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: aiam2388OpenMr. Bing Johnson, 135 Jade Cove Drive, Roswell, Georgia 30075; Mr. Bing Johnson 135 Jade Cove Drive Roswell Georgia 30075; Dear Mr. Johnson: This is in reply to your letter of August 16, 1976 in which you ask about our regulations concerning the modification of 'vans' to make them suitable for camping. The modifications you propose to make include the installation of plumbing, water, electricity, and additional seating.; The National Traffic and Motor Vehicle Safety Act (15 U.S.C. SS 1381 *et seq.*) prohibits the manufacture, offer for sale, sale, introduction in interstate commerce or importation of a motor vehicle that does not comply with all applicable standards in effect on the date of its manufacture. This prohibition does not apply (except for importation) after the first purchase of the vehicle in good faith for purposes other than resale. Under these provisions, you are responsible for the compliance of any vehicle that you modify up to and including the time of first purchase for purposes other than resale.; The manufacturer must comply with all applicable safety standard established by the National Highway Traffic Safety Administration (NHTSA). His certification appears on a completed vehicle. It would be your responsibility to ensure that the vehicle continues to comply with all applicable safety standard after your modifications. Under Part 567 of our regulations, you must attach a label to the vehicle that states that, as altered, the vehicle continued to conform to the standards.; From the description of the modification you describe, it appears tha you might affect the compliance of the vehicle with the following standards: Standard No. 207, *Seating Systems*, Standard No. 208, *Occupant Crash Protection*, Standard No. 210, *Seat Belt Assembly Anchorages*, and Standard No. 302, *Flammability of Interior Materials*. It should be noted that any additional weight created by your modifications or a change in the distribution of weight could also affect the vehicle's compliance with other safety standards whose test procedures required a barrier crash test.; We also would point out that if you modify a Ford 'Econoline' in al probability you would change the vehicle classification from a truck to a multipurpose passenger vehicle. This should be noted on the certification label that you attach to the vehicle. I have enclosed an information sheet that explained where you may obtain copies of these regulations.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam3433OpenMs. Nancy Avery, Calesco, Inc., 5620 Glenridge Drive, N.E., P.O. Box 5041, Atlanta, GA 30302; Ms. Nancy Avery Calesco Inc. 5620 Glenridge Drive N.E. P.O. Box 5041 Atlanta GA 30302; Dear Ms. Avery: This is in response to your letter of November 11, 1980, concerning th application of the Federal odometer disclosure requirements. We regret our delay in responding. The answers to your specific questions are as follows:; 1. Are we required to give the purchaser an odometer statement in th states (such as Massachusetts, Pennsylvania, and Ohio) where the mileage at the time of the vehicle transfer is recorded on the Certificate of Title?; The odometer Disclosure Requirements (49 CFR Part 580) provide that th transferor of a vehicle may substitute the state certificate of title for the Federal odometer disclosure statement, if the state title contains essentially the same information found in the Federal statement. Where the state certificate of title can be substituted for the Federal form, there is no requirement that a separate Federal odometer disclosure statement be issued to the purchaser. However, if the information contained in the state certificate of title varies from that required in the Federal form, the state must obtain the approval of this agency before its certificate of title can be used as a substitute for the Federal form.; In order to spare states the burden of an approval process, the agenc has indicated that certain variations from the Federal form are acceptable. In the *Federal Register* notice of August 1, 1977, which amended the disclosure regulation, we gave examples of shortened forms that would be acceptable. A state title can be considered to be approved for use as a full disclosure statement if it varies from the Federal form in only those aspects noted in the August 1 notice, a copy of which is enclosed.; 2. If we sell a vehicle in Canada or Puerto Rico, is this la applicable?; For purposes of the Motor Vehicle Information and Cost Savings Act, a amended, 15 U.S.C. 1901 *et seq.*, Puerto Rico is a state. Therefore, the Federal odometer disclosure requirements are applicable to the sale of a vehicle in Puerto Rico. However, the agnecy has no jurisdiction over the sale of a vehicle in Canada.; 3. On the odometer statements, is the signature of the purchase required?; The Odometer Disclosure Requirements (49 CFR Part 580.4(e)) provid that the transferee (buyer) shall acknowledge receipt of the disclosure statement by signing it.; 4. If the vehicle is sold as salvage, are we required to give th purchaser an odometer statement?; The Federal odometer disclosure laws are not applicable to vehicle that are sold for salvage. The agency has determined that for purposes of the Federal odometer laws a vehicle is salvage if it is so badly damaged that it cannot be returned to the road. However, if the vehicle is repairable and will subsequently be used as a motor vehicle, disclosure has to be made.; Sincerely, David W. Allen, Assistant Chief Counsel |
