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: aiam1087OpenMr. Alberto Negro, Manager, Research and Development, Fiat Motor company, Inc., 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Alberto Negro Manager Research and Development Fiat Motor company Inc. 560 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Negro: This is in reply to your letter of February 22, 1973, requestin confirmation of your understanding that automobile manufacturers may continue to use glazing materials manufactured before April 1, 1973, that do not conform to the recent amendment to Standard No. 205, 'Glazing Materials', effective on that date, in motor vehicles manufactured after that date.; Standard No. 205, an 'equipment standard', applies to glazing material for use in motor vehicles. It does not apply directly to vehicles in which such materials are used. As a consequence, a vehicle manufacturer may use glazing materials that do not conform to Standard No. 205 as it exists on the date the *vehicle* is manufactured. The glazing material must, however, conform to the standard as it exists on the date that the material is manufactured.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1592OpenMr. R. Vibart, The Secretary General, Societe de Signalisations Automobiles, SEIMA, 11, Chemin des Merisiers, Villemoisson-sur-Orge (1), France, *AIR MAIL*; Mr. R. Vibart The Secretary General Societe de Signalisations Automobiles SEIMA 11 Chemin des Merisiers Villemoisson-sur-Orge (1) France *AIR MAIL*; Dear Mr. Vibart: This is in response to your letter of July 17, 1974, concerning NHTSA' proposal to apply a manufacturer's identification code to motor vehicle lights.; Motor vehicle lights, including those imported in the United States subject to MVSS No. 108, *Lamps, reflective devices, and associated equipment*, would be required to be marked with a manufacturer's identification code under the NHTSA proposal. Just as all motor vehicle lights must meet the performance requirements of Standard 108, if the proposal is adopted as a final rule they would be required to meet the manufacturer's identification code requirement as well.; Thank you for advising us of your views in this matter. We will tak them into account in formulating further action.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam1068OpenMr. Bruce E. Roberts, President, Yuma Tire & Recapping, Inc., Route 3, Gate City, VA 24251; Mr. Bruce E. Roberts President Yuma Tire & Recapping Inc. Route 3 Gate City VA 24251; Dear Mr. Roberts: This is in reply to your letter of February 28, 1973, requesting detailed explanation of what you must do to conform to Motor Vehicle Safety Standard No. 117, 'Retreaded Pneumatic Tires'. You also ask whether there are record keeping requirements, such as to maintain the name and address of customers to whom tires are sold.; There are specific requirements for retreaders and their dealers t record and maintain the name and address of each tire purchaser. This is done through the use of a code number molded or branded onto each tire. These requirements (49 CFR Part 574, copy enclosed) have been in effect since May 22, 1971.; We have enclosed a copy of Standard No. 117. We regret that we canno provide a detailed explanation of these requirements as you request. We refer you to either private counsel or to one of the many associations of retreaders whom we understand can assist you in implementing the standard. If after reading the standard you have questions of a specific nature regarding its provisions, we will respond to them.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4790OpenMr. Robert Roden Roden & Hayes 2015 First Avenue No., Suite 400 Birmingham, AL 35203; Mr. Robert Roden Roden & Hayes 2015 First Avenue No. Suite 400 Birmingham AL 35203; "Dear Mr. Roden: This responds to your questions about the requirement for key-locking systems in section S4.2(b) of Federal Motor Vehicle Safety Standard No. 114, Theft Protection (49 CFR 571.114). As explained below, the enclosed copy of the agency's recent final rule amending this provision may be relevant to your inquiry (55 FR 21868, May 30, 1990). By way of background, the National Traffic and Motor Vehicle Safety Act, ('Vehicle Safety Act,' 15 USC 1381 et seq.) requires every new motor vehicle sold in the United States to be certified as complying with all applicable Federal motor vehicle safety standards. The Vehicle Safety Act specifies that the manufacturer must certify that each of its vehicles complies with all applicable safety standards in effect on the date of manufacture. Any person violating the Vehicle Safety Act by manufacturing or selling new noncomplying vehicles may be liable for potential penalties of $1,000 per violation up to $800,000 for a related series of violations. One such Federal safety standard is Standard No. 114, Theft Protection, which applies to passenger cars, and to trucks and multipurpose passenger vehicles having a gross vehicle weight rating of 10,000 pounds or less. Your first question asked whether section S4.2(b) requires key locking systems to prevent removal of the ignition key except when the transmission is in the 'park' position. Section S4.2(b) currently requires such vehicles to have a 'key-locking system that, whenever the key is removed, will prevent...