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
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ID: aiam3098OpenMr. Dietmar K. Haenchen, Administrator, Vehicle Regulations, Volkswagen of America, Inc., 7111 E. Eleven Mile Road, Warren, Michigan 48090; Mr. Dietmar K. Haenchen Administrator Vehicle Regulations Volkswagen of America Inc. 7111 E. Eleven Mile Road Warren Michigan 48090; Dear Mr. Haenchen: This is in response to your letter of September 25, 1979, requesting a interpretation of the term 'restraint system type' as contained in Table I of S4.5.2 of Federal Motor Vehicle Safety Standard No. 115. In addition, this is in confirmation of Volkswagen's statement of the conclusions reached in the meeting with Messrs. Carson, Parker and Schwartz of the National Highway Traffic Safety Administration.; The agency has carefully considered your request that 'restraint syste type' not be interpreted to require a distinction between active and passive belt systems. The agency must deny your request. As the introduction of mandatory passive restraints approaches, information concerning restraint system type is of exceptional importance to the agency. It is important not only to evaluate the overall effectiveness of the various types of passive restraint system types. Consequently, it is necessary that passive belt systems be differentiated from other restraint systems types by decoding the vehicle identification number (VIN).; The agency has also considered the alternative Volkswagen suggeste which is to submit this information separately to the agency on a magnetic tape. Motor vehicle safety research is carried out by many organizations aside from the NHTSA, however, and Standard No. 115 is intended to make information available to these other researchers as well. Consequently, the agency can not accept the alternative you suggest.; As regards the other questions raised in the meeting with NHTSA staff this is to confirm that paragraphs 2 through 4 of our November 20, 1978, letter remain the position of the agency despite the changes in Standard No. 115 since that time. A copy of that letter is enclosed. Likewise, the agency can confirm that the World Manufacturer Identifiers assigned to Volkswagen by the Society of Automotive engineers fulfill the requirements of S6.1 of Standard No. 115.; As requested, the agency has reviewed the VIN format Volkswagen intend to utilize (attachments 2-4 of this letter) and has determined that it meets the requirements of the standard. As explained at the meeting, specific details concerning an engine need not be encoded so long as the information is available from the manufacturer and different engine types can be differentiated by means of the VIN (S4.5.2).; Volkswagen also pointed out to the agency at the meeting that the firs eight characters of the VIN for a particular model might remain the same for several model years, although the characteristics of the vehicle which they codify might change from model year to model year. For example, a 1981 Dasher might have a different engine that a 1982 Dasher, yet that part od the VIN which contained this information would remain the same. This is authorized by Standard No. 115, so long as the correct information for each model year is submitted to the agency. Volkswagen also asked at the meeting what the correct procedure would be for submitting information to the agency concerning vehicles whose line is not subdivided into several series. In this instance, indicate that the line and series are the same. However, even if the series is not divided into more than one body type, this body type must be reported to the agency (S4.5.2). The engine displacement may be indicated in cubic centimeters, and the horsepower in H.P. SAE net (S3). If only one engine make is used, this information must be submitted to the agency, but need not be directly reflected in the VIN (S6.3).; Volkswagen has also asked when information concerning vehicles importe into the United States must be submitted to the agency. Manufacturers of imported vehicles are required to report VIN codes 60 days before the vehicles are imported into the United States to comply with S6.2.; The agency is considering the petitions of a number of manufacturers t establish engine horsepower groupings for reporting purposes and to establish a flexible effective date for vehicles whose model year begins between September 1, 1980 and December 31, 1980. We expect to respond shortly to the petitions.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3831OpenMr. John B. McMillan, Manning, Fulton, and Skinner, Raleigh, NC; Mr. John B. McMillan Manning Fulton and Skinner Raleigh NC; Dear Mr. McMillan: This is in response to your March 5, 1984 letter regarding the exten to which an automotive remote starting device which one of your clients wishes to market is compatible with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) 114, *Theft Protection*. This device would permit a vehicle to be started from a remote location using a signal transmitter, provided the vehicle's gear shift is in the park position, the emergency brake is set, the hood is closed, and all the vehicle doors are closed. Further, should any of these failsafe systems become deactivated (e.g., gear shift level moved out of the park position), the engine would automatically shut off.; FMVSS 114 requires that passenger cars as well as trucks an multipurpose passenger vehicles with a gross vehicle weight rating of 10,000 pounds or less must have a key locking system that, when the key is removed, will prevent normal activation of the vehicle's engine and either steering or forward self-mobility. We presume that the steering/transmission lock feature is