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: aiam0427OpenMr. T. G. Burke, American Jawa Ltd., 185 Express Street, Plainview, LI, NY 11803; Mr. T. G. Burke American Jawa Ltd. 185 Express Street Plainview LI NY 11803; Dear Mr. Burke: This is in reply to your letter of August 17, 1971, inquiring whethe tires for use on racing motorcycles are subject to the Tire Identification and Record Keeping regulation (49 C.F.R. 574).; The regulation applies to 'manufacturers, . . . of new and retreade tires for use on motor vehicles' and, thus, whether the regulation applies to the tires in question depends on whether they are for use on a 'motor vehicle.' If the tires are for use on a racing motorcycle (i.e., a motorcycle which is not manufactured primarily for use on the public streets, roads, and highways), the tires are not considered to be manufactured for use on a 'motor vehicle' and the regulation does not apply to them. We consider a label such as 'For Racing Purposes Only, Not for Highway Use' as evidence of manufacture for off road use.; The execution of an HS-7 form is unnecessary when racing tires ar imported whether or not they are mounted on a racing motorcycle. However, should it be necessary to execute an HS-7 form to expedite importation, Box 8 should be used to indicate that the items being imported are not considered to be for use on a motor vehicle and are not items of motor vehicle equipment.; Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam4937OpenSue Ellen Russell, Esq. Brand & Lowell 923 Fifteenth Street, NW Washington, DC 20005; Sue Ellen Russell Esq. Brand & Lowell 923 Fifteenth Street NW Washington DC 20005; "Dear Ms. Russell: This responds to your letter of October 24, 1991 concerning Safety Standard No. 210, Seat Belt Assembly Anchorages. You stated that Glaval Corporation, which you represent, recently notified NHTSA of its intention to conduct a notification and remedy campaign to respond to 'an apparent noncompliance with the safety belt anchorage strength requirements as they apply to the rear bench seat in Glaval vans.' According to your letter, these seats contain three designated seating positions, and each seat belt anchorage is 'mounted on the seat, not the floor.' You stated that in the course of evaluating potential remedies, you became aware of an April 9, 1990 interpretation letter sent by this agency to Mr. R.W. Schreyer of Transportation Manufacturing Corporation, in which the agency stated that only floor-mounted anchorages are subject to simultaneous testing. Because the Glaval van bench seat anchorages were tested simultaneously in NHTSA's compliance test, you asked the following questions: 1. Consistent with the Schreyer interpretation, should the seat-mounted anchorages of the Glaval bench seat have been loaded sequentially in NHTSA's test? If so, how does NHTSA's test on the Glaval bench seat, where the loads were applied simultaneously, affect NHTSA's tentative conclusion of noncompliance? You are correct that, consistent with the Schreyer interpretation, only floor-mounted anchorages are subject to simultaneous testing under current requirements. However, based on our understanding of the Glaval design, and as discussed below, we consider the anchorages in the Glaval van to be floor-mounted. Therefore, the Schreyer interpretation is not relevant to whether the Glaval van is in compliance with Standard No. 210. Based on photographs included in the Final Report of FMVSS 210 Compliance Testing of 1991 Glaval Van (Report No. 210-GTL-91-003), it appears that the seat belts are attached to a bar which runs along the floor behind the bench seat. The bar is directly mounted to floor brackets which run along each side of the seat. Section S4.2 of Standard No. 210 specifies that floor-mounted seat belt anchorages for adjacent designated seating positions are simultaneously tested. The term 'seat belt anchorage' is defined in section S3 as 'the provision for transferring seat belt assembly loads to the vehicle structure.' In the design at issue, the seat belt anchorage, or provision for transferring seat belt assembly loads to the vehicle structure, includes the seat belt bar. Since the seat belt bar is mounted to the floor by means of the two brackets along the sides of the seat, the seat belt anchorage is 'floor-mounted.' I note for your information that, on April 30, 1990, the agency published a final rule amending Standard No. 210 to, among other things, require simultaneous loading of all anchorages common to the same occupant seat. This amendment is effective on September 1, 1992. 2. Since Standard 207 requires simultaneous loading of the forces required by Standard 207 along with those required by Standard 210, does the Schreyer interpretation mean that, for a bench seat with seat-mounted anchorages, the proper loading for a test pursuant to FMVSS 207 should be 20 times the seat weight plus the proper load for one designated seating position on the bench seat? Your understanding of the Standard No. 207 test is correct. I hope you find this information helpful. If you have further questions, please contact Mary Versailles of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel "; |
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ID: aiam5625OpenMr. Robert R. Brester Director of Product Engineering Velvac Inc. 2900 South 160th Street New Berlin, WI 53151; Mr. Robert R. Brester Director of Product Engineering Velvac Inc. 2900 South 160th Street New Berlin WI 53151; "Dear Mr. Brester: This responds to your request for an interpretatio concerning how Standard No. 105, Hydraulic Brake Systems, affects the brake products you sell. According to your letter: Velvac Inc. manufactures and sells brake components and power braking systems for trailers and truck tag axles. These brake systems are not part of the primary vehicle braking system. In the case of a tag axle, our customers are retrofitting a standard vehicle with an additional axle to increase its load carrying capacity. In the case of a trailer, our system may be the only source of braking. The brake components Velvac supplies generally include control valving, brake boosters and various types of