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
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ID: nht91-2.4OpenDATE: February 27, 1991 FROM: Charles A. Schue, Jr. TO: Director, Office of Vehicle Safety Compliance, DOT/NHTSA TITLE: None ATTACHMT: Attached to letter dated 3-25-91 from Paul Jackson Rice to Charles A. Schue, Jr. (VSA Sec. 108; Regs. 591) TEXT: Reference is made to your Guide for Complying With Regulations On Imported Motor Vehicles, DOT HS 807 144, Effective January 31, 1990. I just received this guide from your office and was previously unaware of the one provision regarding purchase of the vehicle prior to November 1, 1988. I have been working in Turkey continuously sine June, 1986. This employment has been with two separate United States Companies who are contracted to the U.S. Air Force on the Turkey Base Maintenance Contract. In addition, I retired from the U.S. Army as a Warrant Officer Grade Three in 1974 after 27 years honorable service. I have not imported any other non-conforming vehicle in the past. I purchased my present foreign made automobile on 15 May 1969 from an American employee of my present company who had previously purchased it from another American employee of the same company many years before. Statistics of this automobile are: 1979, Mercedes, 300D, 423 Four Door, Red, SN: 42313010127393. Request waiver of purchase date requirement outlined in your referenced guide. I plan to import this vehicle prior to October 31, 1992. In the event this waiver cannot be granted, please inform me of other provisions under which I may request approval to import this vehicle into the U.S.A. |
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ID: nht91-2.40OpenDATE: March 19, 1991 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: Liam J. Moran -- Hagans, Brown, Gibbs & Moran TITLE: Re Brey v. Spalding & Evenflo Companies, Inc.; Your File No.: 3571 ATTACHMT: Attached to letter dated 3-7-91 from Liam J. Moran to Steven Kratzke TEXT: This responds to your letter to Stephen Kratzke, our Deputy Assistant Chief Counsel for Rulemaking, seeking an interpretation of the labeling requirements in Standard No. 213, Child Restraint Systems (49 CFR S571.213). More specifically, you noted that S5.5.2(g) requires add-on child restraint systems to be permanently labeled with the following: WARNING! Failure to follow each of the following instructions can result in your child striking the vehicle's interior during a sudden stop or crash. Secure this child restraint with a vehicle belt as specified in the manufacturer's instructions located (Insert the location of the instruction booklet). You also noted that Standard No. 213 requires the installation instruction booklet to "explain the primary consequences of not following the warnings required to be labeled on the child restraint system." Parenthetically, I note that your letter erroneously identified S5.6.3 as the source of this requirement. You told Mr. Kratzke in your telephone conversation that your litigation involves an add-on child restraint system. S5.6.3 applies solely to built-in child restraint systems. However, the identical requirement is set forth for add-on child restraint systems in S5.6.1.3 of Standard No. 213. You asked whether the explanation in the instruction booklet of the primary consequences of not following the warnings labeled on the child restraint system (per S5.6.1.3) is required to be something more than the statement required to be labeled on the child restraint system (per S5.5.2(g)). The answer is no. NHTSA explicitly addressed this question in the rulemaking that established the current labeling requirements. A notice of proposed rulemaking was published on May 18, 1978 (43 FR 21470). This proposal did not include any proposed regulatory text to require a label on the child restraint system warning users about the failure to follow the instructions provided by the manufacturer. However, the preamble did have the following discussion: Comments are also requested on whether a brief explanation should be given of the primary consequences of not following the warnings and instructions PROVIDED BY THE MANUFACTURER ON THE RESTRAINT. An example of such an explanation is that failure to attach the tether on systems having top tethers may result in the top part of the system bending forward during a crash and striking the dashboard or back of the front seat, depending on where the restraint is installed. Another example would be to explain that failure to adjust belts snugly may result in the child coming entirely out of the restraint during a crash or in crash forces being placed on the wrong portions of the child's body. (Emphasis added). 43 Fed. Reg. 21476. This request for comments was addressed solely to information that should be labeled on the restraint itself. There is no indication in the proposal that the agency sought comments on or otherwise considered requiring information in addition to this to be provided in the instruction booklet. A final rule implementing this proposal was published on December 13, 1979 (44 FR 72131). That rule included the following discussion: Many commenters (citation omitted) supported the proposed requirement that manufacturers inform consumers about the primary consequences of not following the manufacturer's warning about the correct use of the restraint. Therefore, the visible label must state the primary consequence of misusing the restraint. The SAME INFORMATION would also have to be included in the instruction manual accompanying the restraint. (Emphasis added). 44 Fed. Reg. 72137. The regulatory language that was added to the labeling requirement for child restraints in the final rule to "state the primary consequence of misusing the restraint" was the warning now in S5.5.2(g) of Standard No. 213. The last sentence in the above-quoted section of the preamble expressly states that the instruction booklet that accompanies the child restraint must include the same warning that is required to be labeled on the child restraint. There is, therefore, no basis for the assertion that the instruction booklet must include some warning in addition to the warning required to be labeled on the child restraint system. |