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ID: aiam3063OpenMr. John Riccardo, Chairman of the Board, Chrysler Corporation, P.O. Box 1919, Detroit, MI 48321; Mr. John Riccardo Chairman of the Board Chrysler Corporation P.O. Box 1919 Detroit MI 48321; Dear Mr. Riccardo: This responds to your letter about Chrysler's general need for relie from Federal regulations and the denial of its petition for a one-year exemption from the automatic restraint requirements for Chrysler 1982-model full- size cars. There are several statements by Chrysler regarding the petition denial that you wish placed in the public record. Accordingly, your letter has been placed in the public docket on occupant crash protection (74-14, General Reference).; This agency is fully appreciative of the significance of Chrysler' circumstances and needs. Where relief can be considered consistent with the spirit and provisions of the laws we administer, we will do so. This willingness was amply demonstrated by my recent action in reducing the 1981 fuel economy standard for light trucks. Chrysler's automatic restraint petition presented us with a substantially different situation. Under our statutory authority, the only way we could have exempted Chrysler's large-size 1982 model from compliance with the automatic restraint requirements would have been to classify that vehicle as a unique type of car under our existing authority. Clearly, such a classification would have been challenged in court, and we believe it would not have been sustained. Indeed, such an action would severely strain our credibility with the court which just recently reviewed that very issued. (sic); Regarding your statements about the safety issues associated with th denial, the agency agrees that some safety belt reminder systems can be effective in encouraging belt use. We do not believe, however, that most simple warning systems can equal the life-saving potential of automatic restraints. Further, the NHTSA has no authority under the National Traffic and Motor Vehicle Safety Act to require ignition interlock systems, which are probably the most effective systems for encouraging use of manual belts.; In this particular matter, the law precludes us from granting th relief you seek. I regret that we are unable to assist you under these circumstances.; Sincerely, Joan Claybrook |
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ID: aiam3599OpenMr. Robert P. Donley, President, Weldon Incorporated, 2000 South High Street, Columbus, OH 43207; Mr. Robert P. Donley President Weldon Incorporated 2000 South High Street Columbus OH 43207; Dear Mr. Donley: This is in reply to your letter of December 10, 1981, regardin continuing compliance of lighting equipment after repairs.; You have asked the following questions: '1. If the original lens is replaced during a field repair by one no manufactured by the original manufacturer, would the lamp's original certification with FMVSS 108 be nullified?'; Repair of a vehicle in service is irrelevant to its certification Certification is the assurance given by the manufacturer to distributors, dealers, and purchasers, that Federal standards are met by his product upon its sale when new. There is no requirement that the certification be valid for the life of the product.; '2. Must a lamp in use remain in conformance with FMVSS 108 after suc repair is made?'; This is a good question, and the answer is no. When repairs ar necessary there is no Federal legal requirement that the lamp remain in conformance afterwards. However, manufacturers, distributors, dealers, and motor vehicle repair businesses may not alter fully functional lamps in a manner that renders them nonconforming, or substitute nonconforming equipment. This prohibition does not apply to the vehicle owner, his modifications are subject only to State and local restrictions.; '3. If the lamp must remain in conformance with FMVSS 108 after suc repair is made, who is responsible for certifying same?'; As I stated earlier, repairs of used vehicles and equipment are no subject to conformance or certification. However, if a lamp is replaced in its entirety, the manufacturer of the replacement lamp is responsible for certifying conformity to Standard No. 108 because that standard covers replacement equipment of the types you mentioned ('e.g., stop lamp, turn signal lamp, school bus warning lamp, marker lamp').; I hope this answers your questions. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4749OpenMr. Douglas Mayes President Creative Products, Inc. Number One Carissa Littleton, CO 80127; Mr. Douglas Mayes President Creative Products Inc. Number One Carissa Littleton CO 80127; "Dear Mr. Mayes: This responds to your letter asking questions i relation to your product called 'gyroscopic wheel covers.' We apologize for the delay in our response. According to your letter and accompanying information, you claim that use of 'gyroscopic wheel covers' can reduce stopping distance. You stated that Dr. Carl Clark of this agency suggested that you request this office to provide a letter specifically outlining the requirements of the agency's braking test, and a list of the various testing facilities used by the agency when testing a product for this purpose. You then asked for a letter stating the 'stopping distance test guidelines' of Safety Standard No. l05, Hydraulic Brake Systems,' and a list of laboratories acceptable to DOT that could be used to test your product. You also asked whether an SAE standard is a