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: aiam0510OpenMr. Leonard Teich, Eddington Thread Manufacturing Company, Street & Knights Roads, Eddington, PA, 19020; Mr. Leonard Teich Eddington Thread Manufacturing Company Street & Knights Roads Eddington PA 19020; Dear Mr. Teich: This is in reply to your letter of November 9, 1971, inquiring o behalf of the Ford Motor Company to whom you supply synthetic sewing threads, whether there is a specification for the flammability of sewing thread.; Motor Vehicle Safety Standard No. 302, 'Flammability of Interio Materials' (49 CFR 571.302) (copy enclosed), which becomes effective September 1, 1972, establishes minimum requirements for the flammability of certain motor vehicle components which are listed in S4.1 of the standard. Any synthetic or other thread that is used in the manufacture of any of these components must meet the standards requirements when tested as part of the component.; If you have additional questions, please let us know. Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0005OpenEaton Corporation Truck Components Operations P.O. Box 4013 Kalamazoo, MI 49003; Eaton Corporation Truck Components Operations P.O. Box 4013 Kalamazoo MI 49003; Dear Mr. Batten: This responds to your letter and telephon conversation with Ms. Fujita of my staff concerning Federal Motor Vehicle Safety Standard (FMVSS) No. 124, Accelerator Control Systems. You asked about the standard's 'applicable mileage requirement or time domain' for a truck with a gross vehicle weight rating greater than 10,000 pounds. You informed Ms. Fujita that, stated differently, your question is whether NHTSA requires a used vehicle to continue to meet an FMVSS, and if the answer is yes, for what mileage or amount of time the vehicle must meet the standard. Generally speaking, the answer is no. NHTSA is authorized by the National Traffic and Motor Vehicle Safety Act (Safety Act) to regulate the manufacture and sale of new motor vehicles and motor vehicle equipment. The Safety Act requires a vehicle to comply with applicable FMVSS's until its first purchase in good faith for purposes other than resale. However, you should be aware that manufacturers, distributors, dealers, or motor vehicle repair businesses modifying a vehicle (new or used) are prohibited by section 108(a)(2)(A) of the Safety Act from knowingly rendering inoperative any device or element of design installed on or in a motor vehicle in compliance with an applicable FMVSS. Thus, in the context of Standard No. l24, a person in the aforementioned categories is prohibited from rendering inoperative an accelerator control system that has been installed in compliance with that standard. In addition, if the in-use deterioration of the performance of a vehicle or one of its components creates a safety risk, it could constitute a safety-related defect. Pursuant to sections l5l-l54 of the Safety Act, manufacturers are required to notify NHTSA and owners of such safety-related defects and to remedy such defects without charge. Thus, if the accelerator control systems on your vehicles deteriorate such that they no longer would comply with Standard No l24 and create an unsafe situation, that could be the basis for a defect determination, even though the vehicles met all applicable safety standards when they were new. I also note that our sister agency in the Department, the Federal Highway Administration (FHWA), has operational and equipment requirements for trucks used in interstate commerce. If you are interested in that agency's requirements, you can write to them at the following address: Office of Motor Carrier Standards Federal Highway Administration 400 Seventh Street, S.W. Washington, D.C. 20590 I hope this information is helpful. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam2038OpenMr. Frank C. Howard, Jr., Flenniken Financial Services, Inc., 515 Market Street, Knoxville, Tennessee 37902; Mr. Frank C. Howard Jr. Flenniken Financial Services Inc. 515 Market Street Knoxville Tennessee 37902; Dear Mr. Howard: This responds to your letter of July 1, 1975, concerning the lega duties of a tire recapping firm which you insure.; For your convenience, I have enclosed a copy of Federal Motor Vehicl Safety Standard No. 117, *Retreaded Pneumatic Tires*. This standard does not specify the testing which a manufacturer of retreaded tires must do, it does specify the criteria which the tires must meet when tested by the National Highway Traffic Safety Administration (NHTSA) for compliance. While the surest way for the retreader to be confident of compliance would be to follow the procedures in every detail, he is not legally obligated to do so. Section 108 of the National Traffic and Motor Vehicle Safety Act of 1966, as amended, requires him to assure himself that, when tested by the NHTSA according to the procedures set out in the standard, his tires will meet the specified criteria. In addition, he is required to repair or replace without charge a non-complying tire.