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: aiam2469OpenInterps. File, 49 CFR Part 575.104, (UTQGS); Interps. File 49 CFR Part 575.104 (UTQGS); Subject: Tread Label Format: *Uniform Tire Quality Grading Standards* On December 16, 1976, I received a telephone call from Mr. Calvi Schaffner of B.F. Goodrich Co. (216 379-3470) concerning Figure 2 of the Uniform Tire Quality Grading Standards, 49 CFR S 575.104. That figure depicts the format of the tread label required by the rule.; Mr. Schaffner referred to Figure 2 as it appears in Notice 21 (41 F 54205, December 13, 1976). I explained that, because Notice 21 is a notice of proposed rulemaking rather than final rulemaking, the inclusion of the warnings in the traction and temperature grades is not yet certain. I further explained, however, that (i) in all other respects, the depiction of Figure 2 in that notice was correct, (ii) the appearance of Figure 2 was incorrect in both Notices 17 and 18, due to printing errors at the Federal Register, and (iii) this point would be clarified in a final rulemaking notice.; Mark Schwimmer, Attorney-Advisor |
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ID: aiam0454OpenMr. J.T. Flynt, President, Cox Tire Machinery Company, Inc., 1101 W. First Street, Charlotte, North Carolina 28201; Mr. J.T. Flynt President Cox Tire Machinery Company Inc. 1101 W. First Street Charlotte North Carolina 28201; Dear Mr. Flynt: Your letter of September 29, 1971, to the National Highway Traffi Safety Administration requesting an interpretation of Federal Motor Vehicle Safety Standard No. 117, has been referred to this office for reply.; Within S5 of Standard No. 117, it states that retreaded tires mus conform to S4.2.1 of Standard No. 109 requires a treadwear indicator that will provide a visual indication that the tire has worn to a tread depth of 1/16 inch. For your information, we have enclosed copies of Standard No. 109 and No. 117.; Sincerely, E.T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam2193OpenHonorable John E. Moss, Chairman, Subcommittee on Oversight and Investigations, Committee on Interstate and Foreign Commerce, House of Representatives, Washington, DC 20515; Honorable John E. Moss Chairman Subcommittee on Oversight and Investigations Committee on Interstate and Foreign Commerce House of Representatives Washington DC 20515; Dear Mr. Moss: Thank you for your January 19, 1976, letter asking for furthe explanation of the National Highway Traffic Safety Administration's (NHTSA) position on a school bus seating standard that specifies both passive compartmentalization and the installation of seat belt anchorages.; The NHTSA has issued its school bus seating standard (Standard No. 222 *School Bus Seating and Crash Protection*) in a form that requires compartmentalization of vehicle occupants but does not require installation of seat belt anchorages. There is not sufficient information in the record on which to determine what percentage of school districts would utilize seat belts. The limited evidence available to the NHTSA indicates that only a small fraction of school buses would have belts installed and properly used, and that the decision to mandate seat belt anchorage installation should await further information as to the extent to which belts would be installed and properly used.; The issue of whether the NHTSA is on 'safe legal ground in mandating requirement that in itself does not contribute to motor vehicle safety but requires further action on the part of local officials' has become less urgent in view of the standard's promulgation without anchorage requirements. I would like to respond generally that the NHTSA has always held the opinion in construing the National Traffic and Motor Vehicle Safety Act (the Act) that safety performance requirements that require further action by vehicle users are entirely appropriate. While some safety devices (such as bumpers) are in place and operate passively, most devices, (such as lights and seat belts) require occupant action to gain protection. Seat belt anchorages require more action than simple use to gain their benefits, but this does not appear to be a legally significant distinction. In this case, I decided that substantial controversy over the appropriateness and legality of this protection should not continue to create uncertainty over the ultimate form of the standard, endangering the ability of manufacturers to comply with Congress' maximum 9-month leadtime for upgrading school bus seating systems. We have, of course, left the issue of restraints in school buses.; While the decision on passive restraints could negate the value of sea belt training during the adult years, it should be noted the NHTSA is not proposing passive protection for the rear seats of passenger cars where children are encouraged to ride. They would need to use the seat belts provided to increase their protection in a crash.; Sincerely, James B. Gregory, Administrator |
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ID: aiam5656OpenMr. Richard L. Russell 12475 Central Avenue Suite 352 Chino, CA 91710; Mr. Richard L. Russell 12475 Central Avenue Suite 352 Chino CA 91710; "Dear Mr. Russell: This responds to your FAX of November 15, 1995, t Blane Laubis of this agency, asking for an interpretation of Federal lighting regulations as they may affect your plans to modify your 1956 Jeep. You wish to add two additional auxiliary lights to supplement your upper beams, and you ask whether these lights are 'required to be DOT approved.' The answer is no, the DOT regulation on motor vehicle lighting (Federal Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices, and Associated Equipment does not prescribe requirements for lamps intended to supplement the headlamps, and thus the lamps of which you speak do not have to be certified as meeting Standard No. 108. As a matter of information, your use of the words 'DOT approved' reflects a common misconception. We have no authority to approve or disapprove lighting