unaffected by your client's device. Therefore, the question presented by your client's system is whether that device, which permits activation of the engine when the ignition key is removed, permits 'normal activation' of the vehicle.; In a previous agency interpretation (copy enclosed), the agenc described certain characteristics of a remote starting system similar to your client's which we concluded were outside the concept of 'normal activation.' These characteristics were automatic deactivation of the remotely started engine when a vehicle door is opened, maintenance of the steering column or gear shift locking feature until the ignition key is inserted in the vehicle, and automatic deactivation of the remotely started engine after 15 minutes (unless the key is inserted in the ignition).; Your client's device apparently has some of these same characteristic as this previously considered device, as well as other automatic engine deactivation features which are comparable in nature. Therefore, we conclude your client's device does not conflict with the requirements of FMVSS 114, since it does not permit normal activation of the engine without the ignition key.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2723OpenMr. Lawrence F. Henneberger, Arent, Fox, Kinter, Plotkin & Kahn, Federal Bar Building, 1815 H Street, N.W., Washington, DC 20006; Mr. Lawrence F. Henneberger Arent Fox Kinter Plotkin & Kahn Federal Bar Building 1815 H Street N.W. Washington DC 20006; Dear Mr. Henneberger: This responds to your December 1, 1977, request for agreement by th National Highway Traffic Safety Administration that the installation as original or aftermarket equipment of an electric retarder on the driveline of an air- braked vehicle would not affect its compliance with Standard No. 121, *Air Brake Systems*.; Section 108(a)(1)(A) of the National Traffic and Motor Vehicle Safet Act (15 U.S.C. S 1397(a)(1)(A)) requires, among other things, that no person manufacture or sell any motor vehicle manufactured on or after the date any applicable Federal motor vehicle safety standard takes effect unless it is in conformity with such standard. As your letter indicates, you are aware that this provision makes it impossible for the NHTSA to 'approve' the compliance of a vehicle configuration in advance of manufacture of the vehicle, because there can be no certainty that the vehicle as manufactured will actually comply. In this case, for example, the retarder's weight or the manner in which it is mounted would affect the actual compliance of the vehicle in which it is installed.; Jacobs' September 20, 1977, analysis evaluated the likelihood tha certain retarders to be imported or manufactured by Jacobs would affect compliance. With regard to these retarders, it appears that their installation as original equipment or in the aftermarket in the fashion described would not affect compliance of the vehicle with Standard No. 121. This finding is of necessity limited to the retarders evaluated in the September 20, 1977, analysis.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam2373OpenMr. George R. Semark, Manager, Vehicle Safety Activities, Sheller-Glove Corporation, Vehicle Planning and Development Center, 3555 St. Johns Avenue, Lima, OH 45804; Mr. George R. Semark Manager Vehicle Safety Activities Sheller-Glove Corporation Vehicle Planning and Development Center 3555 St. Johns Avenue Lima OH 45804; Dear Mr. Semark: This responds to Sheller-Globe's July 7, 1976, request for revision o the requirements of S5.4.2.1 of Standard No. 217 *Bus Window Retention and Release*, so that passage of the described parallelepiped through the emergency door can be effected with its lower surface several inches above the bus floor. Section 5.4.2.1 requires that the 45-inch dimension of the parallelepiped remain vertical, that the 24-inch dimension remain parallel to the opening, and that the lower surface remain in contact with the floor of the bus at all times.; The three specifications for passage of the parallelepiped through th opening are intended to describe, for the benefit of the manufacturer, how the NHTSA will conduct its compliance testing. These specifications do not represent a requirement that the opening be constructed without a threshold or corner obstructions. As the agency interprets this requirement, minor obstructions that do not necessitate passage of the parallelepiped through the opening more than 1 inch above the floor are not prohibited by this requirement. Thus, in the case you describe, the NHTSA would move the parallelepiped through the opening with its sides vertical and the rear surface parallel to the rear surface of the bus, just above the obstructions, but no more than 1 inch above the bus floor.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam2689OpenMs. Charlotte A. Hayes, Satterlee, Mestayer & Freeman, 1606 First National Bank of Commerce Building, New Orleans, LA 70112; Ms. Charlotte A. Hayes Satterlee Mestayer & Freeman 1606 First National Bank of Commerce Building New Orleans LA 70112; Dear Ms. Hayes: This is in response to your letter of August 31, 1977, to our For Worth, Texas office and October 7, 1977, telephone conversation with Robert Churella of my staff concerning the existence of any Federal motor vehicle standard that would require doors on garbage trucks.; There are no Federal motor vehicle safety standards that requir vehicles to be equipped with doors. In fact, Federal Motor Vehicle Safety Standard No. 206 (49 CFR 571.206), which regulates door locks and door retention components, specifically exempts from its application those motor vehicles manufactured for operation without doors.; The National Highway Traffic Safety Administration has, however promulgated a standard requiring trucks manufactured after July 1, 1971, to be equipped with seat belts. This requirement would provide protection for an individual riding in a vehicle without a side door.