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: aiam1729OpenHonorable Birch Bayh, United States Senate, Washington, DC 20510; Honorable Birch Bayh United States Senate Washington DC 20510; Dear Senator Bayh: This is in response to your letter requesting information concernin correspondence from Mr. James A. Graham, commenting on a proposed amendment to the Federal bumper standard.; On January 2, 1975, the National Highway Traffic Safety Administratio (NHTSA) issued a *Federal Register* notice (copy enclosed) proposing to reduce the current 5-mph bumper impact requirements to 2.5 mph until the 1979 model year. The impact requirements would have been increased to 4 mph for 1979 and later model year cars.; The proposal was based primarily on the results of two agency-sponsore studies which indicated that the cost and weight of many current production bumpers, in light of inflation and fuel shortages, made the bumpers no longer cost beneficial. Information presented at public hearings on the bumper notice and comments submitted to the docket in response to the proposal have brought to light additional data. The NHTSA has carefully examined all of this evidence and reviewed its studies in light of the new information. As a result, the agency has concluded that the 5-mph protection level should not be reduced. This decision is contained in a *Federal Register* notice that was published March 12, 1975, which is enclosed (Docket No. 74-11, Notice 7, Docket No. 73-19, Notice 6).; In his letter Mr. Graham objects to the standard's regulation o surface damage, such as dents, stating that this is not the type of damage which should be addressed by an agency developing safety standards. The surface damage criteria are proposed as part of a standard being promulgated under Title I of the Motor Vehicle Information and Cost Savings Act (Pub. L. 92-513). The Cost Savings Act directs the National Highway Traffic Safety Administration to develop a bumper standard that will obtain the maximum feasible reduction of costs to the public and the consumer. As such, the standard is not to be limited to affecting safety- related damage. Factors such as insurance costs and consumer time and inconvenience are to be considered in the rulemaking as well.; Mr. Graham's comments will be placed in the public docket where the will receive every consideration.; We appreciate your interest and that of Mr. Graham in this area o motor vehicle safety and performance.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam0991OpenMr. Satoshi Nishibori, Nissan Motor Co., Ltd., 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Satoshi Nishibori Nissan Motor Co. Ltd. 560 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Nishibori: This is in reply to your letter of January 23, 1973, concerning th sequence of manual switch operation under S7.4.4 of Motor Vehicle Safety Standard No. 208. Your question is whether S7.4.4 requires the manual switch and ignition switch to be operated in a specific order.; S7.4.4 does no require any specific sequence. After the ignition ha been turned off, it can be made operable either by turning the ignition switch on, then operating the manual switch, of by operating the manual switch and then turning the ignition on.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1683OpenMr. Jeffrey B. Lugash, Suite 2200, 1801 Century Park East, Los Angeles, California 90067; Mr. Jeffrey B. Lugash Suite 2200 1801 Century Park East Los Angeles California 90067; Dear Mr. Lugash: This responds to your October 30, 1974, questions whether th Department of Transportation or any 'private establishment' requires manufacturers to file specifications for automobile, motorcycle, and airplane tires, whether Standard No. 119, *New pneumatic tires for vehicles other than passenger cars*, lists these specifications, and what the number '222474 7MRR' means on the bead of a motorcycle tire.; The Department of Transportation's National Highway Traffic Safet Administration has issued Standard No. 119 (effective March 1, 1975), which establishes minimum performance and labeling requirements with which the manufacturer must comply. A copy of the standard is enclosed. Certain tire specifications must appear on the sidewall, and certain rim-matching specifications must be published by the manufacturer or appear in a publication of at least one private tire organization.; It is the general practice of the tire industry to list specification of tires in a private publication, such as the 'Year Book' of the Tire and Rim Association in the United States. Their address is: The tire and Rim Association, Inc., 3200 West Market Street, Akron, Ohio 44313.; The NHTSA Tire and Wheel Division has determined that the number whic you cite is of significance only to the manufacturer of the tire.