equipment. Under our statute, a lighting (or vehicle) manufacturer is required to certify that its equipment (or vehicle) meets Standard No. 108 (if it is replacement equipment included in the standard), and the use of the DOT symbol on the item is the most frequently used method of certification. This means that the 'DOT approved' headlamps on your 1956 Jeep are probably replacement sealed beams with DOT markings on them. You ask whether there is any limitation to bulb wattage for auxiliary lamps used to supplement the headlamps when used on the upper beam. There is no wattage limitation, however, if auxiliary lamps were installed by the dealer on a new vehicle before its first sale, we would regard the vehicle manufacturer's certification as negated if the brightness and location of the auxiliary lamps were such as to affect an oncoming driver's ability to perceive the front turn signals. Although your Jeep was manufactured long before the effective date of Standard No. 108 (January 1, 1969), we ask you to consider this safety concern when adding auxiliary lamps. We do not know the local laws on this subject, and recommend that you seek advice from the Department of California Highway Patrol. If you have any further questions, Taylor Vinson of this Office will answer them for you (phone 202-366-5263). Sincerely, Samuel J. Dubbin Chief Counsel"; |
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ID: aiam4944OpenWilliam R. Willen, Esq. Managing Counsel Product Legal Group American Honda Motor Co., Inc. 1919 Torrance Boulevard Torrance, California 90501-2746; William R. Willen Esq. Managing Counsel Product Legal Group American Honda Motor Co. Inc. 1919 Torrance Boulevard Torrance California 90501-2746; "Dear Mr. Willen: This responds to Honda's request for a interpretation of Federal Motor Vehicle Safety Standard No. 123, Motorcycle controls and displays. You stated that Honda is developing a braking system for motorcycles that would offer full proportioning front and rear when utilizing either the front hand control, or the rear control. You asked whether such a system would be permitted by the standard, particularly in light of section S5.2.1. As discussed below, such a braking system would be permissible under Standard No. 123. By way of background information, the National Highway Traffic Safety Administration does not provide approvals of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its vehicles and equipment meet applicable requirements. The following represents our opinion based on the facts set forth in your letter. S5.2.1, Control location and operation, includes the following language: If a motorcycle is equipped with self-proportioning or antilock braking devices utilizing a single control for front and rear brakes, the control shall be located and operable in the same manner as a rear brake control. Table 1 of Standard No. 123 provides that a rear wheel brake control must be a right foot control and must depress to engage. (Table 1 also includes an additional option that is not necessary to address in this letter.) Since Honda's motorcycle would be equipped with a self-proportioning device utilizing a single control for front and rear brakes, it would be subject to this requirement. If Honda's 'rear foot control' is one that is operated by the right foot and must be depressed to be engaged, that control would satisfy S5.2.1. It is our interpretation that so long as one control meets the specified requirements for location and operation, additional controls serving the same purpose may be provided voluntarily by the manufacturer and need not meet those requirements. I note that this view is similar to a position taken in an April 26, 1983 interpretation letter to an addressee whose identity has been withheld for reasons of confidentiality. In that letter, the agency stated, in the context of discussing S5.2.1, that ' u se of ... a self-proportioning device does not preclude additional brake actuation devices.' I am, for your information, enclosing a copy of that letter. In the situation at issue, we would consider the front hand control on Honda's design to be an 'additional brake actuation device,' and therefore, not precluded by Standard No. 123. I hope this information is helpful to you. If you have any further questions or need additional information, please feel free to contact Dorothy Nakama of my staff at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam1615OpenMr. William P. Stallsmith, Jr., Senior General Attorney, Southern Railway System, P.O. Box 1808, Washington, DC 20013; Mr. William P. Stallsmith Jr. Senior General Attorney Southern Railway System P.O. Box 1808 Washington DC 20013; Dear Mr. Stallsmith: This responds to your September 24, 1974, question whether Standard No 121, *Air brake systems*, would apply to trailers manufactured prior to January 1, 1975, although the painting of the trailers and their delivery to Southern had not been completed.; Section 108(a)(1) of the National Traffic and Motor Vehicle Safety Ac of 1966 provides:; >>>(a) No person shall -- (1) manufacture for sale, sell . . . any motor vehicle . . manufactured on or after the date any applicable Federal motor vehicle safety standard takes effect under this subchapter unless it is in conformity with such standard . . .<<<; We consider a vehicle to be 'manufactured' for purposes of the Ac where the vehicle has been completed in all respects except for the addition of readily attachable components or minor finishing operations such as painting undertaken at a later date. A discussion of this point appears in the preamble to a recent Standard No. 121 rulemaking action (39 FR 17564, May 17, 1974). As for possession of the trailers by Southern, delivery of the vehicle is not considered a element of the manufacturing process.