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: aiam2797OpenDonald W. Segraves, Alliance of American Insurers, 20 North Wacker Drive, Chicago, IL 60606; Donald W. Segraves Alliance of American Insurers 20 North Wacker Drive Chicago IL 60606; Dear Mr. Segraves: This is in response to your letter of March 22, 1978, requesting tha the National Highway Traffic Safety Administration (NHTSA) interpret 'primary place of business' under 49 CFR Part 580 to include regional offices and other places of business where companies' records are customarily maintained.; It is our opinion that 'primary place of business' includes, in th case of a business with multiple offices, a regional or local office where transactions involving the subject vehicles took place and the records are maintained, in addition to the home office or headquarters of the business. For example, if a vehicle is repossessed by an insurance company that has its home office in New York, but the regional office in Chicago handled and retained all the paperwork on the repossessed vehicle, then the Chicago office would be the primary place of business for that transaction and the odometer disclosure statements should be retained in the Chicago office. The office that the purchaser dealt with would be the one he would contact if a problem arose at a later time. Therefore, it would be the logical office to maintain the records. If, however, the Chicago office handled the paperwork but upon completion forwarded it to the New York office, the New York office, as the repository for all paperwork, would be the primary place of business and odometer statements, like all other documents should be forwarded to that office. The place of retention, like the manner of retention, must be consistent so that the systematic retrieval is possible.; Sincerely, John Womack, Assistant Chief Counsel |
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ID: aiam5052OpenDale E. Dawkins, Director Vehicle Compliance and Safety Affairs Chrysler Corporation CIMS 414-01-22 12000 Chrysler Drive Highland Park, MI 48288-0857; Dale E. Dawkins Director Vehicle Compliance and Safety Affairs Chrysler Corporation CIMS 414-01-22 12000 Chrysler Drive Highland Park MI 48288-0857; "Dear Mr. Dawkins: This responds to your September 4, 1992 letter, i which you notified the agency of your intention to modify the Hybrid III dummies to be used in your company's certification testing for Standard No. 208. You stated your opinion that the Hybrid III test dummy currently specified in 49 CFR Part 572 Subpart E is unacceptable for determining whether vehicles equipped with two-point automatic belt systems comply with the injury criteria in Standard No. 208. This opinion is based on the chest deflection measurements you have obtained, which you characterize as 'erroneous, erratic, and nonsensical.' You indicated your belief that the inaccurate measurements arise because the ball on the end of the slider rod of the chest deflection transducer 'frequently' will pop out of its guide track. According to Chrysler, this occurs because the rubber bump stops on the dummy's sternum act as a fulcrum to pry the ball on the end of the slider rod out of its guide track during crash tests, during which the two-point torso belt deflects the dummy chest in both the fore-aft and lateral directions. Chrysler believes that this problem can be solved simply by modifying the thorax of the Hybrid III dummy by moving the rubber bump stops from the specified location on the sternum to the spine box of the dummy. Your letter indicates your belief that such a modification will not affect the calibration or measurement accuracy of the chest deflection transducer or the biofidelity of the Hybrid III thorax. You indicated that Chrysler intends to make this modification to the Hybrid III dummy thorax and use the modified dummy for Chrysler's certification testing of a 1994 model year vehicle for purposes of Standard No. 208. NHTSA's position on the issue of what steps manufacturers must take before certifying that their vehicles or equipment complywith an applicable safety standard has been often stated and applies with equal force in this situation. The compliance test procedures set forth in Standard No. 208 must be followed by this agency during our compliance testing. In this instance, that means that NHTSA's compliance testing will be conducted using the Hybrid III test dummy specified in Part 572, Subpart E, with the rubber bump stops in the location specified therein. Manufacturers certifying compliance with the safety standards are not required to follow exactly the compliance test procedures set forth in the applicable standard. In fact, manufacturers are not even required to conduct any actual testing before certifying that their products comply with applicable safety standards. However, to avoid liability for civil penalties in connection with any noncompliance that may be determined to exist, the National Traffic and Motor Vehicle Safety Act (the Safety Act) requires that the manufacturer exercise 'due care' to assure compliance and in making its certification. It may be simplest for a manufacturer to establish that it exercised 'due care' if the manufacturer has conducted testing that strictly followed the compliance test procedures set forth in the standard. However, 'due care' might also be shown using modified test procedures if the manufacturer could demonstrate that the modifications were not likely to have had a significant impact on the test results. In addition, 'due care' might be shown using engineering analyses, computer simulations, and the like. In this case, then, the relevant issue is not