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: aiam1986OpenMr. Warren M. Heath, Commander, Engineering Section, Department of California Highway Patrol, P. O. Box 898, Sacramento, CA 95804; Mr. Warren M. Heath Commander Engineering Section Department of California Highway Patrol P. O. Box 898 Sacramento CA 95804; Dear Mr. Heath: This is in response to your letter dated April 2, 1975, in which yo ask several questions regarding test procedures for Federal Motor Vehicle Safety Standard No. 218, *Motorcycle Helmets*.; We are not aware of any inconsistency between Standard No. 218 and th compliance procedures that our Office of Standards Enforcement has developed in connection with it. If there were any, of course, the standard would be controlling. The standard specifies a drop height, and a 'guided free fall' from that height. We consider 'free fall' to be an objective and unambiguous physical term, meaning a movement in response to the force of gravity unimpeded by any resistance except air resistance. The requirement the equipment must be capable of meeting, therefore, refers to a fall in which the guiding method imparts no significant resistance, *i.e.*, it does not affect the results. Although in practice a perfectly frictionless guided fall may be unachievable, a manufacturer must ensure that his product would meet the requirement no matter how small the friction. An analogy is the fixed collision barrier defined in S 49 CFR 571.3, which requires a vehicle to meet a barrier crash test requirement using a barrier that absorbs no significant part of the vehicle's energy. Helmet manufacturers must assume, therefore, that the government will test their products using test fixtures that impart as little friction to the fall as possible. We therefore consider the issue of what systems were 'in general use at the time ANS Z90.1 and FMVSS 218 were written' to be irrelevant to the question of compliance.; This discussion should answer your first two questions. We do no accord any legal status to 'old' test procedures as opposed to 'new' ones. With regard to the question about correlation studies, we have not conducted any and I know of no plans to do so. Finally, Standard 218 presently covers only size C helmets because drawings and headforms for the other sizes are not yet available. Therefore, no formal compliance testing can be done on other sizes of helmets. We hope soon to publish drawings and make available models of size A, B and D headforms, at which time a date will be set for extending Standard 218 to these other sizes. Your continuing interest in motorcycle safety is greatly appreciated.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam0694OpenMr. L. D. Brown, Manager Truck Tank Division, Renick & Mahoney Division, Garsite Products, Inc., 10 E. Grand Boulevard, Deer Park, L.I., NY 11729; Mr. L. D. Brown Manager Truck Tank Division Renick & Mahoney Division Garsite Products Inc. 10 E. Grand Boulevard Deer Park L.I. NY 11729; Dear Mr. Brown: We have received the pictures of the airport refuelers which yo manufacture. While these pictures were received after we had mailed our letter of April 17, 1972, to you, they confirm the opinion expressed in that letter that these vehicles are motor vehicles under the National Traffic and Motor Vehicle Safety Act, and are considered to be trucks under the Federal motor vehicle safety standards.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1656OpenMr. Gorou Utsunomiya, Liaison Engineer in U.S.A., Toyo Kogyo Detroit Office, 3841 Mystic Valley Drive, Bloomfield Hills, MI 48013; Mr. Gorou Utsunomiya Liaison Engineer in U.S.A. Toyo Kogyo Detroit Office 3841 Mystic Valley Drive Bloomfield Hills MI 48013; Dear Mr. Utsunomiya: This is in acknowledgment of your Defect Information Report, i accordance with the defect reporting regulations, Part 573.; The Defect Information Report involves: 8,422 - Mazda Rotary picku trucks, concerning deformed exhaust pipe protector which may cause tall dry grass to smolder if the vehicle is parked and the grass is in contact with the pipe protector.; The following National Highway Traffic Safety Administratio identification number has been assigned to the campaign *74-0193*. 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 states that a defect exists 'in the exhaust system of the 1974 Mazda. . . .' This does not conform to Part 577.4(b) since, where vehicles are involved, the defect should be described in this sentence as existing in the vehicle. The reference in the regulation to 'item of motor vehicle equipment' only applies to equipment campaigns. Since this discrepancy in your notification letter does not appear to be serious, mailing of a revised letter will not be required.; Sincerely, Andrew G. Detrick, Acting Director, Office of Defect Investigation, Motor Vehicle Programs; |