hoses and fittings. These items can be sold both as components and as complete power brake kits. (See attached catalogue drawings . . . .) You stated that Mr. Richard Carter of this agency advised you that different combinations of braking components may be used to achieve the braking performance requirements of Standard No. 105, and that the responsibility of certifying vehicles to Standard No. 105 lies in the hands of your customers. This information is correct. However, you should be aware that some of the components listed in your catalogue are covered by Standard No. 106, Brake Hoses, and must be certified by their manufacturer as complying with that standard. A further discussion of the issues raised by your letter is provided below. By way of background information, the National Highway Traffic Safety Administration (NHTSA) is authorized to issue Federal motor vehicle safety standards for new motor vehicles and new motor vehicle equipment. NHTSA has exercised this authority to issue several vehicle and/or equipment standards related to braking performance. These standards include the aforementioned Standards No. 105 and No. 106, as well as ones on air brake systems, motorcycle brake systems, and motor vehicle brake fluids. You specifically asked about Standard No. 105. That standard specifies requirements for hydraulic service brake and associated parking brake systems, and applies to passenger cars, multipurpose passenger vehicles, trucks, and buses with hydraulic service brake systems. If your brake products are installed as original equipment on a new vehicle subject to Standard No. 105, the vehicle manufacturer is required to certify that, with the products installed, the vehicle satisfies the requirements of that standard (as well as all other applicable safety standards). If your brake products are added to a previously certified new motor vehicle prior to its first sale, the person who modifies the vehicle would be an 'alterer' under our regulations, and would be required to certify that, as altered, the vehicle continues to comply with all of the safety standards affected by the alteration. If your products are installed on a used vehicle by a business such as a repair shop, the repair shop would not be required to attach a certification label. However, it would have to make sure that it did not knowingly make inoperative any part of a device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable safety standard, such as the hydraulic brake system. Assuming you do not manufacture or alter new vehicles, you do not have a responsibility to certify a vehicle's compliance with Standard No. 105. However, I note that some of the brake products listed in your catalogue are covered by Standard No. 106. That standard specifies requirements for motor vehicle brake hose, end fittings and assemblies. Standard No. 106 applies not only to new vehicles, as is the case with Standard No. 105, but also to brake hoses, end fittings and assemblies that are sold individually or in kit form. Manufacturers of these items must certify that the equipment complies with Standard No. 106, and persons selling these items must sell only certified items. NHTSA also has the authority to investigate safety-related defects. Manufacturers of motor vehicles and items of motor vehicle equipment are subject to statutory requirements concerning the recall and remedy of products with defects related to motor vehicle safety. If a manufacturer or NHTSA determines that a safety-related defect exists, the manufacturer must notify purchasers of its product and remedy the problem free of charge. (This responsibility is borne by the vehicle manufacturer in cases in which your products are installed on a new vehicle by or with the express authorization of that vehicle manufacturer.) Any manufacturer that fails to provide notification of or remedy for a defect may be subject to a civil penalty of up to $1,000 per violation. I have enclosed an information sheet that briefly describes various responsibilities of motor vehicle manufacturers under our regulations, and information on how you can obtain copies of our standards. I hope this information is helpful. If you have any further questions, please call Edward Glancy of my staff at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosure"; |
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ID: aiam0077OpenChester G. Parsons, President, Elgin Sweeper Company, 1300 West Bartlett Road, Elgin, IL 60120; Chester G. Parsons President Elgin Sweeper Company 1300 West Bartlett Road Elgin IL 60120; Dear Mr. Parsons: This is in response to your letter of April 17 requesting eithe confirmation of your opinion that it was 'not the intent of the Federal Motor Vehicle Safety Standards to apply to 'the three wheeled motor street sweeper manufactured by Elgin, or, in the alternative, consideration by the Federal Highway Administration of the establishment of a separate classification for these vehicles.; Three wheeled motor street sweepers are 'motor vehicles' within th meaning of the National Traffic and Motor Vehicle Safety Act of 1966. However, they do not fall into any of the vehicle types defined thus far, to which standards are applicable, and consequently there are no standards applicable to it at this time.; Sincerely, William Haddon, Jr., M.D., Director |
