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: aiam0963OpenMr. Charles J. Simerlein, Engineering Liaison Manager, Volvo of America Corporation, Rockleigh, NJ 07646; Mr. Charles J. Simerlein Engineering Liaison Manager Volvo of America Corporation Rockleigh NJ 07646; Dear Mr. Simerlein: This is in reply to your letter of December 28, 1972, concerning th lateral positioning of the test pendulum under Standard 215.; The provision of paragraph S7.1.4 that the pendulum is to be inboard o the corner test positions appears to be correctly depicted in your drawing. Position 3 of the pendulum would be the most outboard position at which NHTSA could conduct a longitudinal impact test under S7.1.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4023OpenMr. Jean Paul Turgeon, Security and Legality Manager, Prevost Car Incorporated, Ste-Claire, Quebec, Canada, GOR 2VO; Mr. Jean Paul Turgeon Security and Legality Manager Prevost Car Incorporated Ste-Claire Quebec Canada GOR 2VO; Dear Mr. Turgeon: This responds to your August 12, 1985 letter to Administrator Stee regarding Federal Motor Vehicle Safety Standard (FMVSS) No. 217, *Bus Window Retention and Release*. Your letter has been referred to my office for reply. We apologize for the delay in our response.; Your questions concerned paragraph S5.3.2, which applies to buses othe than school buses. You asked whether the requirements of paragraph S5.3.2 may be met by: (1) release mechanisms located within the area defined by Figure 1 of the standard that are operated by a rotary or straight type of motion, and by (2) release mechanisms located within the area defined by Figure 2 operated by a straight type of motion.; Your understanding is correct. Rotary type motions may be used fo release mechanisms located in regions of low force application as shown in Figures 1 or 3 of the standard. Straight motions may be used for release mechanisms located in regions of low force application shown in Figures 1 and 3, and in regions of high force application shown in Figures 2 and 3.; Your second question asked whether the force application for a releas mechanism operated by a rotary motion is limited by S5.3.2 to 20 pounds. The answer is yes. Release mechanisms may be operated by a rotary type of motion in locations shown in Figure 1 or Figure 3 for low-force application. The magnitude of the force application must not be more than 20 pounds.; The second part of your question stated, 'In case of straight motion the force application is limited to 60 pounds.' This statement is not entirely correct. If the release mechanism is located in the low-force application areas shown in Figures 1 or 3, S5.3.2 specifies that the force applications must not exceed 20 pounds.; Your third question concerned the type of motions that are required t operate the release mechanisms. The first part of this question asked whether a rotary motion 'implies a rotation of the hand and twisting of the arm as for turning a door knob.' Standard No. 217 does not restrict you from using the particular type of rotary motion you described, provided that all other requirements of the standard can be met.; The second part of this question asked whether a straight motion mean 'a straight pull perpendicular to the emergency exit surface.' Paragraph S5.3.2(b) describes the direction of a straight high-force application as 'perpendicular to the undisturbed exit surface.' Your understanding, therefore, appears to be in accordance with S5.3.2.; The final part of this question asked whether 'a pull reasonabl perpendicular, i.e. at 70 degrees instead of 90 degrees, would be acceptable.' The answer to your question depends on whether one or two force applications are necessary to release the emergency exit. If only one force application is necessary, the direction of the application must meet the 90 to 180 degree directional requirement of S5.3.2. No variation from the requirements of the standard is permissible. However, paragraph S5.3.2 permits the use of two force applications for a single opening. Only one of the two force applications is required to differ by 90 to 180 degrees from the direction of the initial push-out motion of the emergency exit.; Your final question asked whether a particular type of push out windo in your buses would comply with FMVSS No. 217. As you know, this agency does not pass approval on the compliance of any motor vehicle or item of motor vehicle equipment with a safety standard before the actual events that underlie certification. Under the National Traffic and Motor Vehicle Safety Act of 1966, each manufacturer is required to determine whether its products comply with all applicable safety standards and regulations, and to certify its products in accordance with that determination. Therefore, the following only represents the agency's opinion based on the information provided in your letter.; You asked whether a push out window with a mechanism that can b released by a pull not exceeding 60 pounds in a direction opposite to the direction of the opening would meet the requirements of S5.3.2. The answer to your question depends on the location of the release mechanism. If it is located in the regions shown in Figures 1 or 3 for mechanisms released by low-force applications, the magnitude of the force application must not exceed 20 pounds. Release mechanisms located in regions of high force application must be capable of operation by force applications not more than 60 pounds. Of course, the other requirements in FMVSS No. 217 pertaining to emergency exits and release mechanisms must also be met.; I hope this information is helpful. Please contact this office if yo have further questions.