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ID: nht91-2.41OpenDATE: March 20, 1991 FROM: H. Hurley Haywood -- Vice President, Brumos Motor Cars, Inc. TO: Chief Consul -- U.S. Department of Transportation, NHTSA TITLE: None ATTACHMT: Attached to letter dated 4-8-91 from Paul Jackson Rice to H. Hurley Haywood (A37; Part 591) TEXT: A company in England would like information regarding the sale of a very limited number of specially built cars in the U.S. All component parts, i.e.; engine, suspension, gear box would be manufactured by Porsche. The chassis would be a carbon fiber 962 racing tub with hand built body. The car could be built completely in England or shipped to the U.S. as a kit car and assembled here. The company would like information regarding low-volume manufacturers exemptions from certain DOT regulations, emmissions, passive restraints, bumper height, and all other pertinent information regarding manufacturing and sale of vehicles in the U.S. Thank you for your cooperation. |
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ID: nht91-2.42OpenDATE: March 21, 1991 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: Chris Lawrence -- Chang & Lawrence TITLE: None ATTACHMT: Attached to letter dated 8-17-89 from Stephen P. Wood to Alan S. Eldahr (VSA 108(a)(2)(A)); Also attached to letter dated 1-5-91 from Chris Lawrence to August L. Burgett (OCC 5764) TEXT: This is in reply to your letter to Dr. Burgett of this agency. Though dated January 5, 1991, we did not receive it until March 7. With respect to your wish to produce an electronic sign board for installation in the rear window area, or on the rear, of a passenger car, I enclose a copy of an interpretation of this Office dated August 17, 1989, regarding such a device. Although the interpretation is restricted to an interior-mounted electronic sign board, our conclusion would not be changed were the device to be mounted on the outside of the rear of the vehicle. In that location, and as an item of original equipment, we believe that it would impair the effectiveness of the required rear lighting equipment by its potential to distract following drivers from the signals sent by the rear lamps when they and the sign board are operated simultaneously. Although the considerations for aftermarket devices are expressed differently, as explained in the August 1989 letter, the potential for distraction would appear to create a partial inoperability of the rear lamps within the meaning of the prohibition. |
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ID: nht90-2.88OpenTYPE: Interpretation-NHTSA DATE: June 15, 1990 FROM: James W. Lawrence -- Manager, Compliance and Technical Legislation, Volvo GM Heavy Truck Corporation TO: Stephen P. Wood -- Acting Chief Counsel, NHTSA TITLE: Re Interpretation on Conformance of Aftermarket Parts ATTACHMT: Attached to letter dated 4-9-90 from Stephen P. Wood to Mehdi Rowghani (A35; Std. 214; Part 541); Also attached to letter dated 3-13-91 from Paul Jackson Rice to James W. Lawrence (A37; Std. 214; VSA 108(a)(2)(A)) TEXT: I recently became aware of an Administration interpretation (copy attached) to a parts distribution that states in part as follows: "...there is no requirement that the replacement door restore the vehicle to a condition in which it continues to meet Standard No. 214." In contrast, the Act section 108a(2)(A) prohibits rendering inoperative devices or elements of design installed in compliance to a Safety Standard. I interpret this provision of the Act to require the installation of parts meeting the same performance r equirements as OEM parts. A clarification would be most appreciated. |
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ID: nht90-2.89OpenTYPE: INTERPRETATION-NHTSA DATE: 06/18/90 FROM: PAUL JACKSON RICE -- NHTSA CHIEF COUNSEL TO: JOHN W. GARRINGER TITLE: NONE ATTACHMT: LETTER DATED 05/07/90 FROM JOHN W. GARRINGER TO STEPHEN P. WOOD -- NHTSA, OCC 4751; LETTER DATED 02/01/90 FROM JOHN W. GARRINGER TO TERRY M. GERNSTEIN TEXT: This responds to your letter asking whether Federal law permits the installation of tinted plastic film on the bottom of motor vehicle windshields. The purpose of this film would be to reduce glare for the driver and any front seat passengers. I am ple ased to have this opportunity to explain how our laws and regulations apply to such a product. Our agency is authorized under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq.; the Safety Act) to issue safety standards applicable to new motor vehicles and new items of motor vehicle equipment. NHTSA, however, does not appro ve or certify any vehicles or items of equipment, nor do we endorse any commercial products or processes. Instead, the Safety Act specifies that each manufacturer itself must certify that its products meet all applicable safety standards. The agency pe riodically tests vehicles and items of equipment for compliance with the standards, and also investigates alleged defects related to motor vehicle safety and alleged violations