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 |
|---|---|
ID: aiam2114OpenNaoyoshi Suzuki, Nissan Motor Co., Ltd., P.O. Box 1606, Englewood Cliffs, NJ 07632; Naoyoshi Suzuki Nissan Motor Co. Ltd. P.O. Box 1606 Englewood Cliffs NJ 07632; Dear Mr. Suzuki: This is in response to your letter of October 15, 1975, in which yo request an interpretation of paragraph S7.1.3 of Standard No. 301, as to whether it is permissible to stop an electric fuel pump prior to the rollover test.; Paragraph S7.1.3 provides that 'If the vehicle has an electricall driven fuel pump that normally runs when the vehicle's electrical system is activated, it is operating at the time of a barrier crash.' The static rollover test specified by S6.4 is not a barrier crash, and therefore is not covered by S7.1.3. In the amendments to Standard No. 301 published on October 15, 1975 (40 FR 48352), the addition of the phrase 'In meeting the requirements of S6.1 through S6.3' to S7.1.3 clarifies the intent of the agency not to require that an electric fuel pump be operating at the time of the rollover test, because the rollover test is required by paragraph S6.4. Therefore, you may turn off the pump if it is still working at the time of the static rollover test.; Sincerely, Frank Berndt, Acting Chief Counsel |
|
ID: aiam0129OpenMr. G. Greig, Brixtax(London) Limited, Proctor Works Chertsey Road, Byfleet (Weybridge), Surrey, England; Mr. G. Greig Brixtax(London) Limited Proctor Works Chertsey Road Byfleet (Weybridge) Surrey England; Dear Mr. Greig: This is in reply to your letter of December 9, 1968, in which yo inquire about the certification responsibilities of equipment manufacturers under the National Traffic and Motor Vehicle Safety Act of 1966.; You state that it is your understanding that a vehicle manufacturer ha the responsibility to certify the entire vehicle, including equipment that is produced by other manufacturers and covered by Federal safety standards, as complying with the applicable standards, and that the basis on which that manufacturer satisfies himself that equipment from suppliers conforms to the standards is a matter of his own discretion. I consider that statement to be essentially correct, with the caveat that the manufacturer must be able to show, under S 108(b)(2) of the Act, that 'he did not have reason to know in the exercise of due care' that any included equipment was nonconforming. What constitutes 'due care' must be determined in light of all the circumstances of a particular case. You are also correct in your understanding that approval by the States has no relevance to the question of compliance with this Federal law.; Finally regardless of certification requirements all equipment mus conform to applicable standards, and certification by the equipment manufacturer is required if the equipment is ultimately sold in the aftermarket.; I am pleased to be of assistance. Sincerely, Robert M. O'Mahoney, Assistant Chief Counsel for Regulations |
|
ID: aiam1692OpenMr. J. Y. May, President, Atlas Supply Company, 11 Diamond Road, Springfield, NJ 07081; Mr. J. Y. May President Atlas Supply Company 11 Diamond Road Springfield NJ 07081; Dear Mr. May: This is in reference to your defect notification campaign (NHTSA No 74E-025) involving some H78-15 Cushionaire tires produced by the Kelly-Springfield Tire Company. It was stated that some of these tires fail to meet the high speed test requirements of Federal Motor Vehicle Safety Standard No. 109.; The letter which you have sent to the owners of the subject tires doe not meet the requirements of Part 577(49 CFR), the Defect Notification regulation. Specifically, your letter fails to present information in the form and order specified by Part 577.4. The statements required by Part 577.4(a) and (b) should be quoted exactly and should appear as the first and second sentences respectively of your letter. In this case, where notification is being conducted by the tire brand name owner, the requirements of section 577.4(b)(1) should be met by stating, 'Atlas Supply Company has determined that a defect which relates to motor vehicle (sic) exists in the H78-15 Atlas Cushionaire Tire.' Moreover, the National Highway Traffic Safety Administration has taken the position that defect notification letters regarding failures of compliance with applicable safety standards should refer to that noncompliance, and we believe your letter should include, in addition, a statement that the tires fail to conform to the requirements of Federal Motor Vehicle Safety Standard No. 109.; Your letter also fails to adequately evaluate the risk to traffi safety as required by Part 577.4(d). If vehicle crash is the potential