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: aiam1020OpenMr. Louis M. Cirelli, Trelleborg Rubber Company, Incorporated, P.O. Box 178, New Rochelle, New York 10802; Mr. Louis M. Cirelli Trelleborg Rubber Company Incorporated P.O. Box 178 New Rochelle New York 10802; Dear Mr. Cirelli: #This will acknowledge your letter of february 4 1970, to the National Highway Safety Bureau concerning the labeling requirements for motor vehicle tires manufactured prior to August 1, 1968. #Federal Motor Vehicle SAfety Standard No. 109 requires that all motor vehicle passenger car tires manufactured after January 1, 1968, conform to the requirements as cited. I have enclosed a copy of Standard No. 109 and No. 110 with amendments for your reference. #Section S4.3 specifies the labeling requirements. You will note S4.3.1 permits the sale of tires manufactured during the period January 1, 1968 to August 1, 1968, which have a label or tab affixed that incorporates the specified information. Inclusion of information on the invoice does not relive the manufacturer from affixing the proper labeling on each tire. #Sincerely, Rodolfo A. Diaz, Acting Director, Motor Vehicle Safety Performance Service; |
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ID: aiam1329OpenCar Credit Corporation, 7600 Southwestern Ave., Chicago, IL; Car Credit Corporation 7600 Southwestern Ave. Chicago IL; Dear Sirs: The National Highway Traffic Safety Administration has received complaint from Mr. Stanley Pops of South Forest Street, Chicago, Illinois, that a 1967 Chrysler may have been sold to him with an altered odometer and an incomplete odometer disclosure statement.; This agency administers the Motor Vehicle Information and Cost Saving Act which prohibits the alteration, disconnection, or resetting of odometers and requires a transferor to make a mileage disclosure statement that conforms to Part 580, Odometer Disclosure Requirements. Copies of the law and regulation are enclosed. Under the law, Mr. Pops may have a civil action for damages of $1,500 or more and attorney's fees.; The U.S. Attorney General is authorized to seek injunctive relie against persons who violate the Act. If we receive continued indications of odometer tampering by the Car Credit Corporation, we will ask the U.S. Attorney to investigate the matter and to take appropriate action.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam2025OpenMr. H. Ray Cozad, Chief Engineer, Crane & Excavator Division, 1201 Sixth Street Southwest, Cedar Rapids, IA 52406; Mr. H. Ray Cozad Chief Engineer Crane & Excavator Division 1201 Sixth Street Southwest Cedar Rapids IA 52406; Dear Mr. Cozad: This responds to your July 28, 1975, letter asking whether the unloade vehicle weight of a mobile crane carrier would include components that are essential to its specialized function but are not removed for transit purposes. You also suggest alternative wording for a particular exclusion criterion proposed for mobile crane carriers and similar vehicles under Standard No. 121, *Air Brake Systems*.; I have enclosed a copy of a recent notice that amends Standard No. 121 The preamble to the notice deals with the issues you have raised and should make clear to you that vehicle components are not generally considered part of the rated cargo capacity and therefore would not be subtracted from a vehicle's gross vehicle weight rating to determine the unloaded vehicle weight.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1938OpenMr. Kenneth B. Kramer, Floyd, Kramer & Lambrecht, 220 Western Federal Savings Building, Colorado Springs, Colorado 80902; Mr. Kenneth B. Kramer Floyd Kramer & Lambrecht 220 Western Federal Savings Building Colorado Springs Colorado 80902; Dear Mr. Kramer: #This responds to your letter of April 25,1975 concerning the applicability of Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses*, to the Wabco Westinghouse DuoMatic Coupler. #You have described the Coupler as a device which replaces the glad hand coupler now used by most manufacturers to connect truck tractor and trailer brake lines. Because the brake hose which attaches to the coupler is equipped with its own end fittings, the Coupler itself is not an end fitting, Therefore Standard No. 106-74 is inapplicable, #The Coupler is, however, subject to the requirements of 49 CFR Part 393.45 and 393.46, of which I enclose a copy. Please direct any questions you may have concerning interpretation of these requirements to the Office of the Chief Counsel, Federal Highway Administration, at 400 Seventh St., S.W., Washington, D.C. 20590. #Yours truly, Richard B. Dyson; |
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ID: aiam4330OpenClarence M. Ditlow III, Esq., Center for Auto Safety, 2001 S Street, N.W., Suite 410, Washington, DC 20009; Clarence M. Ditlow III Esq. Center for Auto Safety 2001 S Street N.W. Suite 410 Washington DC 20009; Dear Mr. Ditlow: Thank you for your letter concerning how the provisions of sectio 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act apply to the displaying, test driving, and delivery of a passenger car with an automatic safety belt. The agency has recently issued the enclosed Federal Register notice that addresses the issues you raised.; If you have any further questions, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam0178OpenMr. Warren M. Heath, Commander, Engineering Section, Department of California Highway Patrol, P. O. Box 898, Sacramento, CA 95804; Mr. Warren M. Heath Commander Engineering Section Department of California Highway Patrol P. O. Box 898 Sacramento CA 95804; Dear Mr. Heath: Thank you for your letter of August 29, 1969, to Dr. Robert Brenner Acting Director, National Highway Safety Bureau, concerning the flashing of sidemarker lamps when the turn signal switch is activated.; Paragraph S3.5 of Federal Motor Vehicle Safety Standard No. 108 permit the flashing of sidemarker lamps simultaneously with the turn signal lamps on the side to which a turn is contemplated.; Sincerely, Charles A. Baker, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service; |
