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: aiam3510OpenMr. Ernesto Rodriguez, Cariben, Inc., 144-30 Roosevelt Avenue, Suite 606, Flushing, NY 11354; Mr. Ernesto Rodriguez Cariben Inc. 144-30 Roosevelt Avenue Suite 606 Flushing NY 11354; Dear Mr. Rodriguez: This responds to your letter of September 22, 1981, asking whether an Federal motor vehicle safety standard precludes the importation or sale of your anti-theft device. The device works by blocking the brakes and electric circuits to the motor. In trucks, the clutch is also blocked. Installation of the device requires cutting into a vehicle's braking system.; By way of background information, the agency does not give approvals o vehicles or equipment. The National Traffic and Motor Vehicle Safety Act places the responsibility on the manufacturer to ensure that its vehicles or equipment comply with applicable requirements. A manufacturer then certifies that its vehicles or equipment comply with all applicable standards. We note that the term 'manufacturer' is defined by section 102(5) of the Act to mean 'any person engaged in the manufacturing or assembling of motor vehicles or motor vehicle equipment, *including any person importing motor vehicles or motor vehicle equipment for resale*.' Emphasis added. ; The agency does not have any regulations covering anti-theft device that work by preventing release of the brakes.; However, since installation of your device requires cutting into vehicle's braking system, it may affect a vehicle's compliance with other safety standards.; If your device is added to a new motor vehicle prior to its first sale the person who modifies the vehicle would be an alterer of a previously certified motor vehicle and would be required to certify that, as altered, the vehicle continues to comply with all of the safety standards affected by the alteration. In the case of your device, this would include Safety Standard No. 105, *Hydraulic Brake Systems* (49 CFR 571.105). You will find the specific certification requirements for alterers at 49 CFR Part 567.7, *Certification*. On the other hand, you as the manufacturer of the device would have no certification requirements, because we have no safety standards applicable to your equipment. However, an alterer would probably require information from you in order to make the necessary certification.; If your device is installed on a used vehicle by a business such (sic) garage, the installer would not be required to attach a certification label. However, it would have to make sure that it did not knowingly render inoperative the compliance of the vehicle with any safety standard. This is required by section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act, which states in relevant part:; >>>No manufacturer, distributor, dealer, or motor vehicle repai business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard. . .<<<; Standard No. 105 includes various requirements that might be affecte by installation of your device. We are not able to determine from the drawings included with your letter whether compliance with the standard would be affected. We suggest that you carefully examine all of Standard No. 105's requirements to determine the degree to which installation of your device affects compliance with the standard. Your letter states that when your device is not in use, the vehicle works normally without any interference whatsoever. In addition to requirements specifically concerning stopping performance, the standard also includes requirements related to such things as a split system and the ability to withstand a series of spike stops, which might be affected by your device.; While we do not have any opinion as to the safety of your particula device, we do have a general concern about the safety of anti-theft devices which work by preventing release of the brakes. We note that some manufacturers state in their service manuals that hydraulic brake locking devices should not be used on their vehicles.; Should a safety-related defect be discovered in your device, whether b the agency or yourself, you as the manufacturer would be required under sections (sic) 151 *et seq*. of the Act to notify vehicle owners, purchasers, and dealers and provide a remedy for the defect.; Finally, in addition to the provisions of Federal law discussed above there is a possibility of liability in tort should your device prove to be unsafe in operation. You may wish to consult a local lawyer concerning liability in tort.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3140OpenHonorable John D. Dingell, House of Representatives, Washington, DC 20515; Honorable John D. Dingell House of Representatives Washington DC 20515; Dear Mr. Dingell: This responds to your recent letter on behalf of your constituent, Mr Donald Edwards. Mr. Edwards asks whether the passenger seat in a 1979 Dodge van is required under Federal law to be equipped with a safety belt.; Your earlier answer to Mr. Edwards was correct. Federal Motor Vehicl Safety Standards require light trucks (including vans) to be equipped with safety belts for each designated seating position. The passenger seat in Mr. Edwards' van would qualify as a designated seating position and would be required to have a safety belt.; Under the Federal certification regulations for motor vehicles, an person who alters a vehicle prior to its first purchase for purposes other than resale is required to place an additional label on the vehicle certifying that, as altered, the vehicle continues to be in compliance with all applicable safety standards (49 CFR 567.7). This