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: aiam0116OpenMarti, O'Cara, Dalton and Bruckner, 303 Lincoln Building, Lincoln, NE 68508; Marti O'Cara Dalton and Bruckner 303 Lincoln Building Lincoln NE 68508; Attention: Mr. Warren K. Dalton Gentlemen: Your letter of September 16, 1968, addressed to Mr. George C. Nield o the National Highway Safety Bureau has been forwarded to my office for reply.; From the brief description presented in your letter, it would appea that the proposed Cushman motor vehicle would be considered a 'passenger car' under the definitions included in the Federal Motor Vehicle Safety Standards. At the present time, the standards do not apply to vehicles of 1,000 pounds or less curb weight. However, we are presently contemplating amendment of the Standards to include such vehicles in the near future as presented in the Advance Notice of Proposed Rule Making published October 14, 1967. The rated horsepower of the engine is not relevant in determining applicability of the standards.; Enclosed is a copy of the Advance Notice of Proposed Rule Making fo your perusal.; Sincerely, Eugene B. Laskin, Acting Director, Office of Standard Preparation, Motor Vehicle Safety Performance Service; |
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ID: aiam5314OpenHarry C. Gough, P.E. Automotive Engineering Professional Specialist State of Connecticut Department of Motor Vehicles 60 State Street Wethersfield, CT 06161; Harry C. Gough P.E. Automotive Engineering Professional Specialist State of Connecticut Department of Motor Vehicles 60 State Street Wethersfield CT 06161; "Dear Mr. Gough: This is in reply to your letter of December 2, 1993 with respect to the term 'alternately flashing' as it applies under Safety Standard No. 108 to school bus lamps. You ask for our opinion because a manufacturer of strobe lighting has supplied documentation indicating that the system complies with Standard No. 108. According to your letter, in this system, the lamp on one side of the school bus (front and rear) 'flashes on and off four times in a 255 millisecond period and then stays off for 745 milliseconds, then the lamp on the opposite side of the bus repeats the aforementioned pattern.' You inquire as to whether 'alternately flashing' refers to this pattern, 'or do the four distinct on/off cycles on each side of the school bus defeat the intent of the term alternating.' As you know, paragraph S5.1.4 of Standard No. 108 incorporates by reference SAE Standard J887, School Bus Red Signal Lamps, July 1964, which requires that school bus warning lamp systems 'flash alternately.' We believe that the light emanating from a strobe lamp that flashes four times in 0.255 second will be perceived as a single flash of varying intensity and not as four separate flashes, and that when this is followed by an identical pattern on the other side of the bus, the system is one that is alternately flashing within the meaning of Standard No. 108. Further, under this interpretation, the flash rate meets SAE J887's specification of 60-120 flashes a minute. Unlike other SAE materials incorporated by reference relating to signal lamps (e.g., J1133 School Bus Stop Arms in Standard No. 131 School Bus Pedestrian Safety Devices and J590b Automotive Turn Signal Flashers in Standard No. 108), J887 contains no 'percent current 'on' time' requirements. I hope that this answers your question. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam1357OpenMr. James M. Robertson, University Club Tower, Suite 2410, Tulsa, OK 74119; Mr. James M. Robertson University Club Tower Suite 2410 Tulsa OK 74119; Dear Mr. Robertson: This responds to your December 10, 1973, question whether a deale violates the odometer Disclosure Requirements of the Motor Vehicle Information and Cost Savings Act and 49 CFR Part 580 if he simply duplicates the disclosure made to him when he bought the car.; If the dealer acts in good faith in making his disclosure, he i entitled to rely on the disclosure made to him as the basis of his statement. On the other hand, collusion between the dealer and the former owner to knowingly make a false disclosure would violate the Act. Either might be subject to suit and damages if intent to defraud can be shown.; We realize that such a burden of proof is difficult to meet and w suggest that, with regard to the dealer, an alternative remedy might be a report of possible misrepresentation to the state agency that licenses dealers.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4155OpenMr. Roger Pezzulich, Parts Mgr., Friendly Honda House, 549 Dutchess Turnpike, Poughkeepsie, NY 12603; Mr. Roger Pezzulich Parts Mgr. Friendly Honda House 549 Dutchess Turnpike Poughkeepsie NY 12603; Dear Mr. Pezzulich: This is in reply to your letter of April 28, 1986, to Mr. Vinson o this Office pointing out that a center high-mounted stop lamp may be obscured when a luggage rack is in use, and asking for the legal ramifications involved in such use.; Compliance with the requirements of Federal Motor Vehicle Safet Standard No. 108 *Lamps, Reflective Devices, and Associated Equipment*, under which such lamps are now mandatory on new passenger cars, is judged with the luggage rack in place, but not in use. We are not aware of any State restrictions on use of a luggage rack if it would interfere with the output from a center high-mounted stop lamp.; You may have noted that the lamp is placed between the rack and th deck on the rear of some cars on which racks have been installed as standard equipment, and not behind the rack in the parcel shelf area. This appears to be an effective solution to the problem posed by luggage racks.; I hope that this answers your question. