few years. Further, we have no authority to grant exemptions or other waivers to manufacturers or importers of motor vehicle equipment.; However, the agency is always interested in new headlighting ideas, an I enclose a copy of a Notice of Request for Comments which we recently issued, that I think you will find of interest.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4235OpenMr. Edwin C. Silverstein, 108 Mayfair Lane, Mt. Laurel, NJ 08054; Mr. Edwin C. Silverstein 108 Mayfair Lane Mt. Laurel NJ 08054; Dear Mr. Silverstein: Thank you for your letter of August 16, 1986, concerning how ou standards apply to a product you have invented. According to the literature you provided us, your product, 'Limo Leash' is a harness system used to secure an animal in a vehicle. The system consists of a piece of webbing which can be attached at either end to the 'clothes hooks' installed in a vehicle. A snap hook, which can be attached to the animal's collar, slides along the webbing to allow the animal to move back and forth.; There are no Federal motor vehicle safety standards that apply to harness system used for animals. However, since your product is sold as an accessory for use in a motor vehicle, we would consider it an item of motor vehicle equipment. Thus, the manufacturer of your product would be covered by the agency's regulations on safety-related defects that would pose a hazard to other vehicle occupants. I have enclosed an information sheet which describes those regulations.; Since there may be state regulations governing the manufacture or us of your product, I suggest you check with state transportation officials in the jurisdictions in which you intend to market your product.; If you have any further questions, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam0049OpenMr. John F. Floberg, Vice President, Secretary and General Counsel, The Firestone Tire & Rubber Company, Akron, Ohio 44317; Mr. John F. Floberg Vice President Secretary and General Counsel The Firestone Tire & Rubber Company Akron Ohio 44317; Dear Mr. Floberg: Your petition of March 7,1968, requesting a reduction in the high spee performance test (Section S5.5) of Federal Motor Vehicle Safety Standard No. 109 (23 CFR, Part 255) for special heavy gauge tread taxi tires is denied.; While we agree that some taxis are used for low speed intercit operation, many taxis now use high speed freeways for sustained periods of time. With the continuous expansion of freeways in metropolitan areas, the average service speed for taxi tires is certain to increase. In view of this, and because it is impossible to limit the use of taxi type tires to speeds lower than those presently permitted for other passenger vehicles, an amendment to Standard No. 109 exempting the heavy gauge tread tires from the high speed performance requirements, would not be in the interest of safety.; For your future reference enclosed is a copy of *Rule Makin Procedures: Motor vehicle Safety Standards* as published in the *Federal Register (32 F.R. 15818 - 15820). Your attention is directed to S216.31 which sets forth the procedural regulations for petitions for rule making.; Sincerely, John R. Jamieson, Deputy Federal Highway Administrator |
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ID: aiam2150OpenFile; File; On December 10, 1975, I received a telephone call from Mr. Dan Warne of Transportation Manufacturing Corporation in New Mexico (505 347-2011), concerning the scope of Standard No. 119.; Mr. Warner asked whether the standard required vehicles to be equippe with tires conforming to it. I explained that Standard 119 applies only to tires, while vehicles would be the subject of Standard No. 120. I declined to predict the issue date or effective dates of Standard 120, but assured him that the scheme of effective dates would take into account the realities of production and inventories.; Mark Schwimmer |
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ID: aiam0462OpenMr. K. Krueger, Technical Development, Liason (sic) Engineer, Volkswagen of America, Inc., Englewood Cliffs, NJ 07632; Mr. K. Krueger Technical Development Liason (sic) Engineer Volkswagen of America Inc. Englewood Cliffs NJ 07632; Dear Mr. Krueger: This will serve to confirm your understanding that a retractor capabl of meeting the requirements for a vehicle-sensitive emergency-locking retractor under Standard No. 209 conforms to the Standard even though it is provided with a back-up webbing-sensitive retractor that locks only at webbing accelerations greater than those specified in Standard No. 209.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam5581OpenMr. Lance Tunick Vehicle Services Consulting, Inc. Post Office Box 1015 Golden, CO 80402-1015; Mr. Lance Tunick Vehicle Services Consulting Inc. Post Office Box 1015 Golden CO 80402-1015; Dear Mr. Tunick: This responds to your request for the agency t clarify the requirements of 49 CFR 575.101, which until recently required manufacturers to disclose information about the stopping performance of passenger cars and motorcycles. In particular, you asked how the requirement would apply to vehicles certified to comply with Federal Motor Vehicle Safety Standard No. 135, Passenger Car Brake Systems. I am enclosing a copy of a June 26, 1995, final rule in which the National Highway Traffic Safety Administration (NHTSA) rescinded section 575.101 (60 FR 32918). As a result of this decision, a vehicle manufacturer is no longer required to furnish information about the stopping performance of passenger cars and motorcycles. I hope this information is helpful to you. Should you have any questions or need additional information, please feel free to contact Marvin Shaw of my staff at this address or at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosure; |
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.