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1221OpenMr. M. Ryan, Kazmier Lincoln-Mercury, 500 E. Roosevelt Road, Lombard, IL 60148; Mr. M. Ryan Kazmier Lincoln-Mercury 500 E. Roosevelt Road Lombard IL 60148; Dear Mr. Ryan: It has come to the attention of the National Highway Traffic Safet Administration that Kazmier Lincoln- Mercury may have sold a 1971 Lincoln on April 13, 1973, to Mr. Robert P. Bartl of Westchester, Illinois, without making a written disclosure statement as required by the Motor Vehicle Information and Cost Savings Act and Part 580 of Title 49, Code of Federal Regulations.; For your information, a transferor of a motor vehicle, including a ne or used car dealer, must make a written disclosure of the odometer reading to the transferee prior to transfer of ownership. The enclosed regulation lists the information which must be included in the statement. The regulation became effective on March 1, 1973.; It is the responsibility of the seller to make the statement whether o not the buyer requests it. Section 409 of the Act authorizes a civil action by a buyer who was not provided the statement, and it allows treble damages as proved or $1,500 without proof of damages.; I hope this letter makes clear your responsibilities to Mr. Bart concerning his purchase of a vehicle from your dealership.; Sincerely, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3573OpenMr. Jeff Wimer, P.O. Box 152, Auburn, IN 46706; Mr. Jeff Wimer P.O. Box 152 Auburn IN 46706; Dear Mr. Wimer: This responds to your phone request of June 11, 1982, concernin Federal motor vehicle safety standards that apply to motorcycle sidecars sold as aftermarket motor vehicle equipment.; While there are no 'sidecar' standards, certain of the items o equipment that may be found in sidecars are covered by Federal equipment safety standards. Specifically, brake hoses, lighting equipment, tires, rims, and glazing materials (if provided) would have to comply with Standards Nos. 106, 108, 119, 120 and 205. I have enclosed an information sheet explaining how you can obtain copies of the agency's safety standards.; Because a sidecar itself is an item of motor vehicle equipment, th manufacturer of any sidecar sold in the aftermarket would be responsible for notification and remedy in the event the product was determined to contain a safety-related defect.; If you have any further questions, please let me know. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3089OpenMr. T. Ohinouye, MMC Services, Inc., Suite 1960, 3000 Town Center, Southfield, MI 48075; Mr. T. Ohinouye MMC Services Inc. Suite 1960 3000 Town Center Southfield MI 48075; Dear Mr. Ohinouye: This responds to your recent letter requesting an interpretatio concerning the proper 'designated seating capacity' for the 'Dodge D-50' and 'Plymouth Arrow' pick- up trucks. The trucks with which you are concerned have bench seats with 53.5 inches of hip room, with a contoured indentation at the center position for the gear shift lever. You believe that only two positions should be designated for this type of bench seat.; As stated in the preamble to the recent notice amending the definitio of 'designated seating position', and noted in your letter, the presence of a floor gear-shift lever would not normally be sufficient to discourage or make use of the center position on a large bench seat impossible, even if the bench seat has a slightly indented contour for the shift lever (44 FR 23232, April 19, 1979). The notice did state that there could conceivably be a vehicle design in which the gear-shift lever would constitute an impediment to sitting. For example, if the lever extended to within a few inches of the seat back, the center position could not easily be used. This does not appear to be the case with the 'Dodge D-50' or 'Plymouth Arrow', however.; Since the bench seats in the subject vehicles have 53.5 inches of hi room, well over the 50-inch caveat in the amended definition, it is the agency's opinion that there should be three designated seating positions. The photographs enclosed in your letter show that three test dummies can be placed on the bench seat, even though somewhat crowded. Moreover, these photographs show two 95th-percentile male dummies and one 5th-percentile female dummy. If two (or three) 5th-percentile female dummies had been used in your demonstration, instead, you would have illustrated that there is more than ample room for three passengers to sit comfortably on a 53.5-inch bench seat. Also, human beings obviously have more flexibility than the stiff test dummies used in your demonstration. We believe that if you use human subjects in this same experiment (a 95th-percentile male driver and two 5th-percentile female passengers, for example), you will see that three persons can easily and comfortably occupy these bench seats.; Finally, I would emphasize that this letter only represents th agency's opinion based on the information supplied in your letter. The NHTSA does not pass approval on any vehicle design, for any safety standards, prior to the actual events that underlie certification. It is up to the manufacturer to determine whether its vehicles comply with all applicable safety standards and regulations, and to certify its vehicles in accordance with that determination.