(b) either steering or forward self-mobility of the vehicle, or both.' However, the agency has recently amended section S4.2(b) to read as follows: Each vehicle shall have a key-locking system that, whenever the key is removed, prevents: (a) the normal activation of the vehicle's engine or motor, and (b) either steering or forward self-mobility of the vehicle or both. For a vehicle equipped with an automatic transmission with a 'park' position, the key-locking system shall prevent removal of the key unless the transmission or transmission shift lever is locked in 'park' or becomes locked in 'park' as the direct result of removing the key. You should be aware that this amendment takes effect on September 1, 1992. For vehicles manufactured before September 1, 1992, S4.2(b) merely requires that when the key is removed, the key-locking system must prevent steering or forward self-mobility, or both. This provision does not address the issue of the transmission's position at the time of key removal. In contrast, under the recent amendment applicable to vehicles manufactured on or after September 1, 1992, S4.2(b) requires automatic transmission vehicles to prevent removal of the key unless the transmission or transmission shift lever is locked in 'park' or becomes locked in 'park' as the direct result of removing the key. Your second question asked whether a replacement key-locking system is required to comply with Standard No. 114. Because Standard No. 114 applies to new motor vehicles and not to motor vehicle equipment, the standard does not in itself require aftermarket replacement systems to comply with its requirements. However, you should be aware that section 108(a)(2)(A) of the Vehicle Safety Act prohibits manufacturers, distributors, dealers, or motor vehicle repair businesses from knowingly 'rendering inoperative,' in whole or in part, any device or element of design installed on or in a vehicle to comply with an applicable safety standard. Your third question asked how long the key locking system is required to perform under S4.2(b) of the standard. The Vehicle Safety Act only requires manufacturers to assure that vehicles and equipment comply with applicable safety standards at the time of the first consumer purchase. However, please note that if at any time a manufacturer or the agency determines that a vehicle or item of equipment contains a safety-related defect, which could result from the failure of a system to operate properly, the manufacturer is required to notify all product purchasers of the defect and remedy the defect without charge. See 15 U.S.C. 1411-1414. I hope this information is helpful. If you have any further questions, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel Enclosures"; |
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ID: aiam3055OpenMr. A. L. Bragg, Laboratory Manager, Truck-Lite Co. Inc., 310 East Elmwood Avenue, Falconer, NY 14733; Mr. A. L. Bragg Laboratory Manager Truck-Lite Co. Inc. 310 East Elmwood Avenue Falconer NY 14733; Dear Mr. Bragg: This is in reply to your letter of June 19, 1979, to Mr. W. M. Elliot of this agency requesting clarification of Paragraph S4.3.1.1.1 of Federal Motor Vehicle Safety Standard No. 108.; This Paragraph states: >>>'Clearance lamps may be mounted at a location other than on th front and rear if necessary to indicate the overall width of a vehicle, as for protection from damage during normal operation of the vehicle, and at such a location they need not be visible at 45 degrees in board.'<<<; You have asked the following questions: '1. Is the decision to use another mounting location made at th discretion of the manufacturer?'; Yes. The manufacturer determines whether placement of the lamps i accordance with Standard No. 108 will indicate overall width or whether they are susceptible to damage if so placed, and there is no requirement that it obtain the concurrence of this agency in its decision.; '2. Are there any specific conditions that are required in order t consider it 'necessary' to mount clearance lamps in another location?'; No. The agency has established no criteria of necessity and question on variations from front and rear mounting requirements are treated on an *ad hoc* basis.; '3. When the decision is made to mount the clearance lamps in anothe location, can a manufacturer use *combination* clearance/side