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: aiam2979OpenMr. C. J. Newman, Vice President, Engineering, The Grote Manufacturing Company, State Route 7, P.O. Box 766, Madison, IN 47250; Mr. C. J. Newman Vice President Engineering The Grote Manufacturing Company State Route 7 P.O. Box 766 Madison IN 47250; Dear Mr. Newman: This is in reply to your letter of February 15, 1979, asking for a interpretation of S4.3.1.1.1 of Motor Vehicle Safety Standard No. 108.; You have informed us that dimensional changes in refrigeration units o the front of commercial trailers mean that clearance lamps are no longer visible at 45 degrees inboard if they are mounted as they have been in the past. You have proposed three alternate solutions to the problem.; S4.3.1.1.1 provides in pertinent part that 'clearance lamps may b mounted at a location other than on the front and rear if necessary to indicate the overall width of the vehicle...and at such a location they need not be visible at 45 degrees inboard.' Your first proposed solution is that 'The lamps could be mounted on the front of the vehicle as normal and the 45 degree inboard visibility requirements waived in accordance with S4.3.1.1.1.'; We believe that this is preferable to your other suggested solution that utilize angle-mounted combination lamps. Standard No. 108 appears to prescribe alternate requirements for location and visibility of clearance lamps--preferable on the front and visible throughout 45 degree angles, but if not, elsewhere than the front and where they need not be visible through the 45 degree angles. Your first proposed solution comprises elements of each of Standard No. 108's alternatives, and while it is not expressly permitted by Standard No. 108, it does not appear to violate it.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam0944OpenMr. Tatsuo Kato, Engineering Representative, Nissan Motor Company, Ltd., 560 Sylvan Avenue, Englewood Cliffs, New Jersey 07632; Mr. Tatsuo Kato Engineering Representative Nissan Motor Company Ltd. 560 Sylvan Avenue Englewood Cliffs New Jersey 07632; Dear Mr. Kato: This is in response to your letter of December 28, 1972, concerning th application of Standard 124, 'Accelerator Control Systems', to a particular Nissan design.; Prior to our receipt of your letter, Nissan representatives met wit representatives from our Office of Operating Systems. At this meeting, Nissan representatives explained their questions and left a carburetor with NHTSA staff engineers as an aid to understanding the matters in question. Your company's concern is with the failure of a spring, designated as spring C, which in the event of severance or disconnection, would allow the secondary throttle plate to stay open slightly and thereby increase normal idle speed by approximately 300 rpm. Since spring C only returns the secondary throttle plate to idle position, spring C could not be considered as a return energy source under S5.1 of the standard, and, the failure of Spring C would not fall under the same requirements as a failure of either A or B. Further, spring C is not a part of the 'driver-operated accelerator control system' but is part of the 'fuel metering device', and, as such, severance or disconnection of spring C would not fall within the purview of S5.2.; You also presented a drawing of an accelerator control system and aske which point of severance or disconnection along the system is appropriate when conducting tests for the standard. Since the standard requires that the return to idle time must be met when 'any one component of the accelerator control system disconnected or severed', you ask if this would apply to bolts holding together mounting brackets, or just those components which move in relation to foot-pedal actuation. The components intended to be tested under severance or disconnection in the standard are those which are strictly defined in S4.1 'Driver-operated accelerator control system'. Accordingly, those components which move in accomplishing the regulation of engine speed would be tested, while fixed parts such as brackets and bolts depicted by the drawing you submitted would not be tested.; The carburetor your representatives left with us is being returned t Nissan under Separate cover. Your letter and the attached photographs of the carburetor with labeled springs will be placed in Docket 69-20.; Sincerely, E.T. Driver, Director, Office of Operating Systems |
