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: aiam0758OpenMr. Chester R. Ely, President, Mercury Fabricators, 8335 Atlantic Boulevard, Cudahy, CA, 90201; Mr. Chester R. Ely President Mercury Fabricators 8335 Atlantic Boulevard Cudahy CA 90201; Dear Mr. Ely: This is in reply to your letter of June 20, 1972, in which you as whether Motor Vehicle Safety Standards Nos. 206 (Door Locks and Door Retention Components) and 302 (Flammability of Interior Materials) apply to aluminum sleeper cabs which you manufacture for what appears to be installation on truck tractors.; Each motor vehicle safety standard is by its terms applicable t specific types of motor vehicles and motor vehicle equipment. Each vehicle or item of equipment to which a standard applies must conform to the standard until its first purchase by a user. Components which are incorporated into vehicles before their first purchase are considered to be part of the vehicle, and as a practical matter must conform to all standards applicable to it.; Standard No. 302 becomes effective September 1, 1972, and applies t trucks, which includes truck tractors. If a sleeper cab you manufacture is incorporated into a truck before its first purchase by a user, then it must conform to the standard. Moreover, the components to which the standard applies (paragraph S4.1) include mattress covers, and if you determine the standard applies under the criteria we have provided, mattress covers which you furnish must conform to the standard. You indicate you have tested the flammability of the cab utilizing a torch. While you may test for conformity to the standard in any way you choose, whether or not your product conforms to the standard will be determined by NHTSA utilizing the test procedures specified in the standard. Manufacturers who utilize procedures different from those in the standard should take care to correlate the results they obtained to those that would be obtained using the standard's procedures.; Standard No. 206 also applies to trucks, and will become effective fo all side doors leading to passenger compartments on September 1, 1972. Consequently, if the sleeper cabs you manufacture are incorporated into trucks before their first purchase the sleeper cabs must conform to Standard No. 206.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2765OpenMr. Garry Williams, Body Designer, Telsta Group, General Cable Corporation, P.O. Box 666, Westminster, CO 80030; Mr. Garry Williams Body Designer Telsta Group General Cable Corporation P.O. Box 666 Westminster CO 80030; Dear Mr. Williams: This is in reply to your letter of February 3, 1978, concernin placement of the rear identification lamps on a truck. Because the truck has a mast assembly located on the longitudinal axis of the vehicle and center of the rear axle, you have asked whether the lamps should be mounted 'on the mast as high as possible or on the rear face of the rear floor decking.'; Table II of Federal Motor Vehicle Safety Standard No. 108 requires rea identification lamps to be mounted 'as close as practicable to the top of the vehicle....' If placement on the mast interferes with the operation of the lift, or if the lamp would be easily damaged in that location, that location would not appear to be 'practicable' within the meaning of Standard No. 108, and the deck location would fulfill the practicability requirements.; You have also asked which is more important in locating identificatio lamps: '(1) ...as high as possible on a stationary surface and face the lights toward the rear, or (2) to locate to the most rearward surface and then as high as possible on that surface'. Your first choice is the correct one. The purpose of the three lamp cluster is to identify large and frequently slow moving vehicles under conditions of reduced visibility. Therefore, it is more important for the lamps to be located high than it is for them to be at the rear end of the vehicle, for example, on the cab rather than at the deck end. However, the decision as to what is 'practicable' is initially that of the manufacturer and we have generally found those decisions to be correct.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3877OpenMr. Jerry D. Williams, Senior Vice President, American Transportation Committee, Highway 65 South, Conway, AR 72032; Mr. Jerry D. Williams Senior Vice President American Transportation Committee Highway 65 South Conway AR 72032; Dear Mr. Williams: This is in further response to your December 12, 1984 letter to th National Highway Traffic Safety Administration (NHTSA) concerning our definition of a school bus. Your specific question asked, 'Are vehicles which are built to carry ten school aged passengers or less, and which are used for school or related functions, considered by NHTSA to be school buses or multipurpose passenger vehicles?' As explained below, a vehicle carrying 11 or more persons (i.e., 10 children and a driver) to and from school or related events would be considered