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: aiam1319OpenMr. Allan H. Berger, Director of Equipment Services, Browning-Ferris Industries, Inc., Fannin Bank Building, P.O. Box 3151, Houston, TX 77001; Mr. Allan H. Berger Director of Equipment Services Browning-Ferris Industries Inc. Fannin Bank Building P.O. Box 3151 Houston TX 77001; Dear Mr. Berger: This is in reply to your letter of October 26 to Mr. J.E. Leysath o this office concerning marker and signal lights on your Mack trucks.; Federal Motor Vehicle Safety Standard No. 108 requires that fron clearance and identification lamps be located as close as practicable to the top of the vehicle. Mounting these lamps *on* the top of the vehicles described in your letter does not appear to be practicable because of possible damage to the lamps. If mounting the lamps on the front vertical surface near the top is, in your determination, 'as close to the top as practicable,' then you have met the requirements of Standard No. 108. Mounting an additional side marker lamp (which you have identified as a corner clearance lamp) on each side of the cab, near the front and top of the cab, would not be prohibited by Standard No. 108.; Turn signal lamps and hazard warning signal lamps mounted on the rea of the vehicle may be either red or amber. The color of these lamps was addressed in a Notice of Proposed Rule Making published in the *Federal Register* on October 25, 1972, (Docket 69-19, Notice 3). It was proposed that amber be eliminated as an optional color for these lamps, but no final decision has been made.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam3324OpenLes Sander, Illinois New Car and Truck Dealers Association, P.O. Box 3045, Springfield, IL 62704; Les Sander Illinois New Car and Truck Dealers Association P.O. Box 3045 Springfield IL 62704; Dear Mr. Sander: This is in response to your letter of August 1, 1890, in which yo asked whether the Illinois certificate of title may be used in lieu of a separate Federal odometer form. The Illinois title does not contain the signature of the buyer. The National Highway Traffic Safety Administration believes that the buyer's signature is necessary in order to substantiate that he has seen the odometer information and is aware of the mileage that the vehicle has been driven. Without the signature the Illinois title cannot be used in place of the Federal form.; If you have any further questions or if we can be of any assistance please do not hesitate to write.; Sincerely, John Womack, Assistant Chief Counsel |
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ID: aiam1437OpenMr. John F. McCuen, Attorney, Kelsey-Hayes Company, Romulus, MI 48174; Mr. John F. McCuen Attorney Kelsey-Hayes Company Romulus MI 48174; Dear Mr. McCuen: This responds to your February 1, 1974, request for interpretation o the language 'maximum temperature of 500*+*50 degrees F' appearing in S6.1.8.1 of Standard No. 121, *Air brake systems*, 49 CFR 571.121.; The language is intended to specify a temperature range within which t conduct the burnishing procedure in the event brake applications cause the hottest brake on a vehicle to reach 500 degrees F. The word 'maximum' is inappropriate and will be deleted in an upcoming notice responding to petitions that raised the same point.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4635OpenMs. Dixie Lee Christensen Q. C. Chemist Nippondenso Mfg. Inc., USA One Denso Road Battle Creek, MI 49015; Ms. Dixie Lee Christensen Q. C. Chemist Nippondenso Mfg. Inc. USA One Denso Road Battle Creek MI 49015; "Dear Ms. Christensen: This is in reply to your letter to the agenc asking if there are any Federal regulations concerning the type of data about your products that you should retain, and for what length of time. If there are no data retention requirements, you ask for recommended guidelines. Your company manufactures and supplies component parts to US and Japanese car makers. I regret the delay in responding to your letter. The Department of Transportation has no regulations of the nature you mention. However, as a manufacturer of motor vehicle equipment, your company comes under the jurisdiction of the National Traffic and Motor Vehicle Safety Act which this agency administers. In the absence of knowledge about the kind of equipment your company manufactures, our guidelines will necessarily be general. Your letter indicates that your company provides components for use as original equipment in motor vehicles. As a general rule, all items of motor vehicle equipment must be free of defects relating to motor vehicle safety. If a vehicle manufactured with your products is determined by its manufacturer to incorporate a safety related defect that is attributable to your component, the vehicle manufacturer must notify the agency and purchasers of the vehicles affected, and remedy the defect. Your company must also notify the agency, and, if the component has been used in the vehicles of more than one