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3344OpenMr. R. H. Madison, Engineering Consultant, 12814 Ashbury Drive, Tantallon, MD 20022; Mr. R. H. Madison Engineering Consultant 12814 Ashbury Drive Tantallon MD 20022; Dear Mr. Madison: This responds to your June 25, 1980, letter asking whether a propose air brake system that you submitted would comply with the requirements of Standard No. 121, *Air Brake Systems*.; The National Highway Traffic Safety Administration (NHTSA) does no issue advance approval of systems constructed in compliance with safety standards. It is the responsibility of manufacturers to assure that their vehicles or equipment comply with the requirements of the safety standards. It is frequently impossible for the agency to tell from diagrams and descriptions of devices whether they will comply with the standards. Compliance is based upon testing and observation of the entire vehicle or piece of equipment as it is installed on the vehicle. Without the benefits of such tests, NHTSA cannot state whether your system would comply with Standard No. 121.; Our engineering staff has reviewed your letter and offers the followin information. First, the standard contains no requirements for tractor protection valve control pressures. However, control pressures are usually set so that the trailer brakes apply before the tractor brakes.; Second, you asked whether it is appropriate to require the release o parking brakes by pushing in both the tractor protection control valve and the park valve. The standard states that the parking brake control shall control the parking brakes of the vehicle and any vehicle it is designed to tow. The standard is silent regarding the release of those brakes.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4481OpenMr. Max J. Mizejewski Foreign Marketing Specialists, Inc. 14451 Chambers Rd., Suite 155 Tustin, CA 92680; Mr. Max J. Mizejewski Foreign Marketing Specialists Inc. 14451 Chambers Rd. Suite 155 Tustin CA 92680; "Dear Mr. Mizejewski: This is in response to your letter in which yo asked whether a product your company plans to import would be subject to any Federal motor vehicle safety standard (FMVSS). According to your letter, this product, which you refer to as a 'Roadreader,' attaches to the front of a motor vehicle and has two sensors which give a visual and audible alarm when the vehicle drifts off a road. You indicated that this product would be connected to the wiring related to the turn signals. You noted that this device does not affect vehicle functions such as acceleration, braking, lighting, or visibility. You further stated that if required, you would provide the device to NHTSA or another government agency for inspection. Section 103 of the National Traffic and Motor Vehicle Safety Act ('Safety Act') directs the National Highway Traffic Safety Administration (NHTSA) to establish safety standards for motor vehicles and motor vehicle equipment. Title 49 CFR Part 571 contains the safety standards promulgated by the agency. Although you stated that this device does not affect the electrical wiring related to the turn lights, I suggest you closely review Standard No. 108, Lamps, Reflective Devices, and Associated Equipment (Copy enclosed). This safety standard applies to both motor vehicle equipment installed in new motor vehicles and replacement equipment sold in the aftermarket. While I cannot conclusively say that this standard is or is not applicable to your product based on the limited facts in your letter, this standard may apply to your product because the wiring for your device is connected to components (i.e., turn lights) subject to the standard. For instance, S4.5.11 requires that components including the turn signal lamps must be wired to flash. More generally, S4.1.3 forbids the installation of an additional piece of motor vehicle equipment that impairs the lighting equipment required by Standard No. 108. Therefore, a device such as yours is permissible as original vehicle equipment provided that it does not impair the effectiveness of the lighting equipment required by the standard. As for the sale of your product in the aftermarket for vehicles in use, Section 108 of the Safety Act prohibits a manufacturer, distributor, dealer, or motor vehicle repair business from knowingly rendering inoperative any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with a FMVSS. Since an importer is defined by the Safety Act as a manufacturer, you should assure that installation of your device does not render inoperative, in whole or in part, the turn signal lamp or any other item of motor vehicle equipment subject to Standard No. 108. As for your second question concerning inspection and approval of your product, you should be aware that NHTSA does not provide approvals of motor vehicles and motor vehicle equipment. Under Section 114 of the Safety Act, it is the responsibility of the manufacturer to ensure that its vehicles or equipment comply with all applicable safety standards. Further, as you noted, you would be responsible for recalling any safety-related defects which you or this agency finds in your product. You also should be aware that laws from particular States may apply to your device. Therefore, you may wish to contact the State and local transportation authorities in the areas where you intend to market your product. The American Association of Motor Vehicle Administrators (4600 Wilson Boulevard, Arlington, Va. 22203) may also be able to provide information about State laws concerning devices similar to your product. Sincerely, Erika Z. Jones Chief Counsel Enclosure"; |