occurrence, the letter must state this. Although many owners will assume that replacement tires are presently available, Part 577.4(e) does require that a firm date for parts availability be given, as well as an estimate of the time necessary to perform labor involved in correcting the defect (replacing the tire(s)).; Your statement, 'chunks of rubber may--at excessive speeds--detach fro the tire carcass and tread,' is, in our opinion, inaccurate, and the reference to excessive speeds should be deleted. The word 'excessive' implies that only drivers who drive at unreasonably high speeds may experience a failure. Since it is required, however, that the owners be informed of precautions that can be taken to reduce the chance of malfunction, an admonition against sustained high speed driving may be appropriate.; It is therefore necessary that you revise the owner notification lette and send a copy of the revised letter to this office and all owners who have not yet had their tires replaced.; If you desire further information, please contact Messrs. W. J Reinhart or James Murray at this office at (202) 426-2840. A copy of the Defect Notification regulation is enclosed.; Sincerely, Andrew G. Detrick, Acting Director, Office of Defect Investigation, Motor Vehicle Programs; |
|
ID: aiam0980OpenMr. Michael J. Long, Minister (Commercial), Embassy of Australia, 1601 Massachusetts Avenue, N.W., Washington, DC 20036; Mr. Michael J. Long Minister (Commercial) Embassy of Australia 1601 Massachusetts Avenue N.W. Washington DC 20036; Dear Mr. Long: This is in reply to your letter of January 30, 1973, concerning acryli headlamp covers.; Federal Motor Vehicle Safety Standard No. 108 incorporates Society o Automotive Engineers (SAE) Standard J580a, which prohibits the use of acrylic headlamp covers as original equipment. The requirements of SAE Standard J580a have also been incorporated in a number of State regulations, which are applicable to vehicles in use. Copies of Standard No. 108 and SAE Standard J580a are enclosed for your information.; A Notice of Proposed Rule Making (Docket 69-19, Notice 3) on Standar No. 108 was issued on October 16, 1972. This Notice includes a provision for optional use of headlamp covers which conform to certain performance requirements. Such requirements are specified in paragraph S7.9 of the Notice (copy enclosed). Acrylic Industries Pty. Ltd. may be interested in commenting on this *proposed* revision of Standard No. 108. The closing date for comments is April 18, 1973.; If you have any questions on the enclosed documents, please do no hesitate to contact me.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
|
ID: aiam4490OpenMr. Robert W. Hocken General Manager Phoenix Transit System P.O. Box 4275 Phoenix, AZ 85030; Mr. Robert W. Hocken General Manager Phoenix Transit System P.O. Box 4275 Phoenix AZ 85030; Dear Mr. Hocken: This is in reply to your letter of December l6, l98 to Mr. Vinson of this office requesting an interpretation of Motor Vehicle Safety Standard No. 108. You have received a 'Service Information Safety Related letter' from Flxible Corporation stating that deceleration warning lights installed on your buses do not comply with Standard No. 108. You have also asked how you may file for 'Special Exception' if your buses are not in compliance. This will confirm that Flxible Corporation, pursuant to applicable Federal regulations, has determined that certain buses produced by it, including the 67 units furnished Phoenix, do not comply with Standard No. 108, and has initiated a notification and remedy campaign (Campaign 87V-089). The basis of this determination was the manufacturer's conclusion that flashing amber deceleration warning lamps could create confusion when activated simultaneously with the red steady burning stop lamps. The company has advised you of the corrective action to be taken, that is, to remove the deceleration flasher. Although the agency encourages owners of campaigned vehicles to remedy noncompliances, the decision whether to do so rests with the vehicle owner. There is no Federal requirement that an owner correct a noncompliance that exists in his vehicle, and no penalty for his failure to do so. Thus, no 'Special Exception' is either needed or available for an owner who wishes to continue operating a vehicle in a noncompliant state. We are interested in your comment that you experienced a 44 percent reduction in accidents in l985, the first full year that the system was installed on all your buses, compared with l984. This report compares favorably with the accident reduction experienced in our test fleets of passenger cars equipped with center highmounted stop lamps, which was the basis for eventual adoption of that requirement. The agency is engaged in research pertaining to the conspicuity of large vehicles, and would find it helpful to have a copy of the data upon which you based your comment. It should be sent to Michael Finkelstein, Associate Administrator for Research and Development, NHTSA, 400 Seventh Street, S.W., Washington, D.C. 20590. We appreciate your interest in safety. Sincerely, Erika Z. Jones Chief Counsel; |
