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: aiam2811OpenMr. Doug Mills, Rt. 1 Box 149, Tellico Plains, TN 37385; Mr. Doug Mills Rt. 1 Box 149 Tellico Plains TN 37385; Dear Mr. Mills: This responds to your recent letter asking additional question concerning the responsibilities of a person converting a pick-up truck into a dump truck, under Federal motor vehicle safety standards and regulations. This office explained the general responsibilities of a person who alters a certified vehicle in a letter to your associate, Mr. Henry Brown, dated February 1, 1978. You now ask questions regarding specific aspects of the conversion operating and whether they can be accomplished without destroying a vehicle's compliance with safety regulations.; Unfortunately, it is impossible for the National Highway Traffic Safet Administration (NHTSA) to answer your specific questions. It is the responsibility of the manufacturer or vehicle alterer to determine whether his vehicle is in compliance with applicable safety standards and to certify that vehicle. The NHTSA cannot review an alteration procedure such as the one with which you are concerned and state that it can or cannot be done in compliance with Federal regulations. There are no safety regulations which require a specific number of bolts or specific bolt locations, for instance. Likewise, Safety Standard No. 301-75, *Fuel System Integrity*, is specified only in terms of performance requirements, so the NHTSA cannot tell you whether a modified fuel filler neck will destroy a vehicle's compliance with the standard.; As stated in our previous letter, a person who alters a pick-up truc to convert it to a dump truck must certify that the truck remains in compliance with all applicable safety standards. Further, the person who makes the conversion must assure that the alterations do not result in any 'safety related defects' whether or not there is a specific safety standard that is applicable. Therefore, you must determine for yourself whether the number of bolts you use, the bolt strengths and the bolt locations will result in safety hazards.; I can answer your question number 8 regarding possible liability fo removal and alteration of the truck bumper. The Federal safety standard for bumpers is only applicable to passenger cars, so you may alter a truck bumper with impunity provided the action does not result in a safety related defect.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam2542OpenMr. Robert N. Townsend, Townsend & Townsend Attorneys at Law, P.O. Box 366, 111 W. Second Street, Parsons, TN 38363; Mr. Robert N. Townsend Townsend & Townsend Attorneys at Law P.O. Box 366 111 W. Second Street Parsons TN 38363; Dear Mr. Townsend: This responds to your February 9, 1977, letter in which you ask how th National Highway Traffic Safety Administration determines whether a school bus must comply with the new school bus safety standards.; On April 1, 1977, several new standards will become effective relatin to the construction of school buses: Standard No. 220, *School Bus Rollover Protection*, Standard No. 221, *School Bus Body Joint Strength*, and Standard No. 222, *School Bus Passenger Seating and Crash Protection*. Further, several old standards have been amended to provide special requirements for school buses. These amendments also become effective on April 1.; Section 108(a)(1)(A) of the National Traffic and Motor Vehicle Safet Act (Pub. L. 89-563), as amended (Pub. L. 93-492), prohibits the manufacture for sale, sale, offer for sale, or introduction or delivery for introduction into interstate commerce of any motor vehicle or item of motor vehicle equipment manufactured on or after the date any applicable Federal motor vehicle safety standard takes effect that does not conform to the standard. This means that any school bus manufactured on or after April 1, 1977, must comply with the school bus safety standards, regardless of the date on which the bus is actually sold or introduced into interstate commerce.; For vehicles that you complete by mounting a body on a new chassis, yo are permitted to choose as the date of manufacture either the date of manufacture of the incomplete vehicle (as defined in Part 568, *Vehicles Manufactured in Two or More Stages*), the date of final completion of the vehicle, or a date between those two dates. Only those standards in effect on the date chosen to represent the date of manufacture would be applicable to the vehicle, irrespective of the date upon which the vehicle is sold to the ultimate consumer.; I am enclosing copies of the new school bus safety standards and Par 568 for your information.