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: aiam2721OpenMr. David M. Thompson, Kelsey-Hayes Company, Romulus, MI 48174; Mr. David M. Thompson Kelsey-Hayes Company Romulus MI 48174; Dear Mr. Thompson: This responds to Kelsey-Hayes' September 2, 1977, request to kno whether Standard No. 121, *Air Brake Systems*, allows a burnish of the brake friction elements immediately prior to the parking brake tests of S5.6, and whether the service line air pressure limitation of 100 p.s.i. specified in S5.4.2.1 can be exceeded momentarily.; A burnish prior to the parking brake test is not permitted by Standar No. 121, except that S6.1.8 specifies burnish of the parking brake friction elements before testing in those cases where the parking brake system does not utilize the service brake friction elements. The National Highway Traffic Safety Administration (NHTSA) would consider a provision to deal with the condition of the brake linings prior to the parking brake test upon receipt of technical data showing justification for such an action.; Section S5.4.2.1 of the standard specifies a procedure that state '[t]he service line air pressure shall not exceed 100 p.s.i. during any deceleration.' You describe a condition in which the service line pressure exceeds 100 p.s.i. for a short period (typically 0.1 seconds), which might be traced to characteristics of the friction material, brake mechanism, dynamometer, or instrumentation.; The NHTSA recognizes that peak pressure may be momentarily increased b the initial rush of air pressure into the brake chamber, or by other anomolies (sic). In the case of such momentary pressure increases, the NHTSA interprets S5.4.2.1 to mean that the source of air pressure for applying the brake must never exceed 100 p.s.i. Thus, it would be permissible to experience momentary pressures above 100 p.s.i. in the service line as long as the pressure source never exceeds that level. Sustained periods of pressure above 100 p.s.i. would not be permissible.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3833OpenB. R. Belsches, Captain, Safety Office, Department of State Police, Commonwealth of Virginia, P.O. Box 27472, Richmond, VA 23261-7472; B. R. Belsches Captain Safety Office Department of State Police Commonwealth of Virginia P.O. Box 27472 Richmond VA 23261-7472; Dear Captain Belsches: This is in response to your letter of April 20, 1984, asking for a interpretation of paragraph S4.6(b) of Motor Vehicle Safety Standard No. 108 and 'a history relative to the inclusion of such function of headlamps and marker lamps.'; Paragraph S4.6(b) allows means to be provided for the automati flashing of headlamps and side marker lamps for signaling purposes, as an exception to the general rule that vehicle lamps (other than turn and hazard warning signals, and school bus warning lamps) be steady-burning in use. This confirms your understanding of the wording of the standard and its effect. It does not allow, however, modulating headlamps which do not flash on and off, but deviate between a higher intensity and a lower one.; Originally, paragraph S3.5 of the standard (see *e.g.* 49 CFR 371.21 Standard No. 108 rev. as of January 1, 1970) stated that 'normally steady-burning lamps may be capable of being flashed for signaling purposes.' On January 3, 1970, the agency proposed paragraph S4.6 (35 F.R. 106) as it exists today. It was adopted on October 31, 1970 (35 F.R. 16840). The agency observed that some commenters requested that additional lamps be permitted to flash and some requested that flashing headlamps be prohibited. It also noted that, with the exceptions set forth in S4.6(a), flashing lamps should be reserved for emergency and road maintenance-type vehicles, and that flashing lamps are otherwise prohibited in the Uniform Vehicle Code. The agency further noted that lamps could be flashed by the driver merely by turning the switch on and off, and that it could not prohibit that type of operation, but that the definition of 'Flash,' also adopted in the amendments, made clear that automatic flashers for use with steady-burning lamps other than headlamps and side marker lamps were prohibited.; This is the rulemaking history of paragraph S4.6. I hope that this wil answer your questions.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2371OpenWilliam K. Rosenberry, Esq., Attorney at Law, Parkway Central Plaza, 611 Ryan Plaza Dr., Suite 713, Arlington, TX 76011; William K. Rosenberry Esq. Attorney at Law Parkway Central Plaza 611 Ryan Plaza Dr. Suite 713 Arlington TX 76011; Dear Mr. Rosenberry: This is in reply to your letter of July 14, 1976, to George Shifflet of the Office of Standards Enforcement, on behalf of a client who intends to install a different type of seat, carpeting, and headliner in a pick-up truck, which would then be sold to the general public. You asked whether a fabric supplier must test each fabric lot for flammability before certification to Motor Vehicle Safety Standard No. 302 can be given, and whether your client 'may rely on the warranty of a fabric manufacturer that the fabric sold meets the requirements ' of Standard No. 302.; You are correct in your understanding that the provisions of th National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 *et seq*) apply to your client. His basic responsibility is to ensure that