a school bus. A vehicle carrying 10 or less persons would be a multipurpose passenger vehicle.; Under the definitions section of our Federal Motor Vehicle Safet Standards (49 CFR Part 571.3), vehicles carrying 11 or more persons which are sold for purposes that include carrying students to and from school or related events are 'school buses.' Under our regulations, a vehicle which is designed to carry less than 11 persons would be considered a multipurpose passenger vehicle. Such a vehicle would be certified as complying with the safety standards applicable to multipurpose passenger vehicles.; Ms. Deirdre Hom of my staff informed your associate, Mr. Joe Clark, o the above in a telephone call on December 14, 1985. This letter confirms the information given to Mr. Clark in that conversation.; If you have any further questions, do not hesitate to contact m office.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0308OpenMr. Kenneth W. Brown, Cabot Corporation, 125 High Street, Boston, Massachusetts 02110; Mr. Kenneth W. Brown Cabot Corporation 125 High Street Boston Massachusetts 02110; Dear Mr. Brown: This will acknowledge your letter of March 10, 1971, to the Departmen of Transportation, requesting exemption from Retreaded Standard No. 117.; The Department of Transportation has not promulgated a standar entitled 'Retreaded Standard No. 117' consequently, no conformance is required until such a time as a retreaded standard becomes the law.; Sincerely, E.T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam2335OpenMr. Richard McRay, Chief Engineer, Walter Motor Truck Company, School Road, Voorheesville, NY 12180; Mr. Richard McRay Chief Engineer Walter Motor Truck Company School Road Voorheesville NY 12180; REGISTERED MAIL - RETURN RECEIPT REQUESTED Dear Mr. McRay: This is in reply to your letter of June 18, 1976 providing us you views with respect to defect notification. You appear to have concluded that you were not required to provide either a certification label or an incomplete vehicle document to Advance Mixer, Inc. (AMI) with respect to the 50 mixer trucks in question, but acknowledge the fact that 'the label furnished by us was . . . incorrect.' You wish to correct the error 'by requesting that the customer (AMI) remove the incorrect data plate from the vehicle.'; We have reviewed the information supplied with your letter and you argument that Walter acted as a sub-contractor to AMI for the purposes of constructing and assembling a proprietary item. They do not alter our conclusion expressed on June 10, 1976, that Walter, as the certifying manufacturer of a motor vehicle, has the obligation to inform the purchaser of the defect in the vehicle, and to remedy it.; Mixer trucks are vehicles manufactured in two or more stages as tha term is employed in 49 CFR Part 568. Their manufacture is begun by an 'incomplete vehicle manufacturer' (Walter) and completed by a 'final-stage manufacturer' (AMI). Certification of the completed vehicle, which is required by S 114 of the National Traffic and Motor Vehicle Safety Act of 1966, may be accomplished by either party. If the final stage manufacturer is to certify the completed vehicle, the incomplete vehicle manufacturer is required by S 568.4 to furnish an incomplete vehicle document with its incomplete vehicle. No such document need be supplied where the incomplete vehicle manufacturer is the certifying party. Regardless of what you believe to be the 'unusual circumstances' surrounding the construction of the 50 trucks, it appears that Walter nevertheless allowed itself to be the certifier of the trucks and supplied the incorrect labels that were affixed to them. Under those circumstances we believe that a court of law would find persuasive our argument that Walter was an incomplete vehicle manufacturer that had assumed 'legal responsibility for all duties and liabilities imposed on manufacturers by the National Traffic and Motor Vehicle Safety Act . . . with respect to the vehicle as finally manufactured. . .' within the meaning of S 568.7(a), or alternatively that, it had failed to provide the incomplete vehicle document required by Part 568.; One of the certifying party's obligations is to notify vehicle owner and remedy the defect upon determination of the existence of a safety-related defect in a motor vehicle. We assume, of course, that AMI will cooperate in providing Walter appropriate weight rating information for the labels and a list of the purchasers of the 50 trucks. To expedite this matter I am providing AMI's Washington counsel with a copy of your letter of June 18 and this response.; As you know, pursuant to Section 109 of the Act a maximum civil penalt of $1,000 may be imposed for each violation, and there are 50 trucks involved here. Since the error apparently 'resulted from Walter's administrative misinterpretation' and not from an attempt to evade responsibilities, we would be willing to close our file without imposing civil penalties provided Walter conducts a suitable notification campaign. Otherwise we may institute proceedings under Section 152 to compel notice.; We request your further views within 20 days after receipt of thi letter. We would be willing to help you initiate the campaign by critiquing a draft notification letter should you wish to submit it with your response.