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: aiam0730OpenMr. Irving Frank, Frank and Frank, Counselors at Law, 11 Park Place, New York, New York 10007; Mr. Irving Frank Frank and Frank Counselors at Law 11 Park Place New York New York 10007; Dear Mr. Frank: Thank you for your most recent inquiry regarding hood latch systems dated May 26, 1972.; Examination of the 1964 Chevrolet hood latch system reveals that thi system does meet the requirements of Federal Motor Vehicle Safety Standard No. 113, which was effective on January 1, 1969. While, as stated in our correspondence of February 16, 1972, we favor a system in which two complete operations are necessary, a system which employs two latches having a single operation will meet the requirements of the standard. A current review of our Office of Defects Investigation files reveals that no information relative to 1964 Chevrolet hood latching system has been added since our last communication.; Thank you for your inquiry. Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam1822OpenMr. C.P. Boling, Division Manager, Stratoflex, Inc., 1428 Cliff Road, Burnsville, Minnesota 55337; Mr. C.P. Boling Division Manager Stratoflex Inc. 1428 Cliff Road Burnsville Minnesota 55337; Dear Mr. Boling: #This is to confirm the interpretation of the labelin requirements of Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses*, which I gave in a telephone conversation on February 27, 1975. #S5.2.4 of the standard requires each brake hose assembly to be labeled with a band. The band must include, among other information, 'a designation that identifies the manufacturer of the hose assembly...' A brake hose distributer who manufactures assemblies at multiple locations is not required to assign a designation to each location. A single designation will suffice. #Yours truly, Richard B. Dyson, Assistant Chief Counsel; |
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ID: aiam0225OpenMr. Eisuke Niguma, Manager, Export Vehicle Engineering Dept., Toyo Kogyo Company, Ltd., 6047 Puchu-Mechi, Aki-Gun, Hiroshima, Japan; Mr. Eisuke Niguma Manager Export Vehicle Engineering Dept. Toyo Kogyo Company Ltd. 6047 Puchu-Mechi Aki-Gun Hiroshima Japan; Dear Mr. Niguma: This is in reply to your letter of March 2, 1970, to Mr. Clue D Ferguson, Concerning an interpretation of Federal Motor Vehicle Safety Standard No. 111.; In your letter you indicated that the mirror, as mounted in th vehicle, cannot be hit at a 45 degree angle by a 6.5 inch head form because of the geometric arrangement in your automobile. In this case, we would accept the maximum angle possible with the head form. We must point out, however, that the test also includes any other angle from the one you describe down to a 45 degree angle under the horizontal (re: S3.1.2.2 of Standard No. 111).; Please note that this interpretation in intended to provide you wit information regarding an acceptable test procedure. The Traffic Safety Act places responsibility in the manufacturer to determine whether a given item of equipment meets applicable Federal motor vehicle safety standard and he must certify to that effect.; Sincerely, Rodolfo A. Diaz, Acting Associate Director, Motor Vehicl Programs; |
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ID: aiam2218OpenGeorgette A. Sears, Route 2, Box 133c, Keymar, Maryland 21757; Georgette A. Sears Route 2 Box 133c Keymar Maryland 21757; Dear Ms. Sears: This is in response to your letter of January 6, 1976, requestin information as to the Federal Standards and regulations that are applicable to the manufacture of an '18 inch pull type horse/stock trailer combination.'; Manufacturers of trailers of the type you describe must certify tha their product is in compliance with Federal Motor Vehicle Safety Standard No. 108, *Lamps, reflective Devices, and Associated Equipment*, 49 CFR 571.108, and Standard No. 120, *Tire Selections and Rims for Vehicles Other Than Passenger Cars, 40 CFR 571.120. Please note, however, that Standard No. 120 is not effective until August 1, 1976, for the rim marking requirements (S5.2), and September 1, 1976, for the remaining requirements, so trailers manufactured before these times will not have to be certified as being in compliance with Standard No. 120.; The procedure for certification is specified in 49 CFR Part 567, an requires the manufacturer to affix a label to his product certifying that it is in compliance with the requirements of applicable Federal regulations. You should check the trailer that you purchase to make certain there is a certification label. Part 567.4(d) specifies that the certification label for trailers shall be affixed to a location on the forward half of the left side, such that it is easily readable from outside the vehicle without moving any part of the vehicle.; There