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam5207OpenMr. Dave Beidleman Arizona Department of Transportation Equipment Services; Mr. Dave Beidleman Arizona Department of Transportation Equipment Services; FAX 602-258-5193 Dear Mr. Beidleman: We have received your FAX of Jul 2, 1993, to the attention of Taylor Vinson of this Office, asking for an interpretation of Motor Vehicle Safety Standard No. 108 as it pertains to the location of rear identification lamps. The rear configuration of l0 dump trucks that are being constructed for the Arizona DOT is such that you would like to raise the center lamp of the three- lamp identification lamp cluster approximately 1 1/2 inches, the two outer lamps of the array cannot be raised due to the positioning of the underbody tailgate release mechanism. Table II of Standard No. 108 requires that the identification lamps be mounted 'as close as practicable to the top of the vehicle, at the same height, and as close as practicable to the vertical centerline.' In our opinion, the lamps in an identification lamp cluster must be equally spaced laterally and mounted at the same height in order for the identification lamp system to perform its intended purpose. Therefore, I am afraid the agency cannot accept a lamp display that differs. Although the lamps could be mounted on the rear of the cab, we understand that in that position they could be obscured by the top lip of the dump body. We realize that the contractor has pre-punched holes for the lamps, which would be flush-mounted in the rear cross sill of the truck body. If a way were found to cover the holes, there are surface-mounted lamps available which could be mounted at the same height (your desired height for the center lamp) in a manner than should not affect the positioning of the underbody tailgate release mechanism. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0455OpenMr. J. A. Westphal, Senior Project Manager, FND Corporation, Clintonville, WI 54929; Mr. J. A. Westphal Senior Project Manager FND Corporation Clintonville WI 54929; Dear Mr. Westphal: In response to your letter of September 15, 1971, requesting ou interpretation of certain motor vehicle safety standards and regulations:; >>>1. Federal Motor Vehicle Safety Standard No. 208, 'Occupant Cras Protection,' as amended at 36 F.R. 4600 (March 10. 1971). If trucks over 10,000 pounds GVWR are equipped with a seat belt system as in paragraph S4.3.2, the vehicles need not meet the requirements of paragraphs S5 and S6, which apply only when the complete passive protection system option of paragraph S4.3.1 is adopted. Of course, the seat belt system must conform to the seat belt assembly requirements of Federal Motor Vehicle Safety Standard No. 209, 'Seat Belt Assemblies.'; 2. Federal Motor Vehicle Safety Standard No. 206, 'Door Locks and Doo Retention Components.' Your interpretation of the standard's coverage is correct: there are no requirements in the standard for the installation of the latches and hinges.; 3. Part 573, 'Defect Reports,' 36 F.R. 3064 (February 17, 1971). Th National Traffic and Motor Vehicle Safety Act and our regulations do not require manufacturers to repair defective motor vehicles. Manufacturers are therefore free to make whatever arrangements for repair of defects they wish. Of course, we hope that in making such arrangements the manufacturers will assume the responsibility of assuring that the repairs are made properly.<<<; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam2468OpenInterps. File, 49 CFR Part 575.104, (UTQGS); Interps. File 49 CFR Part 575.104 (UTQGS); Subject: Tread Label Format: *Uniform Tire Quality Grading Standards* On December 16, 1976, I received a telephone call from Mr. Calvi Schaffner of B.F. Goodrich Co. (216 379-3470) concerning Figure 2 of the Uniform Tire Quality Grading Standards, 49 CFR S 575.104. That figure depicts the format of the tread label required by the rule.; Mr. Schaffner referred to Figure 2 as it appears in Notice 21 (41 F 54205, December 13, 1976). I explained that, because Notice 21 is a notice of proposed rulemaking rather than final rulemaking, the inclusion of the warnings in the traction and temperature grades is not yet certain. I further explained, however, that (i) in all other respects, the depiction of Figure 2 in that notice was correct, (ii) the appearance of Figure 2 was incorrect in both Notices 17 and 18, due to printing errors at the Federal Register, and (iii) this point would be clarified in a final rulemaking notice.; Mark Schwimmer, Attorney-Advisor |
