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: aiam2130OpenMr. Bruce J. Smith, Engineering Services Department, Bucyrus- Erie Company, South Milwaukee, WI 53172; Mr. Bruce J. Smith Engineering Services Department Bucyrus- Erie Company South Milwaukee WI 53172; Dear Mr. Smith: This responds to Bucyrus-Erie's October 8, 1975, suggestion that th terms 'unloaded vehicle weight' and 'passenger-carrying capacity' be defined in 49 CFR S 571.3 to reflect explanations of them that appeared in the preamble of recent NHTSA rulemaking on Standard No. 121, *Air Brake Systems*. (40 FR 38160, August 27, 1975). You believe that removable portions of a vehicle that are essential to its function (e.g., the boom on a mobile crane) should not be considered part of the vehicle's 'cargo' as that term is used in the present definition of unloaded vehicle weight.; The NHTSA explained in the preamble to which you refer that th unloaded vehicle weight is easily determined by, in most cases, subtracting the weight of cargo and occupants from the gross vehicle weight rating (GVWR) assigned to the vehicle by the manufacturer. We believe that the term 'cargo' clearly indicates that the manufacturer must only subtract the weight of commodities or freight that the vehicle is designed to carry as a transportation function. Presumably the manufacturer of a mobile crane would have no difficulty in concluding under the present definition of 'unloaded vehicle weight' that its vehicle does not transport 'cargo' and that no value must be subtracted from the GVWR on this account.; It does appear that the term 'passenger-carrying capacity' used i Standard No. 121 could be expanded to reflect the exclusion of the operating crew from consideration as passengers. In response to your request we are considering an amendment of S3 to make this concept clearer.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam5388OpenMr. Alberto Negro Chief Executive Officer Fiat Auto R&D U.S.A. 39300 Country Club Drive Farmington Hills, MI 48331-3473; Mr. Alberto Negro Chief Executive Officer Fiat Auto R&D U.S.A. 39300 Country Club Drive Farmington Hills MI 48331-3473; Dear Mr. Negro: This responds to your letter of May 16, 1994, asking i Standard No. 208, Occupant Crash Protection 'allows the advisory information required by ... S4.5.1 to be printed in English and also in one or more foreign languages.' On March 10, 1994, NHTSA published a notice responding to petitions for reconsideration of the September 2, 1993 final rule which amended Standard No. 208 to require air bag labels (59 FR 11200). In that notice NHTSA stated: NHTSA interprets the labeling requirements of the September 2 final rule as requiring manufacturers to supply the information in English. Once this requirement is met, manufacturers may supply the same information in other languages, so long as it does not confuse consumers. As long as the non-English language label is a translation of the required information, NHTSA does not interpret it to be 'other information.' However, manufacturers are not permitted to include additional information in the non-English label. I am enclosing a copy of that notice for your information. I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosure; |
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ID: aiam1611OpenMr. Tatsuo Kato, Staff, Safety, Nissan Motor Company, Ltd., 560 Sylvan Avenue, Englewood Cliffs, New Jersey 07632; Mr. Tatsuo Kato Staff Safety Nissan Motor Company Ltd. 560 Sylvan Avenue Englewood Cliffs New Jersey 07632; Dear Mr. Kato: This is in reply to your letter of September 11, 1974 asking for a interpretation of paragraph S5.3.5 of Standard No. 105-75. You indicate that a prospective Nissan design uses a common indicator lamp to show both loss if fluid pressure and low brake fluid level. You ask if the indicator lamp lens may be labeled 'Brake Failure.'; The answer is no. If separate indicator lamps are used, Standard No 105-75 allows words in addition to 'Brake' to indicate the specific area where a problem may exist, *e.g.* an indicator lamp may be labelled 'Brake Fluid' to indicate a low level of fluid. However, if a lamp indicates more than one type of condition, paragraph S5.3.5 specifies that only a single word, 'Brake', may be used. This alerts a driver in a general way that a problem exists somewhere in the brake system. We think the restriction of S5.3.5 preferable for most circumstances. In the configuration you propose for example, the word 'Failure' would not accurately describe a low level of brake fluid.; We appreciate your continued interest in vehicle safety. Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam4443OpenMr. Toshio Maeda Executive Vice President & Chief Operating Officer Nissan Research & Development, Inc. P.O. Box 8650 Ann Arbor, Michigan 48104; Mr. Toshio Maeda Executive Vice President & Chief Operating Officer Nissan Research & Development Inc. P.O. Box 8650 Ann Arbor Michigan 48104; Dear Mr. Maeda: This is in reply to your letter of June 30, 1987 asking for an interpretation of paragraph S4.1.1.36(b)(3) of Motor Vehicle Safety Standard No. 108. That paragraph specifies in pertinent part that a replaceable bulb headlamp shall be designed to conform to Section 6.1-Aiming Adjustment Test, of SAE Standard J580 AUG79 Sealed Beam Headlamp Assembly. Section 6.1.1 states that 'when the headlamp assembly is tested in the laboratory, a minimum aiming adjustment of +/-4 deg. shall be provided in both the vertical and horizontal planes.' You have asked whether the aiming adjustment is to be achieved by the headlamp assembly, or by both the headlamp assembly 'and by the headlamp when it is mounted on the vehicle.' SAE J580 applies to the design of headlamp assemblies, including the functional parts other than the headlamps, such as aiming and mounting mechanisms and hardware. The assembly may include one or more headlamps. Although the headlamp assembly is tested in the laboratory, its design must be identical to the headlamp assembly used on the vehicle. Thus, if the aiming adjustment requirement is met by the headlamp assembly in the laboratory, it should also be met when the assembly is installed on the vehicle. An individual headlamp installed on the vehicle need not meet the aiming adjustment test unless that headlamp is part of a headlamp assembly comprising only one headlamp. I hope that this answers your question. Sincerely, Erika Z. Jones Chief Counsel; |
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ID: aiam1847OpenHonorable Stuart Symington, United States Senate, Washington, DC 20510; Honorable Stuart Symington United States Senate Washington DC 20510; Dear Senator Symington: This is in response to your letter of March 5, 1975, requesting ou comment on inquiries you have received concerning a proposed weakening of the 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 then be 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 on March 12, 1975 (Docket No. 74-11, Notice 7, Docket No. 73-19, Notice 6).; Your interest in this matter is appreciated. Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam1891OpenHonorable 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 one of your constituents, Mr. Albert E. Huber, 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).; We appreciate your interest and that of Mr. Huber in this importan area of motor vehicle performance.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam2405OpenMr. Sicks, Fachnormenausschuss Kraftfahrzeuge - FAKRA, D-6000 Frankfurt (Main) 17 - Westendstrasse 61, Postfach 1742 49; Mr. Sicks Fachnormenausschuss Kraftfahrzeuge - FAKRA D-6000 Frankfurt (Main) 17 - Westendstrasse 61 Postfach 1742 49; Dear Mr. Sicks: This is in response to your letter of March 31, 1975, in which yo recommend a modification of the testing procedures pursuant to Standard No. 302, *Flammability of Interior Materials*. Your modification would require the presence of support wires in all tests. After consideration of the recently-compiled test data on the use of support wires in the testing procedures, the NHTSA has decided that modification of the standard should be considered along the lines you suggest.; The NHTSA has interpreted Standard No. 302 to permit the use of suppor wires when any bending of the tested material occurred. At the time of that interpretation, it was believed that support wires would not influence the test results. More recent testing by the agency indicates that the use of support wires does significantly affect burn rates. For this reason, the agency is considering various possibilities in addition to the one you suggest.; Thank you for sending us a copy of your Draft International Standard We appreciate your concern in this matter.