are no Federal regulations concerning the connection of trailer to trucks or other vehicles. Nevertheless, from a safety stand point it is important that you ascertain the hauling capacity of your truck-trailer system in order to avoid overloading that could create potential safety hazards. You should obtain information from the manufacturer concerning the 'tongue weight' of the trailer when fully loaded, and relate it to the gross axle wight ratings of your towing vehicle, found on its certification label on the door or door post. The trailer manufacturer may also have further recommendations as to the capacity of the vehicle needed to tow one of his trailers safely.; Please contact us if we can be(sic) of any further assistance. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam5027OpenMr. Steven Rovtar General Manager Blazer International Corp. 2960 Hart Drive Franklin Park, IL 60131; Mr. Steven Rovtar General Manager Blazer International Corp. 2960 Hart Drive Franklin Park IL 60131; "Dear Mr. Rovtar: This responds to your letter of May 28, 1992, askin for 'a written ruling' that the product you described 'meets current SAE/DOT guidelines.' The product is intended for the vehicle towing trailer market. Currently, lamps on towed vehicles are activated by splicing into the wiring harness of the towing vehicle. Your product eliminates the need for this type of hard wiring. This product 'utilizes photodetectors to read the output of the towing vehicle's stop and turn signal lamps, and in turn activate the lamps of the towed vehicle.' Photodetectors are embedded in suction cups which are attached to the towing vehicle's stop and turn signal lamps. The device is plugged into the cigarette lighter receptacle of the towing vehicle, and the harness of the towed vehicle is plugged into the device. When the stop lamp or turn signals of the towing vehicle are activated, the photodetectors read the light emitted, and the towed vehicle's lamps are activated via the completed circuit. For purposes of this discussion we shall assume that the device is intended for aftermarket distribution. Further, from your description, it appears to be the type of device that is simple enough to be installed by the vehicle owner. The product itself is not directly regulated by Federal Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices and Associated Equipment, because it is not replacement equipment intended to replace original equipment. Its installation on a vehicle in use by the vehicle's owner is outside the prohibition contained in the National Traffic and Motor Vehicle Safety Act. That prohibition forbids 'manufacturers, distributors, dealers, and motor vehicle repair businesses' from 'rendering inoperative, in whole or in part,' mandated safety equipment such as stop lamps and turn signal lamps. Were the device installed by a person in these categories we would be concerned that the addition of the suction cups would partially obscure the original equipment stop and turn signal lamps and, thus, render them 'partially inoperative' within the meaning of the prohibition. That concern is not lessened by the fact that the device may be installed by a person not covered by the prohibition, such as the owner of the towing vehicle. However, as a practical matter, we realize that the safety impact may be minimal since the presence of the trailer will obscure the lamps on the towing vehicle to which the suction cups are applied. We cannot advise you on whether the product meets SAE requirements. The legality of the use of equipment that is not regulated by NHTSA is determinable under the laws of States where the towing-towed vehicle combinations are operated. We are unable to advise you on these laws, and suggest that you write the American Association of Motor Vehicle Administrators, 4600 Washington Boulevard, Arlington, Va. 22203, for an opinion. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam0675OpenMr. Satoshi Nishibori,Engineering Representative,Nissan Motor Co., Ltd.,Liaison Office in U.S.A.,560 Sylvan Avenue,Englewood Cliffs, New Jersey 07632; Mr. Satoshi Nishibori Engineering Representative Nissan Motor Co. Ltd. Liaison Office in U.S.A. 560 Sylvan Avenue Englewood Cliffs New Jersey 07632; Dear Mr. Nishibori:#This is in reply to your letter if April 5 to Mr Schneider asking for an interpretation of Standard No. 106.#You ask whether it is permissible to use a rubber protector on a brake hose which masks in part the identification marking required by Standard No. 106. SAE Standard J40b, *Automotive Brake Hoses*, incorporated by reference in Standard n0.106, requires hose marking to be permanent in nature. Therefor, use of this protector is permissible, provided that its rubbing effect, if any, does not obliterate in time the required marking. #You have also asked whether you may conduct the whip test with the rubber protector removed. We have no objection to this method of conducting the whip test. Standard No. 106 is silent as to how the test may be conducted. Paragraph S5.7.4 of our proposal to amend Standard No. 106 (Docket No. 1-5, Notice 7, 35 F.R. 5855, March 30, 1971) represents our view that 'protective armor' should be removed for the fatigue test, and you may interpret this as including the rubber protectors also.#Yours truly,Richard B. Dyson,Assistant Chief Counsel; |
