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: aiam4381OpenThe Honorable Bill Nelson, U.S. House of Representatives, 2404 Rayburn House Office Building, Washington, DC 20515-0912; The Honorable Bill Nelson U.S. House of Representatives 2404 Rayburn House Office Building Washington DC 20515-0912; Dear Mr. Nelson: Thank you for your letter on behalf of your constituent, Mr. Glen Gourley, who questions the effectiveness of safety belts and opposes the safety belt use law enacted by the State of Florida.; During the past decade, 470,000 persons have died on American highways Each year, an estimated 300,000 are injured seriously enough to require hospital treatment. These traffic deaths and injuries have resulted in an annual cost to society of approximately 57 billion dollars resulting from such costs as emergency medical services, long-term medical care and rehabilitation, worker's compensation, welfare payments, and lost tax revenue.; Numerous analyses have shown that safety belts reduce fatalities b 40-50 percent and reduce serious injuries by 45-55 percent. I have enclosed copies of a safety belt fact sheet and several pamphlets we have published explaining how and why safety belts are so effective. Because of the extensive body of evidence about the effectiveness of safety belts, the United States Supreme Court has said, 'We start with the accepted ground that, if used, seatbelts unquestionably would save many thousands of lives and would prevent tens of thousands of crippling injuries.'; In an effort to protect their citizens by substantially reducin vehicle-related deaths and injuries, and to reduce the financial burden on their taxpayers, 29 States and the District of Columbia have enacted safety belt use laws. I have also enclosed an occupant protection fact sheet. This sheet reports that among front seat occupants, safety belts saved about 2,200 lives in 1986, and 1750 of those lives were saved in States that have safety belt use laws.; I hope this information is helpful. If you have any further questions on this subject, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3917OpenMr. Gordon Bonvallet, Manager, Photometric Division, ETL Testing Laboratories, Inc., P.O. Box 2040, Cortland, NY 13045- 2040; Mr. Gordon Bonvallet Manager Photometric Division ETL Testing Laboratories Inc. P.O. Box 2040 Cortland NY 13045- 2040; Dear Mr. Bonvallet: This is in reply to your letter of February 13, 1985, to this Offic asking whether the agency intended to eliminate the maximum allowable value for parking lamp candlepower in the amendments of November 26, 1984 which established Figure 1b.; Thank you for calling this matter to our attention. The amendmen appears to have the effect you ascribe to it, though it was not the agency's intention that it do so. The maximum values of SAE J222 December 1970 are those that should apply, and we shall reinstate them in the near future.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam0638OpenMr. Satoshi Nishibori, Engineering Representative, Nissan Motor Co., Ltd., 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Satoshi Nishibori Engineering Representative Nissan Motor Co. Ltd. 560 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Nishibori: In your letter of March 3, 1972, you asked for our interpretation o how a rigid bracket installed on the B-pillar to guide the shoulder belt would be treated under Standard 210.; Although the bracket in question does not perform all the functions o the anchorage, in that it would sustain only a fraction of the total force imposed on the anchorage in an accident, it performs a significant anchorage function by controlling the angle at which the shoulder belt crosses the occupant's chest. It is therefore considered a part of the anchorage and must fall within the acceptable range for upper torso anchorage locations specified in Standard 210.; If you have information to indicate that the acceptable zone could b extended forward of its present position without lessening the effectiveness of the shoulder belt, we would be most interested in obtaining it for review.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2605OpenMr. T. V. Barlow, BSG International, Britax (Wingard ) Limited, Chichester West Sussex PO19 2UG, England; Mr. T. V. Barlow BSG International Britax (Wingard ) Limited Chichester West Sussex PO19 2UG England; Dear Mr.Barlow: This responds to your letter of May 5, 1977, requesting clarificatio of the relationship between paragraph S5.3 of Safety Standard No. 208, *Occupant Crash Protection*, and Safety Standard No. 216, *Roof Crush Resistance*. It is your understanding that Standard No. 216 becomes 'obsolete and ineffective' after August 15, 1977.; Your interpretation is incorrect. Standard No. 216 is a separate independent standard from Standard No. 208 and remains effective in its present form regardless of the amendment of Standard No. 208 according to any of the three alternative proposals issued by Secretary Adams (42 FR 15935, March 24, 1977). Standard No. 216 is applicable to all passenger cars except those that conform to the rollover test requirements of paragraph S5.3 of Standard No. 208 by totally passive means.; Under existing Standard No. 208, a manufacturer must meet the rollove requirements of paragraph S5.3 only if he chooses to use option S4.1.2.1 (total passive protection). If the manufacturer chooses this option he can meet the requirements of Standard No. 216 instead of the rollover requirements of S5.3 until August 15, 1977, but not after that date since the alternative then expires. A manufacturer choosing to use either option S4.1.2.2 or option S4.1.2.3 of Standard No. 208 does not have to meet the rollover requirements of paragraph S5.3, at all. As a manufacturer of seat belts, you are undoubtedly aware that a