provision would apply to the dealer who altered Mr. Edwards' vehicle by adding the passenger seat. The label would certify that the vehicle was still in compliance with all standards, including the safety belt requirements. Since the dealer did not install a safety belt, he probably did not place an alterer's label on the vehicle and he would, therefore, be in violation of the certification regulation. If this is the case, the agency has authority to require the dealer to remedy the noncompliance by installing safety belts on the van. Additionally, the dealer could be liable for civil penalties up to $1,000 for failure to comply with the Federal safety standards and regulations.; If Mr. Edwards has any problems in obtaining the required safety belt after receiving this information, please have him contact our Office of Enforcement at 400 Seventh Street, S.W., Washington, D.C. (202/426-9700).; Sincerely, Joan Claybrook |
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ID: aiam4685OpenMr. William Walters 7709 Wallace Street Merrillville, IN 46410; Mr. William Walters 7709 Wallace Street Merrillville IN 46410; "Dear Mr. Walters: This is in reply to your letter of October 8, l990 to Ms. Erika Jones, formerly Chief Counsel of this agency. You have asked that we review the enclosures to your letter, and provide 'the reason why this system is not being used.' The primary material you enclosed is a patent granted May 1, l990, for an 'Automobile Warning Light Improvement.' The purpose of the 'Improvement' is to enhance existing rear signal lamps by sending an advance warning of driving situations which have the potential of impeding the flow of traffic. The device activates the center highmounted stop lamp under situations other than when the brake pedal is applied. According to the patent, the device causes the center lamp to operate in a steady-burning mode when a vehicle is in reverse gear, and in a flashing mode when the turn signals are operating. When activated under these conditions, the center lamp will be deactivated when the accelerator is depressed. The reason why this system cannot presently be used is that its installation would create a noncompliance with existing requirements. The performance of the center highmounted stop lamp is specified by Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices, and Associated Equipment. Paragraph S5.5.4 of the standard specifically states that 'The highmounted lamp on passenger cars shall be activated only upon application of the service brakes.' In addition, the effect of paragraph S5.5.10 is to require all stop lamps to be steady burning when in use. Activation of the center lamp by means other than application of the brake pedal (such as putting the vehicle into reverse gear, or activating the turn signals), and in a mode other than steady burning (flashing with the turn signals) is prohibited by Standard No. 108. The reason why this system is unlikely to be used in the future is that it appears to have little if any potential for improving motor vehicle safety. Backup lamps, turn signal lamps, and center stop lamps have specific and different tasks to perform. Use of the center lamp to assist the other lamps in performing their tasks has the potential for creating confusion. The red center lamp used alone sends an unmistakable message: this vehicle is braking, with a deceleration that may lead to a stop. It is a message to which the motoring public is accustomed. Use of the center lamp when the backup lamps are on sends a false signal that the vehicle may be decelerating in a forward motion or stopped when, in fact, it may be proceeding in a reverse motion. Use of a flashing stop lamp, mounted on the centerline of the car, in conjunction with a turn signal lamp that is flashing either to the right or left of the centerline, has the potential also to create confusion as to the intent of the driver, and distracts attention from the message sent by the turn signal that the vehicle is changing lanes or preparing to turn. We appreciate your interest in safety and in bringing this invention to our attention. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam1487OpenMr. P. K. Kamath, Sr. Safety Engineer, Oshkosh Truck Corporation, P.O. Box 560, Oshkosh, WI 54901; Mr. P. K. Kamath Sr. Safety Engineer Oshkosh Truck Corporation P.O. Box 560 Oshkosh WI 54901; Dear Mr. Kamath: This is in reply to your letter of March 27, 1974, in which you as whether a final-stage manufacturer who mounts a used body on a new chassis is required to certify the conformity of the completed vehicle in accordance with 49 CFR Parts 567, 568.; The answer is yes. A person who mounts a used body on a new chassis i a final-stage manufacturer and is required to certify the conformity of the completed vehicle. The NHTSA has interpreted the Certification requirement as applying to any complete vehicle manufactured using a new incomplete vehicle (chassis) whether or not the body to be installed is new or used.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1192OpenMr. R. Kesler, Kesler Precision Optics, 444 N. Norton Ave., Los Angeles, Calif. 90004; Mr. R. Kesler Kesler Precision Optics 444 N. Norton Ave. Los Angeles Calif. 90004; Dear Mr. Kesler: Thank you for your letter of July 12, 1973, enclosing an accessor passenger car mirror that you feel is a detriment to motor vehicle safety.; Since the unit incorporates to convex mirrors it does not comply wit the requirements of Standard No. 111 *Rearview Mirrors* for original equipment on passenger cars and multipurpose passenger vehicles. However, the Standard does not cover aftermarket items such as the unit you sent, and its sale is therefore not prohibited under Federal Regulations.