marker lamps mounted on the *side of vehicle* to fulfill the clearance lamp requirements.'; Yes, as long as the clearance lamp function is visible from the rea and indicates the overall width of the vehicle.; '4. Section S4.1.1.1 states that in 'such a location they need not b visible at 45 degrees inboard'. Does this mean that they need not be visible from 0 to 45 degrees inboard?'; No. SAE Standard J592e, *Clearance, Side Marker, and Identificatio lamps*, July 1972, requires clearnce (sic) lamps to be visible at the H Point at 10 R and L, 20 R and L, 30 R and L, and at 45 R and L. Paragraph S4.3.1.1.1 specifies that under the alternate mounting positions the lamps need not be visible at the 45 degrees positions. They must, however, be visible at the other positions.; I hope this answers your questions, Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1438OpenMr. Philip H. Taft, Tire Retreading Institute, 1343 L Street, N.W., Washington, D.C. 20005; Mr. Philip H. Taft Tire Retreading Institute 1343 L Street N.W. Washington D.C. 20005; Dear Mr. Taft: This is in reply to your letter of February 22, 1974, concerning a article in the November 1973 *Retreader's Journal* entitled 'Repairing Torn Beads.' You ask whether the article is correct when it states that casings with cord exposed in the bead area may be retreaded.; Standard No. 117 (S5.2) prohibits the retreading of any casing on whic bead wire or cord fabric is exposed before processing. 'Processing' encompasses the entire process, including the making of any needed repairs, by which a casing is retreaded. The NHTSA has taken the position that the only exception to this prohibition is that casings with exposed chafer fabric bay be retreaded. A casing that before processing has any exposed bead or cord material other than chafer fabric, however, may not be retreaded. Therefore, insofar as the Retreader's Journal article states that casings with exposed cord in the bead area may not be retreaded it is incorrect. We have sent a copy of this letter to the *Retreader's Journal*.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam3405OpenMr. James J. Schultz, Severy, Incorporated, 2233 El Segundo Boulevard, El Segundo, CA 90245; Mr. James J. Schultz Severy Incorporated 2233 El Segundo Boulevard El Segundo CA 90245; Dear Mr. Schultz: This responds to your recent letter asking whether a 4-wheel driv pickup truck must comply with Safety Standard No. 216, *Roof Crush Resistance*. You also ask whether the definitions of vehicle classification under Federal regulations are mutually exclusive.; The application section of Safety Standard No. 216, section 3 specifies that the standard applies to passenger cars. This means that the standard applies *only* to passenger cars. Therefore, the standard does not apply to a pickup truck.; The definitions of the basic vehicle classifications found in 49 CF Part 571.3 are mutually exclusive. If a vehicle falls within the definition of a 'truck,' the vehicle is not also within the definition of a 'passenger car.' The definition of a passenger car does not specifically exclude trucks because the definition is based on the function of the vehicle. Thus, a passenger car is defined as a motor vehicle designed for carrying persons. A truck, on the other hand, is defined as a vehicle designed primarily for the transportation of property or special purpose equipment. Since a pickup is designed primarily for carrying property and not persons, it is a truck and not a passenger car. Each motor vehicle has a certification label attached to its door which specifies the vehicle's classification.; I hope this has clarified any questions you had concerning vehicl classification under the Federal Motor Vehicle Safety Standards.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0383OpenMr. Charles J. Calvin, Managing Director, Truck Trailer Manufacturers Association, 1413 K Street, NW., Washington, DC, 20005; Mr. Charles J. Calvin Managing Director Truck Trailer Manufacturers Association 1413 K Street NW. Washington DC 20005; Dear Mr. Calvin: This replies to your letter of June 30, 1971, and has reference t previous discussions your Mr. Gray and Mr. Wilson had with members of my engineering staff concerning lamp and reflector locations for trailers.; We have reviewed the drawings submitted and find that the locations an types of lamps and reflectors to be acceptable under the provisions of the Motor Carrier Safety Regulations. As we noted in past correspondence on this subject, a license plate light is not required by our present regulations. Again, the impression should not be given that this lamp, if not required by State regulation, must be installed on vehicles not certified to comply with Motor Vehicle Safety Standard No. 108.; The Bureau of Motor Carrier Safety appreciates the efforts of you association in aiding motor carriers to understand and comply with the Motor Carrier Safety Regulations.; Sincerely yours,Robert A. Kaye, Director |