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3690OpenMr. F. Michael Petler, Head, Administration, Government Relations Department, Suzuki Motor Co., Ltd., 3251 E. Imperial Highway, Brea, CA 92621; Mr. F. Michael Petler Head Administration Government Relations Department Suzuki Motor Co. Ltd. 3251 E. Imperial Highway Brea CA 92621; Dear Mr. Petler: This responds to your recent letter requesting information concernin the requirements for seat belt anchorages in passenger cars under Safety Standard No. 210. Specifically, you ask whether only Type 1 seat belt anchorages are required in rear seating positions in passenger cars.; The answer to your question is no. Under paragraph S4.1.1 of standar 210, Type 2 seat belt anchorages (for combination lap and shoulder belts) are required as follows: at each front and rear forward-facing outboard designated seating position in passenger cars other than convertibles, and at each front forward-facing outboard designated seating position in vehicles other than passenger cars where Type 2 belts are required by Safety Standard No. 208. All other seating positions in both passenger cars and other vehicles may be equipped with anchorages for either Type 2 belts or Type 1 belts (lap belts). Safety Standard No. 208, *Occupant Crash Protection*, requires Type 2 belts only in *front* outboard designated seating positions in passenger cars, but passenger cars still must be equipped with anchorages for Type 2 belts in rear outboard designated seating positions.; As to your reference to discussion of anchorages in the agency' November 2, 1981 denial notice to Toyo Kogyo (46 FR 54391), that discussion was misleading because it did not provide complete information or distinguish adequately between passenger cars and other types of vehicles. The agency intended to refer to the type of belts required by Safety Standard No. 208, i.e., Type 2 belts in front outboard designated seating positions and Type 1 belts in front center and all rear seating positions.; I hope this has clarified any misunderstanding you may have ha concerning the anchorage requirements. Please contact Hugh Oates of my staff if you have any further questions (202-426- 2992).; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2982OpenMr. W. G. Milby, Manager, Engineering Services, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA 31030; Mr. W. G. Milby Manager Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Milby: This responds to your November 29, 1978, letter asking severa questions about test procedures conducted in accordance with Standard No. 222, *School Bus Passenger Seating and Crash Protection*. Your questions concern the impact and contact area test requirements of the standard.; First, you suggest that the head and knee impact tests should b conducted with only one impact allowed per seat back. The standard states in S5.3.1: 'A surface area that has been contacted pursuant to an impact test need not meet further requirements contained in S5.3.' You apparently interpret 'surface area' to mean an entire seat back.; The purpose of the above-cited sentence in S5.3.1 is to assur manufacturers that the agency will not hit the test seat in the identical spot twice during compliance testing. However, it is permissible for several tests to be run on a seat as long as the test device does not impact the same specific area previously contacted by the device in an earlier test. This test method is appropriate because it approximates accident conditions. A seat is likely to be impacted more than once in an accident when the seat immediately behind it is occupied by three passengers. Accordingly, the agency will continue to run multiple tests on a seat back but will never impact the same 'surface area' more than once.; In your second question, you suggest that a test sequence i appropriate for contact area testing. The agency disagrees. The agency agrees that the head form and knee form impact tests are different tests for the reasons outlined in your letter. However, nothing in those reasons compels the agency to conclude that a test sequence would be appropriate for contact area testing. In an accident, the impact of children on a seat back may or may not be sequential in nature. Therefore, the existing test method, which permits the agency to sequence tests in any manner, closely reflects actual accident experiences. Accordingly, the agency will not adopt a specific sequence in its test procedures.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1707OpenMr. Norman E. Salzman, General Manager, The Fairmount Press, P.O. Box 3, Bronx, NY 10453; Mr. Norman E. Salzman General Manager The Fairmount Press P.O. Box 3 Bronx NY 10453; Dear Mr. Salzman: This is in response to your letter of November 18, 1974, enclosin amended copies of your MVF disclosure form for our review.; The disclosure forms contained in your letter fail to conform to Par 580, *Odometer disclosure requirements*, in two of the aspects described in our letter to you of September 27, 1974. 