the vehicles he modifies are in compliance with the Federal standards when delivered to dealers for sale to the public. (15 U.S.C. 1397(a)(1)(A)) A temporary noncompliance during modifications is permissible if the vehicle is not used on the public roads while noncompliant (15 U.S.C. 1397(a)(2)(A)). Standards which would appear to be affected by your client's modifications include: Standard No. 207 *Seating Systems*, No. 208 *Occupant Crash Protection*, No. 210 *Seat Belt Assembly Anchorages* and No. 302 *Flammability of Interior Materials*.; As a person who alters a certified vehicle other than by the additio of readily detachable (sic) components, your client is also required to attach his own certification of compliance to each modified truck (49 CFR 567.7). Should a noncompliance be discovered as a result of an alterer's modification, the alterer would be liable for a civil penalty unless he could establish that he did not have actual knowledge of the noncompliance, and that he did not have reason to know in the exercise of due care that the vehicle did not comply (15 U.S.C. 1397(b)(2)).; With respect to Standard No. 302, there is no requirement that a fabri supplier 'test each fabric lot for flammability before certification.' In point of fact, 49 CFR 571.302 Motor Vehicle Safety Standard No. 302 does not apply to suppliers but only to vehicle manufacturers (or alterers) and it is they who are required to certify compliance with Standard No. 302. Generally, at a minimum, a vehicle manufacturer will require by contract with the supplier that the fabric meets Standard No. 302. In the exercise of 'due care' the manufacturer may wish to examine the basis for the supplier's assurance of compliance, and to require periodic testing of the fabric being supplied him. Since there is no requirement that each fabric lot be tested, such testing as is conducted should be sufficient to demonstrate in the event of a noncompliance that the vehicle manufacturer has exercised due care. As to whether your client may rely on the 'warranty' of his supplier, it has been our experience that simple reliance is insufficient to establish a 'due care' defense. That manufacturer should examine the supplier's test results to insure that the margin of compliance of the test fabric is great enough that production variables do not result in noncompliance. Some manufacturers even conduct their own test independent of the supplier.; Your client would also be responsible for conducting a notification an remedy campaign (15 U.S.C. 1411 *et seq*) if a noncompliance or safety-related defect occurs in the truck as a result of the alterations.; I enclose copies of the Act, 49 CFR Part 567, and Standards Nos. 207 208, 210, and 302 for your information.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam3999OpenStephen T. Waimey, Esq., Dean Hansell, Esq., Law Offices of Donovan, Leisure, Newton & Irvine, 333 South Grand Avenue, Los Angeles, CA 90071; Stephen T. Waimey Esq. Dean Hansell Esq. Law Offices of Donovan Leisure Newton & Irvine 333 South Grand Avenue Los Angeles CA 90071; Dear Mr. Waimey and Mr. Hansell: Thank you for your letter of April 15, 1985, concerning the automati restraint requirements of Federal Motor Vehicle Safety Standard No. 208, *Occupant Crash Protection*. I regret the delay in our reply.; You asked about the requirement in S4.1.3 of the standard concernin the minimum annual production of passenger cars that must be equipped with automatic restraints. You stated your assumption that the standard applies only to vehicles produced for sale in the United States and asked how a manufacturer is to determine if a vehicle is a part of its annual production for the United States. You pointed out that there are a number of possible sales transactions, beginning with the sale of a vehicle by Porsche to the U.S. importer and ending with the first sale to a consumer in the U.S. that can be used in determining at which point a vehicle becomes part of Porsche's annual production for the United States. I hope the following discussion answers your question.; As discussed in the agency's April 12, 1985, (50 FR 14596) notice o Standard No. 208, your assumption that the term 'average annual production' refers only to cars manufactured for sale in the United States is correct. S4.1.3 specifies that percentages of production are to be based on the number of cars *manufactured* between discrete dates. In the case of foreign cars, as in the case of domestic ones, 'manufactured' means produced or assembled. Part 567 *Certification* (49 CFR Part 567) of the agency's regulation requires all vehicles manufactured for sale in the United States to have a tag affixed to them certifying that they meet all Federal Motor Vehicle Safety Standards. Therefore, in determining which vehicles are to be counted as the manufacturer s average annual production, the manufacturer should determine how many vehicles were produced and certified in accordance with our regulation during the applicable time period. Using production and certification provides the agency and manufacturers with an easily verifiable event to determine which cars are to be counted.; I hope this information is of assistance to you. If you have furthe questions, please let me know.