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ID: aiam2644OpenMr. Phillip A. O'Reilly, Houdaille Industries, Inc., One M & T Plaza, Buffalo, NY 14203; Mr. Phillip A. O'Reilly Houdaille Industries Inc. One M & T Plaza Buffalo NY 14203; Dear Mr. O'Reilly: This is in response to your letter of June 14, 1977, commenting o certain statements made in the May 12, 1977, Federal Register notice (42 FR 24056) responding to petitions for reconsideration of Part 581, *Bumper Standard*. Specifically, you object to the reference in the notice to the Houdaille cost-benefit study and to the statement that the Harris poll indicated that a 'significant' number of people consider 1/2 inch dents to be damage they would repair.; The notice referred to the Houdaille study as one which indicated tha the damage criteria contained in Part 581 could be met in a cost-beneficial manner. The agency did not represent that the Houdaille study demonstrated that Part 581 standard was the most cost-effective standard that could be promulgated.; With regard to your objection to our characterization of the number o people who would repair a 1/2 inch dent as 'significant,' you should note that it is the conclusion of the agency that the percentage of those people polled (25 percent) who expressed concern over a 1/2 inch dent is *significant*.; Regarding your suggestion that a 2 1/2 mph impact test be adopted, th agency proposed such a change in Part 581 on January 2, 1975 (40 FR 10) and determined after a period for submission of comments and a 2-day public hearing that such a reduction should not be adopted (40 FR 11598, March 12, 1975). The agency's position on that matter has not changed.; We appreciate your comments and have placed your letter in the publi docket.; Sincerely, Joan Claybrook |
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ID: aiam0679OpenMr. C. W. Rose, Chairman of the Board, Rose Manufacturing Co., 2700 West Barberry Place, Denver, CO 80204; Mr. C. W. Rose Chairman of the Board Rose Manufacturing Co. 2700 West Barberry Place Denver CO 80204; Dear Mr. Rose: This is in reply to your letters of March 23, 1972, and March 27, 1972 concerning our previous letter to you dated March 10, 1972.; We recognize your contribution to safety and your deep persona involvement in child harnesses. Harnesses, such as yours, offer many desirable features. The child is free to move about, and he is adequately restrained if the harness system is properly adjusted and anchored. Effective harness systems can probably be produced at modest cost.; There certainly can be no objection to the upper torso restrain provided by a good harness system. Indeed, this is a very important feature which is required because of the child's special skeletal structure.; On the other hand, restraints which are anchored to inadequat structures or which allow excessive motion of the child in a crash cannot be condoned. Actual thirty mile-per-hour, sixteen g dynamic sled tests of child harnesses anchored as you recommend have shown that a severe problem exists with the anchorage system. Quoting the University of Michigan Highway Safety Research Institute Report, *Child Seat and Restraint Systems Test Program*, DOT/HS-800-376, in the test at 30 mph the adult seat back broke away due to the load imposed by the restraint system tether. This allowed the dummy to move forward far enough to cause potential contact with the vehicle interior.' This test was conducted using a heavy duty Bostrom truck bucket seat and utilized only the thirty-pound, three-year-old child dummy, restrained by a Sears small harness. The present typical seat back strengths are, thus, inadequate to support a harness system which depends upon the seat back. It is our intention to encourage improvements in seat back strength for automobile production by future rule making action.; Since your harness is recommended for children up to fifty pounds an since most passenger car seats are not as strong as the test seat, we expect the situation to be even more serious in realistic usage conditions which also normally encounter appreciably higher load levels in thirty mile-per-hour crashes. This is why we object to your system of anchorage. Thus, our position is as stated in our previous letter to you.; We hope that you will consider other methods of anchoring your chil harness which will prevent seat back failure and resulting excessive occupant excursions.; We appreciate your sincere interest and concern in this matter. W emphatically do believe that child harnesses play a vital role in child restraints.; Sincerely, Charles H. Hartman, Deputy Administrator |
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.