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: nht79-4.24OpenDATE: 08/14/79 FROM: Frank Berndt; NHTSA TO: Uniroyal GMBH TITLE: FMVSR INTERPRETATION TEXT: This is in response to your letter of July 20, 1979, concerning the Uniform Tire Quality Grading (UTGQ) Standards (49 CFR 575.104). You ask whether it is permissible under the regulation to mold UTQG grades on only one sidewall of a tire and, in the case of a symmetrical black sidewall tire, whether the grades may be molded on the same sidewall as the tire identification number required by 49 CFR 574.5. The UTQG Standards require that tire grades need be molded on only one sidewall of a tire. Since the regulation presently does not specify the sidewall on which tire grades must be molded, Uniroyal is legally permitted to mold UTQG grades on either sidewall of its tires. However, in order to facilitate consumer access to the grading information, the National Highway Traffic Safety Administration (NHTSA) encourages manufacturers to mold tire grades on the sidewall intended to be visible when the tire is mounted on a vehicle. NHTSA will monitor the placement of tire trades to determine whether further action is necessary to assure the accessibility of the grading information. |
|
ID: nht89-2.7OpenTYPE: INTERPRETATION-NHTSA DATE: 06/19/89 FROM: STEPHEN P. WOOD -- NHTSA ACTING CHIEF COUNSEL TO: M. IWASE, -- TECHNICAL INFORMATION DEPT. KOITO MFG. CO., LTD. TITLE: NONE ATTACHMT: LETTER DATED 03/20/89 FROM M. IWASE TO ERIKA Z. JONES -- NHTSA TEXT: Dear Mr. Iwase: This is in reply to your letter of March 20, 1989, asking for an interpretation of Motor Vehicle Safety Standard No. 108 as it applies to the location of the license plate lamp on motor vehicles. You noted the language in Tables II and IV of Standard No. 108 specifying that the lamp is to be located "at rear license plate, to illuminate the plate from the top or sides," for, vehicles other than motorcycles. The requirement for motorcycles (Table IV) is simply that it be located "at rear license plate." You have asked for confirmation that, except on motorcycles, the license plate lamp shall not illuminate the plate from the bottom. Your interpretation is correct. The rationale for the requirement is that in a location other than at the bottom, the license plate lamp is less likely to be obstructed by snow or mud. I hope that this answers your question. Sincerely, |
|
ID: 3038yyOpen Ms. Rosemary Dunlap Dear Ms. Dunlap: This responds to your letter concerning bills under consideration by a number of states which would require disclosure concerning safety features in light trucks and vans and bumper strength. You stated that there is considerable debate about whether such bills would be preempted by Federal law, and noted that opponents have represented that a NHTSA spokesperson indicated that the states are preempted in this area. You stated that you have been unable to locate this statement, and asked whether NHTSA has an official opinion regarding Federal preemption and disclosure. I believe that the statement you refer to was made by NHTSA's Associate Administrator for Rulemaking, Barry Felrice, at the July l990 NHTSA Public/Industry Meeting. Mr. Felrice was responding to a question from the Center for Auto Safety. I have enclosed a copy of the relevant portion of the transcript for that meeting and the question. As you can see from the transcript, Mr. Felrice did not say that states are necessarily preempted from establishing information disclosure requirements. In order to provide an opinion as whether a particular bill would be preempted, I would need to review the specific language of the bill. I hope this information is helpful. Sincerely,
Paul Jackson Rice Chief Counsel Enclosure /ref: VSA d:6/l0/9l |
1970 |
ID: nht93-3.46OpenDATE: May 17, 1993 FROM: Ray Kesler -- Kesler Research Enterprises, Ltd. TO: John Womack -- Acting Chief Counsel, NHTSA TITLE: None ATTACHMT: Attached to letter dated 7/2/93 from John Womack to Ray Kesler (A41; Std. 111) TEXT: Mr. Hufstedler and I would like to thank you for your letter of April 27, 1993. It clarified many things for us which heretofore we had been unsure of, however, there is still one area which is not clear to us. The enclosure you included in your letter was the Federal Register (in part) of September 2, 1982, which addresses FMVSS 111 rear-view mirrors. Section s571.111 states that a deviation of 12.5 percent, plus or minus, from the average radius of curvature, is allowable. Although a method of calculating the radius of curvature is specified in section s12.1 - s12.8, it is not clear how the average radius of curvature is arrived at. We would greatly appreciate it if your office could tell us the maximum amount of deviation we would be a owed from the bottom end of the standard (i.e.: 35" ROC), as well as perhaps explain the method by which the average radius of curvature is arrived at. This information would be of great help to us in our continuing effort to save lives and property damage through the installation and use of our mirror. |
|
ID: nht93-3.48OpenDATE: May 17, 1993 FROM: Ray Kesler -- Kesler Research Enterprises, Ltd. TO: John Womack -- Acting Chief Counsel, NHTSA COPYEE: Lawrence Hufstedler TITLE: None ATTACHMT: Attached to letter dated 7/2/93 from John Womack to Ray Kesler (A41; Std. 111) TEXT: Mr. Hufstedler and I would like to thank you for your letter of April 27, 1993. It clarified many things for us which heretofore we had been unsure of, however, there is still one area which is not clear to us. The enclosure you included in your letter was the Federal Register (in part) of September 2, 1982, which addresses FMVSS 111 rear-view mirrors. Section s571.111 states that a deviation of 12.5 percent, plus or minus, from the average radius of curvature, is allowable. Although a method of calculating the radius of curvature is specified in section s12.1 - s12.8, it is not clear how the average radius of curvature is arrived at. We would greatly appreciate it if your office could tell us the maximum amount of deviation we would be a owed from the bottom end of the standard (i.e.: 35" ROC), as well as perhaps explain the method by which the average radius of curvature is arrived at. This information would be of great help to us in our continuing effort to save lives and property damage through the installation and use of our mirror. |
