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: aiam2555OpenMiss Irene Glessner, 276 Birch Avenue, Elsmere Manor, Wilmington, DE 19805; Miss Irene Glessner 276 Birch Avenue Elsmere Manor Wilmington DE 19805; Dear Miss Glessner: This responds to your March 21, 1977, letter asking whether a tir dealer is required to record the serial numbers of the tires he sells.; The National Highway Traffic Safety Administration (NHTSA) promulgate regulations pertaining to tires. One of these regulations, Part 574, *Tire Identification and Recordkeeping*, requires tire dealers and distributors to obtain information when the tire is sold and to forward that information to the tire manufacturer. I am enclosing a copy of this regulation for your information. In S574.7 of the regulation you will find the exact information for which a tire dealer is responsible.; A tire dealer would not be responsible for the ultimate recall o tires. The information which a dealer submits to a manufacturer enables the manufacturer to undertake recalls. Failure to record and submit the information to a manufacturer would be a violation of Section 108 of the National Traffic and Motor Vehicle Safety Act of 1966 (as amended) (15 U.S.C. 1381, 1397). Each violation is punishable by a civil penalty of $1,000 up to a maximum of $800,000 for a series of violations (15 U.S.C. 1398).; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam2806OpenDr. Arthur Yeager, 1 Park Place, Westwood, NJ 07675; Dr. Arthur Yeager 1 Park Place Westwood NJ 07675; Dear Dr. Yeager: This responds to your telephone request of March 24, 1978, askin whether the seats in school buses are sufficiently strong to allow the installation of seat belts. You stated that some manufacturers are indicating that they cannot install seat belts because the floors of larger school buses cannot withstand the forces generated by seat belts.; As you indicated, Notice 5 of Docket 73-3 stated that school bus seat should be strong enough to withstand the forces seat belts would impose upon them. This statement was based upon the fact that the seats would be designed to comply with the other force requirements of the standard which would increase the strength of the seats making them capable of withstanding seat belt loads. At the time of that notice, there were special seat belt requirements for seat belts in school buses in the then proposed Standard No. 222. These seat belt requirements would have mandated lower belt load requirements than those found in Standard No. 210 which currently applies to school buses (under 10,000 pounds GVWR). The seats in larger school buses should be sufficiently strong to withstand the former proposed force requirements of Standard No. 222, but they might be incapable of withstanding the belt load requirements of Standard No. 210.; Manufacturers who indicate that the seats or floors of larger buses ar not strong enough to install seat belts probably misunderstood the belt requirements for large buses. Seat belts can be installed for passenger seats in larger school buses without complying with any existing seat belt requirements. Seat belts for passenger seats are not required, for example, to comply with Standard No. 210. Therefore, a State would be permitted to establish their own acceptable belt load requirements for these seat belts in large school buses. The National Highway Traffic Safety Administration suggests that States adopt the belt load requirements previously proposed for Standard No. 222. School bus seats currently in production should be sufficiently strong to withstand the former proposed belt load requirements.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3714OpenMr. Louis Gaia, V.P. Purchasing, Ezon Products, Inc., P.O. Box 18134, Memphis, TN 38118; Mr. Louis Gaia V.P. Purchasing Ezon Products Inc. P.O. Box 18134 Memphis TN 38118; Dear Mr. Gaia: In your letter of June 2, 1983, to the Office of Chief Counsel, yo asked if there were 'any D.O.T. requirements on miniature bulbs?'; We understand your question to refer to bulbs used in lighting device other than headlamps. Federal Motor Vehicle Safety Standard No. 108, *Lamps, Reflective Devices, and Associated Equipment*, imposes no performance requirements on individual bulbs used in lighting devices other than those used in replaceable bulb headlamps (an option permissible as of July 1, 1983). Other lighting devices must meet the photometric requirements of the standard with the bulb, chosen by the lighting device manufacturer, installed.; I hope that this answers your question. Sincerely, Frank Berndt, Chief Counsel |
