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: aiam5355OpenHerr Tilman Spingler Robert Bosch GmbH Automotive Equipment Div. 2 Postfach 13 42 D-72703 Reutlingen Germany; Herr Tilman Spingler Robert Bosch GmbH Automotive Equipment Div. 2 Postfach 13 42 D-72703 Reutlingen Germany; Dear Mr. Spingler: This responds to your letter of March 25, 1994 asking for an interpretation of Motor Vehicle Safety Standard No. 108 with respect to integral beam headlighting systems. You reference a letter of this office to Toyota in which we permit location of the light source control module outside the headlamp housing but permanently attached to it by a cable. You have asked whether there are 'requirements for this cable concerning indivisibility and integration . . . .' There are no such requirements for the cable in Standard No. 108, and the headlamp manufacturer may adopt the construction that it has determined is most suitable for its design. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam2490OpenMr. Heinz W. Gerth, Vice President, Engineering and Service, Mercedes-Benz of North America, Inc., P.O. Box 350, Montvale, NY 07645; Mr. Heinz W. Gerth Vice President Engineering and Service Mercedes-Benz of North America Inc. P.O. Box 350 Montvale NY 07645; Dear Mr. Gerth: This is in reply to your letter of December 21, 1976, asking whethe Federal Motor Vehicle Safety Standard No. 108 *Lamps, Reflective Devices, and Associated Equipment* applies to fog lamps installed on the rear of passenger cars.; No requirements of Standard No. 108 apply to fog lamps and they ar subject to regulation by the individual states. Pursuant to S4.1.3, however, they may be prohibited if they impair the effectiveness of lighting equipment required by Standard No. 108.; You also asked that, absent inclusion of these lamps in Standard No 108, your letter be treated as a petition 'for rulemaking to amend Standard No. 108 to include such lighting requirements . . . for optional use on passenger cars.' Your submission does not meet the requirements of our procedural regulations, a copy of which I enclose. Specifically, pursuant to 49 CFR 552.4(c) you should 'set forth facts which it is claimed establish that an order is necessary.' Among these facts should be reasons why you are petitioning for 'optional' rather than mandatory use on passenger cars, and why other vehicles are not included in your petition (if, in fact true).; Sincerely,Frank A. Berndt, Acting Chief Counsel |
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ID: aiam1316OpenMarcia Mellinger, Lane County District Attorney, 450 Lane County Courthouse, Eugene, OR 97401; Marcia Mellinger Lane County District Attorney 450 Lane County Courthouse Eugene OR 97401; Dear Ms. Mellinger: You have asked what information an automobile dealer must provide in Federal odometer statement concerning prior vehicle ownership and mileage over 100,000 miles.; The Federal regulation only requires information which the transfero knows or has good reason to know about the vehicle's mileage. It does not require that he disclose the name of the former owner. It does require that he state the recorded mileage, and if he knows or has good reason to know that the recorded mileage is not correct he must make a further statement that the actual mileage is unknown. In your example, therefore, he would only state the five-digit figure appearing on the odometer, and make the further statement if he knew or had been told that the vehicle had traveled more than 100,000 miles. He is not required to check with former owners as to vehicle history, but he would be accountable under local consumer protection laws for any misleading statements he made about the vehicle's history.; Please contact me if I can be of further assistance. Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam4114OpenMr. Doug Cole, Director of Public Relations and Membership, National Van Conversion Association, Inc., 2 West Main Street, Suite 2, Greenfield, IN 46140; Mr. Doug Cole Director of Public Relations and Membership National Van Conversion Association Inc. 2 West Main Street Suite 2 Greenfield IN 46140; Dear Mr. Cole: Thank you for your letter of December 2, 1985 to Stephen Oesch of m staff concerning how our regulations would affect the placement of a National Van Conversion Association (NVCA) certification decal on vehicle windows by a van conversion company. The material enclosed with your letter explains that the NVCA certification program is a voluntary effort by the van conversion industry to set minimum safety and quality standards for its products. You explained that the decal, which has a diameter of 2 1/2 inches, would be placed on the lower corner of the passenger's side of the windshield by a manufacturer whose products conform to the NVCA program.; Placement of the decals on a vehicle's windshield would be affected b Federal Motor Vehicle Safety Standard No. 