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam5287OpenMr. Richard J. Dessert Proprietor, Sun Cycle Company 1550 Armacost Avenue #201 West Los Angeles, CA 90025; Mr. Richard J. Dessert Proprietor Sun Cycle Company 1550 Armacost Avenue #201 West Los Angeles CA 90025; "Dear Mr. Dessert: This responds to your petition of May 28, 1993, t the Administrator for a temporary exemption for low emission motor vehicles that you would like to produce. These vehicles would be purchased by the Los Angeles Department of Water and Power (LADWP). The response deadline for LADWP's Request for Proposal (RFP) was June 1, 1993. You have informed us that 'As part of LADWP requirements for successful bidders, evidence of progress towards obtaining Federal Motor Vehicle Safety Standards certification may be provided through demonstration that an application was made with NHTSA for a temporary exemption from Federal Motor Vehicle Safety Standards.' Because this matter affects LADWP as well as Sun Cycle Company, we are sending a copy of this response to the designated LADWP contact, Jeffrey S. Silverstone. The National Highway Traffic Safety Administration (NHTSA) did not receive your petition until June 8, and therefore had no chance to advise you with respect to it before the RFP deadline of June 1. We must inform you that the petition does not meet our procedural requirements and is not accepted for processing and action. There are several areas in which the petition is deficient. Most importantly, it appears to be a request for a blanket exemption from compliance with all applicable Federal motor vehicle safety standards. While the applicable law and regulation do not forbid this, you should know that the Administrator has never entertained a petition of this breadth and in all probability would never grant one. An applicant for a low-emission vehicle exemption must provide sufficient information upon which the Administrator may find that an exemption would not unduly degrade the safety of the motor vehicle, and that the exemption is consistent with the public interest and the objectives of the National Traffic and Motor Vehicle Safety Act. We do not believe that the Administrator could make the requisite findings to support a blanket exemption. It is NHTSA's policy to encourage manufacturers to manufacture conforming vehicles to the extent possible, and to narrow the scope of their requests for exemption. Low- emission vehicle petitions generally cover four to 14 standards. As part of your argument, you must set forth each individual standard from which you request exemption, and provide a detailed description of how your vehicle differs from a conforming one. You must also provide reasons why an exemption from each standard for which request is made would not unduly degrade the safety of the vehicle, something more than the general statement you have made that the first prototypes will 'substantially comply with all the safety standards.' Finally, you must present your views why an exemption is in the public interest and consistent with the objectives of the Safety Act. When we have received a petition from you that fulfills these requirements, we shall be pleased to accept it for consideration and public comment. As the vehicle you intend to manufacture is completely unknown to NHTSA, your new petition should also contain photographs or descriptive literature illustrating it. Our closing comment is that you or the LADWP may be unclear about vehicle certification. A manufacturer does not 'obtain' certification from NHTSA. The Safety Act establishes a self-certification scheme under which the manufacturer certifies its vehicles after satisfying itself that it conforms to the standards, aside from those from which it may have been exempted. It does not have to have permission from NHTSA to do so. You intend to test the vehicles, and such testing could provide substantiation for your certification of compliance, or, alternatively, substantiation to NHTSA that an exemption would not unduly degrade the vehicle's safety. If you have any questions about this matter, you may refer them to Taylor Vinson of this Office (202-366-5263). Sincerely, John Womack Acting Chief Counsel cc: Jeffrey S. Silverstone Los Angeles Department of Water and Power Attn: Electric Vehicle RFP P.O. Box 111 Los Angeles, CA 90051-0100"; |
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ID: aiam0085OpenMr. Ferris M. Smith, Jr., President, Horseless Carriage Corp., 1227 N.E. 9th Avenue, Fort Lauderdale, FL 33304; Mr. Ferris M. Smith Jr. President Horseless Carriage Corp. 1227 N.E. 9th Avenue Fort Lauderdale FL 33304; Dear Mr. Smith: This is in response to your letter of June 11, 1968, concerning th applicability of Federal motor vehicle safety standards to motor vehicles which have a curb weight of 1000 pounds or less.; Your reference to section 255.7 of the Federal motor vehicle safet standards and the present applicability of the standards to motor vehicles 1000 pounds or less curb weight is correct. However, we are enclosing a copy of Advance Notice of Proposed Rule Making, Docket No. 5-1, which was published in the *Federal Register* on October 14, 1967. As you can see from the Advance Notice of Proposed Rule Making, the Administrator is considering adding new standards applicable to motor vehicles of 1000 pounds or less curb weight.; Sincerely, Robert M. O'Mahoney, Assistant Chief Counsel |