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ID: aiam2648OpenMr. Donald E. Rutherford, General Manager, Walker Stainless Equipment Co., New Lisbon, WI 53950; Mr. Donald E. Rutherford General Manager Walker Stainless Equipment Co. New Lisbon WI 53950; Dear Mr. Rutherford: This is in response to your letter of May 11, 1977, and your subsequen conversation with Roger Tilton of my staff, concerning the certification of tank type vehicles. You suggest that a vehicle certification label as specified in 49 CFR Part 567, Certification*, be required to state the gross vehicle weight rating (GVWR) and the gross axle weight rating (GAWR) in pounds.; You apparently have misinterpreted our regulations to require that th GVWR and the GAWR be in something other than pounds where a vehicle is designed to carry liquids. Since the density of liquids is not constant, the weight of customary liquid measurements would depend upon the type of liquid being carried. Since liquid measurements have no precise weight value, designating load ratings by those measurements would not ensure that vehicles would not be overloaded. It has always been the policy of the National Highway Traffic Safety Administration to require that the GAWR and GVWR be stated in pounds.; Title 49 CFR Part 568 prescribes the method by which manufacturers o vehicles manufactured in two or more stages must ensure conformity with the Federal motor vehicle safety standards. A final-stage manufacturer is described as one who 'performs such manufacturing operations on an incomplete vehicle that it becomes a completed vehicle.' Both 'incomplete vehicle' and 'completed vehicle' are defined in Section 568.3 of that regulation.; Section 568.6 of Title 49 requires each final-stage manufacturer t certify that the entire vehicle conforms to all applicable standards, in accordance with Section 567.5. That section requires each final stage manufacturer to affix a label to the vehicle containing, among other things, the GVWR and the GAWR. The GVWR is the value in pounds, which is not less than the sum of the unloaded vehicle weight, rated cargo load, and 150 pounds times the vehicle's designated seating capacity. The GAWR is the value specified by the vehicle manufacturer as the load- carrying capacity of a single axle system, as measured at the tire-ground interfaces.; When a vehicle is manufactured in two or more stages 49 CFR 568. requires the incomplete manufacturer to furnish with the incomplete vehicle a document containing the GVWR and GAWR for the completed vehicle for which the incomplete vehicle is intended. These ratings are generally used by the final-stage manufacturer in certifying the vehicle. If he chooses to exceed the stated GVWR and GAWR ratings he must also certify that the vehicle will continue to meet all applicable motor vehicle safety standards.; It is the cargo load rating that is most relevant to the problem o overloading. The rated cargo load should represent the manufacturer's assessment of the vehicle's cargo-carrying capacity and the maximum load at which the vehicle may be safely operated. A manufacturer must consider the maximum load capacity of the vehicle when it designs its cargo-carrying portion. If this is not done, the rated cargo load, and thus the GVWR, may be meaningless since the vehicle may have a cargo-carrying chamber which, if filled, would cause the vehicle to exceed its stated weight ratings. An illustration of such a situation would be a tanker truck which exceeds its GVWR when the tank is filled with a type of material appropriate for carrying in that cargo area. If the manufacturer could reasonably have anticipated that such cargo would be carried in the tanker, yet rated the vehicle with a GVWR which was less than the vehicle's weight when fully loaded with that cargo, a safety- related defect for which the manufacturer is responsible may be considered to exist.; The NHTSA does not expect manufacturers to be omniscient when it come to the use of the vehicles they produce. It does, however, expect the stated weight ratings to reflect the design of the vehicles and the uses to which they can reasonably be anticipated to be put. Where the manufacturer has reason to know the specific commodity intended to be carried in its vehicles and those vehicles