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam3765OpenMs. Patricia Hill, 2150 Hacker Road, Howell, MI 48843; Ms. Patricia Hill 2150 Hacker Road Howell MI 48843; Dear Ms. Hill: This responds to your March 23, 1983, letter asking five specifi questions relating to Standard No. 302, *Flammability of Interior Materials*. Your questions and their answers are listed below:; 1. Provide a definitive interpretation of 'erratic burning' as used i the subject standard that may be related to a test procedure.; 'Erratic burning,' as that term is used in the standard, relates t incidents where the material may soften or bend at the flaming end in a way that would not allow for uniform burning. Erratic burning, therefore, includes, but is not limited to, nonuniform burning as indicated in S5.1.3 of the standard where the use of support wires is mentioned.; 2. Provide a definitive interpretation of the word 'anticipate' as use in TP 302-02. That is, must the expectation of a softening and bending of the flaming end be based upon an actual test of an identical test specimen? A similar test specimen?; In actual practice, a test specimen is observed while burning during compliance test to FMVSS No. 302. If the specimen is found both to soften and bend at the flaming end during testing and also fails to meet the minimum burn rate requirement, a retest is performed using support wires.; 3. Does the agency still plan to issue an interpretive amendmen limiting or clarifying the use of support wires as stated in your 1976 letter? When?; The agency currently has no plans for any modifications of Standard No 302.; 4. How do the procedural requirements of the subject standard apply t a test specimen that bends at the flaming end prior to ignition by a bunsen burner?; We are not certain of the question that you are asking. The materia would not have a flaming end to bend prior to ignition of the bunsen burner. If by this question you mean to ask what we would do about non-flat test specimens, the agency always attempts to test flat specimens only.; 5. Does the NHTSA plan to revise TP 302-02 to reflect your 197 interpretation and your response to this letter? When?; The agency currently has no plans for any modifications to TP 302- 02. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0263OpenMr. E. W. Bernitt, Vice President Safety and Quality Assurance, American Motors Corporation, Jeep Corporation, 940 North Cove Boulevard, Toledo, OH 43601; Mr. E. W. Bernitt Vice President Safety and Quality Assurance American Motors Corporation Jeep Corporation 940 North Cove Boulevard Toledo OH 43601; Dear Mr. Bernitt: This is in reply to your letter of October 12, 1970, to Mr. Charles A Baker of this office in which you requested an interpretation of the phrase 'effective projected illuminated area.'; Class A turn signal lamps are required by Section S3.1 of Federal Moto Vehicle Safety Standard No. 108, which references SAE Standard J588d in Tables I and III for these lamps. The requirements for the illuminated area of a turn signal lamp are specified in J588d as follows:; >>>'The effective projected illuminated area measured on a plane a right angles to the axle of the lamp must not be less than 12 sq. in. for Class A and 3-1/2 sq. in. for Class B.'<<<; In the 45 degree visibility requirements, this standard further state 'To be considered visible, the lamp must provide an unobstructed projected illuminated area of outer lens surface, including reflex,...'.; Our interpretation of effective projected illuminated area follows: Th effective projected illuminated area is that area of the lens measured on a plane at right angles to the axle of the lamp, including reflex reflector, which is not obstructed by an opaque object such as a mounting screw, mounting ring, or an ornamental basel or trim.; The above interpretation allows the area of rings or othe configurations (raised portions) molded in the lens to be considered part of the total effective area, even if this area does not contribute significantly to the total light output.; Sincerely, Roger Crampton, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam1844OpenHonorable Garner E. Shriver, House of Representatives, Washington, DC 20515; Honorable Garner E. Shriver House of Representatives Washington DC 20515; Dear Mr. Shriver: This is in response to your letter of March 6, 1975, forwardin correspondence from one of your constituents, Mr. Dick Robbins, Jr., commenting on a proposed weakening of the 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 then be 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 on March 12, 1975 (Docket No. 74-11, Notice 7, Docket No. 73-19, Notice 6).; Your interest and that of Mr. Robbins in this matter is appreciated. Sincerely, James C. Schultz, 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.