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ID: aiam4454OpenRoderick A. Boutin, Esq. 960 One Main Place 101 S.W. Main Street Portland, Oregon 97204; Roderick A. Boutin Esq. 960 One Main Place 101 S.W. Main Street Portland Oregon 97204; "Dear Mr. Boutin: This responds to your letter to Steve Kratzke, of m staff, asking for a statement of the legal requirements that would apply to a new product one of your clients plans to introduce. You provided no description of this product in your letter, other than to state that it 'alters the alignment of an upper torso restraint to the increased comfort of the wearer.' You also stated in the letter that the product would initially be sold as an aftermarket accessory to be installed by consumers, but that it might eventually be sold to manufacturers to be installed in new vehicles. In a telephone conversation with Mr. Kratzke on November 20, 1987, you stated that this product would clip the shoulder belt to the lap belt near the middle of wearer's abdomen. Although we understand your concern that safety belts be comfortable for the wearer, we have significant reservations about this product. I hope the following discussion explains those reservations and the effect of our regulations on the product. The National Traffic and Motor Vehicle Safety Act (the Safety Act, 15 U.S.C. 1381 et seq.) gives this agency the authority to issue safety standards applicable to new motor vehicles and certain new items of motor vehicle equipment. We have exercised this authority to establish Standards No. 208, Occupant Crash Protection, and No. 210, Seat Belt Assembly Anchorages (49 CFR /571.208 and /571.210, respectively), applicable to new vehicles, and to establish Standard No. 209, Seat Belt Assemblies (49 CFR /571.209), applicable to new seat belt assemblies. It does not appear that any of these regulations would apply to your client's product, however. Additionally, you are not required to get some 'approval' from this agency before selling the product. NHTSA has no authority to approve or endorse motor vehicles or motor vehicle equipment. Instead, the Safety Act establishes a 'self-certification' process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. The agency periodically tests vehicles and items of equipment to ensure their compliance with the safety standards, and also investigates other alleged safety-related defects. While none of our safety standards appear to apply directly to your client's product, there are several statutory responsibilities your client must assume when it manufactures the product. All manufacturers of motor vehicle equipment are subject to the requirements in sections 151-159 of the Safety Act (15 U.S.C. 1411-1419) concerning the recall and remedy of products with defects related to motor vehicle safety. The agency does not determine the existence of defects except in the context of a defect proceeding, so we are unable to say at this time whether this product might or might not contain such a defect. However, this product raises a host of safety concerns that we would advise your client to carefully consider. Section S7.1.2 of Standard No. 208 specifies that the intersection of the shoulder belt with the lap belt shall be at least 6 inches from the front vertical centerline of a 50th percentile adult male occupant with the seat in its rearmost and lowest adjustable position. Attaching the shoulder belt to the lap belt in the middle of the abdomen, instead of joining the belts at the latchplate off to the side of the occupant, would cause the belts to no longer comply with this requirement of Standard No. 208 and would significantly alter the distribution of crash forces on the occupant. The lap and shoulder belts as currently installed distribute the crash forces over the skeletal structure of the occupant. The proposed device to attach the shoulder belt to the lap belt near the middle of the abdomen would significantly increase the loading on the occupant's abdomen, a part of the body that cannot withstand the same loading levels as the skeletal structure. This increase in abdominal loading could have serious safety implications for the wearer of the belt. Additionally, by realigning the shoulder belt, the device would seem to increase the likelihood that a wearer of the belt would twist toward the middle of the vehicle, so that the person could be partially or completely unrestrained by the shoulder belt. Further, it is possible that the device attaching the shoulder belt to the lap belt near the middle of the wearer's abdomen could not withstand the forces of the crash, and would allow the shoulder belt to detach. Since the shoulder belt could have an excessive amount of slack in it, the occupant's head would be likely to contact the vehicle interior. All of these possibilities raise serious safety concerns with respect to this proposed device. In addition, use of this product could be affected by section 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)). That section prohibits commercial businesses from knowingly tampering with devices or elements of design installed in a motor vehicle in compliance with a Federal motor vehicle safety standard. Shoulder belts are installed in the front seating positions of most vehicles with a gross vehicle