manufacturer, you must notify those manufacturers also. If you have manufactured these components as replacement equipment, then the notification and remedy responsibility falls squarely upon your company. The Act requires that the defect be remedied without charge for a period of 8 years after manufacture. This suggests that you should retain manufacturing, production, and sales records for at least 8 years. Some components must also comply with an applicable Federal motor vehicle safety standard, and be so certified by its manufacturer, whether it is used as original or replacement equipment. Notification and remedy is also required if a noncompliance is determined to exist, with remedy at no cost to a purchaser for the 8-year period. We do not know whether your products are directly covered by a Federal motor vehicle safety standard, and would be pleased to answer any further questions you may have. I have enclosed an information sheet for new manufacturers of motor vehicles and motor vehicle equipment. For a fuller understanding of the responsibilities of equipment manufacturers, you should consult the regulations of this agency at Title 49 Code of Federal Regulations Part V (available from your local office of the U.S. Government Printing Office as 'Title 49 Code of Regulations Parts 400 to 999'). Sincerely, Stephen P. Wood Acting Chief Counsel Enclosure"; |
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ID: aiam1067OpenMr. William R. Graham, Bus and Truck Supply Co., 315 Continental avenue, Dallas, TX 75207; Mr. William R. Graham Bus and Truck Supply Co. 315 Continental avenue Dallas TX 75207; Dear Mr. Graham: This is in reply to your letter of February 21, 1973, requesting tha we refer you to either the source or the size of letters used in the Snellen ratio 20/40, which is incorporated into S5.2.2 of Standard No. 217, 'Bus Window Retention and Release.' You state in your letter that you cannot find a source for the letter size required to meet the standard.; Snellen charts are those charts used generally by optometrists or othe persons interested in measuring eyesight. They are universally available from medical supply businesses. I point out that the standard does not require a specific letter size, as your letter implies, but only that a person whose vision has been measured to the specified Snellen ratio be able to read the exit identification required by S5.5. This legibility will be based not only on lettering size, but also on its contrast with its background, its shape, its precise location, and the configuration of the bus interior.; Yours Truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4265OpenThe Honorable Guy Vander Jagt, U.S. House of Representatives, Washington, DC 20515-2209; The Honorable Guy Vander Jagt U.S. House of Representatives Washington DC 20515-2209; Dear Mr. Vander Jagt: Thank you for your November 3, 1986, letter on behalf of you constituent, Miss Reva Darling of Ludington, Michigan, who asked about requirements for safety belts on buses used for school transportation and other purposes. Your letter has been referred to my office for reply, since the National Highway Traffic Safety Administration (NHTSA) is responsible for administering Federal programs relating to school bus safety.; Miss Darling is interested in extending the applicability of Michigan' safety belt use law to belts on 'public' buses. She believes that safety belts should be installed on school buses used by transit and charter companies, and suggests that funding be made available to encourage the installation of belts on those vehicles.; I appreciate this opportunity to respond to your inquiry. By way o background information, under the National Traffic and Motor Vehicle Safety Act, NHTSA is authorized to develop motor vehicle safety standards applicable to all new motor vehicles, including school buses and charter and transit buses. Our belt installation requirements vary according to the type of vehicle, for example, different requirements apply to passenger cars than to buses. For buses generally, our requirements only specify that a safety belt must be installed for the bus driver. They do not require safety belts for passengers on large buses used for pupil transportation and other purposes.; We have not required large buses to have safety belts for passenger because we have not found sufficient justification for such a requirement, given that buses have excellent safety records. This safety record arises impart from the fact that, in crashes with other vehicles, buses tend to be substantially heavier than the other vehicle while cars tend to weigh approximately the same as the vehicle with which they crash. As a result, the crash forces experienced by bus occupants tend to be less than those experienced by car occupants. Also, because of the elevated seating positions in large buses, bus occupants sit above the area typically damaged in a collision with another vehicle. Further, we require large school