majority of vehicle manufacturers choose to comply with Standard No. 208 by means of option S4.1.2.3.; If Secretary Adams' Alternative proposal I or Alternative proposal II becomes a final rule, Standard No. 208 will remain in the form just described above. The Secretary's Alternative II (mandatory passive restraints) proposes to make the lateral (S5.2) and rollover (S5.3) requirements of Standard No. 208 optional. A manufacturer would be permitted to use a totally passive system (meeting S54.1, S5.2, and S5.3) or to install lap belts and only meet the requirements of S5.1. If Alternative II were made final, most vehicle manufacturers would probably choose to install lap belts rather than to provide passive protection that would satisfy S5.3. As you noted, Alternative II also proposes to extend the option in paragraph S5.3 (complying with Standard No. 216 instead) from August 15, 1977, to August 31, 1980.; You are correct in your statement that the Secretary does not expect t reach a final decision on his alternative proposals until July.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1880OpenHonorable Glenn English, House of Representatives, Washington, DC 20515; Honorable Glenn English House of Representatives Washington DC 20515; Dear Mr. English: This is in response to your letter of March 25, 1975, requestin information concerning correspondence from Franklin Motor Company commenting on a proposed amendment to the Federal bumper standard by urging that recyclability of bumpers by required.; Although promulgation of rules that have a direct positive impact o the environmental and energy situation is not within the National Highway Traffic Safety Administration's (NHTSA) jurisdiction, the agency gives serious consideration to the effect any of its standards will have on these important areas of concern.; The NHTSA has examined the environmental and energy ramifications o its proposed bumper standard and is continuing to do so. Our most recent proposal (March 12, 1975, 40 F.R. 11598, Docket No. 74-11, Notice 7, Docket No. 73-19, Notice 6) ensures that a wide variety of materials, including metals, could continue to be used in bumper systems.; We greatly appreciate your interest and that of your constituents i this matter. You can be sure that their comments will be given every consideration.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam0792OpenMr. J. Mulvey, Bakelite Xylonite Limited, Industrial Products Division, Brantham, Manningtree, Essex COll lNJ (sic), England; Mr. J. Mulvey Bakelite Xylonite Limited Industrial Products Division Brantham Manningtree Essex COll lNJ (sic) England; Dear Mr. Mulvey: Thank you for your letter of June 28, 1972, inquiring about th applicability of Federal Motor Vehicle Safety Standard No. 302 to safety glazing.; Safety glazing is not included in the list of motor vehicle interio materials to which Standard No. 302 applies. However, if your plastic material is used as all or part of a component of vehicle occupant compartments included under S4.1 of the standard, then, it is required to meet the requirements of Standard No. 302. A copy of this standard is enclosed for your reference.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam0268OpenCharles O. Verrill, Jr., Esq., Messrs. Patton, Blow, Verrill, Brand & Boggs, 1200 17th Street, N.W., Washington, DC 20036; Charles O. Verrill Jr. Esq. Messrs. Patton Blow Verrill Brand & Boggs 1200 17th Street N.W. Washington DC 20036; Dear Mr. Verrill: In your letter of November 16 you inquire whether the Bureau' interpretation of 'overall width' (49 CFR S 571.21, with reference to Federal Motor Vehicle Safety Standard No. 108) can 'embrace the situation where the entire lighting assembly, including the taillamps, stop lamps, and back-up lamps, as well as signal lamps, add to the dimension of the vehicle'.; Since 'overall width' means 'the nominal design dimension of the wides part of the vehicle exclusive of signal lamps [and] marker lamps . . . .', the Bureau concurs in your requested interpretation. Taillamps, stop lamps, and back-up lamps are 'signal' lamps, and their combined mounting in a fixture which may extend beyond the widest part of a boat trailer does not result in a corresponding increase in the 'overall width' of the trailer.; Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam5590OpenMr. Jim Burgess Engineering Manager Independent Mobility Systems, Inc. 4100 West Piedras St. Farmington, NM 87401; Mr. Jim Burgess Engineering Manager Independent Mobility Systems Inc. 4100 West Piedras St. Farmington NM 87401; Dear Mr. Burgess: This responds to your letter of May 18, 1995 to thi office and your telephone conversations with Walter Myers of my staff on June 14 and 27, 1995, concerning an exclusion in Federal Motor Vehicle Safety Standard (FMVSS) No. 206, Door locks and door retention components. The standard excludes from its requirements doors equipped with wheelchair lifts and either a visual or audible alarm system. You state that your company converts minivans into wheelchair accessible vehicles by lowering the floor and adding a wheelchair ramp to the right rear side sliding door area, with an audible and/or visual alarm. The issue you raise is whether FMVSS No. 206's exclusion of wheelchair-equipped doors also excludes a ramp-equipped door. The answer is no. FMVSS No. 206 requires that side doors leading directly into a compartment containing one or more seating positions must conform to the standard. However, paragraph S4 of the standard states: S ide doors equipped with wheelchair lifts and which are linked to an alarm system consisting of either a flashing visual signal located in the driver's compartment or an alarm audible to the driver which is activated when the door is open, need not conform to this standard. FMVSS No. 206 