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3628OpenMs. Joann Stewart, Account Representative, Fowler-Finch, Inc., P.O. 63, New Lebanon Center, NY 12126; Ms. Joann Stewart Account Representative Fowler-Finch Inc. P.O. 63 New Lebanon Center NY 12126; Dear Ms. Stewart: This responds to your recent letter asking whether the automatic bel systems in 1979 and 1980-model Volkswagens qualify as a 'passive restraint system' under Federal Motor Vehicle Safety Standard No. 208, *Occupant Crash Protection*. You need this information to determine if one of your insureds can obtain the discount your company offers for automobiles equipped with passive restraints.; The answer to your question is yes. The Volkswagen automatic bel system qualifies as a passive restraint. The agency has stated that a 'passive restraint' is a system that requires no action by vehicle occupants in order to obtain protection. The Volkswagen passive belt automatically surrounds the vehicle occupant without any action on the occupant's part other than closing the vehicle door (i.e., the occupant does not have to touch the belt system). Therefore, the Volkswagen belts you mentioned in your letter are passive restraints, and whether the systems are offered as standard or optional equipment is irrelevant.; I hope this answers all your questions. If you require any furthe information, please contact Hugh Oates of my staff (202-426-2992).; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0907OpenMr. Stan Haransky, Associate Director, Truck Body & Equipment Association, Inc., 5530 Wisconsin Avenue, Suite 1220, Washington, DC 20015; Mr. Stan Haransky Associate Director Truck Body & Equipment Association Inc. 5530 Wisconsin Avenue Suite 1220 Washington DC 20015; Dear Mr. Haransky: Thank you for your letter of November 15, 1972, and your kind word about my participation in your convention.; In your letter you asked a question that arose at the convention concerning the responsibility of a tank manufacturer who completes a tank truck for a customer who carries both gasoline an fuel oil. You asked,; >>>'Can a tank manufacturer by simply certifying the GVWR make a uni which will be legal at full load with gasoline, the lighter of the two products, and leave it to the user to ensure that he does not exceed the GVWR when he is carrying a mixed load or fuel oil only?'<<<; On the specific and limited facts that you have given, the answer i that the manufacturer will not be in violation of the Certification regulations. There are two ways in which a manufacturer might find himself liable on slightly different facts, however. If in an way the manufacturer provides information to the purchaser, through owner's manuals, promotional materials, or otherwise, which could reasonably be considered a 'rated cargo load', he will be in violation of S567.5(a)(5) if the GVWR does not reflect that figure. For example, if the vehicle were described explicitly as being capable of carrying 5,000 gallons of fuel oil, we would consider that to be the equivalent of a rating of that volume times the normal density of the oil.; The other possible liability would be for a safety-related defect. Thi would arise in a case where the vehicle was found to be unsafely equipped for carrying the loads that the manufacturer has reason to know would be imposed on it. Such a finding would depend on all the facts of an individual case. Obviously, the best course for the manufacturer, from the standpoint of both safety and the avoidance of liability, is to equip his vehicles fully with equipment that is rated to carry the loads that he believes the vehicles will carry.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4417OpenMr. Robert R. Aronson, President, Electric Fuel propulsion Corp., 366 W. Eight Mile Road, Detroit, MI 48220; Mr. Robert R. Aronson President Electric Fuel propulsion Corp. 366 W. Eight Mile Road Detroit MI 48220; Dear Mr. Aronson: This is in reply to your letter of November 26, 1973, inquiring abou the applicability of Standard No. 301 to your vehicles' gasoline-powered water heaters.; Standard No. 301 was promulgated in order to reduce the incidence o deaths and injuries resulting from fuel-related fires. The standard seeks to accomplish this end by specifying performance requirements which must be met by a motor vehicle's fuel system. Although the fuel systems primarily regulated by the standard are those which propel the vehicle, nothing in the standard limits its application to those systems. A fuel system which powers another aspect of the vehicle's operation, such as the gasoline- powered Stewart Warner Water Heater, is susceptible to the same hazards as the more commonly encountered fuel system, and thus they must be regulated in the same manner in order to fulfill the purposes of Standard No. 301.; Yours Truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1245OpenMr. Keitaro Nakajima, Director/General Manager, Toyota Motors Sales, U.S.A., Inc., 1099 Wall Street, West, Lyndhurst, NJ 07071; Mr. Keitaro Nakajima Director/General Manager Toyota Motors Sales U.S.A. Inc. 1099 Wall Street West Lyndhurst NJ 07071; Dear Mr. Nakajima: This is in reply to your letter of August 24, 1973, concerning Toyota' use of a clip to prevent the shoulder belt from rubbing the occupant's neck. Your questions are (1) whether a clip of this type is permitted by Standard No. 208 and (2) whether the clip would be considered a part of the anchorage under Standard No. 210.; Your description of the clip indicates that it does not restrict th free travel of the webbing. The clip would therefore not inhibit the ability of the belt to adjust automatically to fit the occupant, as required by S7.1.1 of Standard No. 208. It is our opinion that such a clip is permitted by Standard No. 208.; We have also concluded that a plastic guide clip designed so as not t affect the basic geometry of the belt during a crash is not a seat belt anchorage for purposes of Standard No. 210. The clip you describe would therefore not be required to meet the strength of location requirements of that Standard.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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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.