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3123OpenMr. Charles F. Finn, Volkswagen of America, 27621 Parkview Boulevard, Warren, MI 48092; Mr. Charles F. Finn Volkswagen of America 27621 Parkview Boulevard Warren MI 48092; Dear Mr. Finn:#This responds to your letter requesting a interpretation of Federal Motor Vehicle Safety Standard 101-80, Controls and Displays. Specifically, you asked whether a 'barely discernible' light on the headlamp control, which is activated when the ignition is turned to the 'on' position, complies with the requirements of the standard. Under S5.3.3, 'any illumination that is provided in the passenger compartment when and only when the headlights are activated shall also be variable ....' Since the light in question is not activated when the headlamps are activated, it need not meet the intensity requirements of S5.3.3.#Sincerely, Frank Berndt, Chief Counsel; |
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ID: aiam2362OpenMr. Mark T. Lerche, President, Sun Control Products of Virginia, Inc., P. O. Box 122, Petersburg, VA 23803; Mr. Mark T. Lerche President Sun Control Products of Virginia Inc. P. O. Box 122 Petersburg VA 23803; Dear Mr. Lerche: This responds to your June 11, 1976, request that Madico sola protective polyester film be 'designated as acceptable' under Ford Motor Company's DOT code number for the Ford product 'Privacy Glass' or, in the alternative, that the Madico product be assigned a separate DOT glazing code number. You state that the Madico film achieves the same effect as 'Privacy Glass' for reduction of solar heat, glare and fading.; Federal Motor Vehicle Safety Standard No. 205, *Glazing Materials* specifies requirements for glazing materials for use in motor vehicles and motor vehicle equipment. Section S6 of the standard outlines the procedures required for certification and marking of glazing materials, to certify that the glazing complies with all the requirements of the standard. Paragraph S6.2 of that section requires certain manufacturers to mark their glazing materials with the 'DOT' symbol and a manufacturer's code number, which is assigned to the manufacturer by the National Highway Traffic Safety Administration upon written request. Each code number is the unique mark of a single manufacturer, and is intended to facilitate the traceability of the glazing to the original manufacturer. Therefore, Ford's code number (DOT - 75 FM-M73) cannot be used by Madico or by another glazing manufacturer or distributor.; Your letter states that the Madico Product is a solar protective fil that is 'bonded or laminated to existing, installed clear glass.' We conclude that this 'protective film' is not glazing material and is not subject to the requirements of Standard No. 205. Therefore, a glazing manufacturer's code number cannot be assigned for the product.; Whether or not the Madico protective film is otherwise subject t Federal Requirements depends upon who uses the product. If a vehicle manufacturer or a dealer places the film on glazing in a vehicle prior to sale of the vehicle, he must certify that the glazing continues to be in compliance with the requirements of Standard No. 205.; On the other hand, the vehicle owner may alter his vehicle as h pleases, so long as he adheres to all State requirements. The owner could install the protective film on glazing in his vehicle whether or not such installation affected compliance with Standard No. 205. It should be noted, however, that section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act of 1966 provides that no manufacturer, dealer, distributor, or motor vehicle repair business shall knowingly render inoperative any device or element of design installed in a motor vehicle in compliance with an applicable Federal motor vehicle safety standard. Therefore, no manufacturer, distributor, dealer or repair business may knowingly install the Madico protective film on a vehicle for its owner in a manner that would destroy the conformity of the glazing with the requirements of Standard No. 205.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam2698OpenMr. Jay D. Zeiler, Akin, Gump, Hauer & Feld, 1100 Madison Office Building, 1155 Fifteenth Street, N.W., Washington, D.C. 20005; Mr. Jay D. Zeiler Akin Gump Hauer & Feld 1100 Madison Office Building 1155 Fifteenth Street N.W. Washington D.C. 20005; Dear Mr. Zeiler: This responds to your September 26, 1977, letter asking severa questions about the applicability of Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars*, to rims modified subsequent to their initial marking by the rim manufacturer.; Standard No. 120, as it applies to rim manufacturers, requires onl that the manufacturer mark the rim with the information outlined in section S5.2 of the standard, The standard does not contain substantive performance requirements for tire rims that would necessitate extensive testing to comply with the requirements.; In cases where your client modifies previously marked rims, he migh have some responsibilities for compliance with the standard. For those rims where the center disc is only added or