|
ID: aiam1368OpenMr. David C. Keehn, Attorney, Division of Marketing Practices, Bureau of Consumer Protection, Federal Trade Commission, Washington, DC 20580; Mr. David C. Keehn Attorney Division of Marketing Practices Bureau of Consumer Protection Federal Trade Commission Washington DC 20580; Dear Mr. Keehn: Thank you for bringing the Ryder Rental odometer problem to ou attention.; The odometer provisions of the Motor Vehicle Information and Cos Savings Act apply only to tampering that leads to the under-representation of mileage. We recommend that over-representation cases be referred to the State consumer protection office. In this case, of course, Mr. Sharkey registered his complaint there in the first instance.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam3355OpenMr. R.J. Gephart, Director of Safety, City of Phoenix Transit System, P.O. Box 4275, Phoenix, Arizona 85030; Mr. R.J. Gephart Director of Safety City of Phoenix Transit System P.O. Box 4275 Phoenix Arizona 85030; Dear Mr. Gephart: This responds to your letter of August 14, 1980, regarding speedomete requirements on buses. In your letter, you ask us to confirm your belief that buses purchased prior to September 1, 1979, are not required to have speedometers. The key question is the date of manufacture, not the date of purchase. Federal Motor Vehicle Safety Standard (FMVSS) No.127, *Speedometers and Odometers*, requires motor vehicles *manufactured* on or after September 1,1979, to have speedometers that meet certain criteria. Thus, none of your buses that were manufactured before that date are required to have speedometers. To determine the date of manufacture of any of your buses, check the certification label.; We noted your statement that the Phoenix Transit System serves 'onl the Phoenix and surrounding suburbs' passenger population with limited boundaries.' If you begin to offer interstate service, we recommend that you contact the Federal Highway Administration (FHWA), Bureau of Motor Carrier Safety, regarding the regulation of interstate motor carriers. The FHWA may have rules requiring speedometers on all vehicles used in the interstate transportation of passengers. Their address is 400 - 7th St. S.W., Washington, D.C., 20590.; We hope you find this information helpful. Please contact this offic if you have any questions.; Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam1738OpenMr. Louis A. Wilson, General Manager, Page Equipment Sales, Inc., 6768 Highway 99 North, Anderson, CA 96007; Mr. Louis A. Wilson General Manager Page Equipment Sales Inc. 6768 Highway 99 North Anderson CA 96007; Dear Mr. Wilson: This responds to your December 9, 1974, question whether the 'pre-loa unit' of the Page 'Logging Simi' qualifies for an exemption from the requirements of Standard No. 121, *Air brake systems*, until September 1, 1976.; Based on the enclosed description, the 'pre-load unit' appears to be a air- braked trailer without particular brake-line or bed-height characteristics which would qualify it as a Heavy hauler trailer entitled to an exemption until September 1, 1976. Therefore, we conclude that the trailer is subject to the requirements of the standard if manufactured on or after January 1, 1975.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
|
ID: aiam3705OpenMr. Chuck Howard, President, Safety Alert Co., Inc., 1667 9th Street, Santa Monica, CA 90404; Mr. Chuck Howard President Safety Alert Co. Inc. 1667 9th Street Santa Monica CA 90404; Dear Mr. Howard: We have received your petition for rulemaking of April 25, 1983, you letter of May 6 withdrawing it, and your letter of May 5 to Mr. Vinson of my staff asking for an interpretation. All this concerns the applicability of Standard No. 108 to your 'Vehicle Deceleration Warning System.'; As we understand it, this system was originally designed to provide flashing light through the back-up lamp system, in which yellow bulbs were used as substitutes for the white ones required by Standard No. 108. You were informally advised by agency staff that such a system would render the vehicle noncompliant with the requirement that a back-up lamp be white, and that it be steady burning in use.; You asked Mr. Vinson if there were another alternative for