whether Chrysler uses a modified version of the Hybrid III test dummy for its certification testing. Instead, the issue is whether Chrysler can show that it would exercise 'due care' despite using a modified Hybrid III test dummy for its certification testing. This agency does not make any determinations as to whether 'due care' has been exercised except in the context of an enforcement proceeding. Hence, Chrysler will have to make the initial decision as to whether a certification based on the modified Hybrid III dummy could be made in the exercise of 'due care.' Your letter states that Chrysler's modifications to the test dummy 'will not affect the calibration or measurement accuracy of the chest deflection transducer or biofidelity of the Hybrid III thorax.' If Chrysler can demonstrate that these statements are correct, Chrysler may be able to show that it exercised 'due care' in connection with the use of the modified Hybrid III dummy. Of course, a manufacturer that can show it exercised due care would still be subject to the statutory obligation to notify owners and remedy any vehicles that are determined not to conform to Standard No. 208. However, this same obligation would apply even to manufacturers that had conducted testing using an unmodified Hybrid III test dummy. Turning from Chrysler's particular question to the standard in general, NHTSA notes that it has undertaken research examining the issue of chest deflection measurements by the Hybrid III test dummy. An extensive discussion of the agency research and analysis of this issue may be found in the interim final rule postponing the use of the Hybrid III dummy in vehicles that do not use either seat belts or air bags (55 FR 39280, September 26, 1990, copy enclosed). In that notice, NHTSA indicated that it had received significant data from sources outside the agency, including General Motors, Mercedes-Benz, Toyota, INRETS (a French government research and development group), and the Motor Industry Research Association (a British group). The agency would be very interested in examining any data or test results that Chrysler may have on this subject, especially the assertion that the ball on the end of the chest deflection rod comes out of its track during crash test conditions. Please send all such information to: Barry Felrice, NHTSA Associate Administrator for Rulemaking, Room 5401, 400 Seventh Street, S.W., Washington, D.C. 20590. I hope this information is helpful. Please let me know if you need any further information or have some further questions on this subject. Sincerely, Paul Jackson Rice Chief Counsel Enclosure"; |
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ID: aiam0250OpenMr. Lowell A. Kintigh, Vice President, Engineering Staff, General Motors Corporation, General Motors Technical Center, Warren, MI 48090; Mr. Lowell A. Kintigh Vice President Engineering Staff General Motors Corporation General Motors Technical Center Warren MI 48090; Dear Mr. Kintigh: On August 13, 1970, you petitioned, on behalf of General Motor Corporation, for reconsideration of the amendment of 49 CFR 571.3, published on July 14, 1970 (35 F.R. 11242), which established a definition of 'fixed collision barrier'. The views presented in your petition have been carefully considered. For the reasons stated below, your petition is denied.; You argued that the phrase 'absorb no significant portion of th vehicle's kinetic energy' was subjective, and therefore not in accord with the statutory requirement that standards be stated in objective terms. This argument is without merit. It appears to be based on the misconception that the purpose of the definition is to describe, or prescribe standards for, a manufacturer's test barrier, as evidenced by your statement that it 'gives manufacturer no guidelines for determining whether or not he has built a barrier which complies with the definition.' The Bureau does not intend that manufacturers should build barriers to 'comply with the definition.' As stated in the notice,; >>>'this is not intended to be a description of an actual test barrier It is a device used in various standards to establish required quantitative performance levels of a vehicle in a crash situation, and means simply that the vehicle must meet the requirement no matter how small an amount of energy is absorbed by the barrier.'; <<>>there is no known method of measuring the amount of energy absorbe by a barrier. Therefore, there is no way that the manufacturer could even attempt to determine whether or not his barrier complied with the definition, and, more importantly, whether or not his vehicle when tested complied with the performance requirements of the standards.'<<<; The energy absorption of a barrier is a direct function of the movemen of the barrier during the impact. To be sure, there are other properties, such as its effective mass and elasticity, that also are factors in energy absorption. But it is clear that as the barrier movement approaches zero, the energy absorption also approaches zero, and the barrier movement can be measured, as you indicated by your recommendation that a specified amount of movement be allowed. In all cases where the vehicle has a tangible margin of safety performance over the required minimum, therefore, a manufacturer will have no difficulty in determining that his vehicle complies.; If our standards 'allowed' barrier movement, it would be far mor difficult to establish conclusively that a given vehicle did *not* meet the standard, since it would always be open to the manufacturer to argue that the Bureau's barrier did not move as far, and consequently did not absorb as much energy, as the standard allowed. To the extent that there may be a small degree of uncertainty as to the variance in the vehicle test performance caused by the variance of a barrier from zero absorption, that uncertainty must rest with the manufacturer, who is free to design into his vehicles whatever margin of performance he desires.; This matter was thoroughly considered by the Bureau, and the opinion of knowledgeable members of the public were sought and carefully evaluated. For these reasons, your petition for reconsideration must be denied.; We appreciate your cooperation in the field of motor vehicle safety. Sincerely, Douglas W. Toms, Director |