buses to provide passenger crash protection with higher and stronger seats, additional seat padding, and better seat spacing and performance. That approach, together with the other attributes of large school buses, provides adequate levels of crash protection in school buses without safety belts. I have enclosed a copy of a NHTSA publication, 'Safety Belts in School Buses,' which addresses in more detail the issue of whether safety belts should be required on school buses.; NHTSA does not prevent States and local jurisdictions that wish t order safety belts on their own large buses from doing so. Although large buses are not required by Federal law to have passenger safety belts, bus owners are free to purchase their buses with safety belts installed if they believe their particular circumstances warrant such installation. However, we have no reason at this time to believe that such an installation is necessary as a Federal requirement applicable to all transit buses.; Miss Darling asked whether there have been any proposals to appl Michigan's safety belt use law to public buses. Safety belt use requirements are a matter of State rather than Federal law. Therefore, Michigan state officials would be able to answer Miss Darling's particular question concerning the state law.; On a final matter, Miss Darling suggested that funding be mad available to equip buses with safety belts. For your information, while the Administration has not proposed any legislation effecting school buses, H.R. 749 (introduced in the 99th Congress) proposed incentive grants to the States encouraging the adoption and enforcement of laws requiring the use of safety belts in school buses. H.R. 749, however, was not enacted.; I hope this information is helpful. Please contact my office if we ca be of further assistance.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam0226OpenMr. J. C. Eckhold, Ford Motor Company, The American Road, Dearborn, MI 48121; Mr. J. C. Eckhold Ford Motor Company The American Road Dearborn MI 48121; This is in reply to your letter of March 19, 1970 with which yo submitted for our examination a sample format for consumer information produced by a computer.; The sample that you submitted does deviate from the requirements of th consumer information regulations in that the required warnings and explanations are placed on a sheet that is separate from the numerical data. The regulations generally require that the information be presented in the form illustrated by the published figures, with the explanatory matter in proximity to the numerical data. I believe that computer printing is flexible enough to allow you to accomplish this.; Sincerely, Douglas W. Toms, Director |
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ID: aiam5024OpenThe Honorable George Allen U. S. House of Representatives 255 West Main Street, Room 102 P.O. Box 136 Charlottesville, VA 22902-0136; The Honorable George Allen U. S. House of Representatives 255 West Main Street Room 102 P.O. Box 136 Charlottesville VA 22902-0136; "Dear Mr. Allen: Thank you for your letter in support of Philatro International's request for an immediate temporary exemption from the oil resistance requirement of Federal Motor Vehicle Safety Standard 106, Brake Hoses. The National Highway Traffic Safety Administration (NHTSA) can appreciate the concern you have for distributors of Philatron's brake hoses such as your constituent, Truck Parts East. NHTSA closely examined Philatron's request and determined that the agency cannot provide the requested exemption. The reasons underlying this conclusion are fully explained in a May 26, 1992, letter from Chief Counsel Paul Jackson Rice to Anthony D. Padgett, counsel for Philatron. In his letter, the Chief Counsel explained that Philatron, as a manufacturer of motor vehicle equipment, is not eligible to be considered for an exemption under the National Traffic and Motor Vehicle Safety Act. The Chief Counsel also concluded that a proceeding resulting from Philatron's rulemaking petition must include a full notice and comment procedure. A copy of the letter is enclosed. I would like to clarify an aspect of our rulemaking procedures mentioned in your letter. While it is correct that the National Highway Traffic Safety Administration granted Philatron's rulemaking petition to amend Standard 106's oil resistance requirement, the agency did not inform Philatron that such an amendment would in fact be adopted. Whenever the agency grants a rulemaking petition, it states that it will subsequently decide whether to issue the requested rule based on all available information developed in the course of the rulemaking proceeding, in accordance with statutory criteria. We hope that this information is helpful. Sincerely, Frederick H. Grubbe Acting Administrator Enclosure Letter Dated May 26, 1992 cc: Washington Office"; |