49 CFR Part 580.4(a) specifies that the transferor of a motor vehicle must furnish his transferee with a written odometer disclosure statement 'before issuing any transfer of ownership document.' Subparagraph (1) of that subsection requires that the disclosure statement include the 'odometer reading at the time of transfer.' The mileage disclosure section of your form is phrased so as to suggest that the odometer mileage was disclosed *after* the completion of transfer. This is contrary to the regulation's provisions and should be corrected to clearly express that the mileage is being disclosed at the time of the vehicle's transfer. Insertion of the word 'is' instead of 'was ' just prior to the odometer mileage disclosure will bring your form into conformity with the regulation.; The requirement in section 580.4(3) of the regulation provides that th transferor make an odometer disclosure by executing 'the disclosure form specified'. While we have not gone so far as to interpret this to require a verbatim copy of our format, we do insist that any variations do not change the significance of the specified formula. In our form, the use of the words 'I, *(transferor's name) state that . . .' is intended to make it clear that the factual representations of the form are those of the transferor. Any formula that fails to accomplish this will not be considered in conformity with the regulation.; I have enclosed a corrected copy of your disclosure form in order t make clear the changes necessary for compliance.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam2828OpenMr. Karsten J. Vieg, Director, Division of Traffic Safety, Illinois Department of Transportation, 2300 South Dirksen Parkway, Springfield, IL 62764; Mr. Karsten J. Vieg Director Division of Traffic Safety Illinois Department of Transportation 2300 South Dirksen Parkway Springfield IL 62764; Dear Mr. Vieg: This responds to your May 10, 1979, (sic) letter asking questions abou the applicability of Standard No. 222, *School Bus Passenger Seating and Crash Protection*, to buses with gross vehicle weight ratings (GVWR) of 10,000 pounds or less.; First you ask whether seat spacing must be maintained at a maximum o 21 inches in these vehicles. The answer to your question is no. As you correctly point out in your letter, section S5.2 of the standard that regulates maximum seat spacing does not apply to buses with GVWRs of 10,000 pounds or less. Maximum seat spacing is limited in larger buses as a means of compartmentalizing students to prevent injury in crashes. Compartmentalization, and therefore maximum seat spacing, is not necessary in smaller buses since they are required to be equipped with seat belts which afford significant protection in accidents.; Your second question asks whether it is permissible to have one larg seat belt in a school bus seat that might wrap around two students or whether each designated seating position must have an individual belt system. The agency concludes that the use of one large belt to cover more than one designated seating position violates section S5 of the regulation. That section states that each seating position must comply with seat belt requirements. To meet this requirement, each seating position in a small bus must be equipped with its own belt system.; If we can be of further assistance, do not hesitate to contact us. Sincerely, Joan Claybrook |
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ID: aiam0815OpenMr. Robert F. Farrelly, Safety Products, Inc., 331 East Brooks Road, Suite 11, Memphis, TN 38109; Mr. Robert F. Farrelly Safety Products Inc. 331 East Brooks Road Suite 11 Memphis TN 38109; Dear Mr. Farrelly: This is in reply to your letter of July 17, 1972, in which you as whether a person who installs on new vehicles a device you manufacture called the Safti-Stabilizer is required to recertify the vehicle.; A person will be required to recertify a new, completed vehicle if h modifies it is such a manner that he becomes a 'manufacturer' under the National Traffic and Motor Vehicle Safety Act. A person will be considered a manufacturer if the modifications he performs produce significant changes in the vehicle's configuration or purpose. while this determination is generally made on a case by case basis, examples of modifications which the NHTSA has considered to be 'manufacturing' include the addition of new axles, or the changing of a completed truck van into a motor home.; The NHTSA has taken the position, in close cases, that it will accept good-faith determination of a person modifying new vehicles as to whether the modification is of such a nature so as to make that person a manufacturer. Based on the information you have provided to us, it appears that the installation of the Safti-Stabilizer does not significantly change the vehicle's configuration or purpose. Consequently, we would accept a determination that the installation of the Safti-Stabilizer does not constitute remanufacturing, and a person who installs the device on new vehicles need not recertify them.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4505OpenMr. M. Arisaka Manager, Automotive Lighting Homologation Sec. Stanley Electric Co. Ltd. 2-9-13, Nakameguro, Meguro-ku Tokyo 153 JAPAN; Mr. M. Arisaka Manager Automotive Lighting Homologation Sec. Stanley Electric Co. Ltd. 2-9-13 Nakameguro Meguro-ku Tokyo 153 JAPAN; Dear Mr. Arisaka: This is in reply to your letter of June l0, 1988 describing a 'flash to pass' headlighting feature and asking whether it is permissible under Federal Motor Vehicle Safety Standard No. 108. Enclosed is a copy of the agency's letter of June 17, 1987, to MMC Services, Inc. commenting on a similar device. The fact that Stanley's passing beam would project through an amber lens rather than a clear, or noncolored one, does not affect this interpretation. The address of the American Association of Motor Vehicle Administrators is now 4600 Wilson Boulevard, Arlington, Va. 33203. Sincerely, Erika Z. Jones Chief Counsel /Enclosure; |
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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.