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: aiam0968OpenMr. James E. Bates, Executive Director, Fire Equipment Manufacturers' Association, Inc., 604 Davis Street, Evanston, IL 60204; Mr. James E. Bates Executive Director Fire Equipment Manufacturers' Association Inc. 604 Davis Street Evanston IL 60204; Dear Mr. Bates: This is in reply to your letter of December 22 to Mr. Lew Owen of thi Office concerning definitions of mobile homes, motor homes, and recreational vehicles.; For our purposes, mobile homes are regarded as mobile structur trailers. A trailer is 'a motor vehicle with or without motive power, designed for carrying persons or property and for being drawn by another motor vehicle.' A mobile structure trailer is 'a trailer that has a roof and walls, is at least 10 feet wide, and can be used off-road for dwelling or commercial purposes.'; Motor homes are regarded as multi-purpose passenger vehicles, which ar defined as 'a motor vehicle with motive power, except a trailer, designed to carry 10 persons or less which is constructed either on a truck chassis or with special features for occasional off- road operation.'; We have no definition for 'recreational vehicle.' Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam3169OpenMr. Thomas F. Brown, Mack Trucks, Engineering Division, P.O. Box 1761, Allentown, PA 18105; Mr. Thomas F. Brown Mack Trucks Engineering Division P.O. Box 1761 Allentown PA 18105; Dear Mr. Brown: This responds to your October 17, 1979, letter asking about the prope certification label for an intermediate manufacturer that alters the tires and rims on a chassis thereby affecting the gross axle and vehicle weight ratings. In your letter, you suggest an abbreviated certification label that would list the manufacturer's name and date of manufacture, and would make the statement that the vehicle will conform to certain standards if the incomplete vehicle document is followed. The agency agrees that this is a correct certification.; Intermediate manufacturers are required to attach labels to vehicle that they modify to indicate that some manufacturing operation has occurred on a vehicle between the manufacture of its chassis and its final manufacture. The intermediate manufacturer is permitted to select, from among a number of certification statements, the statement or statements that accurately represent the nature of the work undertaken by that manufacturer. Therefore, it is not necessary for an intermediate manufacturer to use all of the certification statements on its labels.; In the situation that you describe, the intermediate manufacturer wil make a statement on its label identical to one of the statements made by the chassis manufacturer. Although this appears to be redundant, it is necessary to have the intermediate manufacturer's label on the vehicle making the required certification statement so that a final-stage manufacturer can continue to rely upon the certification labels and upon the statements made in the incomplete vehicle document.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1154OpenMs. Cam Brame, Quality Assurance Analyst, Bendix Automotive Aftermarket, 1217 South Walnut Street, South Bend, Indiana 46620; Ms. Cam Brame Quality Assurance Analyst Bendix Automotive Aftermarket 1217 South Walnut Street South Bend Indiana 46620; Dear Ms. Brame: This is in reply to your letter of May 30, 1973 and confirms th telephone conversation with Mr. Vinson of my staff on June 14, 1973.; The amendments to Motor Vehicle Safety Standard No. 116 published o May 17, 1973 modified container labelling requirements only for silicone-based brake fluid and hydraulic system mineral oil (paragraph S5.2.2.3) and did not affect the requirements for conventional DOT 3 and DOT 4 fluids (paragraph S5.2.2.2) as you assumed. Therefore you appear to have no problem, and it is not necessary to consider your letter as a petition for reconsideration.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam3493OpenMr. H. Nakaya, Mazda (North America), Inc., 23777 Greenfield Road, Southfield, MI 48075; Mr. H. Nakaya Mazda (North America) Inc. 23777 Greenfield Road Southfield MI 48075; Dear Mr. Nakaya: This responds to your recent letter requesting an interpretatio regarding Safety Standard No. 207 as it would apply to a new seat design your company is considering. This design includes additional seat track forward of the seat track positions that are included as normal riding positions. Since there are no locking positions on this additional seat track, the vehicle seat cannot comply with the loading requirements of Standard No. 207 when in this position. Those requirements must be satisfied in any position to which a seat can be adjusted. You ask whether the extended track would be considered part of the seat track for purposes of Standard No. 207 and for purposes of the adjustment requirements in testing under Safety Standard No. 208.; The answer to your question is yes unless some mechanism is include which will automatically return the seat to a locked position on the track when the seat back is in its upright position and no force is being applied. Most motor vehicle seats will travel some short distance forward of the forward-most adjustment locking position. However, they are designed to return to the nearest locked adjustment position when the adjusting force is removed from