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: aiam0918OpenMr. Lawrence H. Hodges, Vice-President, Farms, National Safety Council, 425 No. Michigan Avenue, Chicago, Illinois 60611; Mr. Lawrence H. Hodges Vice-President Farms National Safety Council 425 No. Michigan Avenue Chicago Illinois 60611; Dear Mr. Hodges: This is in response to your letter of November 20, 1972, regardin Motor Vehicle Safety Standard No. 125, Warning devices, issued by the National Highway Traffic Safety Administration on March 9, 1972. You refer to the Docket entry submitted by the National Safety Council to NHTSA on February 3, 1971, and reiterate the Council's concern that the triangular warning device described in Standard 125 would lessen the effectiveness of the triangular reflective Slow Moving Vehicle emblem presently in use because of the similar configuration of the two devices.; The Council's comments were considered, along with all comment submitted, in the promulgation of the final rule. The agency as well as several commenters supported the dual use of the triangular device because the triangular shapes would be used for similar purposes: To alert oncoming traffic that a reduction of speed is necessary due to a vehicle ahead. In other words, it is our position that the warning device and the SMV emblem will be complementary, rather than conflicting.; We appreciate your interest in motor vehicle safety. Sincerely, J. Volpe, Secretary of Transportation |
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ID: aiam2925OpenMr. Donald W. Vescio, Sr., Director of Engineering, R. E. Dietz Company, 225 Wilkinson Street, Box 1214, Syracuse, NY 13201; Mr. Donald W. Vescio Sr. Director of Engineering R. E. Dietz Company 225 Wilkinson Street Box 1214 Syracuse NY 13201; Dear Mr. Vescio:#This responds to your letter of September 21, 1978 requesting interpretation of Federal Motor Vehicle Safety Standard No. 101-80, *Controls and Displays*.#In your first set of questions, you ask about the application of the display requirements to trucks with GVWR of 10,000 pounds or more. Those requirements do not apply to such trucks. Under S5 of the standard, the only trucks required by the standard to comply with the display requirements are those with a GVWR less than 10,000 pounds.#In your second set of questions, you pose various questions about the identification and illumination of controls. In the first question, you ask whether the turn signal control symbol must be placed on the control itself. The answer is 'no.' S5.2.1 provides that the symbol shall be placed on *or* adjacent to the control. You also ask if there is any size requirement. The answer is again 'no.' There are no size requirements for any of the control symbols.#In your second question, you ask about the size requirements for the hazard warning signal control. As indicated above, there are no size requirements. As to illumination, S5.3.1 provides that hand- operated controls mounted on the steering column are not required to be illuminated. Thus, neither the turn signal control symbol nor the hazard warning control symbol need be illuminated. With regard to the non-mandatory red lens between the turn signal control symbol, if that lens is intended to call attention to the location of the hazard warning control, we urge that it be triangular. If it is intended to call attention to the turn signal control, we urge that the shape be made less similar to the hazard warning symbol to avoid confusion.#In your third question, you asked about the relationship between the control and display requirements in FMVSS 101 and those in FMVSS 108. The agency will soon issue a notice dealing with this issue.#Sincerely, Joseph J. Levin, Jr., Chief Counsel; |
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ID: aiam4058OpenCommander, Naval Safety Center, Naval Air Station, Norfolk, VA 23511-5796, Ref: 5100, Ser 42/5064; Commander Naval Safety Center Naval Air Station Norfolk VA 23511-5796 Ref: 5100 Ser 42/5064; Dear Commander: Thank you for your letter of December 5, 1985, following up on a numbe of phone conversations between your staff and mine, concerning the effective dates of the Federal standard requiring the installation of safety belts in motor vehicles. As requested by your staff, we have prepared the enclosed information sheet to be used as a guide by your security personnel in enforcing the safety belt use requirements on naval installations.; If you have any further questions, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3267OpenJ. P. Koziatek, P.E., Director, Technical Services, Questor Juvenile Products Company, 771 N. Freedom Street, Ravenna, OH 44266; J. P. Koziatek P.E. Director Technical Services Questor Juvenile Products Company 771 N. Freedom Street Ravenna OH 44266; Dear Mr. Koziatek: This responds to your letter of January 25, 1980, requesting a interpretation of section S6.1.2.2.1 (c) of Standard No. 213, *Child Restraint Systems*. Section S6.1.2.2.1(c) specifies that in the 20 mph test of forward facing child restraints with fixed or movable surfaces designed to restrain the child, the restraint system's belts are not to be attached 'unless they are an integral part of the fixed or movable surface.' You asked whether the crotch strap used in your Kantwet 'One Step' Model 400 child restraint would be considered an integral part of the movable shield used on that