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ID: aiam2687OpenMs. Martha Storts Amster, 5301 East Osborn Road, Phoenix, AZ 85018; Ms. Martha Storts Amster 5301 East Osborn Road Phoenix AZ 85018; Dear Ms. Amster: This responds to your June 20, 1977, letter concerning Federal schoo bus safety standards. Your letter was forwarded to us by Ms. Margaret Costanza, Assistant to the President, since these standards are promulgated by the National Highway Traffic Safety Administration (NHTSA).; As you may know, several new school bus safety standards are applicabl to school buses built after April 1, 1977. These standards were established in accordance with a directive from Congress in the Motor Vehicle and School Bus Safety Amendments of 1974 (Pub. L. 93-492). Congress enacted that directive after determining that school buses deserved additional safety protection to prevent deaths and reduce injuries.; In your letter, you contend that our standard pertaining to school bu seating (Standard No. 222) requires seat spacing that is too small for older school children. It is our understanding after extensive consultations with bus manufacturers that the new school bus seat spacing requirements result in seat spacing that is essentially equivalent to seat spacing in buses manufactured prior to April 1. Therefore, most new school buses should be manufactured similar to older buses as far as seat spacing is concerned. Some school buses, however, may have slightly reduced seat spacing. We are aware of concerns expressed about reduced seat spacing in some new buses. We are not convinced that the problem originates from the requirements of Standard No. 222, however. Currently, we are examining buses manufactured in accordance with the requirements of the standard to determine whether a modification of the standard is necessary.; Maximum seat spacing has been controlled in buses to provide for th passive restraint of school bus occupants. The seat backs in the new buses are designed to absorb the force of children colliding with them during a crash. If seat spacing were increased, the seats in these buses would not be capable of absorbing sufficient impact force to protect children in accidents. The NHTSA adopted the passive restraint approach to school bus safety in response to public comments claiming that to require only seat belts in school buses would not be sufficient since the belts might not be used by many children. Accordingly, to provide a significant increase in occupant protection, the agency adopted the passive restraint approach to school bus seat safety.; In a final question in your letter, you ask about the costs an benefits of the new school bus safety standards' requirements. The agency has estimated that the total industry cost of compliance with those standards is approximately $40 million annually. The benefits should include a reduction in the number of deaths and injuries resulting from school bus accidents.; If I can be of further assistance to you, do not hesitate to contac me.; Sincerely, Joan Claybrook |
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ID: aiam3995OpenMr. Leo Kagan, Director of Marketing, Automotive Division, Amco Manufacturing Corporation, 7425 Fulton Avenue, North Hollywood, CA 91605; Mr. Leo Kagan Director of Marketing Automotive Division Amco Manufacturing Corporation 7425 Fulton Avenue North Hollywood CA 91605; Dear Mr. Kagan: This is in reply to your letter of July 19, 1985, asking if deck-mounted rack loaded with luggage would cause a violation of the center high-mounted stop lamp provisions of Motor Vehicle Safety Standard No. 108.; The answer is no. Compliance with Standard No. 108 is determine independent of whether the luggage rack is loaded. However, if the rack is installed before sale of the vehicle to its first purchaser, or if it is installed after sale by a person other than the vehicle owner, care must be taken to insure that the photometric and visibility requirements for center high-mounted stop lamps continue to be met with the unloaded rack in place.; The lamp is intended to reduce the incidence of rear end collisions Loading the rack in a manner that obscures the light will reduce the safety benefits that the lamp provides both the driver of the car, and of any vehicle that follows, and is a practice that should be discouraged.; If you have any further questions, we shall be happy to answer them. Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam0340OpenAndrew R. Hricko, Esq., General Counsel, Insurance Institute for Highway Safety, Watergate Six Hundred, Washington, DC 20037; Andrew R. Hricko Esq. General Counsel Insurance Institute for Highway Safety Watergate Six Hundred Washington DC 20037; Dear Mr. Hricko: This is in reply to your letter of April 30, 1971, requesting a interpretation of the terms 'cooling system' and 'fuel system' as used in Motor Vehicle Safety Standard No. 215.; You first ask whether 'cooling system' includes the various component of the vehicle's air conditioning system. The term is not intended to include the air conditioning system.; Your second question is whether 'fuel systems' would include pollutio control vapor cannisters (sic) and other components used to reduce fuel emissions. If such components contain fuel or fuel vapor they are considered to be a part of the fuel system.; Please advise us if further clarification is needed. Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam5512OpenMr. Marshall S. Reagle Sate-Lite Mfg. Co. 6230 Gross Point Road Niles, IL 60714; Mr. Marshall S. Reagle Sate-Lite Mfg. Co. 6230 Gross Point Road Niles IL 60714; "Dear Mr. Reagle: This is in reply to your recent FAX to Pat Boyd o this agency asking for a confirmation of an interpretation of certain reflex reflector requirements of Motor Vehicle Safety Standard No. 108, specifically S5.7.2.1(b) and (c). For your future reference, requests for interpretation should be addressed to the Chief Counsel. You state that Mr. Boyd informed you that 'any retro-reflector would have to be made in intervals of 4 inches' with the 0 degree at the two-inch mark, and that the reflective reading would have to comply with S5.7.2.1(b) or (c). He also informed you that, regardless of whether the segment was 4, 8, or 12 inches in length, the agency will test in 4-inch segments. This is correct. According to paragraph S5.7.2.2(a) and (b) of Standard No. 108, each reflector shall be installed 'with the center of each reflector not more than 100 mm from the center of each adjacent reflector.' As 100 mm is approximately 4 inches, this effectively limits the size of a reflector to a maximum length of 4 inches. However, this does not prohibit the mounting of two or three adjacent reflectors in 'segments' of 8 or 12 inches, whether separately or in a housing. As Mr. Boyd informed you, each discrete 4-inch segment must comply with paragraph S5.7.2.1(b) or (c). Paragraphs S5.7.2.1(b) and (c) specify reflectivity values for red and white reflex reflectors respectively 'at any light entrance angle between 30 degrees left and 30 degrees right, including an entrance angle of 0 degrees,' as well as 'any light entrance angle between 45 degrees left and 45 degrees right.' Your drawing of a 4-inch reflector correctly depicts the 0 degree light entrance angle at the 2-inch mark, in the center of the reflector. However, SAE Standard J594f, Reflex Reflectors, January 1977, incorporated by reference in Standard No. 108, requires the measurement of the other light entrance angles also with respect to the center of the reflector, rather than with respect to the ends as pictured in your drawing. If you have any further questions, you may call Taylor Vinson of this Office (202-366-5263). Sincerely, Philip R. Recht Chief Counsel"; |
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ID: aiam0710OpenMr. Edwin P. Palumbo, Executive Director, Rhode Island Consumers' Council, 365 Broadway, Providence, Rhode Island 02909; Mr. Edwin P. Palumbo Executive Director Rhode Island Consumers' Council 365 Broadway Providence Rhode Island 02909; Dear Mr. Palumbo: We have received your letter of March 15, 1972, which was forwarded t us by the Federal Trade Commission, concerning problems experienced by Mr. Ronald Dandeneau regarding a repossessed vehicle he purchased which was equipped with tires marked 'NA.' Mr Dandeneau claims he was told by a tire dealer that such tires are considered unserviceable, cannot be repaired, and are unsafe.; The sale of these tires by the tire manufacturer (we understand tha the practice is not limited to Uniroyal) is not prohibited by the National Traffic and Motor Vehicle Safety Act, and the Federal standard applicable to passenger car tires. The Federal standard applies only to tires before their first sale to a consumer, and does not apply to used tires such as these.; We understand that tires marked 'NA' are tires that have been adjuste previously, but for reasons that are not considered to affect the safety of the tire. Examples of such reasons are a lack of roundness and uniformity. While these conditions may produce riding qualities which some people find unsatisfactory, we presently have no evidence that such tires cannot be repaired or that they are unsafe.; 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.