proper example of a stopping distance test. You stated that it is your intention to use these testing standards and one of the acceptable laboratories so as to properly document your product's test results in compliance with the DOT testing standards. By way of background information, the National Highway Traffic Safety Administration (NHTSA) 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 products meet applicable standards. Safety Standard No. l05, Hydraulic Brake Systems, applies to passenger cars and other motor vehicles. The standard specifies, among other things, a number of stopping distance tests that each motor vehicle must meet. I have enclosed a copy of the standard for your information. I note that Standard No. l05 was not designed for the purpose of evaluating whether a product such as yours can improve stopping distance. We are unable to offer an opinion as to the appropriateness of using Standard No. l05's stopping distance tests for that purpose, or how such a test program would best be carried out. This agency does not provide recommendations or endorsements for particular testing laboratories. I have, however, enclosed a list of the independent laboratories conducting compliance tests for NHTSA's Office of Vehicle Safety Compliance during the current fiscal year. I have also enclosed a copy of an information sheet we have prepared which provides information for new manufacturers of motor vehicles and motor vehicle equipment. I hope this information is helpful. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam3576OpenMr. Arnold P. Fuchs, 68 Roslyn Road, Grosse Pointe Shores, MI 48236; Mr. Arnold P. Fuchs 68 Roslyn Road Grosse Pointe Shores MI 48236; Dear Mr. Fuchs: This letter is to confirm your view, expressed in a telephone call wit Edward Glancy of this office, that the requirements of Standard No. 206, *Door Locks and Door Retention Components*, are not applicable to a replacement latch for a truck built in 1969.; The requirements of Standard No. 206 are applicable to passenger cars multipurpose passenger vehicles and trucks. See S2 of that Standard. However, its requirements are not applicable to replacement parts for installation in used vehicles of these types.; Further, the 'render inoperative' provisions of the National Traffi and Motor Vehicle Safety Act are not relevant to the installation of such a latch. Under section 108(a)(2)(A) of that Act, a business such as a garage must make sure that it does not knowingly render inoperative the compliance of a vehicle with any applicable safety standard. With respect to a 1969 truck and Standard No. 206, there is no compliance which could be rendered inoperative since the Standard was never applicable to that truck. That Standard applies only to trucks manufactured on or after January 1, 1972.; I would note that even in the absence of an applicable safety standard the defect provisions of the Act may be applicable. Sections 151 *et seq*. of the Act provide that manufacturers of motor vehicles and motor vehicle equipment must notify owners of vehicles and equipment with safety-related defects and remedy those defects free of charge.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4319OpenMr. Jerome A. Czarnowski, 3746 N. Tripp Avenue, Chicago, IL 60641; Mr. Jerome A. Czarnowski 3746 N. Tripp Avenue Chicago IL 60641; Dear Mr. Czarnowski: In September 1986, you sent information concerning your Emergency Ai Reserve System (EARS) to Dr. Carl Clark of the National Highway Traffic Safety Administration's (NHTSA's) Office of Research and Development. According to your letter, EARS is a separate high-pressure system intended to provide an emergency vehicle with enough air volume and pressure to charge the vehicle's integral system to operating pressure. You stated that the system does not violate the integrity of the vehicle's system, since check-valves, a relief valve and one-way regulator are present.; Later, in February 1987, you asked Dr. Clark for information concernin whether EARS is permitted under Federal Motor Vehicle Safety Standard No. 121, *Air Brake Systems*. This letter responds to that request.; By way of background information, NHTSA does not provide approvals o 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 or equipment comply with all applicable standards. The following represents our opinion based on the facts provided in your letter.; NHTSA does not have any specific regulations covering auxiliary device for the quick pressurizing of air brake systems. However, since your device is tied into a vehicle's air brake system, it could affect a vehicle's compliance with Standard No. 121.; If your device is installed as original equipment on a new vehicle, th vehicle manufacturer is required to certify that, with the device installed, the vehicle satisfies the requirements of all applicable safety standards.; One issue we have examined is whether your device is considered a integral part of the brake system in the sense that it would need to comply with certain of Standard No. 121's requirements, e.g., those for reservoir strength. A related issue is whether certain parts of the device are considered brake hose and therefore subject to the requirements of Standard No. 106, *Brake Hoses*.; It is our opinion that your device is not considered part of th braking system, so long as the device is separated from the vehicle's main braking system by a check valve in such a way that the main braking system will not be affected by a leakage failure in the device. Thus, since your letter