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ID: aiam4213OpenMr. Gerald B. Eastland, Chief, Title Division, Mississippi State Tax Commission, P.O. Box 960, Jackson, MS 39205-0960; Mr. Gerald B. Eastland Chief Title Division Mississippi State Tax Commission P.O. Box 960 Jackson MS 39205-0960; Dear Mr. Eastland: This is in response to your letter of August 14, 1986, concernin Mississippi House Bill 64 and Federal odometer disclosure requirements.; I have reviewed House Bill 64 and the reverse side of the ne Mississippi certificate of title. The disclosure statements as set forth in lines 155-164 of the bill and on the reverse side of the title conform to the Federal odometer disclosure requirements, 49 C.F.R. S 580.4. However, even assuming the front of the title includes the vehicle's year, make, model and body type and the vehicle identification number, the title fails to include a space for the buyer's signature. The National Highway Traffic Safety Administration considers the signature to be essential because it is an acknowledgement that the purchaser is aware of the mileage. Furthermore, the signature prevents the purchaser from later alleging that he was not informed of the mileage or that the mileage was different from that appearing on the title.; Because the title does not contain all the information required b Federal regulation, transferors of motor vehicles in Mississippi must continue to issue a separate odometer disclosure statement. In addition, dealers and distributors must retain, for four years, each odometer statement they receive and a copy of each odometer statement they issue.; I hope this information will help you in your efforts to assist dealer in complying with the Federal regulations. If I could be of further assistance, do not hesitate to contact me.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1011OpenMr. John H. Fildew, Attorney, Fildew, Gilbridge, Miller & Todd, 3156 Penobscot Building, Detroit, MI 48226; Mr. John H. Fildew Attorney Fildew Gilbridge Miller & Todd 3156 Penobscot Building Detroit MI 48226; Dear Mr. Fildew: This is in response to your letter of February 14, 1973, in which yo asked about the responsibilities with respect to the motor vehicle safety standards of an automobile dealer who sends a new vehicle to specialty manufacturer for modifications. You asked whether the dealer must file reports as a final-stage manufacturer, or ascertain whether the specialty manufacturer has filed reports or certified the vehicle.; The final-stage manufacturer in the case you describe is the specialt manufacturer, and all the responsibilities that pertain to that category lie with him, not the dealer. There is also no obligation for the dealer to ascertain that the specialty manufacturer has filed reports.; The answer with respect to the dealer ascertaining that the final stage manufacturer has certified the vehicle is somewhat less clear. There is no direct responsibility for this, a failure of the final-stage manufacturer to certify would not itself bring down any penalties on the dealer. However, the certification is designed to protect the dealer, in cases of nonconformity with the standards of which the dealer does not have actual knowledge. (See sections 108(b)(2) and 114 of the National Traffic and Motor Vehicle Safety Act, 15 U.S.C. 1397(b)(2), 1403.) To put it negatively, if the vehicle were completed in violation of applicable standards and it were not certified, a dealer might be considered to have sold a nonconforming vehicle without the exercise of due care, in violation of the Act. The question is further complicated by the fact that not all alterations would rise to the level of manufacturing (addition of trailer hitches probably would not, for example). and these minor changes would not require additional certification by anyone. In sum, although there is no direct legal obligation for the dealer to see that there is a certification where there are major alternations, it is a very good idea, for his own protection.; The regulations on this subject are codified in Parts 567 and 568 o Title 49, Code of Federal Regulations. The October 1, 1972 edition of that title is current with respect to those parts. We do have a proposal outstanding to make some amendments regarding the certification of altered vehicles (37 FR 22800, October 25, 1972), and an amended rule may be issued in the near future.