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam3130OpenMr. Roger E. Maugh, Director, Automotive Safety Office, Ford Motor Company, The American Road, Dearborn, MI 48121; Mr. Roger E. Maugh Director Automotive Safety Office Ford Motor Company The American Road Dearborn MI 48121; Dear Mr. Maugh: Re: Distribution of Imported Vehicles Brought Into Conformity Wit Applicable Federal Motor Vehicle Safety Standards; This is in reply to Mr. Eckhold's letter of September 28, 1979, to Mr Vinson of this office asking for our concurrence in Ford's wish to sell 60 1978 model Ford Fiestas on the American market.; According to Mr. Eckhold's letter, 56 of the cars did not comply wit the Federal motor vehicle safety standards at the time they entered the United States for use by Ford in testing and training programs. Ford represents that all these have now been brought into compliance. The four remaining Fiestas conformed at the time of entry but, presumably, because of the execution of the HS-7 importation form, were not certified.; We concur with Ford's opinion that all conforming vehicles may now b sold in the United States. However, since such sales are to first purchasers for purposes other than resale, a certification label must be attached to each that meets the requirements of 49 CFR Part 567.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3560OpenMr. M. W. Urban, Sure-View, Inc., 1337 N. Meridian Street, Wichita, KS 67203; Mr. M. W. Urban Sure-View Inc. 1337 N. Meridian Street Wichita KS 67203; Dear Mr. Urban: This responds to your letter of April 5, 1982. I believe that the cop which I recently sent you of my May 14, 1980, letter to Mr. Seashores clearly and carefully explains the agency's statutory authority to regulate design elements such as size and dimension. As my letter of March 25, 1982, to you noted, S9.1 of Standard No. 111 is consistent with that statutory authority.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2058OpenMr. Robert G. Brewer, Bendix-Westinghouse, 901 Cleveland Street, Elyria, Ohio 44035; Mr. Robert G. Brewer Bendix-Westinghouse 901 Cleveland Street Elyria Ohio 44035; Dear Mr. Brewer: #I am writing in response to the question you raise in a September 5, 1975, telephone conversation with Mark Schwimmer of this agency, concerning the labeling requirements of Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses*. #You asked whether the designation 'AI & AII' is permitted on air brake hose for which the Type I and Type II dimensions listed in the standard are identical. In a letter to the Gates Rubber Company (copy enclosed), the National Highway Traffic Safety Administration interpreted S7.2 of the standard as not permitting the designation 'AI-II'. For similar reasons, the designation 'AI & II' does not comply with S7.2. The designation 'AI & AII' would comply with the standard. #Sincerely, Frank A. Berndt, ACting Chief Counsel; |
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ID: aiam0065OpenMr. Warren M. Heath, Commander, Engineering Section, Department of California Highway Patrol, P. O. Box 898, Sacramento, CA 95804; Mr. Warren M. Heath Commander Engineering Section Department of California Highway Patrol P. O. Box 898 Sacramento CA 95804; Dear Commander Heath: Thank you for your letter of January 16, 1968, your referenc 61.A218.A1115, to the National Highway Safety Bureau concerning applicability of Federal Motor Vehicle Safety Standards 108 and 205 to campers.; Your questions along with our corresponding answers are listed below: >>>Question: 1. Do Federal Standards Nos. 108 and 205 apply to campe bodies which are not manufactured as a part of a vehicle but which may be purchased separately and later installed on a pickup truck by its owner?; Answer: The enclosed Notice of Ruling Regarding Campers affirms th applicability of Federal Standard No. 205 to camper bodies. Federal Standard No. 108 is a standard applicable to chassis cabs and to complete motor vehicles.; Question: 2. Do Federal Standards Nos. 108 and 205 apply to camper which are sold by the pickup truck dealer as part of a new vehicle even though the camper body itself is actually a load on the pickup and is designed to be removed from the pickup when the owner decides to transport other types of loads?; Answer: The applicability of Federal Standard No. 205 is covered in th enclosure. Federal Standard No. 108 is a requirement upon the dealer who sells a motor vehicle. If the vehicle is designed for more than one configuration in use, the dealer must provide that both configurations are in compliance with Federal Motor Vehicle Safety Standards.; The enclosed information on the National Traffic and Motor Vehicl Safety Act of 1966 are provided to further assist you.; Sincerely, Joseph R. O'Gorman, Acting Director, Office of Performanc Analysis, Motor Vehicle Safety Performance Service; |