have a totally enclosed cargo area, as with a tanker, the rated cargo load is relatively easy to determine.; In your particular case, your responsibility for any subsequen overloading of the vehicles you manufacture would be determined by the reasonableness of your GVWR's and GAWR's, given the size and configuration of your vehicles and the types of loads which they could reasonably be expected to carry. In the case of flat beds (no enclosed cargo area) a manufacturer would obviously not be able to provide weight ratings sufficiently high to prevent over-loading in all instances. The design of flat beds necessarily permits overloading since the cargo area is unrestricted. Thus if the weight ratings specified appear to have been arrived at by a good faith determination based upon the types of loads the manufacturer anticipates will be carried, its responsibility with regard to weight rating specifications will have been satisfied and no safety-related defect will be attributable to it.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1967OpenMr. James J. Schintz, Managing Director, Pennsylvania Independent Automobile Dealers Association, 229 State Street, Harrisburg, PA 17101; Mr. James J. Schintz Managing Director Pennsylvania Independent Automobile Dealers Association 229 State Street Harrisburg PA 17101; Dear Mr. Schintz: You (sic) letter of April 21, 1975, to the Federal Trade Commissio concerning the validity of an enclosed odometer disclosure form has been forwarded to this office for reply.; The odometer mileage disclosure portion of the East End Motors' sale contract does not satisfy the requirements of the odometer disclosure regulation (49 CFR Part 580). In order to fulfill the requirements, the following information must be added: the vehicle identification number, the vehicle's last plate number, the vehicle transferor's address, the date of the disclosure statement, a reference to the Motor Vehicle Information and Cost Savings Act (Pub. L. 92-513) and the liability it imposes, and a statement, if applicable, that the vehicle's actual mileage differs from the odometer reading for reasons other than odometer calibration error and the actual mileage is unknown.; Failure to include all of the above information on the odomete disclosure statement executed at the time ownership of a vehicle is tranferred (sic) constitutes a violation of section 408 of the Cost Savings Act and may make the violator liable in the amount of $1,500 or treble damages.; For your information I have enclosed copies of the relevant portions o the Act and the disclosure requirements. You will note that S 580 of the regulation contains a sample odometer mileage statement. Incorporation of this format into a sales contract would satisfy the Federal requirements.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam5477OpenMs. Jane L. Dawson Specifications Engineer Thomas Built Buses, Inc. P.O. Box 2450 1408 Courtesy Road High Point, NC 27251; Ms. Jane L. Dawson Specifications Engineer Thomas Built Buses Inc. P.O. Box 2450 1408 Courtesy Road High Point NC 27251; "Dear Ms. Dawson: This responds to your letter of August 8, 1994 regarding the test procedure in Standard No. 210, Seat Belt Assembly Anchorages. I apologize for the delay in our response. Your letter asks whether a seat manufacturer can certify that a passenger seat complies with Standard No. 210 with the seat attached to a 1/2' steel plate test fixture rather than with the seat attached to a typical 14 gauge school bus floor. If the seat manufacturer can certify using 1/2' steel plate, your letter also asks whether the final stage school bus manufacturer must retest using a typical 14 gauge school bus floor to certify that the vehicle complies with Standard No. 210. By way of background information, each of this agency's safety standards specifies the test conditions and procedures that this agency will use to evaluate the performance of the vehicle or equipment being tested for compliance with the particular safety standard. The National Highway Traffic Safety Administration precisely follows each of the specified test procedures and conditions when conducting its compliance testing. However, as your letter recognizes, manufacturers are not required to test their products only in the manner specified in the relevant safety standard, or even to test the product at all, as their basis for certifying that the product complies with all relevant standards. A manufacturer may choose any means of evaluating its products to determine whether the vehicle or equipment will comply with the safety standards when tested by the agency according to the procedures specified in the standard. Section S2 of Standard No. 210 states that the standard applies to 'passenger cars, multipurpose passenger vehicles, trucks, and buses.' The