the seat, i.e., when the occupant releases the adjustment lever and stops pushing the seat forward. Many seat designs accomplish this result by spring- loading the seat. Therefore, the seat track portion labeled 'A- B' in your diagram would not be considered part of the seat track for purposes of Safety Standard No. 207 and Standard No. 208 if the seat is designed to return automatically to position 'B' and lock when the seat back is in its upright riding position.; None of the other alternative solutions you mentioned would b sufficient. All of the alternatives fail to prevent the seat with its seat back in the upright position from being adjusted to a position on the 'A-B' portion of the track, all of which are unlocked positions. With one limited exception, none of the alternatives would aid the seat in meeting the forward and rearward loading requirements when the seat is adjusted somewhere on the 'A-B' portion of the track. The exception concerns the alternative of strengthening the stopper at the 'A' position. This alternative might enable the seat to meet the forward loading requirements of Standard No. 207, but only when the seat was adjusted to the 'A' position on the 'A-B' portion of the track. The seat would not be able to meet the aft loading requirements at the 'A' position, however.; I would like to point out that the agency does not provide advanc approval of any device or element of design in a motor vehicle. The National Traffic and Motor Vehicle Safety Act makes the vehicle manufacturer responsible for determining whether its vehicles are in compliance with all applicable safety standards and for certifying that compliance. This letter only represents the agency's informal opinion based on its understanding of the information supplied in your letter.; Also, if you desire to have the information concerning this seat desig treated as confidential business information by the agency, you will have to submit sufficient information to justify such treatment. I am enclosing proposed guidelines for seeking confidential treatment. If you do not choose to follow this procedure, we will have to place this interpretation in our public redbook file for the benefit of all interested persons.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4356OpenMr. Jack De Nijs, DeRonde Casings, Ltd., 202 Walden Avenue, Buffalo, NY 14211; Mr. Jack De Nijs DeRonde Casings Ltd. 202 Walden Avenue Buffalo NY 14211; Dear Mr. De Nijs: This responds to your letter to this office, in which you asked whethe you could import into the United States foreign truck tire casings that do not have either a DOT symbol or a tire identification number on the sidewall. You stated in your letter that you would either retread these tires yourself or sell them to other retreaders to be retreaded. Subject to certain conditions, you may import these casings.; The general provision dealing with the importation of items of moto vehicle equipment such as tires are set forth in section 108(a)(1)(A) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397 (a)(1)(A)). That section makes it unlawful for any person to import into the United States any item of motor vehicle equipment manufactured on or after the date that an applicable Federal motor vehicle safety standard takes effect, unless the equipment (tire) is in conformity with the standard. Federal Motor Vehicle Safety Standard No. 119, *New Pneumatic Tires for Vehicles Other Than Passenger Cars* (49 CFR S571.119) took effect on March 1, 1975. Standard No. 119 requires that truck tires and other tires for use on vehicles other than passenger cars pass certain performance tests and be labeled with certain safety information, including the tire identification number. The tire manufacturer is required to certify that each of its truck tires complies with Standard No. 119 by permanently molding the symbol DOT into or onto the sidewall that were manufactured on or after March 1, 1975 would not be in compliance with Standard NO. 119 and could not legally be imported into the United States.; However, the agency reached a somewhat different conclusion wit respect to the permissibility of importing truck tire casings in a June 18, 1981 letter from former Chief Counsel Frank Berndt to Mr. Roy Littlefield (copy enclosed). In that letter, the agency concluded that truck tire casings that have less than 2/32 inch of tread and which are imported *solely* to be retreaded are *not* 'items of motor vehicle equipment' within the meaning of section 108(a)(1)(A) of the Safety Act. This conclusion means that truck tire casings that meet these conditions may be imported into the United States. Please note that you cannot legally import any non-complying casings that will not be retreaded before they are used on the public roads.; If you have any further questions on this subject, please feel free t contact Steve Kratzke of my staff at this address or by telephone at (202) 366-2992.