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ID: aiam5267OpenRonald L. Signorino, Director Health, Safety & Regulatory Affairs Universal Maritime Service Corp. Suite 1600 10 Exchange Place Jersey City, NJ 07302; Ronald L. Signorino Director Health Safety & Regulatory Affairs Universal Maritime Service Corp. Suite 1600 10 Exchange Place Jersey City NJ 07302; "Dear Mr. Signorino: We have received your FAX of November 3, 1993 with respect to the trailer conspicuity specifications of Federal Motor Vehicle Safety Standard No. 108. First, we regret the confusion that has been caused by our letter of October 20, 1993, to James Peepas of Selecto-Flash, Inc., which modified our earlier interpretation dated July 26, 1993. Mr. Peepas has made a number of calls to this Office seeking an understanding of the conspicuity requirements on Maersk's behalf, and, in our view, has pursued the matter with diligence. You have presented three 'Facts' and ask whether each is right or wrong. 'Fact: With particular reference to Maersk Line's prospective order for forty-foot gooseneck chassis (drawing accompanies this fax) your October 20 letter makes clear that calculable conspicuity treatments must not be obscured by trailer cargo.' If calculable means 'required', this is a correct statement. Our letter of October 20 refers to the requirement of paragraph S5.7.1.4.2(a) that 'at the location chosen, the strip of sheeting shall not be obscured in whole or in part by other motor vehicle equipment or trailer cargo.' 'Fact: In calculating the area of conspicuity treatment for such chassis, the gooseneck section, as it is often hidden from view by mounted intermodal containers (trailer cargo), cannot properly be considered an appropriate site, and' The length of the gooseneck is included in determining the overall length of the trailer for purposes of calculating the half length that must be covered by the conspicuity treatment (which, of course, would be greater than half the length behind the gooseneck). There is nothing in Standard No. 108 that precludes the application of auxiliary retroreflective sheeting to the gooseneck. Indeed, some manufacturers may wish to do so to provide conspicuity of the trailer side when the trailer is traveling without its cargo. However, any conspicuity treatment on a gooseneck is not counted in determining whether at least half the trailer side is covered. 'Fact: In determining the fifty percent of side surface area to receive conspicuity treatment on such chassis, the length of the chassis, from its rear bolster to its point immediately behind the gooseneck's terminus, is solely relevant.' This assertion is wrong, and the correct requirement is most clearly illustrated by the following example. Let us say that the overall length of the trailer is 40 feet, including an 8-foot gooseneck. The amount of the side to be covered is not less than 20 feet. The area to be covered is the 32 feet between the rear bolster to the point immediately behind the gooseneck's terminus. Thus, at least 20 feet of this 32-foot length must be covered in order to comply with Standard No. 108. I hope that this clarifies the matter for you. Sincerely, John Womack Acting Chief Counsel cc: James Z. Peepas"; |
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ID: aiam2408OpenMr. Katsuhiko Yokoi, Toyoda Gosei Co., Ltd., 9, I-chome, Nishiyabushitacho, Nishiku, Nagoya, Japan; Mr. Katsuhiko Yokoi Toyoda Gosei Co. Ltd. 9 I-chome Nishiyabushitacho Nishiku Nagoya Japan; Dear Mr. Yokoi: #This is in belated response to your April 9, 1976 letter concerning the application of Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses*, to certain combination hydraulic brake hose assemblies. #Figure 3 of your letter depicts two typical brake hose assemblies that are connected end-to-end. Figure 4 depicts the intended installation of such a pair of assemblies, with the joined fittings meeting at a bracket that is attached to a shock absorber. Figure 1 and 2 show two designs to simplify the structure at this juncture. #Treating these figures in reverse order, the 'B type' design shown in Figure 2 is similar to the pair of assemblies shown in Figure 3, except that the pair of joined end fittings is replaced with a single center fitting. The National Highway Traffic Safety Administration (NHTSA) considers such a construction to be two distinct brake hose assemblies, which would be tested separately for compliance with Standard No. 106-74. The center fitting would simply be considered an end fitting for each of these assemblies. #the 'A type' design shown on figure 1 would be treated differently, however. In this design, the two separate pieces of hose are replaced by a single piece that runs the full length between the outermost end fittings. in place of joined fittings as in Figure 3 or a center fitting as in Figure 2, this hose would be surrounded by molded rubber and a metal ring. The ring would be mounted in the bracket that is attached to the shock absorber. The NHTSA considers this construction to be a single brake hose assembly, and testing for compliance with Standard No. 106-74 would be conducted accordingly. For example, the tensile strength test would be performed by pulling at the outermost fittings, on the full length of the hose. However, this interpretation would not require the assembly to be capable of meeting the whip resistance requirements of S5.3.3 with the full length subject to flex. The NHTSA considers such a brake hose assembly to have two distinct 'free lengths'--one on either side of the center metal ring. Therefore, the whip resistance test would be performed separately on each of these portions. In other words, the metal ring would be treated as an 'end fitting,' for the purposes of the whip resistance test described in S6.3. #Sincerely, Frank A. Berndt, Acting 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.