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ID: aiam5657OpenTerence J. Kann, P.A. 115 N.E. Seventh Avenue Gainesville, FL 32601; Terence J. Kann P.A. 115 N.E. Seventh Avenue Gainesville FL 32601; Dear Mr. Kann: This responds to your letter of November 14, 1995, t Ricardo Martinez, M.D. Administrator of the National Highway Traffic Safety Administration. You have asked whether 'pole trailers such as those used in the logging industry, are required to have retro-reflective sheeting, reflex reflectors, or a combination?' If not, you asked whether NHTSA issued 'any explanation for failing to extend the requirements to pole trailers.' As you noted, Section S3(a) of Motor Vehicle Safety Standard No. 108 applies to 'trailers (except pole trailers) . . . .' This means that pole trailers, as defined in 49 CFR 571.3(b) are exempted from all the requirements of Standard No. 108 including those of Section S5.7 which specifies conspicuity requirements for 'each trailer of 80 or more inches overall width and with a GVWR over 10,000 pounds'. Pole trailers have always been excluded from Standard No. 108 (see 23 CFR 255.51, Motor Vehicle Safety Standard No. 108, Section S2, effective January 1, 1968). Thus, the agency never proposed in the first instance that conspicuity requirements apply to pole trailers, and there was no discussion of pole trailers in the preambles to the proposal and final rule. Apparently, pole trailers were defined and excluded on the basis of comments to Standard No. 108 as originally proposed late in 1966 that a standardized lighting scheme might be impracticable for this category of vehicle. If you have any questions, you may refer them to Taylor Vinson of this Office (202-366-5263). Sincerely, Samuel J. Dubbin Chief Counsel; |
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ID: aiam2192OpenMr. James A. Witt, General Counsel, General Teamsters Local 959, State of Alaska, P.O. Box 2092, Anchorage, AK 99510; Mr. James A. Witt General Counsel General Teamsters Local 959 State of Alaska P.O. Box 2092 Anchorage AK 99510; Dear Mr. Witt: This responds to your January 29, 1976, questions whether a owner-operator of a vehicle manufactured to comply with Standard No. 121, *Air Brake Systems*, may legally disconnect portions of the brake system after a vehicle is delivered, or specify that the vehicle be delivered without certain portions of the brake system installed. your members are asking about the antilock portion of the brake systems installed to meet the 'no lockup' provisions of the standard (S5.3.1).; Two provisions of the National Traffic and Motor Vehicle Safety Act (1 U.S.C. S 1381 *et seq*.) are involved. Section 108(a)(1)(A) prohibits the sale of any vehicle unless it complies with all applicable safety standards that were in effect on the date of the vehicle's manufacture. This means that a member cannot purchase a newly-constructed tractor with portions of the brake system disconnected, if those portions are installed in compliance with the standard. The antilock portions of the system are, as far as I know, installed in compliance with the standard and therefore cannot be disconnected prior to sale.; Section 108(a)(2)(A) with which you are familiar prohibits, with on exception, knowing disconnection of the antilock system by manufacturers, distributors, dealers, repair businesses. Thus, there is no prohibition on disconnection by an owner- operator of his own vehicle's system under the Traffic Safety Act. However, other State or Federal statutes, or the regulations of the Bureau of Motor Carrier Safety may prohibit disconnection. In any case, the NHTSA urges that you not disconnect safety devices without consultation with the vehicle manufacturer with regard to the safest configuration of the vehicle.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam4945OpenMr. S. Suzuki Managing Director Suzusho Trading Co. Center Building No. 601 Fuchucho 1-12-7, Fuchu-shi Tokyo, Japan; Mr. S. Suzuki Managing Director Suzusho Trading Co. Center Building No. 601 Fuchucho 1-12-7 Fuchu-shi Tokyo Japan; Your ref: ST-9015/91 Dear Mr. Suzuki: This responds to your letter o October 16, l991, to the Director, Office of Public and Consumer Affairs, with reference to the 'Safety Shot' lighting device that you have developed. You have enclosed photographs illustrating three types of this device in operation. In brief, the device consists of a center red highmounted stop lamp, immediately flanked by amber lamps that serve as supplementary