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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: aiam4028OpenMr. D. F. Landers, President, The London Coach Co., Inc., 25 Eldredge, P.O. Box 1183, Mt. Clemens, MI 48043; Mr. D. F. Landers President The London Coach Co. Inc. 25 Eldredge P.O. Box 1183 Mt. Clemens MI 48043; Dear Mr. Landers: This responds to your June 6, 1985 letter concerning Federal Moto Vehicle Safety Standard No. 207, *Seating Systems*. We apologize for the delay in our response. You asked whether your vehicle's 'folding flip seats' are required by section S4.3 of the standard to be equipped with a restraining device. As discussed below, the answer is no.; By the (sic) way of background information, this agency does no provide approvals of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its vehicles or equipment comply with applicable safety standards. The following represents our opinion based on the facts provided in your letter.; Section S4.3 of Standard No. 207 states: >>>...a hinged or folding *occupant seat* or occupant seat back shal be equipped with a self-locking device for restraining the hinged or folding seat or seat back and control for releasing that restraining device. (Emphasis added.)<<<; The term 'occupant seat' is defined in section S3 of Standard No. 20 as, 'a seat that provides at least one designated seating position.' The term 'designated seating position' is defined in 49 CFR Part 571.3(b) as:; >>>any plan view location capable of accommodating a person at least a large as a 5th percentile adult female, if the overall seat configuration and design is such that the position is likely to be used as a seating position while the vehicle is in motion, *except for the auxiliary seating accommodations such as temporary or folding jump seats.... (Emphasis added.)<<<; The issue raised by your letter is whether your folding flip seats ar seats that provide a designated seating position, within the definition of 49 CFR Part 571.3(b). If a seat provides a designated seating position, it is an occupant seat under Standard No. 207 and subject to section S4.3's requirement for a restraining device.; It is our opinion that your folding flip seats are 'auxiliary seatin accomodations (sic)' and therefore not subject to the Standard No. 207's requirement for a restraining device. This conclusion is based on the information shown on your brochure. The brochure shows that each of the flip seats normally remains folded up. When they are temporarily needed to accommodate additional passengers, they can be folded down to form a seating surface.; While folding jump seats are not subject to a number of safet requirements, including those of Standards No. 207 and 208, *Occupant Crash Protection*, we encourage you to ensure that the seats provide safe performance when in use. In particular, we would encourage you to provide safety belts for these seats to ensure that their occupants will have adequate crash protection.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3217OpenThomas G. Richards, SAFECO, SAFECO Plaza, Seattle, WA 98185; Thomas G. Richards SAFECO SAFECO Plaza Seattle WA 98185; Dear Mr. Richards: This is in response to your letter of February 29, 1980, requestin information on the Federal odometer disclosure requirements. The question you raised is whether odometer disclosure statements have to be executed and retained when the vehicle involved in a purchase and sale is a salvage vehicle.; If the vehicle is repairable and will subsequently be used as a moto vehicle, disclosure must be made. However, if the vehicle is so badly damaged that it cannot be returned to the road, it will have ceased to be a motor vehicle for purposes of the odometer regulations (49 CFR Part 580). Disclosure would therefore not be required. You must keep in mind that this is a judgement that will have to be made in good faith by the seller of the vehicle.; Sincerely, John Womack, Assistant Chief Counsel |