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ID: aiam3959OpenMr. M. Ojima, Manager, Asahi Glass Company, Ltd., 1-2, Marunouchi 2-Chome., Chiyoda-Ku, Tokyo, Japan; Mr. M. Ojima Manager Asahi Glass Company Ltd. 1-2 Marunouchi 2-Chome. Chiyoda-Ku Tokyo Japan; Dear Mr. Ojima: Thank you for your letter of May 8, 1985, to Administrator Stee concerning the requirements of Standard No. 205, *Glazing Materials*, that apply to glass-plastic glazing. The answers to your questions are discussed below.; Your first question concerns the requirements of the boil and humidit tests that apply to glass-plastic glazing. You explained that after the boil test and the humidity test, your plastic material develops a haze. You stated that the maximum haze resulting from the boil test is approximately 45 percent and the maximum haze resulting from the humidity test is approximately 10 percent. However, after the sample had been left at room temperature for 24 hours, the plastic haze disappeared and the plastic 'completely recovered to the original condition.'; As you correctly noted, Standard No. 205 requires glass-plastic glazin to pass Test No. 3, Humidity, and Test 4, Boil Test, of the American National Standard Institute's 'Safety Code for Safety Glazing Materials for Glazing Motor Vehicles Operating on Land Highways' Z26.1-1977, January 26, 1977 as supplemented by Z26.1a, July 3, 1980, which is incorporated by reference in our standard. As explained in the preamble to the November 16, 1983, final rule setting performance requirements for glass-plastic glazing, the purpose of the humidity and boil tests is to ensure that the plastic layer of glass-plastic glazing does not delaminate when exposed to high temperatures and humidity. Since the temporary haze does not result in a permanent change in the structure of the glazing, which would occur if the glazing delaminated, we do not consider the temporary haze to be a failure of the boil or humidity tests. The glazing must, of course, comply with Test No. 17, Abrasion Resistance, as modified by Standard No. 205, which is directly meant to limit haze.; Your second question concerned whether you should mark glass-plasti glazing as 'AS1' or 'AS14'. You noted that ANSI Z26.1-1983 specifies that glass- plastic glazing should be marked 'AS1', while our standard specifies the use of 'AS14'. Standard No. 205 incorporates by reference the 1977 version of Z26.1, as supplemented by Z26.1a, July 3, 1980, and does not incorporate Z26.1-1983. Therefore, in accordance with S6.1 of Standard No. 205, you must mark glass- plastic glazing manufactured for sale in the United States with 'AS14'.; If you have any further questions, please let me know. Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam1964OpenMr. Robert P. Crawford, President, Athens Sport Cycles, Inc., 20 W. Stimson Avenue, Athens, OH 45701; Mr. Robert P. Crawford President Athens Sport Cycles Inc. 20 W. Stimson Avenue Athens OH 45701; Dear Mr. Crawford: This is in response to your letter of May 18, 1975, in which you ask number of questions relating to tire registration procedures, and in amplification of your telephone conversation with Mr. Schwartz of my office. We will answer your questions in the order raised.; >>>1 and 2. There is a universal tire registration form (figure 3 i the enclosed Part 574) which manufacturers are required to furnish to you or you may reproduce pursuant to S 574.7 of the regulation.; 3. Since the regulation requires that the manufacturers or their agent maintain the records, the forms should either be sent to the manufacturer or his designated agent. A number of manufacturers utilize services such as the Tire Safety Registry in New Jersey to keep their records, but they merely act as the manufacturer's agent. There is to our knowledge no central place to send the forms for all manufacturers.; 4. We have no idea what is meant by a retailer I.D. number. Ou recommendation is that you contact the manufacturers to determine what they mean.; 5. Our tire recordkeeping regulation only applies to tires for use o motor vehicles. Thus, tires for use on off-road vehicles would not fall within the regulation.; 6. As required by S 574.8 of the enclosed regulation, completed form must be sent to manufacturers every 30 days. The only exception is where you sell less than 40 tires of all makes and manufacturers in the 30- day period, in which case you may wait until you sell 40 tires or for 6 months, whichever comes first.; 7. Retailers are not required to keep any tire owner forms. 8. It is the responsibility of the dealer to mail the forms, althoug he may ask the customer to fill out the form at the time of purchase.<<<; On behalf of the National Highway Traffic Safety Administration, let m commend you for your desire to fully comply with the requirements of our tire recordkeeping regulations. It is through the efforts of dealers such as you that motorcyclists and their passengers are protected against tire defects which might lead to injury or death.; Yours truly, Richard B. Dyson, Assistant 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.