flashing re lights that would comply with Standard No. 108, and, in your letter of the 6th, whether use of the hazard warning system was acceptable. You also inquired about retrofitting vehicles manufactured before hazard warning signals were required, so that your system would work through the rear turn signals.; In the context of Federal regulations an optional system such as your is acceptable as original equipment, or equipment added before initial sale of the vehicle, if it does not impair the effectiveness of lighting equipment required by Standard No. 108. In our view, it is permissible to use any rear lighting system Standard No. 108 allows to flash for signalling purposes. Thus, your system could operate through the rear hazard warning system, or the rear turn signal system (red or amber) as long as the color of light or photometrics required by the standard was not changed.; As an aftermarket device intended for installation on vehicles in use it must not render inoperative in whole or in part Federally- mandated lighting equipment. Subject to the restrictions noted above, your system would not violate this prohibition were it installed to work through the hazard warning or turn signal systems. However, since your system involves an aspect of performance not covered by Standard No. 108, each State may regulate its use as it sees fit.; Passenger cars built since January 1, 1969, have been required to hav hazard warning signal systems. Use of the turn signal system of a vehicle built before that date is not prohibited under Federal regulations but is also a matter to be determined by local law.; I hope that this is responsive to your questions. Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam2817OpenMr. R. O. Sornson, Manager, Environmental Relations, Office of Public Responsibility and Consumer Affiars (sic), Chrysler Corporation, P.O. Box 1919, Detroit, MI 48231; Mr. R. O. Sornson Manager Environmental Relations Office of Public Responsibility and Consumer Affiars (sic) Chrysler Corporation P.O. Box 1919 Detroit MI 48231; Dear Mr. Sornson: This is in reply to your letter of May 4, 1978, to Howard Dugof requesting confirmation of two interpretations of Motor Vehicle Safety Standard No. 108. You have cited our letter of December 29, 1976, to your Mr. Weil as support for your views.; With respect to your first concern, you have stated your understandin that in a multiple compartment taillamp the manufacturer has the option of using one or more compartments to meet the minimum photometric requirements specified for taillamps, but when the intensity ratio of the turn signal lamp to the taillamp is computed, the ratio must be determined with all taillamp compartments lighted.; As we interpret Standard No. 108's requirements for taillamps (SA Standard J585d, *Tail Lamps (Rear Position Light)*, August 1970), a single compartment lamp may be used as a taillamp, but if a multiple compartment lamp or multiple lamps are used to meet the photometric requirements, S3.1 of J585d requires that the combination of the compartments or lamps must be used to meet the photometric requirements for the corresponding numbers of lighted sections (Table 1, J585d) in those instances where the distances between filament centers do not exceed 22 inches for two- compartment or lamp arrangements, and 16 inches for three compartment or lamp arrangements. If these distances are exceeded, each compartment or lamp must comply with the photometric requirements for one lighted section. Therefore your interpretation is incorrect that a manufacturer may use only one compartment of a multi-compartment lamp when considering compliance with the photometric requirement for taillamps.; Your second concern is the requirement for multiple lamps in excess o three. You have noted that Table 1 of SAE J585 makes no provision for candlepower requirements where there are more than three lighted sections. Noting that the maximum candlepower permissible rises in increments of 5 per section (15 for one section, 20 for two sections, 25 for three sections) you have asked for confirmation of your opinion that 'it appears logical that the allowable candle-power for a four compartment system should be 30 candlepower.'; Standard No. 108 does not specify requirements for compartments o lamps in excess of three. If you wish to use a four compartment or lamp system you are legally free to distribute the candlepower as you deem appropriate. Accordingly we have no objection to your belief that 30 candlepower is allowable provided that the multiple compartment lamp or multiple lamp arrangement meets all other requirements of J585d.; 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.