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 |
|---|---|
ID: aiam3224OpenMr. C. Crissy, Manager, Mechanical Products, Aeroquip Corporation, 300 South East Avenue, Jackson, MI 49203; Mr. C. Crissy Manager Mechanical Products Aeroquip Corporation 300 South East Avenue Jackson MI 49203; Dear Mr. Crissy: This responds to your Janaury 17, 1980, letter asking whether th performance requirements of the parking brake sections of Standard No. 121, *Air Brake Systems*, permit the use of a common piston for both the service and parking brakes.; In our August 9, 1979, Federal Register notice (44 FR 46850), we state that the performance requirements of the parking brake system must be achieved with any single leakage- type failure in the service brake system, including a ruptured diaphragm. The use of the diaphragm example was intended only to clarify a question that had been raised by a commenter to the notice proposing the parking brake amendment. The diaphragm example does not limit the requirement that any single leakage- type failure of a component of the service brake system must not affect the peformance of the parking brake system.; With respect to your question, you state that a piston does not fail i the sudden manner of a diaphragm. Although this may be accurate, it is not the correct approach for interpretation of the performance requirements of the parking brake sections of the standard. If your parking brake system would comply with the requirements of the standard once the piston in the service brake system has failed, then you would be permitted to use a common piston. If, on the other hand, a failure of the service brake piston would cause the parking brake system to fail the requirements, a common piston would not be allowed.; Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam1219OpenMr. D. Black, Technical Director, Alfa Romeo, Inc., 250 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. D. Black Technical Director Alfa Romeo Inc. 250 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Black: This is in response to your letter of August 9, 1973, in which yo inquire whether Alfa Romeo may add to the consumer information 'handouts' for prospective purchasers, required by NHTSA regulations, the consumer information required by the Environmental Protection Agency.; As long as the information required by NHTSA is presented in conformit with 49 CFR Part 575, we have no objection to the inclusion within the same covers of additional information relative to EPA requirements.; The wall posters you mentioned are not required by our regulations, s you may do with them as you please.; Sincerely, Lawrence R. Schneider, Chief Counsel |
|
ID: aiam0058OpenMr. C. A. Pierquet, Truck Equipment, Incorporated, 680 Potts Avenue, P. O. Box 2345, Green Bay, WI 54306; Mr. C. A. Pierquet Truck Equipment Incorporated 680 Potts Avenue P. O. Box 2345 Green Bay WI 54306; Dear Mr. Pierquet: Thank you for your letter of March 6, 1968, to Mr. Lowell K. Bridwell Federal Highway Administrator, in which you inquired about certification responsibility for lighting on your truck bodies.; Federal Motor Vehicle Safety Standard No. 108 on lighting applies t motor vehicles, not to motor vehicle equipment such as truck bodies.; When the body is mounted on the chassis cab, the lighting requirement of Federal Standard No. 108, not certified by the manufacturer, must be fulfilled.; Certification must be provided to the dealer when the chassis cab i completed for the dealer. A dealer selling to the final purchaser need not certify, but is responsible for lighting to be in compliance with Federal standard No. 108, for that part of the lighting (or other standards) which have not been previously certified.; Trusting this information answers your questions. Sincerely, Joseph R. O'Gorman, Acting Director, Office of Performanc Analysis, Motor Vehicle Safety Performance Service; |
|
ID: aiam2065OpenMr. Joseph E. Casson, Arent, Fox, Kintner, Plotkin & Kahn, Federal Bar Building, 1815 H Street, N.W., Washington, DC 20006; Mr. Joseph E. Casson Arent Fox Kintner Plotkin & Kahn Federal Bar Building 1815 H Street N.W. Washington DC 20006; Dear Mr. Casson: This responds to your September 23, 1975, request for confirmation tha a manufacturer of air-braked buses that conform to Standard No. 121, *Air Brake Systems*, may direct owners of these vehicles to disconnect the antilock system used to meet the standard, for the period necessary to correct a safety-related defect in the system that may make its operation hazardous. Your concern is with S 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397(a)(2)(A)) that states:; >>> S 1397 (2)(A) No manufacturer, distributor, dealer, or motor vehicle repai business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard <<<; Section 108(a)(2)(A) prohibits, with one exception, the knowin disconnection of the antilock system by a manufacturer, distributor, dealer, or motor vehicle repair business. This prohibition does not prevent an owner of air- braked buses from disconnection of the antilock system. The NHTSA has determined that a manufacturer of air-braked buses that conform to Standard No. 121 may instruct the owners of its products to disconnect the antilock system used to meet the standard, for the period necessary to correct a safety-related defect in the system that may make its operation hazardous.; A manufacturer that has determined the existence of a safety- relate defect in his vehicle must, of course, comply with the Defect Report requirements of 49 CFR Part 573 and the Defect Notification requirements of 49 CFR Part 577.; Sincerely, Frank Berndt, Acting Chief Counsel |