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ID: aiam5275OpenMs. Amantha L. Barbee Sales Coordinator Thomas Built Buses, Inc. Post Office Box 2450 High Point, NC 27261; Ms. Amantha L. Barbee Sales Coordinator Thomas Built Buses Inc. Post Office Box 2450 High Point NC 27261; "Dear Ms. Barbee: This responds to your letter to me of October 14 1993, and your telephone conversation with Walter Myers of my staff on October 22, 1993. You stated in your letter that you are the Head Start Sales Coordinator for Thomas Built Buses, Inc., and in that capacity you have found that many Head Start agencies are using conventional vans to transport Head Start students to and from their programs. You stated that when you asked the directors of the agencies why they did not use vehicles that comply with Federal motor vehicle safety standards (FMVSS) for school buses, their usual answer was 'because we have not been told otherwise.' You then asked whether this practice is illegal and if so, what your organization can do to rectify the situation. As Mr. Myers explained in your telephone conversation, this agency has repeatedly stated that Head Start facilities are preprimary schools. Therefore, new buses sold to Head Start centers for use in transporting Head Start participants to and from school must comply with all Federal motor vehicle safety standards applicable to school buses. However, Federal law does not require Head Start facilities to use complying school buses or any other particular vehicles. The individual states, not the Federal government, have authority over the use of vehicles. As promised by Mr. Myers, please find enclosed interpretation letters previously issued by us on this issue, as follows: to Hon. Paul David Wellstone, U.S. Senate, dated Jan. 26, 1993, to Mr. Chuck Anderson, dated Aug. 21, 1992, and to Mr. Charles Pekow, dated Sept. 27, 1985. I hope this information will be useful. If you have any further questions or desire any further information, please feel free to contact Mr. Myers at this address or at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosures "; |
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ID: aiam3572OpenMr. 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: aiam3088OpenMr. 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: aiam3122OpenMr. 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: aiam2363OpenMr. Malcolm B. Mathieson, Engineering Manager, Thomas Built Buses, Inc., 1408 Courtesy Road, P. O. Box 2450, High Point, NC 27261; Mr. Malcolm B. Mathieson Engineering Manager Thomas Built Buses Inc. 1408 Courtesy Road P. O. Box 2450 High Point NC 27261; Dear Mr. Mathieson: this responds to Thomas Built Buses' June 4, 1976, question whether th requirements in S5.1.3 and S5.1.4 of Standard No. 222, *School Bus Seating and Crash Protection*, to 'Apply additional force...through the...loading bar until (a specified number) of inch-pounds of energy has been absorbed in deflecting the seat back...' can be satisfied in part by the energy that is returned to the load bar as it is withdrawn from the seat back. You also ask if there are minimum or maximum time limits on withdrawal of the loading bar from the seat surface.; The requirement for the absorption of a minimum amount of energy i deflecting the seat back in the forward and rearward directions is calculated to provide adequate measurement of the energy involved in the impact between the bus occupants and the seating in a percentage of school bus crashes. The agency calculated the amount of energy to be consumed by the seat back that would result in adequate protection. The specification requires the seat to 'absorb' (i.e., receive without recoil) a specific amount of energy. This value is represented by the amount of energy that is not returned to the loading bar as it is withdrawn. Described graphically, the area that represents returned energy under the seat back force/deflection curve must be subtracted from the entire area that lies under the curve in order to calculate the energy 'absorbed' by the seat back.; With regard to your second question, no time limits have bee established for withdrawal of the loading bar. The agency intends to utilize a withdrawal time that is not more than five minutes so that creep will not be a significant factor in determining energy absorption. Because the time is not specified, the manufacturer is free to use any reasonable time that does not significantly affect the elastic and plastic components of the seat back loading.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam2699OpenMr. Tokio Iinuma, Nissan Motor Co., Ltd., P.O. Box 1606, 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Tokio Iinuma Nissan Motor Co. Ltd. P.O. Box 1606 560 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Iinuma: This is in response to your letter of October 11, 1977, askin questions regarding application of the set and dent limitations contained in Part 581, *Bumper Standard*.; Your letter contained a series of diagrams about which questions on th applicability of the bumper damage criteria were asked. The questions are answered in the order in which they were posed.; 1. A total deformation of 9/8-inch is allowed only at the points on th bumper which actually come into contact with the impact ridge of the pendulum test device or the barrier face. All other bumper surfaces are limited to deformation no greater than 3/4-inch set.; 2. The crack illustrated in Question 2 would not be a dent as describe in S 581.5(c)(11)(ii). A crack that did not entail a measurable separation of the exterior surface of the bumper face bar, would not constitute a deviation in the contour of that component.; 3. Dimension A measures the change in contour and should be used t determine the size of the dent at the point of contact with the impact ridge of the pendulum test device or the barrier face.; 4. The straight line to measure the dent would be that labeled 'D since it connects the bumper contours adjoining the area of contact with the impact ridge of the pendulum test device. The size of the dent would be the distance from the original contour surface to the final deformation surface at the point of contact with the impact ridge.; 5. Dimension B identifies the amount of bumper set since it marks th distance of maximum change in the position of the bumper face bar relative to the vehicle frame.; 6. Since dents only occur at the point of contact with the impact ridg of the pendulum test device or the barrier face, the deformations described in the illustrations would be set.; 7. Since the deformation is not at the point of contact with either th impact ridge of the pendulum test device or the barrier face, it is set.; 8. If the operating force initially required to open the hood followin impact is within a range that permits operation by the normal universe of drivers, unaided by any tools, it would probably not be considered a noncompliance under the standard.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.