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3539OpenH. A. Kendall, Ph.D., United Sidecar Association, Inc., 1621 Palomino Lane, Kingwood, TX 77339; H. A. Kendall Ph.D. United Sidecar Association Inc. 1621 Palomino Lane Kingwood TX 77339; Dear Dr. Kendall: This is in reply to your letter of February 20, 1982, with respect t pulsating headlamps.; You have interpreted my letter of February 9, 1982, as stating tha 'for daytime operation of a motorcycle headlight, the light may be permitted to pulsate or modulate from one level of brightness to another.' On the contrary, I stated that 'a lamp whose intensity varies from a higher output to a lower output...would be prohibited.' However, I also stated that, if complete deactivation occurs (i.e., from a higher output to no output), then that mode of operation is permissible.; With respect to your latest letter and the problems of headlighting i older motorcycles, there would be no need to have the smaller bulb illuminated, and the 'definite on/off/on/off sequence' you mention is sufficient for compliance with Standard No. 108.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1504OpenMr. R. W. Cheetham, Director of Quality Assurance, Armstrong Rubber Company, 500 Sargent Drive, New Haven, CT 06507; Mr. R. W. Cheetham Director of Quality Assurance Armstrong Rubber Company 500 Sargent Drive New Haven CT 06507; Dear Mr. Cheetham: This is in reply to your letter to Michael Peskoe of NHTSA's Chie Counsel's Office asking our comments on a sample defect notification letter Sears plans to send to known purchasers of the Armstrong L78-15 Allstate Wideguard Dynaglass tire having the identification number CEV3FP1372.; The sample notification letter you enclose would not conform to 49 CF Part 577, 'Defect Notification' in several respects. To comply with section 577.4(b) we believe your letter should include, in addition to the existing statement, a statement that the tires failed to conform to the requirements of Federal Motor Vehicle Safety Standard No. 109. We have taken the position that defect notification letters resulting from failures of compliance with applicable safety standards should contain that information, as it would be required under section 575.5(b) were the notification sent following an administrative proceeding.; We also believe the letter should include precautions the purchaser ca take to reduce the chance that the failure will occur (S 577.4(c)(4)). Such precautions could be stated as the corollary to the failure mode you describe, *i.e.*, avoid prolonged driving.; The letter further fails to conform to Part 577 in that it does no evaluate the risk to traffic safety in the manner set forth in section 577.4(d). Vehicle crash would seem to be a potential result of tire failure, and the letter should therefore contain language meeting section 577.4(d)(1).; Finally, the letter does not conform to section 577.4(e). It is no clear whether the 'replacement free of charge' will include mounting or balancing, both of which might be considered by consumers as part of a free replacement. Consequently, we find that the description required by section 577.4(e)(1) is incomplete. There is further no attempt to meet the requirements of 577.4(e)(2) or (e)(3), requiring a date by which replacement parts (tires) are available (if they are presently available, the letter should so indicate) and how much time will be necessary to perform whatever labor is included in the replacement.; In order for your letter to conform to Part 577, it must be modified i each of the respects described above.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4706OpenMr. Thomas D. Turner Manager, Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley, GA 31030; Mr. Thomas D. Turner Manager Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; "Dear Mr. Turner: This responds to your letter seeking a interpretation of the meaning of the term 'front outboard designated seating position,' for the purposes of Standards No. 202, Head Restraints (49 CFR 571.202) and No. 208, Occupant Crash Protection (49 CFR 571.208). Specifically, you referred to a typical seating arrangement on a small bus your company manufactures. In this seating arrangement, the driver's seating position is located immediately to the rear of the left side of dashboard. There are no other seating positions in the same row as the driver's seat. Instead, a side entrance door and stepwell are to the right of the driver's seat with an unobstructed passage between the driver's seat and the entrance door. To the rear of the driver's seat, there are four rows of passenger seats on each side of the bus, separated by a center aisle that runs the length of the bus. You offered your opinion that the forwardmost passenger seating position on the right side of the bus, which is to the rear of the driver's seating position and the entrance door and stepwell, is not a front outboard seating position for the purposes of Standards No. 202 and 208. Your understanding is correct. While NHTSA has never specifically defined 'front' seating positions, the agency has used that term to refer to the driver's seating position and all other seating positions in the same transverse or lateral row as the driver's seating position. In the small bus described in your letter, the forwardmost passenger seat on the right side of the bus is not in the same transverse row as the driver's seat, it is to the rear of that row. Therefore, the forwardmost passenger seat on the right side of your bus would not be a 'front' seat for the purposes of Standards No. 202 or 208. Sincerely, Stephen P. Wood Acting Chief Counsel"; |
