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
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ID: aiam0244OpenLouis C. Lundstrom, Director, Automotive Safety Engineering, General Motors Corporation, General Motors Technical Center, Warren, MI 48090; Louis C. Lundstrom Director Automotive Safety Engineering General Motors Corporation General Motors Technical Center Warren MI 48090; Dear Mr. Lundstrom: This is in reply to your letter of June 26, 1970, to Mr. Douglas W Toms, Director, National Highway Safety Bureau, concerning plastic materials for reflex reflectors.; The contents of your letter, including the technical data an information enclosed therewith, have been carefully reviewed by interested members of this Bureau. As a result of this review and evaluation, and also considering the nature and intent of the requirements in question, we concur, basically, with your interpretation of the requirements of SAE J576b, as subreferenced in Federal Motor Vehicle Safety Standard No. 108. Your interpretation of the requirements of paragraphs 3.4 and 4.2 of SAE J576b, as quoted from your letter, is as follows:; >>>'A plastic material used in a lamp or reflector assembly so that i is covered by other material and is not directly exposed to sunlight meets the requirements of SAE J576b if, when so covered, it satisfies the requirements of paragraphs 3.4 and 4.2.'<<<; We would fully concur with this interpretation if it is rephrased t read as follows:; >>>'A plastic material used in a lamp or reflector assembly so that i is covered by other material and is not directly exposed to sunlight meets the requirements of paragraphs 3.4 and 4.2 of SAE J576b if, when so covered, it satisfies the requirements of those paragraphs.'<<<; To test for compliance, using this interpretation, the test sampl discs, as specified in SAE 576b, would be exposed to the outdoor exposure test (paragraph 3.4) while covered with the actual lens material used in production lamp assemblies. In your particular case, the discs would be the polycarbonate ('Lexan') material and the 'covering material' would be the red taillamp lens molded for production use.; Sincerely, Rodolfo A. Diaz, Acting Associate Director, Motor Vehicl Programs; |
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ID: aiam2279OpenMs. Constance Newman, Assistant Secretary for Consumer Affairs and Regulatory Functions, Department of Housing and Urban Development, 451 Seventh Street, S.W., Washington, DC, 20410; Ms. Constance Newman Assistant Secretary for Consumer Affairs and Regulatory Functions Department of Housing and Urban Development 451 Seventh Street S.W. Washington DC 20410; Dear Ms. Newman: I am writing in response to questions that have been raised about th National Highway Traffic Safety Administration's (NHTSA) authority to regulate mobile homes. As you may know, mobile homes have been considered to be 'motor vehicles' as that term is defined in the National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. 1391 et seq.) ('the Vehicle Safety Act'). As such, they have been subject to Federal Motor Vehicle Safety Standard No. 108 (*Lamps, Reflective Devices, and Associated Equipment*) and to our authority regarding the notification and remedy of noncompliances and defects related to motor vehicle safety.; The National Mobile Home Construction and Safety Standards Act of 197 (42 U.S.C. 5401 et seq.) ('the Mobile Home Act') established within the Department of Housing and Urban Development a comprehensive program for the regulation of mobile homes. We have concluded that one result of that statute's enactment was the implied repeal of the NHTSA's authority with respect to mobile homes. Accordingly, we consider that the enactment had the effect of amending the Vehicle Safety Act's definition of 'motor vehicle' to exclude 'mobile homes' as the latter term is defined in the Mobile Home Act. We are preparing a Federal Register notice that will reflect this conclusion.; Sincerely, James B. Gregory, Administrator |