altered by your client, there would be no requirement for him to provide his own markings on the tire rim. The rim manufacturer's markings would still contain the accurate size information.; For rims that your client modifies by the insertion of a steel plat increasing the dimensions of the rim, he becomes the rim manufacturer, As a rim manufacturer, it is his responsibility to mark the rim with the information listed and in the manner prescribed in S5.2 of the standard. This information includes the DOT symbol which indicates that he has complied with the requirements of Standard No. 120. Since the rim would have been marked initially with a different size, the National Highway Traffic Safety Administration (NHTSA) would require that the first markings be removed from the rim the avoid the possibility of confusion to persons who might read the incorrect size listing. This could result in the mismatching of a tire to the modified rim.; In a conversation between Ms. Maryanne Kane of your office and Mr Roger Tilton of my staff, it was asked whether the NHTSA Standard No, 120 requirements would be applicable to rim manufactured entirely for off-road use. The NHTSA regulates only motor vehicles and motor vehicle equipment. by definition a motor vehicle is a vehicle used on the roads. Accordingly, vehicles designed for off-road use do not fall within the ambit of our regulations. The same is true for equipment designed for use on those off-road vehicles. The determination of whether a vehicle is an off-road vehicle depends upon its use. I have enclosed an interpretive letter that described the criteria for determining what vehicles are motor vehicles under the National Traffic and Motor Vehicle Safety Act (Pub. L. 89-563) (the Act).; You should note further that any time your client undertakes a alteration of a rim, he is performing a manufacturing function that places him within the scope of the Act. Therefore, he would be responsible for any safety-related defects resulting from his manufacturing processes.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam2732OpenMr. Takashi Shimoda, Nichirin Rubber Industrial Co., Ltd., 1118, Sazuchi, Bessho, Himeji, Japan; Mr. Takashi Shimoda Nichirin Rubber Industrial Co. Ltd. 1118 Sazuchi Bessho Himeji Japan; Dear Mr. Shimoda: This responds to your letter dated November 29, 1977, asking about th procedures for obtaining approval of hydraulic brake hoses. Your company is altering the labeling on some of its hose and asks whether the hose must be retested and whether notice of the changes must be given.; The National Highway Traffic Safety Administration (NHTSA) does no approve in advance motor vehicles or motor vehicle equipment. It is up to manufacturers to certify that their products comply with all applicable safety standards and regulations. The NHTSA conducts compliance testing for purposes of enforcement.; It is, therefore, up to your company to decide whether to test its hos according to the procedures specified in Safety Standard No. 106, *Brake Hoses*. The NHTSA only requires that you determine in the exercise of due care that the hose meets all requirements specified in the standard. Further, you do not have to give the NHTSA notice when you change the labeling information on your hose, unless you change the designation identifying your company. In that case, the new designation would have to be filed with the NHTSA according to the specifications of paragraph S5.2.2(b) of Standard 106.; You will have to contact the American Association of Motor Vehicl Administrators directly to determine their requirements for approval and notification following your labeling changes.; Please contact me if our office can be of any further assistance. Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3820OpenHerbert T. Thrower, Jr., P.E., President, Dotech, Inc., 306 Clanton Road, Charlotte, NC 28210; Herbert T. Thrower Jr. P.E. President Dotech Inc. 306 Clanton Road Charlotte NC 28210; Dear Mr. Thrower: This is in response to your letter of February 14, 1984, to Mr. Vinso of my staff asking 'is there any reluctance on the part of NHTSA to make a patented device a legal option under Federal Motor Vehicle Safety Standard No. 108?'; At present, Standard No. 108 mandates specific items of lightin equipment not optional ones (though 'options' as to matters such as size and shape exist among headlamps which are required items). Instead, NHTSA points out that, pursuant to S4.1.3 optional lighting devices (proprietary or not) are allowable, provided that they do not impair the effectiveness of the lighting equipment the standard requires. When proprietary rights are involved in mandated lighting equipment, manufacturers have been willing to waive their rights.; You have also said that you 'presume that other patented automotiv devices also must have DOT approval before their optional public use is permissible.' I don't know what you have in mind, but under the National Traffic and Motor Vehicle Safety Act, no 'approval' by DOT is necessary to market 'optional' motor vehicle equipment of any sort. Such equipment is subject only to the general requirement that its installation must not affect the compliance of the vehicle with any Federal motor vehicle safety standard.; If you have further questions, please let us know. 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.