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam3174OpenMr. Thomas F. Brown, Executive Engineer, Vehicle Regulations and Standards, Mack Trucks, Inc., P.O. Box 1761, Allentown, PN 18105; Mr. Thomas F. Brown Executive Engineer Vehicle Regulations and Standards Mack Trucks Inc. P.O. Box 1761 Allentown PN 18105; Dear Mr. Brown: Thank you for your letter of November 21, 1979, pointing ou discrepancies in Federal Motor Vehicle Safety Standard No. 108 as published in the Code of Federal Regulations and as published in 'Federal Motor Vehicle Safety Standards and Regulations.'; You are correct that the version of S4.1.5 appearing in 'Federal Moto Vehicle Safety Standards and Regulations' erroneously incorporates the paragraph of the Federal Register amendment notice finding that good cause had been shown for an immediate effective date. The error does not appear, however, in the official version of Standard No. 108 which appears in the Code of Federal Regulations.; The footnote reference to 'S4.4.2' and the reference to 'S3.1' in th interpretation do appear, however, in the Code of Federal Regulations. Originally, there was a paragraph S4.4.2 prescribing the testing sequence of combination turn signal and hazard warning signal flashers, referenced by footnotes in Tables I and III. As you may recall, there was a Standard No. 108a scheduled to become effective on January 1, 1973, which omitted S4.4.2 with its footnote reference, and added detailed performance and testing requirements for flashers under a new paragraph, S4.6. When Standard No. 108a was revoked, S4.4.2 was never reinstated as a requirement, though the footnote references to it still appear in Tables I and III as you have noticed.; With respect to the reference to 'S3.1' appearing in Note 2 to Standar No. 108 in the Code of Federal Regulations, this is the S3 which appeared in the December 16, 1967, version of Standard No. 108 cited by the Note. When Standard No. 108 was amended effective January 1, 1972, S3.1 became S4.1. Thus, the continued reference to S3.1, though confusing, is correct in its context.; Your final comment is that the amendments to Tables I and III affecting headlamps, as published on July 27, 1978, have not been picked up by the agency's publication 'Federal Motor Vehicle Safety Standards and Regulations.' You are correct. We hope that recent steps taken by this agency will end the problems that have been experienced with this publication. However, I must emphasize that the only legal version of Standard No. 108 is that appearing in the Code of Federal Regulations, currently revised as of October 1, 1978, plus amendments and corrections published in the *Federal Register* since that date.; We appreciate your calling these mistakes to our attention. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1149OpenMr. David J. Humphreys, RVI, Inc. Suite 406, 1140 Connecticut Avenue, Washington, DC 20006; Mr. David J. Humphreys RVI Inc. Suite 406 1140 Connecticut Avenue Washington DC 20006; Dear Mr. Humphreys: This is in reply to your letter of May 18, 1973, concerning a defec notification campaign involving furnaces manufactured by Suburban Manufacturing Company of Dayton, Tennessee, that have been used in recreational vehicles. You ask whether the obligation of the individual vehicle manufacturers under the Safety Act and applicable regulations may be met if the appropriate documents and notices are sent or filed by Suburban Manufacturing.; Suburban Manufacturing Company may prepare and submit to NHTSA or mai to purchasers, on behalf of the individual vehicle manufacturers, the information required by 49 CFR Part 573 'Defect Reports,' 49 CFR Part 577, 'Defect Notification,' and Section 113 of the Safety Act (15 U.S.C. 1402). However, the requirements must be met as they apply to manufacturers of motor vehicles, and not manufacturers of equipment. Moreover, the vehicle manufacturers themselves will still be responsible if any of the documents filed or sent by Suburban Manufacturing Company fail to fully conform to all applicable requirements.