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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: aiam1379OpenMr. Richard Wright West, West & Wilkinson, P.O. Box 257, 2815 Huntington Avenue, Newport News, VA 23607; Mr. Richard Wright West West & Wilkinson P.O. Box 257 2815 Huntington Avenue Newport News VA 23607; Dear Mr. West: This is in response to your letter of January 2, 1974 requestin information concerning the legal permissibility of an automobile dealership furnishing private passenger motor vehicles with add-on gasoline tanks or modifying existing gasoline tanks.; Motor Vehicle Safety Standard No. 301, *Fuel System Integrity* establishes minimum performance requirements for motor vehicle fuel systems. Compliance with the level of performance mandated by the standard is enforced by Section 108(a)(1) of the National traffic and Motor Vehicle Safety Act which prohibits the manufacture, sale, delivery, or importation of vehicles or mtor vehicle equipment that do not meet the requirements of applicable safety standards. Therefore, if your client modified a motor vehicle fuel tank in such a manner that it no longer complied with Standard No. 301 and then offered it for initial sale for purposes other than resale he would be in violation of the Motor Vehicle Safety Act and would be subject to civil penalties of not more than $1,000 for each such violation. If, however, your client performed a fuel tank modification on a vehicle that was already owned by and in the possession of a buyer who purchased the vehicle for purposes other than resale, no violation of the Act could result. the installation of an add-on fuel tank would be considered a modification. Therefore, the fuel system would have to comply with Standard No. 301 with the add-on fuel tank considered as part of the system.; There are no Motor Vehicle Safety Standards applicable to add-o gasoline tanks since these are items of motor vehicle equipment and standard No. 301 restricts its application to motor vehicles. Section 113(e)(2) of the Motor Vehicle Safety Act, however, authorizes the Secretary of Transportation to determine whether or not an item of motor vehicle equipment contains a defect which relates to motor vehicle safety. If the Secretary finds that a safety-related defect exists, your client may be compelled to notify all purchasers of vehicles with the add-on fuel tanks of the attendant hazard.; The action of installing add-on gasoline tanks in motor vehicle exposes your client to the requirements of yet another safety regulation (49 CFR 567.7). If the vehicle in which he installs the fuel thank is a certified and complete vehicle that has not yet been purchased ingood faith for purposes other than resale, your client will be considered an alterer of the vehicle, and he must provide a certification that the vehicle as altered still conforms to the standards.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2943OpenMr. Heinz W. Gerth, Mercedes-Benz of North America, Inc., One Mercedes Drive, P. O. Box 350, Montvale, NJ 07645; Mr. Heinz W. Gerth Mercedes-Benz of North America Inc. One Mercedes Drive P. O. Box 350 Montvale NJ 07645; Dear Mr. Gerth: This responds to your letter of December 19, 1978, asking whether manually adjustable seat belt anchorage for the upper torso portion of a 3-point safety belt is permissible under Safety Standard No. 210, *Seat Belt Assembly Anchorages*. You state that this new anchorage is adjustable over a certain range and is intended to increase wearing comfort by providing a better 'fit' for all occupants.; We have reviewed the drawings and specifications enclosed with you letter and determined that the proposed adjustable anchorage design would not be precluded by Safety Standard No. 210 if the design meets the following two conditions: (1) the anchorage complies with the zone location requirements of the standard in any of the positions to which it can be adjusted, and (2) the anchorage complies with the strength requirements of the standard at all times, even when the adjusting mechanism (bolt) is in its loosened status. There is nothing in the standard that prevents the use of adjustable anchorages, per se.; From discussions with your engineers, we found that the proposed desig would require the use of a tool to tighten the adjusting bolt. We are concerned that this feature could reduce potential increases in belt use. For example, if driver A adjusts the belt anchorage to its lowest position, will driver B readjust the belt when he enters the car if the two drivers are of different sizes and the lowest position is uncomfortable for driver B? If the readjustment requires the use of a wrench to loosen and retighten the anchorage bolt, will driver B simply choose not to wear the belt? We believe that a manually adjusting anchorage that does not require the use of tools would be a preferable design in terms of potential seat belt use.; The agency is of course very interested in any seat belt design tha will increase comfort and convenience and, thereby, seat belt use. Therefore, we encourage innovative designs. Please keep us informed about the progress of your work on your new anchorage system.; The National Highway Traffic Safety Administration hereby grants you request for confidential treatment of the drawings included in your letter (enclosures 1, 2 and 4). We have preliminarily determined that the drawings and specifications contain privileged commercial information that is exempt from disclosure under 5 U.S.C. 552(b)(4).; Sincerely, Joseph J. Levin, Jr., 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.