|
ID: aiam4918OpenMr. Robert A. Nordmeyer Nordic Associates P.O. Box 925 Woodland Hills, CA 91365; Mr. Robert A. Nordmeyer Nordic Associates P.O. Box 925 Woodland Hills CA 91365; "Dear Mr. Nordmeyer: This responds to your September 18, 1991 letter t NHTSA's Rulemaking office concerning your design for an aftermarket sun visor. Your letter has been referred to me for reply. The National Traffic and Motor Vehicle Safety Act authorizes our agency to issue Federal motor vehicle safety standards that apply to new motor vehicles and items of motor vehicle equipment. The Act also authorizes us to require the recall and remedy of any motor vehicle or item of motor vehicle equipment that contains a safety defect. There is currently no Federal motor vehicle safety standard that applies to an aftermarket sun visor. The safety standards relating to sun visors (Standard 201, Occupant Protection in Interior Impact, and 302, Flammability of Interior Materials) apply only to new motor vehicles and not to items of aftermarket equipment. The sun visor in a new vehicle is regulated by Standard 201, which requires that the visor be 'constructed of or covered with energy-absorbing material' and that the visor's mounting must 'present no material edge radius of less than 0.125 inch that is statically contactable by a spherical 6.5-inch diameter head form.' The purpose of that requirement is to reduce the injuries that occur when unrestrained occupants strike the visor or its mounting with their heads. If your sun visor were installed by the manufacturer of a new motor vehicle, the visor would have to comply with the visor requirements of Standard 201. I am enclosing a copy of the standard for your review. Standard 302 requires sun visors in new vehicles to meet the flammability resistance requirements of the standard. The standard specifies that the material used on the visor must not burn at a rate of more than four inches per minute. A copy of the standard is enclosed. Although your sun visor would be sold in the aftermarket, not as an item of original equipment, Standards 201 and 302 can nonetheless affect persons who install the visor. The Safety Act provides that a person who manufactures, distributes, sells or repairs motor vehicles cannot 'render inoperative' a regulated device such as a sun visor or its mountings. If a repair shop were to remove a vehicle's sun visor and replace it with your visor, the shop would be in violation of the Act unless your visor complied with the standards. An individual owner may install a visor in his or her own vehicle without regard to the standards. You should also be aware that our safety defect authority has a bearing on the manufacture and sale of your visor. Under the Safety Act, your product is considered to be an item of motor vehicle equipment. A manufacturer of motor vehicle equipment is subject to the requirements in sections 151-159 of the Act concerning the recall and remedy of products with safety defects. I have enclosed an information sheet that briefly describes those responsibilities. In the event that NHTSA or a manufacturer determines that the manufacturer's product contain a safety-related defect, the manufacturer would be responsible for notifying purchasers of the defective equipment and remedying the problem free of charge. Please contact us if you have further questions. Sincerely, Paul Jackson Rice Chief Counsel Enclosures"; |
|
ID: aiam0408OpenSSGT S. Jackson-Smith, Box 2708, 513 HQ SQ, APO NY, 09127; SSGT S. Jackson-Smith Box 2708 513 HQ SQ APO NY 09127; Dear SSGT Jackson-Smith: This is in reply to your recent letter inquiring about the mounting o a spare time between headlights of a Volkswagen Camper.; There is no Federal regulation that prohibits the mounting of the spar tire on the front of a vehicle. Federal motor vehicle safety standards apply to new vehicles and regulate manufacturers so as to assure compliance with applicable requirements. The standards do not regulate the vehicle purchaser and owner.; However, in the importation of vehicles into the United States, certai requirements must be met. These requirements are described in the enclosed pamphlet dated October 1969. If your vehicle has been manufactured more recently, up-to-date requirements may be obtained from your Volkswagen dealer.; It is recommended that inquiry be made of the State in which th vehicle will be licensed or driven for applicable laws and regulations in this area.; We appreciate your concern for motor vehicle safety. Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
|