205, *Glazing Materials*, which specifies performance and location requirements for glazing used in vehicles. These requirements include specifications for minimum levels of light transmittance (70% in areas requisite for driving visibility, which includes the windshield in motor vehicles).; Part 567, *Certification*, of our regulations requires each vehicl manufacturer to place a plate within the vehicle certifying that the vehicle conforms to all applicable Federal motor vehicle safety standards. A person, such as a van converter, who makes significant modifications to a vehicle prior to its first sale to a consumer is considered a vehicle alterer under our regulations. Under Part 567.7, an alterer must also add a plate to the vehicle certifying that the vehicle, as altered, still continues to conform to all applicable Federal motor vehicle safety standards. Thus, no manufacturer or alterer is permitted to install solar films and other sun screening devices or other opaque materials in new vehicles without certifying that the vehicle continues to be in compliance with the light transmittance and other requirements of the standard.; After a vehicle is first sold to a consumer, modifications to a vehicl are affected by section 108(a)(2)(A) of the Vehicle Safety Act. That section prohibits commercial businesses from tampering with safety equipment installed on a vehicle in compliance with our standards. Thus, no dealer, manufacturer, repair business or distributor can install a sun screen device for the owner of the vehicle, if the device would cause the window not to meet the requirements of Standard No. 205. Violation of the 'render inoperative' provision can result in Federal civil penalties of up to $1,000 for each violation.; We have not previously ruled on whether these prohibitions apply to th installation of State vehicle inspection and private industry regulatory decals by commercial businesses. In general, these decals are small in size and placed in locations which minimize the obstruction, if any, to the driver's vision. In contrast, tinting films and other sun screening devices are generally applied to the entire window and thus can substantially obscure the driver's vision if they do not meet the light transmittance and other performance requirements of the standard. As with State regulatory decals, your proposed decal is small in size and would be placed in the lower right corner of the vehicle windshield, an area which should minimize any possible obstructing of the driver's vision. Given these considerations, we would consider the placement of the NVCA decal in the lower right hand corner of the windshield to be merely a technical violation of Standard No. 205, and would exercise our prosecutorial discretion and not bring an enforcement action.; I hope this information is of assistance to you. If you have an further questions, please let me know.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam0854OpenMr. E. M. Anderson, Vice President, Ingram Manufacturing Co., P.O. Box 2020, San Antonio, TX 78297; Mr. E. M. Anderson Vice President Ingram Manufacturing Co. P.O. Box 2020 San Antonio TX 78297; Dear Mr. Anderson: I apologize for the delay in answering your letter regarding Part 566 Manufacturer Identification. You describe the vehicles you manufacture and ask whether you are a manufacturer within the meaning of the regulation and therefore required to submit information regarding your products.; Part 566 applies to manufacturers of motor vehicles and motor vehicl equipment to which a motor vehicle safety standard applies. 'Motor vehicle' is defined in the National Traffic and Motor Vehicle Safety Act as 'any vehicle driven or drawn by mechanical power manufactured primarily for use on the public streets, roads, and highway'. Since the portable tandem rollers you describe appear to be manufactured for construction or farm use you are not considered a manufacturer of motor vehicles and are not covered by Part 566. Therefore you are not required to submit information under that regulation. For similar reasons you are not covered by the certification requirements of Part 567 and 568 which you also mentioned.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2869OpenMr. E. M. Ryan, Chief Design Engineer, Ward Industries, Inc., P. O. Box 849, Conway, AR 72032; Mr. E. M. Ryan Chief Design Engineer Ward Industries Inc. P. O. Box 849 Conway AR 72032; Dear Mr. Ryan: This responds to your August 22, 1978, letter asking whether you proposed emergency door label complies with the requirements of Standard No. 217, *Bus Window Retention and Release*.; Paragraph S5.5.3 requires that each school bus emergency exit shal have the designation 'Emergency Exit' or 'Emergency Door' as appropriate, in letters at least 2 inches high, of a color that contrasts with its background, located at the top of or directly above the emergency exit on both the inside