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: aiam3647OpenMr. H. Nakaya, Mazda (North America), Inc., 23777 Greenfield Road, Suite 462, Southfield, MI 48075; Mr. H. Nakaya Mazda (North America) Inc. 23777 Greenfield Road Suite 462 Southfield MI 48075; Dear Mr. Nakaya: This responds to your letter asking about the definition of occupan compartment air space for purposes of determining the application of Standard No. 302, *Flammability of Interior Materials*. You asked whether the cargo areas of two cars must comply with the standard if these areas always or sometimes open into the occupant compartment.; The term 'occupant compartment air space' is defined in the standard a 'the space within the occupant compartment that normally contains refreshable air.' In previous interpretations regarding the applicability of the standard to a particular area of a vehicle, the question has turned upon whether people can and do ride in the area in question. In letters regarding vans, the agency has taken the position that the space to the rear of the rearmost seat was not part of the occupant compartment. The reasoning underlying those interpretations was that that area was not typically occupied by passengers. However, the agency came to a different conclusion regarding the space behind the rear seat in station wagons. Since passengers can and do ride in that area, the agency concluded that it was part of the occupant compartment. For this interpretation, see the last page of the enclosed letter.; The Case I car in your letter presents a situation seemingly similar t that of station wagons. The Case I car appears to be a liftback car with a cargo carrying area behind the rear seat. If passengers can ride in the area behind the rear seat, then that area would be part of the occupant compartment and would be subject to the standard. As to the Case II car, which appears to be a sedan with internal access to the trunk by means of the folding backs of the rear seats, the agency does not regard the trunk area as part of the occupant compartment. It does not appear from your diagrams that people would ride in that area.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2955OpenMr. William J. Baldridge, City Manager, City of Royal Oak, P.O. Box 64, Royal Oak, MI 48068; Mr. William J. Baldridge City Manager City of Royal Oak P.O. Box 64 Royal Oak MI 48068; Dear Mr. Baldridge: This responds to your December 21, 1978, letter asking the Nationa Highway Traffic Safety Administration (NHTSA) to permit the City of Royal Oak, Michigan to obtain a waiver from the safety standards applicable to one of its vehicles. In particular, you ask that several standards be waived because the vehicle, as altered by the addition of an aerial bucket, would no longer comply with them.; Your letter does not clearly indicate the cause of the noncomplianc with Federal safety standards. The NHTSA concludes that the noncompliance probably arises because the altered vehicle will exceed the 'unloaded vehicle weight' that is used in determining its compliance with several of the agency's standards. Although the agency appreciates the problems that your city has with obtaining a complying vehicle, the NHTSA has no authority to grant exemptions from safety standards for individual vehicle *users*.; The manufacturer and alterer of the vehicle are responsible fo certifying that it complies with all Federal safety standards. The Federal government does not issue certificates that any vehicle complies with safety standards. The manufacturer or alterer, as part of its certification, must insure that its vehicle does not exceed the weight restrictions that are appropriate for the vehicle. Accordingly, if a vehicle alterer has informed you that an alteration cannot be done without exceeding the manufacturer's established weight restrictions, then the alterer could not truthfully certify the vehicle for compliance.; The NHTSA regrets the problems caused to Royal Oak by th implementation of the safety standards. The agency has received a petition from the Truck Body and Equipment Association asking for rulemaking to prevent future problems such as yours. The NHTSA currently is evaluating that petition. To resolve your problem, the agency suggests that you consider selling the chassis and utility body that you currently own and purchase another chassis and body that has a sufficient 'unloaded vehicle weight' to accommodate the alteration you intend. This will enable the vehicle that you finally obtain to comply with safety standards. These standards improve vehicle safety, and we are sure that Royal Oak would not want to purchase an unsafe vehicle.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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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"; |
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.