indicates that such a check valve is provided, your device itself would not be subject to the requirements of Standards No. 106 and 121. This opinion is limited to the specific factual situation raised by your letter. We note that the device is not intended to replace a vehicle's normal braking system but instead to provide auxiliary air pressure for certain emergency situations. We also note that the requirements of Standards No. 106 and 121 were not written to cover the high air pressures used in your system.; If the device is added to a previously certified new motor vehicl prior to its first sale, the person who modifies the vehicle would be an alterer of a previously certified motor vehicle and would be required to certify that, as altered, the vehicle continues to comply with all of the safety standards affected by the alteration.; If the device is installed on a used vehicle by a business such as garage, the installer would not be required to attach a certification label. However, it would have to make sure that it did not knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard. This is required by section 108(a)(20)(A) (sic) of the National Traffic and Motor Vehicle Safety Act.; In response to a request you made to Dr. Clark, Edward Glancy of m staff previously sent a general information sheet to your attorney, Ralph Rath, Esq. The information sheet identifies relevant Federal statutes and NHTSA standards and regulations affecting motor vehicle and motor vehicle equipment manufacturers. We are also sending a copy of this letter to Mr. Rath.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3126OpenMr. G. Frinken, Manager, Automotive Engineering Europe, Uniroyal GmbH, Postfach 410, 5100 Aachen 1, West Germany; Mr. G. Frinken Manager Automotive Engineering Europe Uniroyal GmbH Postfach 410 5100 Aachen 1 West Germany; Dear Mr. Frinken: This is in response to your letter of October 12, 1979, asking whethe the character height of 5/32nds of an inch, stated in the Uniform Tire Quality Grading (UTQG) Standards (49 CFR 575.104, Figure 1), is considered by the National Highway Traffic Safety Administration (NHTSA) to specify the only acceptable height for UTQG sidewall molding, or whether the agency interprets this measurement as a minimum value.; The specification of 5/32nds of an inch tire sidewall characters wa intended by NHTSA to establish a minimum requirement to assure readability of the UTQG information presented. The agency has no objection to the use of characters of a height greater than 5/32nds of an inch, so long as all characters used to convey UTQG information are of the same height.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5158OpenMr. Scott R. Dennison Vice-President - Production Excalibur Automobile Corporation 1735 South 108th Street Milwaukee, WI 53214; Mr. Scott R. Dennison Vice-President - Production Excalibur Automobile Corporation 1735 South 108th Street Milwaukee WI 53214; Dear Mr. Dennison: Robert Hellmuth, Director of the Office of Vehicl Safety Compliance, has asked us to respond to your FAX of March 12, 1993. You offer your input and assistance 'regarding the alleged debate over the treatment of vehicles replicating pre-safety standard vehicle designs and their compliance with current Federal Motor Vehicle Safety Standards.' We are unsure what you mean by 'debate.' Under the National Traffic and Motor Vehicle Safety Act, all new motor vehicles, including replica vehicles, must conform to the Safety Standards unless exempted by the Administrator from one or more of those standards pursuant to 49 CFR Part 555. This regulation has been in effect since l972, and is intended to assist temporarily those manufacturers whose products may differ from those of conventional motor vehicles. I should note that the predecessor owners of Excalibur have been able to certify compliance of this replica vehicle since 1972 with all Safety Standards without seeking a temporary exemption from them. However, the Safety Standards do not cover a vehicle in use. Occasionally, situations arise in which a vehicle is newly manufactured, but contains a substantial number of parts from a vehicle previously in use. In these instances the question arises whether the vehicle may be considered 'new' and required to comply with the Safety Standards, or one that may be regarded as having been a vehicle in use for which compliance is not required. Perhaps this is the 'debate' to which you refer. We handle these situations according to the facts of each. If you wish to offer further comments, we would be pleased to consider them. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam2367OpenMr. Thomas S. Pieratt, Executive Director, Truck Equipment & Body Distributors Association, 602 Main Street, Cincinnati, OH 45202; Mr. Thomas S. Pieratt Executive Director Truck Equipment & Body Distributors Association 602 Main Street Cincinnati OH 45202; Dear Mr. Pieratt: This responds to your July 28, 1976, request for confirmation that boat-carrying trailer which has a primary cargo-carrying surface less than 40 inches from the ground qualifies as a 'Heavy hauler trailer', and that such trailers are not required to meet the requirements of Standard No. 121, *Air Brake Systems*, until September 1, 1977.; '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 boat-carrying trailer which you describe as having a bed height o 18 3/4 inches would qualify for exemption until September 1, 1977.; Yours truly, Frank Berndt, Acting 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.