was amended to add the wheelchair lift exception by final rule dated March 27, 1985 (50 FR 12029, copy enclosed). The agency's rationale was that when not in use, wheelchair lifts are stowed in a vertical position parallel to and in close proximity to the interior surface of the vehicle door, thus providing a barrier to occupant ejection if the door opened while the vehicle was in motion or in the event of a crash. The alarm requirement was intended to alert the driver to a door that was open on a vehicle that was in motion. While the information you provided us showed that your wheelchair ramp is also stowed in a vertical position parallel to and in close proximity to the door and that you install audible and/or visual alarms for the driver, wheelchair lifts and wheelchair ramps are distinctly different components. Although they serve the same purpose and are similarly configured when in the stowed position, this agency cannot by interpretation say that 'lift' includes 'ramp.' In order to amend the standard to exclude wheelchair ramps as well as lifts, rulemaking action would be required. You may petition this agency to do rulemaking, under 49 CFR Part 552 (copy enclosed). This agency will entertain your petition and decide whether a rulemaking proceeding is appropriate. I hope this information is helpful to you. Should you have any further questions or need any additional information, please feel free to contact Mr. Myers at this address or at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosures (2) 1985 final rule Part 552; |
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ID: aiam2255OpenMr. J.L. Chancey, President, Trail-O-Matic, Inc., P.O. Box 2367, Jacksonville, FL 32203; Mr. J.L. Chancey President Trail-O-Matic Inc. P.O. Box 2367 Jacksonville FL 32203; Dear Mr. Chancey: This responds to your March 8, 1976, request to know the status of 'lo trailers' under Standard No. 121, *Air Brake Systems*, whether the exclusion for 'heavy hauler' trailers terminates September 1, 1976, and what the penalties are for non-compliance with an applicable Federal motor vehicle safety standard. You indicate that you may know of some manufacturers that do not comply with Standard No. 121 and suggest that all persons concerned with the standard be advised of the status of the regulation.; Without description of the 'log trailers' in question, it is no possible to determine if Standard No. 121 applies to them. Most pole trailers and trailers equipped with any axle having a gross axle weight rating of 24,000 pounds or more are examples of vehicles that may be excluded from the standard. Mr. Herlihy of this office has already sent applicable documents to you under separate cover. The exclusion from the standard for 'heavy hauler' trailers was extended recently and now terminates September 1, 1977.; Section 108(a)(1) of the National Traffic and Motor Vehicle Safety Ac (15 U.S.C. S1397(a)(1)) prohibits the sale and false or misleading certification of a non-complying vehicle to which a standard is applicable. Each violation of these provisions makes the manufacturer liable to a maximum civil penalty of $1,000 for each violation, up to a total of $800,000 for a related series of violations. (15 U.S.C. S1398). You may advise our Office of Standards Enforcement of any violations of which you are aware.; The NHTSA finds it impracticable to notify directly every intereste person of each of its regulatory actions. Each action is made public and is widely distributed by commercial services and trade associations. Enclosed is an information sheet that explains the various means to obtain copies of our regulations.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam0507OpenMr. Albert D. Ekegren, Vice President and General Manager, Cats-Eye Lamp Division, Holophane Company, Inc., P.O. Box 567, Columbus, OH, 43216; Mr. Albert D. Ekegren Vice President and General Manager Cats-Eye Lamp Division Holophane Company Inc. P.O. Box 567 Columbus OH 43216; Dear Mr. Ekegren: This is in response to your letter of October 27, 1971, to David H Soule of the National Highway Traffic Safety Administration concerning the requirements of Motor Vehicle Safety Standard No. 108 for school bus lighting.; You are concerned with paragraph S4.1.4(b)(ii) which reads: >>>'The system shall be wired so that the amber signal lamps ar activated only by manual or foot operation, and if activated, are automatically deactivated and the red signal lamps automatically activated when the bus entrance door is opened.'<<<; You have commented that 'the use of the automatic system would make i mandatory that the red lights go on when the door is open and stop traffic where unnecessary--such as railroad crossings.' That is not correct. You will see from S4.1.4(b)(ii) that the red lamps are not automatically activated when the bus entrance door opens unless there has been prior manual or foot activation of the amber signal lamps.; You are also concerned with the fact 'that this automatic system i patented and only one manufacturer has the right to make it.' Since you have not enclosed the copy of the patent enclosed in attorney Smith's letter to you dated June 4, 1970, I am unable to comment on your statement. I would like to point out that Standard No. 108 does not mandate the use of an amber-red lamp system, a system of red lamps only is also permissible. If the amber-red lamp system is used, paragraph S4.1.4(b)(ii) does not specify system design but only that the system be wired so that the driver can activate the amber lamp system at his option, and if he does activate it, that it automatically be deactivated and the red system automatically activated when the bus entrance door is opened.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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.