ID: aiam2435OpenMr. Lewis C. Coffey, Chief Engineer, Gillig Bros., Box 3008, 25800 Clawiter Road, Hayward, CA 94540; Mr. Lewis C. Coffey Chief Engineer Gillig Bros. Box 3008 25800 Clawiter Road Hayward CA 94540; Dear Mr. Coffey: This is in response to your letter of September 13, 1976, in which yo ask whether Standard No. 222, *School Bus Passenger Seating and Crash Protection*, requires that the 20-inch maximum separation between the seating reference point and the rear surface of the restraining barrier be measured at the point of greatest distance between the two.; The restraining barrier you describe has padded tubing around it circumference which would be closer to the seating reference point than the center section of the barrier. The National Highway Traffic Safety Administration (NHTSA) interprets the requirements of paragraph S5.2.1 of Standard No. 222 to mean that the 20-inch distance must be measured from the seating reference point to the surface of the seat back or restraining barrier, exclusive of portions which protrude from the basic contour of the surface. The side tube portion would constitute such a protrusion.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
|
ID: aiam4332OpenMr. John B. Krueger, Staff Engineer, Society of Automotive Engineers, Inc., 3001 West Big Beaver, Suite 602, Troy, MI 48084; Mr. John B. Krueger Staff Engineer Society of Automotive Engineers Inc. 3001 West Big Beaver Suite 602 Troy MI 48084; Dear Mr. Krueger: This is in reply to your letter of February 10, 1987, asking th National Highway Traffic Safety Administration (NHTSA) to define the term 'optically combined' as used in paragraph S4.4 of Federal Motor Vehicle Safety Standard No. 108. Presently, the SAE is circulating for comment its own proposed definition of the term, to be incorporated into SAE J387 *Terminology -Motor Vehicle Lighting*.; For Many years paragraph S4.4 (your referenced S4.4.1 which wa renumbered recently) has contained a prohibition against optically combining a clearance lamp with a taillamp or an identification lamp. NHTSA has provided written interpretations to those who have asked whether specific designs are 'optically combined' within the meaning of paragraph S4.4, but the agency has not added a definition to paragraph S3, the definition section of the standard. If a definition is to be provided, it must be incorporated into the standard, and the agency is unable to do that without first formally proposing the definition and offering the public an opportunity to comment upon it. I can say, however, that the SAE's proposed definition is not inconsistent with the interpretations of the agency.; These interpretations are available in the NHTSA docket room (Roo 5109, 400 Seventh St., S.W., Washington, D.C.) for your reference should you or other SAE staff or committee members wish to examine them.; Sincerely, Erika Z. Jones, Chief Counsel |
|
ID: aiam1130OpenMs. Mary Deane Dowdy, Virginia-Carolina Auto Auction, Inc., Post Office Box 2244, Danville, VA 24541; Ms. Mary Deane Dowdy Virginia-Carolina Auto Auction Inc. Post Office Box 2244 Danville VA 24541; Dear Ms. Dowdy: This is in response to your letter of May 11, 1973, in which you ask i the federal odometer disclosure statement may be incorporated in the title of an automobile transfered (sic) at auction.; You may include the disclosure statement on the title or other documen which accompanies the transfer so long as it is executed prior to the transfer. In addition to recording the mileage on the title, the statement would have to contain (1) the date of the transfer, (2) transferor's name and current address, (3) vehicle identification or serial number, make, model, year, body-type, last plate number, (4) a statement that actual mileage differs from recorded mileage if such is the case and the transferor knows it, and (5) reference to the Motor Vehicle Information and Cost Savings Act with the statement that incorrect information may result in civil liability under it.; An example of an adequate statement and format is enclosed for you information.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam4762OpenMr. Pat Crahan Director, Government Relations U-Haul International 2727 North Central Avenue P. O. Box 21502 Phoenix, Arizona 85036-1502; Mr. Pat Crahan Director Government Relations U-Haul International 2727 North Central Avenue P. O. Box 21502 Phoenix Arizona 85036-1502; "Dear Mr. Crahan: Thank you for your letter to Dr. August Burgett o this agency, seeking an interpretation of Standard No. 115, Vehicle Identification Number -- Basic Requirements (49 CFR 571.115). I apologize for the delay in this response. Specifically, you stated that U-Haul manufactures its trailers itself and never sells those trailers to any other party. You asked if Standard No. 115 requires trailers that are used exclusively by the party that manufactures them to be identified with a vehicle identification number (VIN). The answer to your question is yes. S2 of Standard No. 115 specifies that the standard applies to trailers, and makes no exception for trailers that are used exclusively by the manufacturer. S4.1 of Standard No. 115 provides that: 'Each vehicle manufactured in one stage shall have a VIN that is assigned by the manufacturer.' Again, no exceptions are set forth for vehicles that will be used exclusively by the manufacturer. Because those regulatory provisions do not include any special exceptions, every new trailer must have a VIN, irrespective of whether the trailer will only be used by the same party that manufactured it. I hope this information is useful. If you have any further questions or need any additional information about this topic, please feel free to contact Dorothy Nakama of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice 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.