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam3524OpenMr. Brian Gill, Manager, Certification Department, American Honda Motor Co., Inc., P.O. Box 50, Gardena, CA 90247; Mr. Brian Gill Manager Certification Department American Honda Motor Co. Inc. P.O. Box 50 Gardena CA 90247; Dear Mr. Gill: This is in reply to your letter of December 11, 1981, asking fo confirmation of your interpretation of paragraph S5.2.5 of Motor Vehicle Safety Standard No. 123, *Motorcycle Controls and Displays*.; Paragraph S5.2.5 requires that 'Each footrest for a passenger othe than an operator shall fold rearward and upward when not in use.' Honda would like to use a 'footboard' instead of a 'footrest'. In folding, the footboard folds upward in a clockwise manner and rearward and Honda believes that this meets Standard No. 123. We consider that the purpose of S5.2.5 is to prevent accidents caused by rigid footrests contacting the ground in a banking turn. The outer edge of the footboard in plan view lies inboard of wider parts of the vehicle such as the engine guard pipe and side bumper. This means that these portions of the motorcycle would contact the ground in an extreme banking turn before the proposed footboard.; The standard specifies no direction of upward motion of the footrest We believe your design complies with the intent of Standard No. 123.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1519OpenMr. John W. Kourik, Chief Engineer, Automotive Products, Wagner Electric Corporation, 6400 Plymouth Avenue, St. Louis, MO 63133; Mr. John W. Kourik Chief Engineer Automotive Products Wagner Electric Corporation 6400 Plymouth Avenue St. Louis MO 63133; Dear Mr. Kourik: This responds to your May 7, 1974, request to know whether check valve or equivalent devices must be placed immediately adjacent to or within each service reservoir in a trailer air brake system to comply with S4.2.1.5 of Standard No. 121, *Air brake systems*, and whether the standard intends each axle subsystem to have a separate service reservoir and check valve system, with particular regard to arrangements for liftable axle systems. S5.2.1.5 states:; >>>S5.2.1.5 Each service reservoir shall be protected against loss o air pressure due to failure or leakage in the system between the service reservoir and its source of air pressure by check valves or equivalent devices.<<<; The answer to both of these questions is no. In an April 3, 1974 letter to Great Dane Trailers, Inc., we interpreted S5.2.1.5 to permit location of the check valve at the isolated reservoir, permitting that valve to also guard the service reservoirs on that axle system. The language of S5.2.1.5 is unclear in this regard, and may be amended in the future. In response to your specific question, it is permissible to use a single check valve to protect more than one reservoir in a subsystem.; Standard No. 121 does not require a separate service reservoir chec valve for each axle system in a tandem axle. As you point out this could decrease total vehicle reliability, and abuse in this area could lead to amendment of the provision. In answer to your fourth question, a single check valve could be utilized to protect the air reservoir or reservoirs required for a liftable axle system or subsystem.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3031OpenMr. Moe Pare, Jr., Director of Design, Cars & Concepts, Inc., 12500 E. Grand River, Brighton, MI 48116; Mr. Moe Pare Jr. Director of Design Cars & Concepts Inc. 12500 E. Grand River Brighton MI 48116; Dear Mr. Pare: This responds to your May 21, 1979, letter concerning the markin requirements for vehicle windshields having shade bands. You asked whether the 'A S1' marking symbol required by Safety Standard No. 205, *Glazing Materials*, can be placed on the tint band itself rather than on the glazing material below the band, if the tint band is a flexible sheet applied on top of the glazing.; Safety Standard No. 205 incorporates by reference the American Nationa Standard 'Safety Code for Safety Glazing Materials', ANS Z26. The ANS Z26 standard requires special additional markings for glazing that has shade bands or tinted areas:; >>>'Glazing materials, which in a single sheet of material, ar intentionally made with an area having a luminous transmittance of not less than 70 percent (Test NO. 2), adjoining an area which has less than 70-percent luminous transmittance, shall be permanently marked at the edge of the sheet to show the limits of the area which is intended to comply with Test No. 2. The markings shall be A S1 or A S2, etc., the direction of the arrow indicating the portion of the material which complies with Test No. 2 and the number indicating the item with which that portion of the sheet complies ....'<<<; You will note from the quoted portion of this specification that th special marking is only required if the tinted shade band area of the windshield has a luminous transmittance of less than 70 percent. Your letter states that the transparent windshield tint band that you intend to use allows 70 percent light transmission. Therefore, you would not be required to use the 'A S1' special marking either on the band itself or on the glazing.; For removable tint bands of this type that do not have a 70 percen light transmission, however, the agency would permit the 'A S1' marking to be on the tint band itself rather than on the underlying glazing, provided the marking is located at the lowest possible portion of the tint band.; Sincerely, Frank Berndt, 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.