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4643OpenMr. Michael E. Kastner National Truck Equipment Association--Washington Office 1350 New York Avenue, N.W., Suite 800 Washington, D.C. 20005-4797; Mr. Michael E. Kastner National Truck Equipment Association--Washington Office 1350 New York Avenue N.W. Suite 800 Washington D.C. 20005-4797; Dear Mr. Kastner: Thank you for your letter to Secretary Skinne concerning the National Highway Traffic Safety Administration's (NHTSA's) actions to extend certain Federal Motor Vehicle Safety Standards (FMVSS's) to light trucks and vans. The Secretary has asked me to reply. Your letter was especially concerned with NHTSA's November 1987 amendment to FMVSS 204, Steering Control Rearward Displacement, and our denial of NTEA's petition for reconsideration of that rule. I regret that I am unable to respond to your comments at this time. As you know, the Department and NTEA are presently involved in litigation concerning those actions. In view of the litigation, we feel it would be inappropriate to address your comments in this letter. We appreciate your interest in informing the Department of your views. I can assure you that Secretary Skinner is actively interested in each of the letters he receives regarding NHTSA's mission to improve motor vehicle safety. Let me assure you also that the potential impacts on small businesses is one of our concerns in each of our rulemaking actions. A copy of your letter, and this response, will be placed in NHTSA's docket section. Sincerely, Jeffrey R. Miller Acting Administrator; |
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ID: aiam3186OpenMr. Charles Sidner, Products Safety Engineer, Grumman Flxible Corporation, 970 Pittsburgh Drive, Delaware, OH 43105; Mr. Charles Sidner Products Safety Engineer Grumman Flxible Corporation 970 Pittsburgh Drive Delaware OH 43105; Dear Mr. Sidner:#This is in response to your request for a interpretation of Federal Motor Vehicle Safety Standard No. 101-80, *Controls and Displays*. In a telephone conversation with Ms. Debra Weiner of my office, you asked whether section S5.2.2 of the standard would apply to the windshield wiper controls which Grumman Flxible intends to install in its transit buses. As I understand your description, there are to be separate controls for the left and right windshield wipers and each control will allow for operation of the wiper over a continuous range of speeds.#The answer to your question is no. Section S5.2.2 of Standard 101-80 provides that:#>>>Identification shall be provided for each function of any automatic vehicle speed system control and any heating and air conditioning system control, and for the extreme positions of *any such control* that regulates a function over a quantitative range. (emphasis added).<<<#The function identification requirements are not applicable since their applicability is expressly limited to speed controls and to heating and air conditioning controls. The applicability of the extreme position identification requirements is similarly limited since 'such controls' refers back to those controls already identified in S5.2.2.#Sincerely, Frank Berndt, Chief Counsel; |
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ID: aiam1441OpenMr. Hayso Hirai, Technical Representative, MAZDA, 1444 McGaw Avenue, Irvine, California 92705; Mr. Hayso Hirai Technical Representative MAZDA 1444 McGaw Avenue Irvine California 92705; Dear Mr. Hirai: This is in reply to your letter of February 8, 1974, which requests review of your new accelerator system to determine compliance with Standard No. 124, 'Accelerator Control Systems.'; The NHTSA does not provide a technical review of a manufacturer' product nor certify that a particular design meets the requirements of a standard. That is the manufacturer's responsibility. We will interpret or clarify the meaning of the standard in response to specific questions.; We understand your question to be whether two springs surrounding spring guide and separated by a washer meet the stipulation in S5.1 of Standard No. 124 for '... at least two sources of energy ...' This arrangement of springs would be considered 'two sources of energy' within the meaning of the standard.; As you requested, the technical description has been held confidentia as a 'trade secret' and we are returning it to your herewith.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0483OpenMr. R. O. Sornson, Manager, Environmental and Safety Relations Department, Chrysler Corporation, P O Box 1919, Detroit, MI, 48231; Mr. R. O. Sornson Manager Environmental and Safety Relations Department Chrysler Corporation P O Box 1919 Detroit MI 48231; Dear Mr. Sornson: This is in reply to your letter of November 4, 1971, to Mr. J. E Leysath of this Office, concerning the maximum candlepower for taillamps as specified in Federal Motor Vehicle Safety Standard No. 108.; Paragraph S5.1 of Standard No. 108 (35 FR, 16840, October 31, 1970) i quoted as follows:; >>>'S5.1 SAE Standards and Recommended Practices subreferenced by th SAE Standards and Recommended Practices included in Tables I and III and paragraphs S4.1.4 and S4.5.1 are those published in the 1970 edition of the SAE Handbook.'<<<; Subreferenced SAE Standard J575, as published in the 1970 edition o the SAE Handbook, is the 'd' revision (SAE J575*d*, August 1967). SAE Standard J575d specifies a maximum of 15 candlepower for a single compartment taillamp, 20 candlepower for a 2-compartment taillamp, and 25 candlepower for a 3- compartment taillamp. These maximum candlepower values are, therefore, applicable requirements under Standard No. 108 (35 FR, 16840, October 31, 1970).; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam2144OpenMr. Byron A. Crampton, Manager of Engineering Services, 5530 Wisconsin Avenue, Suite 1220, Washington, D.C. 20015; Mr. Byron A. Crampton Manager of Engineering Services 5530 Wisconsin Avenue Suite 1220 Washington D.C. 20015; Dear Mr. Crampton: #In response to your November 24, letter concernin the relationship between Federal Motor Vehicle Safety Standards Nos. 109 and 119, I am enclosing a copy of a prior interpretation letter on the same subject, which was sent to Mr. C.D. McCarthy of the B.F. Goodrich Company on October 15, 1975. #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.