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ID: aiam3891OpenMs. Phyllis A. Sirine, Administrative Secretary, St. Peter's School, 319 Lombard Street, Philadelphia, PA 19147; Ms. Phyllis A. Sirine Administrative Secretary St. Peter's School 319 Lombard Street Philadelphia PA 19147; Dear Ms. Sirine: This responds to your letter to me concerning your use of 13 and 1 passenger vans to transport students to and from extracurricular activities. In a telephone call on January 30, 1985, Mr. John Womack explained how our school bus regulations affect your school's choice of buses. This letter follows up on that conversation and confirms Mr. Womack's discussion of our regulations.; As I understand it, Pennsylvania has recently amended its law to defin 'bus' to mean 'a motor vehicle designed for carrying more than ten persons, including the driver.' The old definition had excluded the driver. In effect, a van designed to carry more than ten persons is now a 'bus' under Pennsylvania law. To transport students in a van of that size, a school would need to conform the van to the State's requirements for school buses.; The recent change in Pennsylvania law does not in any way affect ho our regulations apply to your 13 and 15 passenger vans. Your vehicles have always been classified as buses under Federal law, since under our regulations a bus is defined as a motor vehicle designed for carrying more than ten persons. Further, your vehicles are 'school buses' as that term is defined in the Vehicle Safety Act. The basic test under the Vehicle Safety Act is whether, as determined at the time of its first sale, a bus would be used to transport school children to or from school or related events. It is not relevant that the school uses the vehicles only occasionally. When the buses were sold to your school, it should have been clear to the dealer or manufacturer that the vehicles would be used as school buses.; It appears that St. Peter's purchase of new vans for the transportatio of students raises questions of compliance with Federal law by the dealers who sold you the vans. The Vehicle Safety Act required the dealer or manufacturer to sell vehicles which were certified as meeting all applicable motor vehicle safety standards. With respect to your future purchases of new vehicles, I urge you to keep in mind that the dealers are obligated to sell you vehicles that meet the school bus safety standards. They should know that they are at risk if they sell nonconforming vehicles.; The Vehicle Safety Act does not prohibit you from operating the 13 an 15 passenger vans. There might, however, be impediments under Pennsylvania State law. We administer a set of guidelines for state highway safety programs under the authority of the Highway Safety Act (Public Law 89-564). These guidelines, called Highway Safety Program Standards, cover a wide range of subjects, including school buses. Individual states have chosen to adopt some or all of the guidelines as their own policies governing their highway safety programs. Highway Safety Program Standard No. 17 (HSPS 17), specifies that a bus used to transport 16 or less students must either be identified with the words 'School Bus' and comply with the standard's requirements for color, mirrors and signal lamps, or be devoid of all of these characteristics. As it happens, however, a bus sold for use as a school bus is required by the Vehicle Safety Act to have warning lights and mirrors (as well as many other safety features). Because it must have this equipment, a 13 or 15 passenger bus in a State whose law fully incorporates HSPS 17 would have to be painted and signed as a school bus. For a state that has adopted this standard as its own policy, these specifications apply to activity buses as well as to the buses used for daily transportation.; I want to stress that HSPS 17 will affect you only if Pennsylvania ha adopted it and if Pennsylvania accepts our view that the specifications apply to activity buses. Your State officials will be able to give you more information about other State requirements for school buses.; Please let me know if you have any further questions. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5046OpenRichard Allison Program Manager The Bott Group, Inc. 32330 Howard Avenue Michigan Heights, MI 48071; Richard Allison Program Manager The Bott Group Inc. 32330 Howard Avenue Michigan Heights MI 48071; "Dear Mr. Allison: This responds to your letter of August 20, 199 requesting an interpretation of Standard No. 216, Roof Crush Resistance. Specifically, you requested 'an interpretation of 1) the proper application and orientation of the test device (S6.2 of this standard) and 2) the distance the test device is allowed to travel (paragraph S4 of this standard), when testing vehicles equipped with roof mounted accessories, such as roof racks (luggage racks).' You believe that there are three possible test conditions. The first condition would conduct the test either without the roof rack installed or with the roof rack removed, and with the test device positioned