and outside surfaces of the bus. The label that you propose would be located on the inside of the glass but would be visible from the outside of the vehicle.; The National Highway Traffic Safety Administration (NHTSA) ha indicated in the past that the location of the emergency exit label can be directly above or on the top half of the emergency exit. Your location near the top of the glass on the rear emergency door appears to fall within this acceptable area. The standard further requires that the label be located on both the inside and outside surfaces of the bus. The intent of this requirement is to provide a visible emergency exit designation on both the inside and outside of a bus. Since your label would be visible outside the school bus even though its location would be on the inside of the glass, the NHTSA concludes that it complies with this requirement. In reaching this conclusion, the agency assumes that you will have a similar label that will be visible inside the bus.; In summary, since your described label is the required size, consist of contrasting colors, and is placed in the appropriate location, it appears to comply with the requirements of Standard No. 217.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1746OpenMr. L. W. Steenbock, Designer, FWD Corporation, Clintonville, WI 54929; Mr. L. W. Steenbock Designer FWD Corporation Clintonville WI 54929; Dear Mr. Steenbock: This is in acknowledgment of your Defect Information Report, i accordance with the defect reporting regulations, Part 573.; The Defect Information Report involves: 316 - 1965 through 1973 FWD an Seagrave firetrucks. Possibility that the upper steering arm may crack and in some cases break in the mid-section of the steering arm resulting from excessive stresses due to power steering assist. This information was furnished in your letter of December 18, 1974.; The following National Highway Traffic Safety Administratio identification number has been assigned to the campaign *74-0245*. The first quarterly status report for this campaign is required to be submitted by February 5, 1975. Please refer to the above number in all future correspondence concerning this campaign.; The letter which you have sent to the owners of the subject vehicle does not meet the requirements of Part 577(49 CFR), the Defect Notification regulation. Specifically, the second sentence of your letter does not conform to Part 577.4(b) due to inclusion of the word 'may' and because the defect is described as existing in the steering arm rather than the vehicle itself. In cases where a vehicle manufacturer is notifying owners of vehicles, the letter should state that the defect exists in the vehicle itself, even though it may be caused by only one specific part. If the defect is not present in every vehicle, this may be stated in an additional statement.; Your letter also does not evaluate the risk to traffic safety a required by Part 577.4(d). Furthermore, since it appears that the labor cost for performing the corrective action must be born by the owners, Part 577.4(e)(3) should have been followed. It is therefore necessary that an estimate of the labor time necessary for replacing the arm and recommendations as to where the necessary work can be done be given. Your instructions for replacement of the arm are also inadequate since they seem to be limited primarily to the visual inspection and do not outline the actual replacement procedure. It is therefore necessary that you send a revised notification letter to those owners who have not yet had their vehicles corrected. A copy of the revised letter should also be sent to this office.; We also wish to inform you that it is not necessary to submit a copy o every single notification letter that is mailed. When letters are identical, except for the address, only one sample copy need be submitted. The names and addresses of vehicle owners need only be submitted when specifically requested. A copy of Part 577 is enclosed. If you desire further information, please contact Messrs. W. Reinhart or James Murray of this office at (202) 426-2840.; Sincerely, Andrew G. Detrick, Director, Office of Defect Investigation, Motor Vehicle Programs; |