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ID: aiam2112OpenMr. Jack A. Johnson, Chief Engineer, MOTAC, Inc (sic), 8400 East Slauson Avenue, Pico Rivera, CA 90660; Mr. Jack A. Johnson Chief Engineer MOTAC Inc (sic) 8400 East Slauson Avenue Pico Rivera CA 90660; Dear Mr. Johnson: This responds to MOTAC's September 18, 1975, question whethe rebuilding a platform trailer constitutes the manufacture of a new vehicle subject to applicable motor vehicle safety standards when the running gear (the axles, wheels, suspension, and related components sometimes known as a bogie) and the platform of a wrecked trailer is used (1) in combination with entirely new frame members, (2) in combination with one main frame member of the wrecked vehicle and one new frame member, and (3) in combination with part of one or both main frame members. You also ask whether the addition of a second axle to a single axle trailer, or the deletion of one axle on a tandem axle trailer, qualifies as the manufacture of a new vehicle subject to applicable safety standards.; In response to your first question, the National Highway Traffic Safet Administration (NHTSA) has determined (in the Stainless Tank and Equipment letter to which you refer) that, as a minimum, the running gear and main frame of the existing trailer must be used to qualify the rebuilding operation as a repair where all other materials are new. This position does not apply to the three situations you describe in which only the main frame members, and perhaps several cross members, are replaced. Therefore a repair of this type is not considered the manufacture of a new trailer.; In response to your second question, the NHTSA would not consider th addition of a second axle to a single axle trailer, or the removal of one axle from a tandem axle vehicle, to constitute the manufacture of a new vehicle.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam5638OpenThe Honorable Bob Clement U.S. House of Representatives Washington, DC 20515-4205; The Honorable Bob Clement U.S. House of Representatives Washington DC 20515-4205; "Dear Congressman Clement: Thank you for your letter of October 3 1995, enclosing correspondence from Mr. Dale Allen Pommer concerning his attempts to have a third seat belt installed in the back seat of his 1983 Chevrolet S-10 Blazer. Mr Pommer has been told that this cannot be done because of safety laws. You requested comments on Mr. Pommer's letter. As explained below, there is no Federal prohibition against the modification Mr. Pommer would like done to his vehicle. However, Federal law does place some limits on how the modification is done. The installation of additional seat belts must be done in a way that does not compromise the performance of the existing seat belts. Some background information about the agency may be useful. NHTSA has the authority to issue Federal motor vehicle safety standards applicable to new motor vehicles and new items of motor vehicle equipment. Federal motor vehicle safety standards are minimum standards, and may be exceeded by manufacturers. Federal law prohibits the manufacture or sale of any new motor vehicle or new item of motor vehicle equipment which does not conform to all applicable Federal motor vehicle safety standards in effect at the time of manufacture. After the first retail sale, there is a limit on the modifications that can be made by certain businesses to vehicles. Manufacturers, distributors, dealers, and repair businesses are prohibited from 'knowingly making inoperative' any device or element of design installed on or in a motor vehicle in compliance with an applicable safety standard (49 USC 30122). In general, the 'make inoperative' prohibition would require a business which modifies motor vehicles to ensure that it does not remove, disconnect, or degrade the performance of safety equipment installed in compliance with an applicable safety standard. A safety belt is an item of motor vehicle equipment and all safety belts sold in the United States must be certified as complying with Standard No. 209, Seat Belt Assemblies, regardless of whether the belts are installed as original equipment in a motor vehicle or sold as a replacement part. Standard No. 209 sets forth strength, elongation, webbing width, durability, and other requirements for seat belt assemblies. The additional belt which might be added to Mr. Pommer's