turn signal/hazard warning signal lamps. Although the photos are not entirely clear, the device appears to consist of segmented compartments in a common housing, with thicker dividers separating the signal and stop functions. Type I incorporates an L.E.D. and is mounted at the top of the rear window. Type II also incorporates an L.E.D. and is mounted at the bottom of the window. Type III is located at the top of the rear window and uses conventional bulbs for its light source. You have been referred to us by Chrysler Corporation. We assume that you approached Chrysler with a view towards having your device accepted as original motor vehicle equipment. You have asked for our views on whether it is possible to use this device in the U.S. market. In the United States, the applicable Federal motor vehicle safety standard for rear lighting is Standard No. 108, Lamps, Reflective Devices, and Associated Equipment. Section S5.4 of Standard No. 108 does not allow a center high-mounted stop lamp to be physically combined with any other lamp or reflective device. Because Safety Shot appears to have a common housing for signalling and stopping functions, the lamps are 'combined' within the meaning of the prohibition. This means that the Safety Shot may not be used as original equipment on motor vehicles, and it may not be offered as a replacement for original equipment center highmounted stop lamps (required on each passenger car manufactured on or after September 1, l985). If you wish to sell the Safety Shot as an accessory in the aftermarket, for passenger cars manufactured before September 1, l985, different considerations apply. Installation of the Safety Shot by a manufacturer, distributor, dealer, or motor vehicle repair business is not permitted if it renders inoperative, in whole or in part, the function of any other rear lighting device. The question, therefore, is whether the effectiveness of the function of any other rear lighting device is compromised by the Safety Shot to the extent that the other device's function is rendered, at the minimum, partially inoperative. We note that original equipment amber signal lamps are not prohibited from flashing when the stop lamps are operating. It would not appear that the addition of the Safety Shot to a passenger car manufactured before September 1, l985, would compromise the signals from the original turn signal and stop lamps in a manner to render them, at least, partially inoperative. However, the Safety Shot is subject to regulation by the individual States of the United States in which it is sold or used. We are unable to advise you on State laws, and suggest that you write for an opinion to American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203. Motor vehicles are also required to be manufactured to conform to Standard No. 111, Rearview Mirrors. Under this standard, if installation of the Safety Shot prevents the vehicle from meeting the rearview mirror field of view requirements specified, the manufacturer, distributor, dealer, or motor vehicle repair business installing the Safety Shot must install a rear view mirror on the passenger side of the vehicle (as a practical matter, most vehicles in the U.S. are manufactured with this additional mirror). Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam3629OpenMr. Gene Wright, Vice-President, Manufacturing, CAPACITY OF TEXAS, INC., P.O. Box 7848, Longview, TX 75607; Mr. Gene Wright Vice-President Manufacturing CAPACITY OF TEXAS INC. P.O. Box 7848 Longview TX 75607; Dear Mr. Wright: This responds to your letter of October 11, 1982, concernin regulations specifying the type of steering system required in vehicles. In particular, you asked if a mechanical link is required in the steering system or whether a hydraulic system is acceptable. As explained below, a manufacturer can use either a mechanical or hydraulic system to meet the requirements of the applicable Federal Motor Vehicle Safety Standards.; There are two Federal Motor Vehicle Safety Standards that apply t vehicle steering systems: Standard No. 203, *Impact Protection for the Driver Steering Control System*, and Standard No. 204, *Steering Column Rearward Displacement*. Both standards, copies of which are enclosed, establish performance requirements to protect the driver from steering column-related injuries in a crash. Any type of steering system, either mechanical or hydraulic, can be used as long as it meets the applicable requirements of those standards.; If you have any further questions please let me know. Sincerely, Frank Berndt, Chief Counsel |
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Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.