standard does not apply to seats as items of equipment. Therefore, it is the vehicle manufacturer rather than the seat manufacturer that is required to certify compliance with the standard. More specifically, the vehicle manufacturer must certify that the vehicle, with the seat installed, complies with Standard No. 210. Of course, one of the bases for the vehicle manufacturer's certification may be test results and other information provided by the seat manufacturer. If the agency testing shows that an apparent noncompliance exists in a vehicle or item of equipment, the manufacturer is asked to show the basis for its certification that the vehicle or equipment complies with the relevant safety standard or standards. If in fact there is a noncompliance, the manufacturer is subject to civil penalties unless it can establish that it exercised 'reasonable care' in the design and manufacture of the product (through actual testing, computer simulation, engineering analysis, or other means) to ensure compliance, but nevertheless did not have reason to know that the vehicle or item of equipment did not in fact comply with the safety standards (49 U.S.C. 30112(b)(2)(A)). Standard No. 210 includes strength requirements for seat belt anchorages. The test procedure requires the specified force to be applied through body blocks at specified angles and for specified periods of time. As you state in your letter, the procedure allows the agency to replace the seat belt webbing with 'material whose breaking strength is equal to or greater than the breaking strength of the seat belt assembly.' If substitute material is used, the test procedure requires the material to 'duplicate the geometry, at the initiation of the test, of the attachment of the originally installed seat belt assembly.' This provision was included to ensure that the material was strong enough to pass the load to the anchorage during the test and, therefore, that the strength of the test anchorage rather than the seat belt was tested. Your letter asks whether a seat manufacturer may base its certification on a test performed with the seat attached to a 1/2' steel plate test fixture rather than with the seat attached to a typical 14 gauge school bus floor. This, in effect, is a request for a determination of whether a vehicle manufacturer's reliance on the fact that the seat belt anchorages did not fail when a 1/2' steel plate test fixture is used would constitute 'reasonable care' in assuring that the completed vehicle complied with the standard. This agency has long said that it is unable to judge what efforts would constitute 'reasonable care' in advance of the actual circumstances in which a noncompliance occurs. What constitutes 'reasonable care' in a particular case depends on all relevant facts, including such things as the limitations of current technology, the availability of test equipment, the size of the manufacturer, and, above all, the diligence exercised by the manufacturer. However, I would like to say that attachment of a seat or anchorage to stronger material (whether 1/2' steel plate or some other material) than the material used in the construction of the vehicle in which it will actually be installed would not appear to provide a manufacturer with information on whether or not the anchorage, when attached to the vehicle structure, will withstand the specified loads. You should also note that, while the exercise of 'reasonable care' may relieve a manufacturer of liability for civil penalties in connection with the manufacture and sale of noncomplying vehicles, it does not relieve a manufacturer of the responsibility to notify purchasers of the noncompliance and remedy the noncompliance without charge to the purchasers, if either the manufacturer or this agency determines that vehicles do not comply with all applicable safety standards. I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, Philip R. Recht Chief Counsel"; |
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ID: aiam3409OpenMr. Jim Tydings, Thomas Built Buses, Inc., 1408 Courtesy Road, P. O. Box 2450, High Point, NC 27261; Mr. Jim Tydings Thomas Built Buses Inc. 1408 Courtesy Road P. O. Box 2450 High Point NC 27261; Dear Mr. Tydings: This responds to your April 14, 1981, letter asking whether a fold-u seat that you plan to build in a school bus would comply with the Federal motor vehicle safety standards.; You state in your letter that the seat would comply with all of th requirements of Standard No. 222, *School Bus Passenger Seating and Crash Protection*. If the seat complies with that standard and if its location in the bus will not interfere with the requirements applicable to emergency exits, then the seat should comply with all of the Federal safety standards.; 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.