weight rating of 10,000 pounds or less in compliance with Standard No. 208. If the installation of this product causes the shoulder belts to offer less effective occupant protection, commercial establishments could not legally install the product on customers' vehicles. The prohibition in section 108(a)(2)(A) does not apply to individual vehicle owners who may install or remove any items on safety belt systems regardless of the effect on compliance with Standard No. 208. However, our policy is to encourage consumers not to tamper with the safety belts installed in their vehicles. Installation of this product by any person would be inconsistent with that policy. If you have any further questions, please contact Mr. Kratzke at this address or by telephone at (202) 366-2992. Sincerely, Erika Z. Jones Chief Counsel"; |
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ID: aiam3391OpenMs. Mary Donovan, 51 Earl Street, Springfield, MA 01108; Ms. Mary Donovan 51 Earl Street Springfield MA 01108; Dear Ms. Donovan: This is in response to your letter of January 28, 1981 concerning th problems you've experienced with the odometer in your car.; The Motor Vehicle Inforamtion and Cost Savings Act (15 U.S.C. S198 *et. seq*) prohibits the disconnection, resetting, or alteration of a vehicle's odometer with the intent to change the number of miles indicated therein. The law also requires that a written disclosure of the mileage registered on an odometer be provided by the seller to the purchaser at the time the ownership of a vehicle is transferred. If the odometer mileage is incorrect, the Act requires a statement to that effect to also be furnished in written form to the buyer.; This disclosure can be made on the state's certificate of title if th certificate of title contains essentially the same information found in the Federal odometer disclosure statement. *Odometer Disclosure Requirements* (49 CFR Part 580.4(f)(1). The odometer statement on the Massachusetts certificate of title is consistent with the requirements of the Federal law and can be substituted for the Federal form. All of the other provisions of the Federal odometer laws are applicable in Massachusetts.; Accordingly, if the odometer is incapable of registering the *sam mileage after its repair or replacement, a notice in writing should be attached to the left door frame of the vehicle by the owner specifying the date the odometer was repaired or replaced and the mileage at that time. However, since you did not indicate the odometer reading was *reset*, this provision does not appear to be applicable to your case.; Sincerely, Shirley Ransom, Trial Attorney |
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ID: aiam1206OpenMr. Arthur E. Allen, President, SCARTI, 2042 S. Sepulveda, Los Angeles, CA 90025; Mr. Arthur E. Allen President SCARTI 2042 S. Sepulveda Los Angeles CA 90025; Dear Mr. Allen: This is in reply to your letter of July 19, 1973, to the Administrator. The exemption provided vehicles with a curb weight of 1,000 pounds o less will cease to exist as of January 1, 1974, and lightweight vehicles manufactured on or after that date will be required to meet all Federal motor vehicle safety standards applicable to their vehicle category, *e.g.* passenger cars.; Under the circumstances you indicate, you would be the final-stag manufacturer of a vehicle manufactured in two or more stages, under 49 CFR Parts 567 and 568 of our regulations. We refer you specifically to sections 567.5 and 568.6 of those regulations.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4004OpenMr. Larry J. Black, Motorists Insurance Companies, 471 East Broad Street, Columbus, OH 43215-3861; Mr. Larry J. Black Motorists Insurance Companies 471 East Broad Street Columbus OH 43215-3861; Dear Mr. Black: This is in response to your letter of August 2, 1985, in which yo asked for a determination from the Agency concerning your company's use of Motor Vehicle titles to fulfill Federal odometer disclosure requirements.; You proposed photocopying the title, which has the odometer disclosur on the back, and retaining the copy for a four year period. The applicable Federal regulation, 49 CFR Part 580, provides that State titles or other ownership documents may be used as substitutes for the Federal odometer disclosure statement if they contain essentially the same information required by paragraphs (a),(b),(c) and (e) of section 580.4.; I have reviewed State titles contained within *The Original Peck' Title Book*. This book, published by Stephens - Peck, Inc., is revised periodically and supplemented as changes in State title laws occur. To date, the title documents of the following States may be used in lieu of a separate odometer disclosure form:; >>>Delaware, Maryland, Michigan, Minnesota, Nebraska, North Carolina North Dakota, Ohio, Pennsylvania, South