vehicle must comply with the requirements of Standard No. 209. In addition to Standard No. 209, the agency has issued two additional safety standards which apply to new vehicles and affect safety belts: Standard No. 208, Occupant Crash Protection, which sets forth requirements for occupant protection at the various seating positions in vehicles, and Standard No. 210, Seat Belt Assembly Anchorages, which establishes strength and location requirements for seat belt anchorages. The 1983 Chevrolet S-10 Blazer would have been required to have, at a minimum, a lap belt at each rear designated seating position. A 'designated seating position' is defined by NHTSA regulations as: any plan view location capable of accommodating a person at least as large as a 5th percentile adult female, if the overall seat configuration and design and vehicle design is such that the position is likely to be used as a seating position while the vehicle is in motion...Any bench or split-bench seat ...having greater than 50 inches of hip room (measured in accordance with SAE Standard J1100(a)) shall have not less than three designated seating positions. Since the 1983 Chevrolet S-10 Blazer had a rear bench seat with 49.5 inches of hip room, that seat was required to have a minimum of two lap belts. The 'make inoperative' prohibition discussed earlier would not prohibit a business from adding a third seat belt to Mr. Pommer's vehicle. In addition, the anchorages would not have to comply with Standard No. 210. However, in adding the third seat belt, it is possible that the existing belts and anchorages would have to be relocated. The businesses contacted by Mr. Pommer may be concerned that the belts and anchorages could not be removed and replaced without 'making inoperative' the compliance of those belts and anchorages. I hope this information has been helpful. Sincerely, Samuel J. Dubbin Chief Counsel"; |
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ID: aiam2407OpenHonorable Carl Albert, Speaker of the House of Representatives, Washington, DC 20515; Honorable Carl Albert Speaker of the House of Representatives Washington DC 20515; Dear Mr. Speaker: This letter is to inform you that the effective date that has bee established for implementation of the Federal bumper standard issued pursuant to Title I of the Motor Vehicle Information and Cost Savings Act (Pub. L. 92-513) is more than 18 months after the date on which the final rule was promulgated. Section 102(d)(2) of Title I directs the National Highway Traffic Safety Administration (NHTSA) to provide Congress with a detailed explanation of the effective date of the Federal bumper standard where more than 18 months leadtime has been provided. This letter describes the basis for the agency's decision to establish an effective date 30 months after the standard's date of promulgation.; The NHTSA, on March 4, 1976, published a Federal bumper standard, 4 CFR Part 581, pursuant to Title I of the Act. Title I directs the NHTSA to develop standards that 'seek to obtain the maximum feasible reduction of costs to the public and to the consumer' occasioned by low-speed collisions. Part 581 moves toward accomplishing this goal by limiting the damage that is allowed to vehicle bumpers and exterior surfaces in low-speed crashes. Petitions for reconsideration of the rule have been submitted and will be responded to shortly. The agency's response to these petitions will complete the final rulemaking step in the issuance of the standard.; On March 12, 1975, the NHTSA proposed three alternative effectiv dates--September 1 of 1976, 1977, or 1978--for implementation of the Part 581 requirements. Interested persons were asked to comment on the feasibility of satisfying the standard's damage criteria within those alternative time periods. Comments were received from seven motor vehicle manufacturers on the subject of Part 581's initial effective date. Five manufacturers specifically urged an effective date of September 1, 1978, stating that earlier compliance would impose high development costs and involve the use of bumper systems that have not been optimized. One manufacturer did not specifically favor any of the suggested implementation dates, but stated that early compliance could only be achieved if the standard were modified. Only one manufacturer said that it could meet the standard earlier than 1978. It stated that it could satisfy Part 581 by September 1, 1977, and emphasized that significant costs would be involved if an earlier effective date were prescribed.; During the phase effective on September 1, 1978, the Part 581 standar will prohibit any damage to vehicle exterior surfaces during prescribed front and rear 5 mph pendulum and barrier crash tests. Only the bumper itself will be permitted to sustain damage. Compliance with these