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1468OpenMr. Fred A. Hogan, President, Hawk Motor Homes, Inc., 142 Second Street, Belleville, MI 48111; Mr. Fred A. Hogan President Hawk Motor Homes Inc. 142 Second Street Belleville MI 48111; Dear Mr. Hogan: This is in reply to your letter of March 27, 1974, enclosing a sampl certification label and requesting that we approve as an alternate location the inside wall left of the driver's seat beneath the driver's side window, to the left of the dash.; The labels you supply state in day, month, and year, the dates o complete and incomplete vehicle manufacture, and that date by which applicable standards are determined. The Certification regulations (49 CFR Parts 567, 568) call for these dates to be stated only by month and year. While we prefer that the regulation be followed specifically, and thus that month and year only be specified, we will accept the format you have submitted which includes the day. The other information on the labels conforms to the Certification requirement.; With respect to your request for an alternate location, we approve th alternate location you request.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam4390OpenMr. William R. Graham, Bus and Truck Supply Co., 315 Continental Avenue, Dallas, TX 75207; Mr. William R. Graham Bus and Truck Supply Co. 315 Continental Avenue Dallas TX 75207; Dear Mr. Graham: This is in reply to your letters of August 6, 1969, and August 15 1969, in which you request approval of an alternative to the label locations specified in Section 367.4(c) of the Certification Regulations that will be effective as to vehicles manufactured on or after September 1, 1969.; The location you have selected is not considered to be in the sam general area, left side of the vehicle, as specified. In view of the fact that interested parties will be looking for the label in that general area, your proposed location, on the right side forward of the entrance door, is not approved. Please select another location that would be in the general area of the driver's seat and submit for approval.; The nomenclature of your label, as shown in drawing No. BS6111-007 does not fulfill the requirements of Part 367.4(g) of the regulations in that the required information is not presented in the order prescribed.; Your cooperation is appreciated. Sincerely, Robert Brenner, Acting Director |
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ID: aiam3455OpenMr. Paul Hingtgen, 7104 San Bartolo, Carlsbad, CA 92008; Mr. Paul Hingtgen 7104 San Bartolo Carlsbad CA 92008; Dear Mr. Hingtgen: This responds to your recent inquiry to Joseph F. Zemaitis, Moto Vehicle Program Director, Region IX, regarding the applicability of Safety Standard No. 205, *Glazing Materials*, to auxiliary wind deflectors. You state that this office informed you last October that your auxiliary wind deflector must comply with Standard No. 205. However, G. & C. Mills Plastics, Inc., the manufacturer of the 'Weathershield,' has shown you correspondence from NHTSA and the Department of Commerce implying that the Federal motor vehicle safety standards do not apply to auxiliary wind deflectors. You consider this disparate treatment to be unfair, and you ask for an explanation.; Our position on the applicability of the Federal motor vehicle safet standards to your auxiliary wind deflector was stated in our October 8, 1980, letter (copy enclosed) and it remains unchanged. In that letter, we stated that on the basis of the information you provided in your letter of August 13, 1980, we find your wind deflector to be subject to Standard No. 205. This is because paragraphs S1 and S3 of Standard No. 205 provide that the regulation applies to all glazing materials used in motor vehicles and motor vehicle equipment. Section 102(4) of the National Traffic and Motor Vehicle Safety Act, as amended in 1974 (the Act), defines 'motor vehicle equipment' to include any 'accessory or addition to the motor vehicle.' Since an auxiliary wind deflector is an accessory to the motor vehicle, it is an item of motor vehicle equipment, and the glazing used in the deflector must comply with the requirements of Standard No. 205.; Mr. Zemaitis is presently in the process of obtaining from G. & C Mills Plastics, Inc. some additional information about the nature and use of the 'Weathershield.' If the 'Weathershield' is in fact an auxiliary wind deflector, then the glazing materials it contains must comply with Standard No. 205. The responsibilities and liabilities imposed by the Act on you as a manufacturer of motor vehicle equipment to which a safety standard applies (as discussed in our October 8, 1980, letter) would be equally applicable to G. & C. Mills Plastics, Inc.; The information that was provided to Mr. L. J. A. Mills by NHTSA an the Department of Commerce in 1979 is misleading. The July 13, 1979, letter from this agency states that ' t he NHTSA safety regulations apply to new vehicles--they do not apply to aftermarket applications where the driver installs various devices on his car.' The letter also states that 'the law does not allow a dealer or manufacturer to install devices which adversely affect the original safety standards established by the NHTSA.' These statements imply that the Federal motor vehicle safety standards do not apply to accessory equipment such as auxiliary wind deflectors which are designed to be installed on the vehicle by the vehicle owner, and that manufacturers