device. After reviewing the diagrams and description contained in your letter, I conclude that the crotch strap is not an integral part of the movable surface and thus must not be connected during the 20 mph test.; Amended Standard 213 is intended to address, among other things, th problem of misuse of child restraints. The principal misuse involves the failure to attach buckles and latches. To ensure that children using child restraints are afforded protection notwithstanding such misuse, the standard specifies that the belts are to be attached to restraining shields during testing only if they are integral parts of the shields. Webster's New Collegiate Dictionary (1977) defines 'integral' as meaning 'formed as a unit with another part.' Attachment of belts that are integral parts is permitted since they are intended to remain attached whether or not the restraint is in use and thus are not subject to the type of misuse described above.; The crotch strap used in the Kantwet 'One Step' is not an integral par of the movable shield. The movable shield is a complete unit by itself. The crotch strap is a separate device that must be manually connected to the shield every time the unit is used. In contrast, the two upper torso restraints appear to be integral parts of the shield since they are designed to remain attached to an adjustment device and anchorage which are in turn permanently affixed to the shield. Nevertheless, we are concerned about the possibility that the upper torso restraint could be detached from the adjustment device. We urge that you and other manufacturers take the additional step of assuring that the belts permanently remain integral parts of the adjustment device.; If you have any further questions, please let me know. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3772OpenD.Ing.h.c. F. Porsche AG, z. H. Herrn Mayer/ESV, Postfach 11 40, 7251 Weissach, West Germany; D.Ing.h.c. F. Porsche AG z. H. Herrn Mayer/ESV Postfach 11 40 7251 Weissach West Germany; Dear Mr. Mayer: This is in response to your letter of October 13, 983, to Nelso Erickson of this agency, requesting our interpretation of certain requirements in Federal Motor Vehicle Safety Standard (FMVSS) No. 118, *Power-Operated Window Systems*.; A recent amendment to section 3(d) of FMVSS 118 (48 Fed. Reg. 46793 October 14, 1983, copy enclosed) permits power window operation during the 'interval between the time the locking device which controls the activation of the vehicle's engine is turned off and the opening of either of a two-door vehicle's doors or, in the case of a vehicle with more than two doors, the opening of either of its front doors.' As you point out in your recent letter, the opening of the vehicle's front doors would typically be sensed through the interior roof lamp electrical circuit. This circuit would be activaetd when the door is opened 8 to 10 inches from the frame. You ask whether it is permissible under the standard to have power windows remain operable until the door is opened to this point where the roof lamp is activated.; FMVSS 118 is primarily intended to prevent the unsupervised operatio of power windows by children remining in a vehicle. See 48 Fed. Reg. 46793. Paragraph 3(d) was drafted to be consistent with this goal, since it is highly probably that the driver would still be in the vehicle during the specified time interval. Your proposed interpretation is also consistent with the standard's goal, since the driver would not likely be able to leave the vehicle with the door only ajar.; Therefore, we agree that power systems may remain operable unde paragraph 3(d) of FMVSS 118 until the door is opened far enough to permit a small adult to leave the vehicle. The 8 to 10 inch point where the roof lamp is activated appears to be within this permissible range.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2860OpenMr. Heinz W. Gerth, Mercedes-Benz of North America, Inc., One Mercedes Drive, P.O. Box 350, Montvale, NJ 07645; Mr. Heinz W. Gerth Mercedes-Benz of North America Inc. One Mercedes Drive P.O. Box 350 Montvale NJ 07645; Dear Mr. Gerth: This responds to your recent question whether Mercedes may use dynamic test to evaluate seat structure integrity instead of the static test specified in the testing procedures of Safety Standard No. 207.; The answer to your question is yes. A manufacturer is permitted to us whatever test procedures or methods of evaluation he chooses to assure its vehicles are in compliance with Federal motor vehicle safety standards. The legal requirement under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1391, *et seq*.) is that the manufacturer exercise *due care* to determine that his vehicles will be in compliance with all applicable standards when tested by the agency in accordance with the test procedures specified in those standards.; Therefore, you may use a dynamic test method to determine the integrit of your vehicle seats if this constitutes the exercise of due care to assure the seats meet the performance requirements specified in Standard No. 207. Of course, it cannot be determined whether a manufacturer in fact exercised due care in advance of the actual events leading to the certification of compliance. Likewise, the agency will not approve a manufacturer's method of testing in advance of certification.; Please contact me if you have any further questions. Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3288OpenMr. Donald E. Boyd, Donald Boyd & Associates, Inc., 5617 W. 6th Street, Stillwater, OK 74074; Mr. Donald E. Boyd Donald Boyd & Associates Inc. 5617 W. 6th Street Stillwater OK 74074; Dear Mr. Boyd: This responds to your recent letter requesting confirmation that larg commercial truck tractors do not have to comply with Federal Motor Vehicle Safety Standard No. 216, *Roof Crush Resistance*. You also asked whether large trucks should be designed to comply with the 'belt system' option under Safety Standard No. 208, *Occupant Crash Protection*.; You are correct in your assumption that large commercial trucks woul not have to comply with Safety Standard No. 216 since that standard only applies to passenger cars. You are also correct in stating that trucks with a GVWR greater than 10,000 pounds may meet the seat belt option of Safety Standard No. 208 found in paragraph S4.3.2. Under S4.3.1, manufacturers do have the option of meeting the crash protection requirements of S5 by means that require no action by vehicle occupants (with current technology this means air cushion restraints or automatic seat belts). Further, vehicles manufactured prior to August 15, 1977, were permitted to comply with Safety Standard No. 216 in lieu of the 'roll-over' requirements of Standard No. 208, and for large trucks this would have been a simple test to meet. However, since the vehicle would also have been required to meet the 'frontal' and 'lateral' requirements by automatic means if option S4.3.1 were taken, no truck manufacturers chose to comply with the 'rollover' requirements of Standard No. 208 via the Standard No. 216 option. Rather, seat belts were installed on all large trucks.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3322OpenMr. Terry Coleman, Codes and Safety Manager, Airstream, Jackson Center, OH 45334; Mr. Terry Coleman Codes and Safety Manager Airstream Jackson Center OH 45334; Dear Mr. Coleman: This responds to your June 13, 1980, letter asking whether your compan would be considered a chassis-cab manufacturer subject to the labeling requirements of Part 567, *Certification*. You indicate that you take another manufacturer's incomplete chassis with a motor and add to it a cab and body with bumpers, mirrors, and exterior trim. This vehicle is then sent to a final-stage manufacturer for final completion. We would not consider you to be a chassis-cab manufacturer subject to the certification requirements.; As you know, a chassis-cab is defined in Part 567 as 'an incomplet vehicle, with a completed occupant compartment, that requires only the addition of cargo carrying, work performing, or load bearing components to perform its intended functions.' The incomplete vehicle upon which your manufacturing operation begins is simply a chassis without the cab. As such, that vehicle is subject to the incomplete vehicle document requirements of Part 568, but it is not subject to the chassis-cab certification requirements.; Your modification adds on a bus body which then needs final work befor it can be used. Since you do not complete the occupant compartment as required by the definition of 'chassis-cab', you are not required to attach a certification label. You are simply an intermediate manufacturer. The final- stage manufacturer would attach the only label to the vehicle.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2163OpenMr. LeRoy E. Mueller, President, Wisconsin Trailer Company, Inc., Richfield, WI 53076; Mr. LeRoy E. Mueller President Wisconsin Trailer Company Inc. Richfield WI 53076; Dear Mr. Mueller: This responds to your November 26, 1975, request for confirmation tha the NHTSA permits the establishment of gross axle weight ratings (GAWR) for trailer axles based on use at a speed of less than 60 mph.; Your interpretation is incorrect. In the April 28, 1975, interpretatio letter to Mr. James Srch that was enclosed in the NHTSA's recent letter to you, it was stated that '. . .NHTSA has found it necessary to specify that GAWR's and GVWR's be calculated on the basis of highway speeds and not qualified by reduced speed ratings. . . .'; Since the NHTSA's November 20, 1975, letter to you, the agency ha published a proposal that would amend the definition of GAWR to conform to this interpretation. A copy is enclosed for your information.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2499OpenHonorable Mark O. Hatfield, United States Senate, Washington, D.C. 20510; Honorable Mark O. Hatfield United States Senate Washington D.C. 20510; Dear Senator Hatfield: With regard to my letter to you of July 1, 1976, concerning th application of Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other than Passenger Cars*, to the paver manufactured by Layton Manufacturing Company of Salem, Oregon, I would like to advise you of a clarification of the requirements of the standard that may be relevant to Layton's product.; Essentially, it has been clarified that the requirement of S5.1.1 o the standard accommodates a manufacturer's decision to equip its motor vehicle with tires other than 'tires for highway service.' This means that Layton can choose to use tires that do not conform to the requirements set forth in S5.1.1 of the standard. I have enclosed a copy of the notice that contains a detailed discussion of this clarification.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.