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ID: aiam3281OpenMr. Thomas E. Cole, Tire Division, Rubber Manufacturers Association, 1901 Pennsylvania Avenue, N.W., Washington, DC 20006; Mr. Thomas E. Cole Tire Division Rubber Manufacturers Association 1901 Pennsylvania Avenue N.W. Washington DC 20006; Dear Mr. Cole: This is in response to your letter of April 14, 1980, regarding tw apparent discrepancies in the revised Uniform Tire Quality Grading tread label format, published on November 29, 1979, in Docket 25, Notice 35 (44 FR 58475). As you note, the word 'Vehicle' was omitted from the term 'Federal Motor Vehicle Safety Standard No. 109' under the heading 'Temperature' in Figure 2, Part II, of the regulation as published. This was an inadvertent omission which the National Highway Traffic Safety Administration (NHTSA) plans to correct in a future notice.; You also point out that paragraph (d)(1)(i)(B)(1) of the regulation (4 CFR 575.104(d)(1)(i)(B)(1)), applicable to tires manufactured prior to October 1, 1980, provides for use of the heading 'DOT QUALITY GRADES' in capital letters, while Part I of Figure 2 of the regulation contains the heading 'DOT Quality Grades' using lower case letters. The label format specified in paragraph (d)(1)(i)(B)(1) parallels the label format originally announced in Docket 25, Notice 24 (43 FR 30542, July 17, 1978), the heading of which used all capital letters. Since Part I of Figure 2 is not required on labels printed in accordance with paragraph (d)(1)(i)(B)(1), the use of lower case letters in the heading of Part I does not affect the requirements of paragraph (d)(1)(i)(B)(1). NHTSA will permit, at the manufacturer's option, the use of all capital letters in the heading of Figure 2, Part I, in printing labels to comply with the new two-part label format.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4544OpenMr. Byung M. Soh Marketing Director Target Marketing Systems, Inc. P.O. Box 59483 Chicago, IL 60659-0483; Mr. Byung M. Soh Marketing Director Target Marketing Systems Inc. P.O. Box 59483 Chicago IL 60659-0483; Dear Mr. Soh: This is in reply to your letter of June 20, 1988, wit respect to two motor vehicle lighting products which you intend to import into the United States. You have asked 'whether these devices require approvals from D.O.T.' First let me explain that the Department of Transportation does not 'approve' or 'disapprove' specific products. It does advise whether a product appears allowable under the National Traffic and Motor Vehicle Safety Act and the Federal Motor Vehicle Safety Standards. Your letter does not indicate whether you wish to market these devices as original equipment to be installed before initial sale of a motor vehicle, by either its manufacturer or dealer, or whether you intend to market them solely through the aftermarket. I shall address each situation. The Federal motor vehicle safety standard that applies to original equipment is Standard No. 108 Lamps, Reflective Devices and Associated Equipment. Paragraph S4.1.3 of Standard No. 108 allows additional motor vehicle equipment provided that it does not impair the effectiveness of the lamps and reflectors required as original equipment. Effectiveness may be impaired if the device creates a noncompliance in the existing lighting equipment or confusion with the signal sent by another lamp, or functionally interferes with it, or modifies its candlepower to either below the minima or above the maxima permitted by the standard. In addition, a motor vehicle must remain in conformance with Standard No. 108 (and all other safety standards) until its first purchase for purposes other than resale. There is no Federal standard that applies to your devices as aftermarket equipment, but the National Traffic and Motor Vehicle Safety Act prohibits a manufacturer, distributor, dealer, or motor vehicle repair business from knowingly rendering inoperative, in whole or in part, original lighting equipment. Your first device is called a 'foglight converter.' The advertising literature attached states that its function is to turn 'the existing headlights...into foglights....' In our opinion, such a device would create a noncompliance with Standard No. 108 by rendering the headlamp function unavailable when the fog lamp converter is in use. We shall assume that the headlamp would be converted into a fog lamp meeting the specifications of SAE Standard J583 May81 Front Fog Lamps. None of the photometric test points of SAE J583 coincide with those specified for headlamps. Our further concern with this device is that a driver might fail to return to the headlamp mode from the fog lamp mode, and operate the vehicle with reduced frontal lighting. The situation differs with respect to the aftermarket. Under the National Traffic and Motor Vehicle Safety Act, a manufacturer, distributor, dealer, or motor vehicle repair business may not perform modifications that render inoperative, in whole or in part, equipment such as headlamps added pursuant to a Federal safety standard. We believe that the installation of the converter could affect the operability of the headlamp within the meaning of the statutory prohibition. However, we note that the foglight converter is advertised as 'easy for any driver to attach to any vehicle.' As an owner is not a manufacturer, distributor, dealer, or motor vehicle repair business, the owner is not restricted under Federal law from modifications to his vehicle. He is, however, subject to the laws of the States in which his vehicle is registered and operated. We are not conversant with how State lighting laws might affect use of the