of other statutory provisions. Pursuant to this authority, NHTSA has issued Standard No. 205, Glazing Materials (49 CFR @ 571.205), which sets forth performance requirements for windows and other glazing items installed in motor vehicles. Among the requirements set forth in Standard N o. 205 are specifications for minimum levels of light transmittance. A minimum of 70 percent light transmittance is required in glazing areas requisite for driving visibility, which includes all windows in passenger cars. In trucks and buses, the winds hield and windows to the immediate right and left of the driver and the rearmost window, if the latter is used for driving visibility, are considered to be requisite for driving visibility, and therefore subject to the 70 percent minimum light transmitta nce requirement. Your letter did not provide any information on the light transmittance that would be measured through glazing with your Hood Glare product installed on it. The combination of the glazing material and your tinting film must allow at least 70 percent light transmittance to comply with the requirements of Standard No. 205. No manufacturer or dealer would be permitted to install your tinting film on the glazing materials on new vehicles, unless the manufacturer or dealer certifies that the vehicle continue s to comply with the 70 percent minimum light transmittance and other requirements of Standard No. 205. After a vehicle is first sold to a consumer, modifications to the vehicle are affected by section 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)). That section prohibits any manufacturer, dealer, distributor, or repair business from "rendering i noperative" any device or element of design installed in a vehicle in compliance with any safety standard. This provision of the law means that no manufacturer, dealer, distributor, or repair business could install tinting film if the addition of the ti nting film to the glazing would result in a light transmittance of less than 70 percent, or otherwise cause the vehicle to no longer comply with the applicable requirements of Standard 205. Violations of this "render inoperative" prohibition can result in Federal civil penalties to the manufacturer, dealer, distributor, or repair business of up to $ 1000 for each noncomplying installation. Section 108(a)(2)(A) of the Safety Act does not affect vehicle owners. Hence, vehicle owners themselves may install tinting film or any other product on the glazing of their vehicle, regardless of whether the installation causes the vehicle to no longer comply with Standard No. 205. Individual States have the authority to regulate the operational use of vehicles by their owners, and, therefore, have the authority to regulate or preclude individual owner modifications to the glazing of their vehicles. I have enclosed an information sheet that summarizes the relationship between Federal auto safety laws and motor vehicle window tinting. I hope this information is helpful. If you have any further questions or need any additional information about this topic, please feel free to contact Dorothy Nakama of my staff at this address or by telephone at (202) 366-2992. ENCLOSURE
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ID: nht90-2.9OpenTYPE: INTERPRETATION-NHTSA DATE: APRIL 9, 1990 FROM: STEPHEN P. WOOD TO: GARY R. BALANZA TITLE: NONE ATTACHMT: LETTER DATED 10-11-89 TO NHTSA FROM GARY R. BALANZA ATTACHED. TEXT: This is in reply to your letter asking for an interpretation whether your invention "will interfere with the standard equipment" required by Motor Vehicle Safety Standard No. 108. I regret the delay in responding. Your invention, "Pinlights", is described as an auxiliary lighting system designed to fit an automobile's side contours. Its purpose is to light up the entire length of a vehicle, so that it will be more conspicuous at night. We note your uncertainty a s to "number of stripes allowed on Bcar", "colors allowed on a car", and "maximum brightness allowable." There are two ways to approach your invention under the National Traffic and Motor Vehicle Safety Act, our authority for the issuance of the motor vehicle lighting standard, Standard No. 108. The first is as an item of original equipment, in place on th e vehicle at the time it is bought by its first owner. You have asked the correct question: does the invention impair the effectiveness of the lighting equipment required by Standard No. 108? The equipment most likely to be impaired are the side marke r lamps and reflectors. These items are located near the front and rear of the vehicle, to enhance vehicle conspicuity by affording an approximation of vehicle length, and an indication of the vehicle's front and rear. The lamps are amber to the front, and red to the rear. Your invention would be located along the side of the vehicle, from front to rear. This suggests that the color of your device should similarly be amber to the front and red to the rear, so as not to impair the effectiveness of th e directional function of the side marker lamps. The second way to approach your invention is as an item available in the aftermarket. Standard No. 108 does not apply to a vehicle in use. However, as it applies to your question, the vehicle Safety Act prohibits modifications by manufacturers, distribu tors, dealers, or motor vehicle repair businesses if they render inoperative, in whole or in part, any of the required lighting equipment. In most cases, we consider an impairment of new vehicle equipment to be equivalent to a partial inoperability. Fu rther, if installation of aftermarket equipment directly affects the performance of original equipment (such as a reduction of light output through an interference with the wiring), that would certainly be considered a partial inoperability. Lighting equipment that is not covered by Standard No. 108 remains subject to the requirements of each State in which a vehicle on which it is installed is registered and/or operated. We are unable to advise you on State laws, and suggest that, for an o pinion, you write the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203. |