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ID: aiam1931OpenMr. Kenneth B. Kramer, Floyd, Kramer & Lambrecht, 220 Western Federal Savings Building, Colorado Springs, CO 80902; Mr. Kenneth B. Kramer Floyd Kramer & Lambrecht 220 Western Federal Savings Building Colorado Springs CO 80902; Dear Mr. Kramer: This responds to your letter of April 25, 1975, concerning th applicability of Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses*, to the Wabco Westinghouse Duo-Matic Coupler.; You have described the Coupler as a device which replaces the glad han coupler now used by most manufacturers to connect truck tractor and trailer brake lines. Because the brake hose which attaches to the Coupler is equipped with its own end fittings, the Coupler itself is not an end fitting. Therefore, Standard No. 106-74 is inapplicable.; The Coupler is, however, subject to the requirements of 49 CFR Par 393.45 and 393.46, of which I have enclosed a copy. Please direct any questions you may have concerning interpretation of these requirements to the Office of the Chief Counsel, Federal Highway Administration, at 400 Seventh St., S.W., Washington, D.C. 20590.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1927OpenMr. H. Miyazawa, Stanley Electric Co., Ltd., 2-9-13 Nakameguro, Meguro-Ku, Tokyo 153, Japan; Mr. H. Miyazawa Stanley Electric Co. Ltd. 2-9-13 Nakameguro Meguro-Ku Tokyo 153 Japan; Dear Mr. Miyazawa: This responds to your letter of May 15, 1975, regarding Federal Moto Vehicle Safety Standard (FMVSS) No. 108 requirements for Type 1A and 2A automotive headlamps.; The following answers are provided for your specific questions: >>>1. FMVSS No. 108 would not prohibit use of metal-back Types 1A an 2A headlamps that conform to all requirements of the standard.; 2. The National Highway Traffic Safety Administration does not issu approvals on automotive equipment. The equipment manufacturer self certifies that the equipment conforms to the applicable FMVSS. The various states may, however, require equipment approval. Information on these approvals may be obtained from the America Association of Motor Vehicle Administrators, 1201 Connecticut Avenue, Washington, D. C. 20036.; 3. The drawings of the Type 1A and 2A headlamp submitted with you letter, indicate that aiming pads have been deleted. Aiming pads are required by FMVSS NO. 108.<<<; For your information enclosed is a copy of FMVSS No. 108, whic includes requirements for Types 1A and 2A headlamps, and a copy of Docket No. 75-8, Notice 1, that proposes to allow use of the four-lamp rectangular systems indefinitely.; Sincerely, E. T. Driver, Director, Office of Crash Avoidance, Moto Vehicle Programs; |
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ID: aiam1414OpenMr. John H. Rose, Transportation Supervisor, West Branch - Rose City Area Schools, School Bus Garage, 224 Thomas Street, West Branch, MI 48661; Mr. John H. Rose Transportation Supervisor West Branch - Rose City Area Schools School Bus Garage 224 Thomas Street West Branch MI 48661; Dear Mr. Rose: This responds to your February 8, 1974, letter asking whether antiloc devices are required on air-braked buses manufactured after September 1, 1974, if the chassis manufacturer is the party for compliance, and whether the September 1, 1974, effective date will be delayed.; The National Highway Traffic Safety Administration has issued Standard No. 121 on air brake systems, of which Docket 73-13, Notice 3, is only one part. It regulates all air-braked motor vehicles, including new school buses, manufactured after the effective date. We have delayed the effective date to January 1, 1975, and eased the requirements somewhat for an introductory period of January 1, 1975, to September 1, 1975.; As you stated, the regulation is directed to chassis manufacturers an dealers, who under the law are prohibited from selling vehicles which do not comply with the standard.; The standard does not require antilock devices, but generall manufacturers have indicated that they will use an antilock system to meet the requirements of the standard.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4095OpenMr. Earnest Farmer, Director of Pupil Transportation, Tennessee Department of Education, Nashville, TN 37219-5335; Mr. Earnest Farmer Director of Pupil Transportation Tennessee Department of Education Nashville TN 37219-5335; Dear Mr. Farmer: This responds to your February 19, 1986 letter to the National Highwa Traffic Safety Administration (NHTSA) asking whether Federal motor vehicle safety standards prohibit commercial businesses from using fiberglass on the exterior of school buses. As explained below, the answer to your question is no.; The National Traffic and Motor Vehicle Safety Act authorizes NHTSA t issue minimum performance standards for school buses. Our safety standards do not specify the materials to be used for the exterior of school buses. However, the materials chosen by a manufacturer must be strong enough to enable the bus to meet the requirements of those standards. Among those requirements are the rollover protection ones of Standard No. 220, fuel system requirements of Standard No. 301, and strength requirements of Standard No. 221, *School Bus Body Joint Strength*, for body panel joints on school buses with gross vehicle weight ratings over 10,000 pounds. Manufacturers of new school buses using fiberglass for school bus exteriors must certify that their vehicles conform to the requirements of all applicable school bus safety standards.; I hope this information is helpful. Please contact my office if yo have further questions.; Sincerely, Erika Z. Jones, 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.