Dakota, Virginia, Wyoming<<<; I must qualify this list, however. With regard to the Michigan an Minnesota titles, it is only the initial assignment which meets all disclosure requirements. Reassignments by a licensed dealer do not, as there is no space for the purchaser's signature. Furthermore, when vehicles are transferred in Delaware, Maryland, Nebraska, North Dakota, Ohio, Pennsylvania, Wyoming or Virginia, the title can be used in lieu of a separate odometer disclosure statement only if the purchaser completes all information concerning the application for title. Unless the application is completed, the title will not include the buyer's signature. The National Highway Traffic Safety Administration considers this signature to be essential, because it is an acknowledgement that the purchaser is aware of the mileage. The signature prevents the purchaser from later alleging that he was not informed of the mileage or that the mileage was different from that appearing on the title.; If you have any additional questions, do not hesitate to contact Judit Kaleta of my staff at (202) 426-1834.; Sincerely, Kathleen DeMeter, Assistant Chief Counsel for General Law |
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ID: aiam0047OpenMiss Dorothy P. Ferguson, Managing Editor, Fire Engineering, The Reuben H. Donnelley Corporation, 466 Lexington Avenue, New York, NY 10017; Miss Dorothy P. Ferguson Managing Editor Fire Engineering The Reuben H. Donnelley Corporation 466 Lexington Avenue New York NY 10017; Dear Miss Ferguson: Thank you for your letter of February 27, 1968, to the Federal Highwa Safety Bureau, in regard to obtaining information about *Safety Standard No. 209,* seat belt assemblies.; Regarding your question on seat belt usage as pertaining to a fir apparatus vehicle, seat belts are not required to be installed, however, if seat belts are installed on a truck by a manufacturer, the seat belt assemblies, as equipment, must meet the requirements of Standard 209, specifically, requirements of the Department of Commerce, National Bureau of Standards for seat belts for use in motor vehicles (15 CFR 9)(30 FR 8432).; Thank you again for your interest in the safety program. Sincerely, Joseph R. O'Gorman, Acting Director, Office of Performanc Analysis, Motor Vehicle Safety Performance Service; |
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ID: aiam2580OpenMr. John W. Kourik, 1135 Olivaire Lane, St. Louis, Missouri 63132; Mr. John W. Kourik 1135 Olivaire Lane St. Louis Missouri 63132; Dear Mr. Kourik: This responds to your March 24, 1977, letter asking whether Standar No. 107, *Reflecting Surfaces*, incorporates by reference the SAE Recommended Practice J941 as of November 1965 or as amended through February 1975.; As you note in your letter, Part 571.5 (49 CFR 571.5) of ou regulations establishes guidelines for materials incorporated by reference. That section states that materials which are subject to change, such as the SAE Recommended Practice you mention, are incorporated by reference as they are in effect on the date of adoption of the standard unless otherwise specified. Standard No. 107 refers specifically to the 1965 version of the SAE Recommended Practice. Subsequent amendments of that document by the SAE Technical Committee have no effect upon the Federal Standard.; Thank you for your offer of assistance in amending Standard No. 107 t reflect more recent changes in the SAE Recommended Practice. We Will keep your offer in mind should we determine that a change in the standard is warranted.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam5245OpenMr. Thomas Dougherty C.A.P.S. Inc. 1712 Rudder Industrial Park Drive Fenton, MO 63026; Mr. Thomas Dougherty C.A.P.S. Inc. 1712 Rudder Industrial Park Drive Fenton MO 63026; "Dear Mr. Dougherty: This responds to your letter asking about how thi agency's regulations might apply to your product, the 'E.A.R.S.' system. You state that your product contains an LED light and an 82 decibel tone and serves to alert hearing impaired drivers of approaching emergency vehicles. You further state that the part of the system that alerts drivers plugs into the cigarette lighter, while a microphone is placed outside the vehicle. (You did not explain how or where the microphone is placed or whether a hole is drilled through the windshield.) I am pleased to have this opportunity to explain our regulations. I am also enclosing a copy of a fact sheet titled 'Information for New Manufacturers of Motor Vehicles and Motor Vehicle Equipment.' By way of background information, the National Highway Traffic Safety Administration (NHTSA) is authorized to issue Federal motor vehicle safety standards (FMVSS's) for new motor vehicles and new items of motor vehicle equipment. Section 102(4) of the National Traffic and Motor Vehicle Safety Act (the 'Safety Act') defines, in relevant