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ID: aiam1857OpenHonorable Vance Hartke, United States Senate, Washington, DC 20510; Honorable Vance Hartke United States Senate Washington DC 20510; Dear Senator Hartke: Thank you for your letter of March 7, 1975, asking for detaile consideration of Mr. David L. Daugherty's concern that final-stage manufacturers will be unable to fulfill their certification responsibilities on air-braked trucks built after March 1, 1975. As you know, Standard No. 121, *Air brake systems*, became effective for trucks and buses on March 1, 1975.; Mr. Daugherty has raised one of the most critical aspects of truc manufacturing in assuring a minimum brake performance level. Unlike passenger cars, the vast majority of heavy trucks are manufactured by adding specialized bodies or equipment to a chassis-cab. These additions affect the center of gravity, dynamic load transferral, and other characteristics of the truck which determine in large part its stopping capability.; As a practical matter, meaningful dynamic brake performance standard cannot be developed without regulating the truck as it is completed and sold.; The National Highway Traffic Safety Administration (NHTSA) recognize that Standard No. 121, as the first comprehensive performance requirement for trucks, will limit somewhat the freedom of manufacturers to modify brake systems and mount bodies without regard for their effect on braking. We consider the increased care exercised by final-stage manufacturers to be one of the most significant benefits of the standard.; Mr. Daugherty correctly points out that chassis-cab manufacturer released the necessary information on their chassis only a short time before March 1, 1975. The two trade associations for final-stage manufacturers petitioned for delay of the standard for this reason. After careful consideration of possible relief, NHTSA denied those petitions. It was concluded that every form of relief had obvious drawbacks and would not achieve the objective of final-stage manufacturers to receive 121-type chassis to use in re-engineering their body and equipment installations. It was concluded that if the standard for completed vehicles were suspended, chassis manufacturers would no longer have to provide incomplete vehicles with the necessary equipment and final-stage manufacturers would be unable to develop solutions for their engineering problems. Even if incomplete vehicles could be certified and completed vehicles could be exempt, serious danger would exist when modifications of the new systems were undertaken without consideration of the handling consequences.; I would like to point out that the March 1, 1975, effective date doe not require an instantaneous ('one day') change for final-stage manufacturers. Part 568 of our regulations (49 CFR Part 568) permits a final-stage manufacturer to use the date of completion of the chassis as the date of certification of the completed vehicle. This means that the chassis manufactured prior to March 1 may be completed at any later period without meeting Standard No. 121. It is not until final-stage manufacturers begin to receive the chassis which have just started to be produced that they will have to complete vehicles in conformity with the standard. They now have data on the new chassis, and thus have a period in which to make modifications. Several manufacturers have large inventories of pre-121 chassis and it should be several months before all trucks will be completed in conformity with Standard No. 121.; Thank you for your continuing interest in motor vehicle safety. Sincerely, James B. Gregory, Administrator |
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ID: aiam0745OpenMr. Stan Haransky, Associate Director, Truck Body and Equipment Association, Inc., 5530 Wisconsin Avenue, Suite 1120, Washington, DC 20015; Mr. Stan Haransky Associate Director Truck Body and Equipment Association Inc. 5530 Wisconsin Avenue Suite 1120 Washington DC 20015; Dear Mr. Haransky: This is in reply to your letter of May 30, 1972, forwarding to u correspondence you received from Mr. Calvin D. Kunkle of FMC Corporation. Mr. Kunkle's question, as explained in a telephone conversation we had with him on June 16, 1972, is whether building vehicles whose actual loaded weight exceeds the gross vehicle weight rating of the chassis violates Federal law. Mr. Kunkle stated that he believed certain manufacturers of fire-fighting vehicles were presently doing that.; If the loaded weight is clearly inconsistent with the definitions o GVWR and GAWR as specified in 49 CFR 571.3, the manufacturer will be in violation of the Certification regulations, (49 CFR Part 567) and may be subject to civil penalties. Also, if the loaded weight of the completed vehicle or the weight imposed on any of its axle systems exceeds the stated ratings, the vehicle might be found by NHTSA to contain a safety-related defect. In such a case, the manufacturer is required to mail notification of the defect to all the purchasers. In addressing whether such a safety defect exists, the NHTSA considers the situation as a whole, including such factors as the manufacturer's ratings, and the true capacity of the vehicle.; We advised Mr. Kunkle during our conversation that if he will furnis to NHTSA the names of companies he suspects are involved in this practice, we will take action to bring them into conformity with the requirements.; Yours truly, Richard B. Dyson, Assistant 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.