foglight converter, and you may wish to obtain an opinion from the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, VA 22203. We have several other comments as well. The literature you enclosed depicts the foglight converter attached to what appears to be the European-designed H-4 bulb. Standard No. 108 does not permit headlamps with H-4 light sources to be sold for use on 4-wheeled motor vehicles. In addition, the application of the device where motion is translated from the lamp's exterior to the interior by a linkage in the bulb base would affect compliance with the requirement that the bulb base withstand a pressure differential of l0 psi. Additionally, creating a hole or passage for a linkage has the potential of rendering the headlamp noncompliant with Standard No. 108's requirements for certain environmental tests, such as resistance to dust, corrosion, and humidity. Your second device is a 'headlamp intensity modulator,' adjusting a headlamp beam 'automatically from low to high beam through a middle beam.' According to your literature, when a sensor notes the beams of an oncoming car 500 meters ahead the upper beam gradually passes through a middle beam and diminishes into a lower beam when the vehicles are 150 meters apart. This device is also advertised as capable of owner installation, and without the modification of any vehicle parts. The system appears to operate by a switch. This device directly conflicts with Standard No. 108, and its use would create a noncompliance with it. Headlamps are defined as producing upper and lower beams, and means must be provided for switching between these beams. Use of the device would alter upper and lower beam characteristics from those required by Standard No. 108, and in effect create an infinite number of beams while passing from a conforming upper beam at one extreme to a conforming lower beam at the other. This precludes its use as original equipment. We believe that its aftermarket legality would be limited. Although Federal law would not preclude an owner from installing it, the instructions are sufficiently complex that in our opinion many purchasers would seek help from a 'dealer' or 'motor vehicle repair business,' which could not be legally given. There would also remain the question of legality with State laws. These appear to be innovative devices and we regret that we cannot be more encouraging. Sincerely, Erika Z. Jones Chief Counsel; |
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ID: aiam2886OpenMr. William M. Nettles, Rome Engineering & Manufacturing Co., P.O. Box 707, Claxton, GA 30417; Mr. William M. Nettles Rome Engineering & Manufacturing Co. P.O. Box 707 Claxton GA 30417; Dear Mr. Nettles: This responds to REMCO's September 14, 1978, request to know th Federal braking requirements for an air-braked or pulpwood trailer.; In addition to the requirements of Standard No. 106-74, *Brake Hoses* the only Federal Motor Vehicle Safety Standard regulating the braking of air-braked vehicles is Standard No. 121, *Air Brake Systems*. As you know, Federal Motor Carrier Safety Standards also apply to the use of air-braked vehicles in interstate commerce.; All of the requirements of Standard No. 121 apply to the manufacture o a logging or pulpwood trailer except for the 'no lockup' provision of S5.3.2. Specifically, S5.3.2.2 of the standard states:; >>>S5.3.2.2 When stopped in accordance with S5.3.2, any traile designed exclusively for harvesting logs or pulpwood and constructed with a skeletal frame and no means for attachment of a solid bed, body, or container, and with an arrangement of air control lines and reservoirs designed to minimize damage in off- road operations, need not meet the requirements relating to wheel lockup, but must nevertheless meet the requirements of staying within the 12-foot lane.<<<; There is no exclusion from the parking brake requirements of S5.6 Therefore, a parking brake capability using an energy source unaffected by loss of service brake air pressure is required. The standard specifies performance, not design, and does not require installation of a spring brake design. I have enclosed a copy of a recent proposal that would modify the requirements so that pulpwood trailers would not be required to provide parking brake capability. The reasons for this proposal are listed in the preamble to the notice. This proposal has not been made final.; For clarification, I would add that 'heavy hauler' trailers ar excluded from the entire standard until January 1, 1979. Heavy hauler trailers are defined to include the so-called 'pole trailers' used in logging that have air brake lines that adapt to fore-and-aft extension of the trailer.; I am also enclosing a *Federal Register* notice that explains th effect of a recent court decision on the 'no lockup' requirement for trailers.; Sincerely, Joseph J. Levin, Jr., 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.