|
ID: nht76-5.42OpenDATE: 06/02/76 FROM: AUTHOR UNAVAILABLE; S. P. Wood; NHTSA TO: General Motors Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of March 8, 1976, asking for an amendment of S4.1.1.21 of Motor Vehicle Safety Standard No. 108 to allow a plus tolerance of 7.5 percent on maximum wattage requirements for Type 1A and 2A headlamps. I enclose a copy of an interpretation furnished the General Electric Company which states that such a tolerance is allowed. However, to clarify our intent we plan to amend Standard No. 108 in the near future in the manner that you suggest. |
|
ID: nht71-5.39OpenDATE: 09/28/71 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: Electric Device Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of September 1, 1971, to Mr. Douglas Toms, Administrator, National Highway Traffic Safety Administration, concerning your request for an interpretation relative to your safety backing system and the Federal Standards. The use of your School Bus Safety Backing System is neither required nor prohibited in Federal Motor Vehicle Safety Standard No. 108 and the proposed Pupil Transportation Safety Standard. However, it would appear that the regulations of the individual States apply to the use of your system in those States. |
|
ID: nht67-1.8OpenDATE: 09/21/67 FROM: William Haddon, Jr., M.D.; NHTSA TO: Kurzman & Goldfarb TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of August 29 requesting a verification of the interpretation of Standard No. 205 contained in a letter to you dated August 10 from Max Brand of Mercedes-Benz of North America. Mr. Brands's understanding that glazing materials manufactured on or after January 1, 1968, for use in passenger cars, multipurpose passenger vehicles, motorcycles, trucks and buses must conform to Standard No. 205, but that dealer inventories of prestandard materials manufactured before January 1, 1968, may be used for replacement purposes until exhausted is correct. |
|
ID: nht95-6.46OpenTYPE: INTERPRETATION-NHTSA DATE: September 18, 1995 FROM: Alison Vredenburgh -- Vice-president, Research and Development, Error Analysis, Inc. TO: Kenneth Hardie -- NHTSA TITLE: NONE ATTACHMT: 12/8/95 letter from Samuel J. Dubbin to Alison Vredenburgh (A43; Std. 108) TEXT: I am currently directing a research project pertaining to motorcycle conspicuity. We have developed, and are testing a Motorcycle Conspicuity Enhancement System (MCES). A copy of the paper, which I will present at the Annual Human Factors and Ergonomics Society (HFES) meeting next month, is enclosed. As a human factors and safety consultants we have been asked to investigate several cases where a lack of motorcycle conspicuity has been a factor in accident causation. The development of the MCES was inspired by these cases. It is designed to attach to the front of motorcycles to enhance visibility using a series of small lights (xenon strobes) that are supplemental to the headlight. The MCES was built by Dr. Brian Andresen, Director of the Forensic Science Center of Lawrence Livermore National Laboratory. We are are in the early stages of considering patenting the MCES and hope to make it available to motorcycle riders. In reviewing the laws pertaining to motorcycle lighting, we understand that this system may only be used during daylight hours and may not affect the headlight. If there are any additional regulations pertaining to this system of which we should be aware, please contact me directly at (619) 434-4741. Enclosure ENHANCED MOTORCYCLE VISIBILITY THROUGH USE OF MOTORCYCLE CONSPICUITY ENHANCEMENT SYSTEM (Report omitted) |
|
ID: nht95-4.24OpenTYPE: INTERPRETATION-NHTSA DATE: September 18, 1995 FROM: Alison Vredenburgh -- Vice-president, Research and Development, Error Analysis, Inc. TO: Kenneth Hardie -- NHTSA TITLE: NONE ATTACHMT: 12/8/95 letter from Samuel J. Dubbin to Alison Vredenburgh (A43; Std. 108) TEXT: I am currently directing a research project pertaining to motorcycle conspicuity. We have developed, and are testing a Motorcycle Conspicuity Enhancement System (MCES). A copy of the paper, which I will present at the Annual Human Factors and Ergonomic s Society (HFES) meeting next month, is enclosed. As a human factors and safety consultants we have been asked to investigate several cases where a lack of motorcycle conspicuity has been a factor in accident causation. The development of the MCES was inspired by these cases. It is designed to attach t o the front of motorcycles to enhance visibility using a series of small lights (xenon strobes) that are supplemental to the headlight. The MCES was built by Dr. Brian Andresen, Director of the Forensic Science Center of Lawrence Livermore National Laboratory. We are are in the early stages of considering patenting the MCES and hope to make it available to motorcycle riders. In reviewing the laws pertaining to motorcycle lighting, we understand that this system may only be used during daylight hours and may not affect the headlight. If there are any additional regulations pertaining to this system of which we should be aware , please contact me directly at (619) 434-4741. Enclosure ENHANCED MOTORCYCLE VISIBILITY THROUGH USE OF MOTORCYCLE CONSPICUITY ENHANCEMENT SYSTEM (Report omitted) |
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.