in accordance with S6.2. The second condition would conduct the test with the roof rack installed, and with the test device positioned using the point of contact established under test condition 1. The third condition would conduct the test with the roof rack installed, and with the test device positioned in accordance with S6.2 to the roof rack. You requested our interpretation as to which is the correct test condition. In addition, you asked if we determined that either test condition 2 or 3 was correct, could the amount of distance traveled before contact with the roof be added to the allowable distance of test device travel under S4. We would conduct our compliance testing for Standard No. 216 with roof mounted accessories such as roof racks removed (your test condition 1). We would do so because the purpose of the test is to measure the strength of the roof, not the strength of roof mounted accessories. Further, as you have noted, conducting the test with roof mounted accessories in place could influence the positioning of the test device. I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam2783OpenMr. Stan Haransky, Truck Body and Equipment Association, Inc., 5530 Wisconsin Avenue, Suite 1220, Washington, DC 20015; Mr. Stan Haransky Truck Body and Equipment Association Inc. 5530 Wisconsin Avenue Suite 1220 Washington DC 20015; Dear Mr. Haransky: This responds to your February 21, 1978, letter asking whether sectio 567.5(c)(7) of Part 567, *Certification*, requires a manufacturer to use all of the described statements on its certification label.; The answer to your question is no. That section provides that th listed certification statements are to be used as appropriate. Therefore, it is anticipated that a manufacturer will select for inclusion on its certification labels only those certification statements in subparagraph (c)(7) that are appropriate for the certification of its vehicles.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1906OpenBenjamin Sachs, M.D., Associate Director, Division of Local Health Services, Room 360, Massachusetts Department of Public Health, 600 Washington Street, Boston, MA 02111; Benjamin Sachs M.D. Associate Director Division of Local Health Services Room 360 Massachusetts Department of Public Health 600 Washington Street Boston MA 02111; Dear Dr. Sachs: In response to your request of April 4, 1975, I am enclosing a copy o Federal Motor Vehicle Safety Standard No. 208, several *Federal Register* notices which have modified the basic standard, and the Motor Vehicle and Schoolbus Safety Amendments of 1974. Also enclosed is a circular explaining how all the safety standards and regulations of the National Highway Traffic Safety Administration (NHTSA) may be obtained.; Until October 29, 1974, section S4.1.2 of the standard required a ignition interlock on 1974- and 1975-model passenger cars. As noted in the enclosed amendment (Docket 74-39, Notice 1), recent legislation mandated the deletion of this requirement, which was accomplished by NHTSA on October 29, 1974.; Manufacturers may now meet Standard No. 208 by providing (1) lap an shoulder belts at front outboard positions and lap belts at other positions, and (2) a continuous or flashing reminder light that operates only during the 4- to 8-second period after the ignition is operated and a continuous or intermittent audible warning signal which operates only during the 4- to 8-second period after the ignition is operated if the driver's lap belt is not in use. They may also provide certain types of 'passive restraint' devices in place of the seat belt assemblies.; Although the seat-belt interlock system is not prohibited, it is n longer a means of complying with the standard.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0614OpenMr. George A. Maty, Vice President and Sales Manager, Lindburg Cadillac, 2350 Market Street, St. Louis, MO 63103; Mr. George A. Maty Vice President and Sales Manager Lindburg Cadillac 2350 Market Street St. Louis MO 63103; Dear Mr. Maty: Thank you for your letter of February 16, 1972, to Secretary Joh Volpe, concerning the length of seat belts in a 1972 Cadillac automobile.; Federal Motor Vehicle Safety Standard No. 208 Occupant Cras Protection, copy enclosed, specifies requirements for occupant restraint systems. Effective January 1, 1972, car manufacturers are required to provide Type 2 belt assemblies (lap-shoulder belts) at the front outboard seating positions and lap belts at other positions. The Type 2 belt assemblies may have either integral or detachable