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ID: nht90-2.90OpenTYPE: INTERPRETATION-NHTSA DATE: 06/18/90 FROM: PAUL JACKSON RICE -- NHTSA CHIEF COUNSEL TO: DOUGLAS MAYES -- PRESIDENT CREATIVE PRODUCTS, INC. TITLE: NONE ATTACHMT: LETTER DATED 10/17/89 FROM DOUGLAS MAYES -- CREATIVE PRODUCTS TO NHTSA; RE BRAKING DISTANCE TEST AND LABORATORIES USED BY DOT; OCC 4087 TEXT: This responds to your letter asking questions in relation to your product called "gyroscopic wheel covers." We apologize for the delay in our response. According to your letter and accompanying information, you claim that use of "gyroscopic wheel covers" can reduce stopping distance. You stated that Dr. Carl Clark of this agency suggested that you request this office to provide a letter specifically ou tlining the requirements of the agency's braking test, and a list of the various testing facilities used by the agency when testing a product for this purpose. You then asked for a letter stating the "stopping distance test guidelines" of Safety Standar d No. 105, Hydraulic Brake Systems," and a list of laboratories acceptable to DOT that could be used to test your product. You also asked whether an SAE standard is a proper example of a stopping distance test. You stated that it is your intention to us e these testing standards and one of the acceptable laboratories so as to properly document your product's test results in compliance with the DOT testing standards. By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of th e manufacturer to ensure that its products meet applicable standards. Safety Standard No. 105, Hydraulic Brake Systems, applies to passenger cars and other motor vehicles. The standard specifies, among other things, a number of stopping distance tests that each motor vehicle must meet. I have enclosed a copy of the stand ard for your information. I note that Standard No. 105 was not designed for the purpose of evaluating whether a product such as yours can improve stopping distance. We are unable to offer an opinion as to the appropriateness of using Standard No. 105's stopping distance tests fo r that purpose, or how such a test program would best be carried out. This agency does not provide recommendations or endorsements for particular testing laboratories. I have, however, enclosed a list of the independent laboratories conducting compliance tests for NHTSA's Office of Vehicle Safety Compliance during the cur rent fiscal year. I have also enclosed a copy of an information sheet we have prepared which provides information for new manufacturers of motor vehicles and motor vehicle equipment. I hope this information is helpful. [NHTSA STANDARD NO 105 HYDRAULIC BRAKE SYSTEMS; 49 CFR CHAPTER V; DATED 10/01/89 OMITTED] |
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ID: nht90-2.91OpenTYPE: Interpretation-NHTSA DATE: June 20, 1990 FROM: Dennis T. Johnston -- Senior Executive Engineer, Product Engineering and Regulatory Affairs, Sterling Motor Cars TO: General Jerry R. Curry -- Administrator, NHTSA TITLE: Re Sterling Superlocking System ATTACHMT: Attached to letter dated 10-5-90 from B. Felrice to D.T. Johnston (A36; Part 543) TEXT: Rover Cars of North America (formerly Austin Rover Cars of North America, d.b.a. Sterling Motor Cars), importer of the British Sterling passenger car, manufactured by the Rover Group Ltd., U.K. sent you a letter dated March 14, 1990 outlining a proposed modification to our antitheft system in the 1991 Model Year. Due to marketing considerations, this enhanced system, referred to as 'superlocking' will not be available for the 1991 Model Year. Therefore Sterling would like to withdraw that submission. If we elect to offer this system at some point in the future we will resubmit a request for de minimus change to our currently approved theft prevention system. We would like to introduce a minor revision to our currently approved system for the 1991 Model Year, however. Our present system, once armed, will activate if the trunk is opened, even using the key, unless the system is disarmed. Our proposed modific ation would allow the system to be disarmed when the trunk is opened by the key and rearmed when the, trunk lid is closed. Forcing open of the trunk without using the key would still activate the alarm. If you have any questions regarding this request please feel free to contact me on (213) 437-6282 at your earliest convenience. |
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ID: nht90-2.92OpenTYPE: Interpretation-NHTSA DATE: June 22, 1990 FROM: Ed McCarron -- Western Star Trucks Inc. TO: Dee Fujita -- Chief Counsel's Office, NHTSA TITLE: FMVSS 302 Burn Test ATTACHMT: Attached to letter dated 6-29-90 to E. McCarron from P. J. Rice; (A35; Std. 302) TEXT: As per our conversation, below is a sketch (cross section). This shows the corner of a cushion, specifically a mattress. (Graphics omitted See illustration on original. 1) cover 2) foam 3) foam backing 4) fill 5) corner reinforcement 6) fill backing (at corners) Can you please recommend how this would be tested. |
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.