part, the term 'motor vehicle equipment' as: any system, part, or component of a motor vehicle as originally manufactured or any similar part or component manufactured or sold for replacement or improvement of such system, part, or component or as any accessory, or addition to the motor vehicle ... (emphasis added). In determining whether an item of equipment is considered an accessory, NHTSA applies two criteria. The first criterion is whether a substantial portion of the expected use of the item is related to the operation or maintenance of motor vehicles. We determine a product's expected use by considering product advertising, product labeling, and the type of store that retails the product, as well as available information about the actual use of the product. The second criterion is whether the product is intended to be used principally by ordinary users of motor vehicles. If the product satisfies both criteria, then the product is considered to be an 'accessory' and thus is subject to the provisions of the Safety Act. Applying these criteria to the E.A.R.S. system, it appears that this product would be an accessory and thus an item of motor vehicle equipment under the Safety Act. Based on our understanding of the product, it appears that the entire portion of the expected use of the E.A.R.S system relates to motor vehicle operation. That is, the system is intended to alert the vehicle driver about an oncoming emergency vehicle. Also, it appears that the product would typically be used by ordinary users of motor vehicles, in particular, hearing impaired drivers. While it appears that the E.A.R.S. system is an item of motor vehicle equipment, NHTSA has not issued any standards for such a device. Nevertheless, there are other Federal laws that indirectly affect the manufacture and sale of your product. You as the product's manufacturer are subject to the requirements in sections 151-159 of the Safety Act concerning the recall and remedy of products with defects related to motor vehicle safety. In the event that the manufacturer or NHTSA determines that the product contains a safety related defect, the manufacturer would be responsible for notifying purchasers of the defective equipment and remedying the problem free of charge. A commercial business that installs the E.A.R.S. system would also be subject to provisions of the Safety Act that affect modifications of new or used vehicles. Section 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)) provides that: No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle ... in compliance with an applicable Federal motor vehicle safety standard. This means that a manufacturer, distributor, dealer, or motor vehicle repair business must not install your device if the system renders inoperative the vehicle's compliance with the FMVSS's. For instance, compliance with Standard No. 205 might be degraded if it were necessary to drill a hole through the windshield. Any violation of this 'render inoperative' prohibition would subject the violator to a potential civil penalty of up to $1,000 for each violation. Please note also that the render inoperative prohibition does not apply to modifications that vehicle owners make to their own vehicles. Thus, Federal law would not apply in situations where individual vehicle owners install the E.A.R.S. system in their own vehicles, even if the installation were to result in the vehicle no longer complying with the safety standards. However, NHTSA encourages vehicle owners not to degrade any safety device or system installed in their vehicles. In addition, individual States have the authority to regulate modifications that individual vehicle owners may make to their vehicles, so you might wish to consult State regulations to see whether your device would be permitted. I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosure"; |
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ID: aiam0417OpenMr. Hal H. Newell, Manager-Government Relations, Eaton Corporation, Government Relations Office, Suite 838 Pennsylvania Building, 425-13th Street, N.W., Washington, DC 20004; Mr. Hal H. Newell Manager-Government Relations Eaton Corporation Government Relations Office Suite 838 Pennsylvania Building 425-13th Street N.W. Washington DC 20004; Dear Mr. Newell:#In your letter of July 22 you ask if Standard No. 101 as amended, requires the illumination of controls on after market auto and truck air conditioners.#Standard No. 101 does not apply to after market equipment items. It requires that vehicles meet control location, identification, and illumination requirements at the time of sale to the first purchaser for purposes other than resale, and places compliance responsibility upon the vehicle's manufacturer, distributor, and dealer.#Sincerely, Lawrence R. Schneider, Acting 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.