requirements, according to manufacturers, will entail a degree of redesign and retooling. The requested effective dates indicate the amount of leadtime considered necessary to accomplish these vehicle changes in a cost-efficient manner.; Since the purpose of the Title I bumper standard is to achieve a cos savings for consumers, all costs involved in its implementation must be closely examined. Based upon the information submitted by manufacturers, compliance with Part 581 would be significantly more costly before September 1, 1978. The agency has determined that such additional costs would not be justified as they would undermine the benefits to be provided to consumers. A September 1, 1978, effective date is appropriate since it will give manufacturers adequate leadtime to develop and optimize bumper systems that meet the performance level of Part 581.; In keeping with the Act's requirement that the agency publish it reasons for providing more than 18 months leadtime, the basis for the NHTSA's decision to specify a September 1, 1978, effective date is thoroughly explained in the *Federal Register* notice establishing the Part 581 bumper standard as a final rule.; Sincerely, John W. Snow, Administrator |
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ID: aiam0590OpenMrs. I. Goliath, Technical Relations, BASF Syandotte Corporation, 100 Cheery Hill Road, P.O. Box 181, Parsippany, NJ, 07054; Mrs. I. Goliath Technical Relations BASF Syandotte Corporation 100 Cheery Hill Road P.O. Box 181 Parsippany NJ 07054; Dear Mrs. Goliath: This is in reply to your letter of February 9, 1972, inquiring as t the length of time, after the manufacture of an automobile, that it must still comply with the requirements of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials.' You indicate that due to the influence of cleaning or preservative agents, the flammability properties could change over a period of time.; The safety standards do not apply to a domestic vehicle after it ha been sold to a purchaser for purposes other than resale. Until this point of first sale, however, regardless of the time interval after manufacture, the vehicle must comply with the standards.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam5268OpenMr. Donald W. Vierimaa Vice President-Engineering Truck Trailer Manufacturers Association 1020 Princess Street Alexandria, VA 22314; Mr. Donald W. Vierimaa Vice President-Engineering Truck Trailer Manufacturers Association 1020 Princess Street Alexandria VA 22314; Dear Mr. Vierimaa: This responds to your letter of October 19, 1993 with respect to the trailer conspicuity requirements of Standard No. 108. You report that ' o ften a new tank trailer will be sold to a customer who will contract with another party to have a lining installed in the tank.' Because of the high heat used in the installation of the lining, retroreflective sheeting cannot be applied before the lining is installed. We believe that the trailer manufacturer is a more appropriate person for ensuring that its product meets the conspicuity requirements of Standard No. 108 than the installer of the lining, or the owner of the trailer. We would like to suggest alternative methods of compliance, other than a direct application of retroreflective tape to the trailer sides, as a resolution of this problem. Standard No. 108 permits the use of reflex reflectors as an alternative to retroreflective sheeting. If the trailer manufacturer prefers retroreflective sheeting, the sheeting may be applied at a lower level if deemed 'practicable', or it may be applied to horizontal strips of aluminum that can be fastened to the sides of tank trailers and removed during the installation of the lining. You also state that 'non-tank trailers may be sold without conspicuity treatment when the owner wishes to contract the application of special paint and logo schemes.' Sale of a trailer under these circumstances, without its compliance with the conspicuity requirements of Standard No. 108, would be an apparent violation of the National Traffic and Motor Vehicle Safety Act. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam2057OpenMr. Mike M. Simovich, President, Champ Corporation, 2500 N. Rosemond Blvd., P.O. Box 3637, EL Monte, California 91733; Mr. Mike M. Simovich President Champ Corporation 2500 N. Rosemond Blvd. P.O. Box 3637 EL Monte California 91733; Dear Mr. Simovich: I am writing in response to your July 14, 1975, letter concerning th classification of your rough terrain fork lift trucks for the purposes of the Federal motor vehicle safety standards. A copy of our September 5, 1975, letter on this subject to Congressman Danielson is enclosed. We hope it clarifies the status of your products.; Yours truly, Richard B. Dyson, Assistant 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.