shoulder belts, but the distance between the intersection of the lap- shoulder belt and the vertical centerline of a 50th-percentile adult male occupant must be at least six inches when the seat is in its rearmost position. The purpose of this requirement is to reduce the possibility of the shoulder belt pulling the lap belt up onto the occupant's abdomen where it could cause serious injury in a crash.; We have examined several 1972 model cars and have found that som manufacturers have chosen belt designs that provide distances of ten inches or more between the lap-shoulder belt intersection and the centerline of the occupant. The standard does not prohibit distances greater than six inches, but it is obvious that the greater this distance, the closer the inboard end of the belt is to the seat and the more difficult it is to buckle the belt. I am happy to inform you that we have already initiated rule making action to amend Standard No. 208 that would prohibit such excessive distances.; Under the requirements of the National Motor Vehicle and Traffic Safet Act, copy enclosed, it is a violation of the law to sell a vehicle that does not conform to an applicable standard. Although the Act does not prevent the purchaser of a vehicle from altering or removing a safety device, after he has completed the purchase, we strongly advise him against such action. A dealer who performs such services after he has sold the vehicle does not violate the law, but he does his customer a disservice.; In regard to the belts in the Cadillac you sold to Mr. and Mrs. T Albert McCulley, we do not have the authority to grant or deny you permission to lengthen the inboard end of the belt. We can only suggest that perhaps you could lengthen the belt only to the extent that is necessary to provide a distance of not less than six inches between the intersection of the lap-shoulder belt and the centerline of a 50th-percentile adult male occupant measured in accordance with paragraph S7.1.2 of Standard No. 208.; Thank you for your interest in motor vehicle safety. If we can be o further assistance, please do not hesitate to contact us.; Sincerely, Robert L. Carter, Acting Associate Administrator, Moto Vehicle Programs; |
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ID: aiam2629OpenHonorable Dixy Lee Ray, Governor of Washington, Olympia, WA 98501; Honorable Dixy Lee Ray Governor of Washington Olympia WA 98501; Dear Governor Ray: The purpose of this letter is to express this agency's views o legislation recently enacted by the State of Washington, which appears to be preempted by Federal regulation of the same subject matter.; Specifically we understand that R.C.W. S45.37.320 was amended in Ma 1977 to require that motor vehicle 'lighting devices'; >>>'...shall correlate with, and, so far as practicable, conform to th then current standards and specifications of the society of automotive engineers applicable to such equipment and to the headlamp standards established by the United Nations agreement concerning the adoption of approval and reciprocal recognition of approval for motor vehicle equipment and parts done at Geneva on March 20, 1958, as amended and adopted by the Canadian standards association (CSA standard D106.2): *Provided*, that the sale, installation, and use of any headlamp meeting the standards of either the society of automotive engineers or the United Nations agreement, as amended, shall be lawful in this state.'<<<; Under 15 U.S.C. 1392(d): >>>'Whenever a Federal motor vehicle safety standard established unde this title is in effect, *no State* or political subdivision of a State *shall have any authority* either *to establish*, or to continue in effect with respect to any motor vehicle or item of motor vehicle equipment *any safety standard applicable to the same aspect of performance of such vehicle or item of equipment which is not identical to the Federal standard.' [Emphasis added.]