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ID: aiam1380OpenHonorable Charles H. Percy, United States Senate, Washington, DC 20015; Honorable Charles H. Percy United States Senate Washington DC 20015; Dear Senator Percy: This is in reply to your communication of January 3, 1974, forwardin to us correspondence dated November 29, 1973, from Mr. Bruce Motyka of Des Plaines. Mr. Motyka requests information regarding laws relating to pickup truck and camper weight limits, laws or studies relating to the sale of trucks exceeding GVW (Gross Vehicle Weight) rate minimums, and regulations or studies regarding maximum weights for tires.; The NHTSA has issued regulations relating to the installation o campers onto pickup trucks. Motor Vehicle Safety Standard No. 126 'Truck camper loading' (49 CFR S 571.126) requires each camper to bear a permanent label containing information on its maximum loaded weight. The standard also requires each camper to be furnished with an owner's manual that contains information on total camper weight, the selection of an appropriate pickup truck, appropriate methods of camper loading, how to determine the camper's center of gravity and where it should be placed in the truck cargo area. A companion 'Consumer Information' regulation, 'Truck camper loading' (49 CFR S 575.103) requires that written information be provided at the sale of each truck capable of being equipped with a slide-in camper that deals with the correct installation of a slide-in camper in that vehicle. This information is also required to be available in dealers' showrooms for retention by prospective purchasers of such trucks.; Other NHTSA regulations (49 CFR Part 567, 'Certification') requir every motor vehicle, including pickup trucks, to be labeled, usually on the driver's door or door jam, with its gross vehicle weight rating, and the gross axle weight rating for each axle. Each of these ratings is intended to be based on the weight of a fully loaded vehicle, as determined by the vehicle's manufacturer. While it is possible for manufacturers proposed course of action appears to have the aim of generating dissatisfaction with Federal tire regulations among dealers and distributors, and could, by lessening cooperation at the retail level, interfere with your client's ability to fulfill its obligations under the regulations.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam4478OpenMr. Al Cunningham Chief Engineer Wesbar Corporation P.O. Box 577 West Bend, WI 53095; Mr. Al Cunningham Chief Engineer Wesbar Corporation P.O. Box 577 West Bend WI 53095; Dear Mr. Cunningham: This is in reply to your letter of September l4 l988, attaching two lamps, and asking for an interpretation of Motor Vehicle Safety Standard No. 108 with respect to each. Specifically, you wish clarifications of SAE J588e, 'the definition...2.2 'Multiple Compartment Lamp' and the term used in 3.1 'Single Compartment Lamp''. SAE Standard J588e Turn Signal Lamps, incorporated by reference in Standard No. 108, defines a multiple compartment lamp as 'a device which gives its indication by two or more separately lighted areas which are joined by one or more common parts such as a housing or lens.' The term 'single compartment lamp' is not used in section 3.1, though the term 'single compartment photometric requirements' is used in referencing the values for one 'lighted section' given in Table 1 of J588e. For purposes of this discussion we shall define a 'single compartment lamp' as one that gives its indication by one lighted area. You have described your first lamp as 'a housing with back and four sides containing a two filament bulb with a single lens covering face of housing.' The lamp photometrically complies to the basic requirements of a Class A tail, stop and turn signal lamp. You have asked if this lamp is a single compartment lamp. The answer is yes, your model 3504 Exp. contains a single light source and has a single lighted area. Your second lamp is described as 'a housing with a back, two sides and one end, containing one; 57 bulb and one 1157 (2 filament) bulb. This housing is closed with two red lenses, on on the end and one on the face with an additional clear lens on bottom side. This lamp also complies to all standards of a class A tail, stop and turn lamp plus side marker clearance, license plate illuminator and class a reflex reflector side and rear'. You ask if this also is a single compartment lamp. The answer is yes. The term 'separately lighted area' in the definition of a multiple compartment lamp is understood to mean an area that is illuminated by a separate light source. In your model 3504 the turn signal light is provided by the; 1157 bulb alone, and not in tandem with the 57 bulb. I hope that this provides the clarification you seek. We ar returning your lamps under separate cover. Sincerely, Erika Z. Jones Chief Counsel; |
Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.