of such equipment are not required to comply with any applicable regulations. This is *not* the case. It is true that an individual person can modify his or her own vehicle or equipment in any fashion without violating the Act. But this does not mean that the safety standards do not apply to equipment that is designed to be installed on the vehicle by the vehicle owner, or that the manufacturers or sellers of such equipment do not have to comply with applicable regulations. Section 108(a)(1)(A) of the Act prohibits any person from manufacturing for sale or selling any item of motor vehicle equipment that does not comply with all applicable safety standards in effect on the date of manufacture. The ability of an individual to install a noncomplying device on his vehicle without penalty is irrelevant to the obligation of the manufacturer or seller of that device to ensure that the device complies with *all* applicable safety standards. Thus, while an individual can install an auxiliary wind deflector that does not comply with Standard No. 205 on his own vehicle, you violate the Act if you manufacture or sell such a device.; The Department of Commerce states in its letter of August 8, 1979, tha 'the Department of Transportation does not have to approve your accessory item unless it involves the safe operation of an automobile, such as brakes, lights, etc.' This statement implies that the Department of Transportation 'approves' those items of motor vehicle equipment that are 'safety-related.' This is not true. NHTSA is empowered under the Act to establish Federal motor vehicle safety standards regarding motor vehicles and motor vehicle equipment. All motor vehicles and items of motor vehicle equipment must comply with all applicable Federal safety standards in effect on the date of manufacture. NHTSA does not grant approval of vehicles or equipment prior to their sale. Rather, the Act provides that it is the manufacturer's responsibility to determine whether its vehicles or equipment are in compliance with all applicable safety standards and to certify its vehicles or equipment in accordance with that determination. The certification requirements for a manufacturer of auxiliary wind deflectors are discussed on page 2 of our letter of October 8, 1980. A manufacturer or seller of a vehicle or item of motor vehicle equipment that does not comply with all applicable Federal safety standards in effect on the date of its manufacture or that does not properly certify its products violates Section 108(a)(1)(A) of the Act. This is discussed on page 2 of our October 8, 1980, letter. The Department of Commerce is not empowered or authorized to make statements or issue interpretations regarding the authority or regulations of the Department of Transportation or NHTSA. Therefore, the August 8, 1979, letter from Commerce may not be relied upon.; We intend to contact G. & C. Mills, Inc. and inform them that th 'Weathershield' must comply with Standard No. 205 if it is an auxiliary wind deflector. We hope this letter satisfies your concerns. Please contact Ms. Joan Griffin of my staff (202-426-9511) if you have further questions.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1038OpenMr. Jim Peters, Florida Department of Agriculture and Consumer Services, Tallahassee, FL 32304; Mr. Jim Peters Florida Department of Agriculture and Consumer Services Tallahassee FL 32304; Dear Mr. Peters: This is in response to your letter of February 27, 1973, concerning a instance of odometer tampering reported to your office by Mr. J. L. Scott.; The National Highway Traffic Safety Administration has been delegate authority to administer Title IV, Odometer Requirements, of the Motor Vehicle Information and Cost Savings Act, P.L. 92-513. Although the Act establishes private civil actions as the principal means of enforcement (section 409), we find it useful to learn of cases such as the one you report.; In Mr. Scott's case, however, the sale of the ranch wagon with th suspect odometer occurred before January 18, 1973, the effective date of the Federal act. The resetting of the odometer was therefore not a violation of Federal law, and Mr. Scott has no Federal recourse.; We would be interested to know if you have other reports concerning th dealer from whom Mr. Scott purchased his vehicle. If it appears that the dealer has made a business of resetting odometers, we would consider injunctive action against him.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3005OpenMr. D. L. Haines, BFGoodrich Company, Dept. 7089, Bldg. 24C, 500 South Main Street, Akron, OH 44318; Mr. D. L. Haines BFGoodrich Company Dept. 7089 Bldg. 24C 500 South Main Street Akron OH 44318; Dear Mr. Haines: This responds to a January 15, 1979, request from Mr. A. J. Burt t permit adjustment of foundation brakes during the burnish procedures in S6.1.8 and S6.2.6 of Standard No. 121, *Air Brake Systems*, for any reason. At present, such adjustments can only be made to control brake temperature, as stated in our January 24, 1979, letter to Mr. Burt.; The National Highway Traffic Safety Administration is unaware of reason other than control of brake temperature which would justify adjustments during burnish. Accordingly, we decline to grant your request. The NHTSA would, of course, be willing to consider any data or other information you have which would indicate that the present interpretation of burnish procedures may be too narrow in this respect.; Sincerely, Frank Berndt, Chief Counsel |
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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.