<<<; Pursuant to 15 U.S.C. 1392(a) [Section 103(a) of the National Traffi and Motor Vehicle Safety Act of 1966] Federal Motor Vehicle Safety Standard No. 108, *Lamps, Reflective Devices, and Associated Equipment* (49 CFR 571.108), has been established, effective January 1, 1972, as the Federal standard for lighting devices both as original and replacement equipment on motor vehicles.; Although Standard No. 108 incorporates by reference many lightin standards of the society of Automotive Engineers (SAE) it contains numerous qualifications of, and variations from, the SAE specifications. Even when Federal requirements and SAE specifications are identical, amendments by the SAE, which occur frequently, do not amend the corresponding Federal requirements. In short, that portion of the amendment to RCW S46.37.320 requiring compliance to SAE specifications does not establish requirements that are identical to those of Standard No. 108 and, in our opinion, are preempted by 15 U.S.C. 1392(d) and of no legal effect.; In addition, the United Nations Agreement, as amended by the Canadia Standards Association, permits the use of motor vehicle headlamps that are not of sealed beam construction and whose candlepower output may exceed 75,000. Further, it does not require that the headlamps be mechanically aimable. Standard No. 108, on the other hand, requires that headlamps on passenger vehicles be of sealed beam construction, imposes a limit of 75,000 candlepower on all but one type of headlamp, and specifies that all headlamps be mechanically aimable. Thus, the United Nations Agreement, as amended by the Canadian Standards Association, does not specify requirements for headlamps that are identical to those of Standard No. 108. This means that this part of the amendment to R.C.W. S46.37.320 is, in our opinion, also preempted by 15 U.S.C. 1392(d), and of no legal effect.; As a consequence, it is our conclusion that any person in Washingto manufacturing for sale, selling, offering for sale, introducing or delivering for introduction in interstate commerce, or importing in the United States through the State of Washington any lighting equipment that does not conform to Standard No. 108, in reliance upon R.C.W. S46.37.320, could be subject to civil penalties for apparent violations of 15 U.S.C. 1397(a) (1) (A) in an amount up to $800,000 (15 1399(a)). There is no preemption, however, of your State's right to specify requirements for lighting equipment not currently included in Standard No. 108 (*e.g.* foglamps).; Section 1392(d) and the Act's preemptive effect have been invariabl upheld. (See *e.g. Chrysler Corp. v. Malloy,* 294 F. Supp. 524 (U.S.D>C. Vt. 1968), *Chrysler Corp. v. Tofany*, 419 F.2d 499 (C.C.A. 2 1969)). We would also observe that the interpretation by an administering agency of its own statutes and regulations, has been viewed by courts as 'of controlling weight.' (*Thorpe v. Housing Authority of Durham* 393 U.S. 268 (1969) quoted with approval in *Chrysler Corp. v. Tofany, supra*, at 512.); We would appreciate the view of the State of Washington on thi subject. Questions on it may be referred to the Chief Counsel of this agency, Joseph J. Levin, Jr.; Sincerely, Joan Claybrook |
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ID: aiam5416OpenMr. Rick Rogers 9624 Davis Road Tampa, FL 33637-5004; Mr. Rick Rogers 9624 Davis Road Tampa FL 33637-5004; Dear Mr. Davis: Robert Hellmuth of this agency has sent us for repl your letter of June 8, 1994, commenting that 'a car's brake lights should go on not only when the brake pedal is pressed, but should also go on when the gas pedal is released.' The enclosed copy of a letter dated January 25, 1990, to Larry Snowhite, Esq., represents the agency's views on this matter, now as then. We appreciate the concern for safety that prompted you to get in touch with us. Sincerely, John Womack Acting Chief Counsel Enclosure; |
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ID: aiam3468OpenMr. Don W. Upson, Colt Industries, Inc., 1901 'L' Street, N.W., Suite 303, Washington, DC 20036; Mr. Don W. Upson Colt Industries Inc. 1901 'L' Street N.W. Suite 303 Washington DC 20036; Dear Mr. Upson: This responds to your recent letter asking whether any Federa regulations apply to propane fuel systems designed for use in motor vehicles.; I am enclosing an information sheet which sets forth the implication under Federal law of converting gasoline-powered vehicles to use propane or other gas, as well as a general discussion of auxiliary fuel tanks. From that discussion, you will see that there are no safety standards directly applicable to propane fuel tanks as pieces of automobile equipment. There are, however, specifications under the Bureau of Motor Carrier Safety regulations relating to propane fuel systems on commercial vehicles or to tanks used for shipment of propane gas in interstate commerce. If your tanks will be used on other than private vehicles, these regulations may be of interest to you. For further information, you may contact Mr. W. R. Fiste of the Bureau of Motor Carrier Safety (202-426-0033).; 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.