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5459OpenVincent Ugoletti, Chief Engineer Great Lakes Communications, Inc. 3514 State St. P.O. Box 860 Erie, PA 16512; Vincent Ugoletti Chief Engineer Great Lakes Communications Inc. 3514 State St. P.O. Box 860 Erie PA 16512; "Dear Mr. Ugoletti: This responds to your September 7, 1994 letter t this office in which you stated your intention to modify a 'conversion' van into a 'production' van by replacing the original front seats with seats that swivel. You stated in an October 4 telephone conversation with Walter Myers of my staff that the vehicle in question is a 1994 cargo van. The vehicle has two front seats, and a gross vehicle weight rating (GVWR) of 9,680 pounds (lbs.). You also explained that the work will be done by a commercial vehicle modification shop. You asked us about the requirements for swivel front seats. By way of background, 49 U.S.C. 30101, et seq. authorizes this agency to issue Federal motor vehicle safety standards (FMVSSs) applicable to new motor vehicles and new items of motor vehicle equipment. Under 49 U.S.C. 30112, each person selling a new vehicle must ensure that the vehicle is certified as complying with all applicable FMVSSs. NHTSA has five safety standards, described below, applicable to motor vehicle seats. The original seats and seat belts on your van were required to meet the requirements of those standards when the new van was sold to you. The five standards set performance criteria ensuring that seats and seat belts provide safety benefits in a crash. Standard No. 207, Seating systems (49 CFR section 571.207), establishes strength and other performance requirements for vehicle seats. The standard does not prohibit the installation of swivel seats in vans. Standard No. 208, Occupant Crash Protection (49 CFR 571.208), specifically section S4.2.3, sets forth occupant protection requirements at the various seating positions in vehicles such as yours manufactured after September 1, 1991, and with a GVWR not greater than 10,000 lbs. Standard No. 209, Seat Belt Assemblies (49 CFR 571.209), sets strength, durability, and other requirements for seat belts. Standard No. 210, Seat Belt Assembly Anchorages (49 CFR 571.210), establishes strength and location requirements for seat belt anchorages. Standard No. 302, Flammability of Interior Materials (49 CFR 571.302), specifies the flammability resistance of the seats and seat belts. Copies of those standards are enclosed, as well as a fact sheet explaining how to obtain copies of all FMVSSs. Generally speaking, once a motor vehicle is sold to its first retail purchaser, its use and any modifications made to it become a matter of state interest. Thus, owners of used vehicles may personally make any modifications or alterations they want to their vehicles without regard to the FMVSSs, subject only to applicable state requirements. There is, however, a limitation on modifications of used vehicles by commercial entities. 49 U.S.C. 30122 provides that a manufacturer, distributor, dealer, or motor vehicle repair business may not knowingly make inoperative any device or element of design installed on or in a motor vehicle or equipment in compliance with an FMVSS. Since the seats and their safety belts are devices or elements of design that were installed in your van in compliance with applicable FMVSSs (particularly the five standards listed above), a business listed in section 30122 cannot modify the vehicle in such a manner as to remove the seats and/or safety belts from compliance. Accordingly, the vehicle modifier should ensure that the swivel seats and any seat belts it installs are installed in accordance with the requirements of the standards. You indicated that Great Lakes Communications wishes to maintain the safety of the original seats and seat belts. We commend that decision. NHTSA urges vehicle owners not to degrade the performance of the safety systems on their vehicles. I hope this information is helpful. Should you have any further questions or need additional information, feel free to contact Walter Myers or Mary Versailles of my staff at (202) 366-2992. Sincerely, Philip R. Recht Chief Counsel Enclosure"; |
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ID: aiam1949OpenMr. E. Alan Moss, Moss Motor, Ltd., P.O. Box 'MG', 5775 Dawson Avenue, Goleta, California; Mr. E. Alan Moss Moss Motor Ltd. P.O. Box 'MG' 5775 Dawson Avenue Goleta California; Dear Mr. Moss: #The President has asked me to reply to your letter o February 9, 1976, concerning the application of Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses*, to replacement brake hoses for MG sports cars built from approximately 1945 to 1955. #All brake hose and brake hose end fittings manufactured on or after September 1, 1974, must meet the performance and labeling requirements of Standard No. 106-74. All brake hose assemblies manufactured on or after March 1, 1975, must meet those performance and labeling requirements in the standard that apply to assemblies and, with an exception noted below, must be constructed of conforming hose and end fittings. #The Federal motor vehicle safety standards are not applicable to classic or antique card in the following sense: a standard applies only to a motor vehicle or item of motor vehicle equipment that is manufactured after its effective date. Thus, for example, there is no requirement that MG's in question be retrofitted with conforming brake hose. However, any person manufacturing brake hose for use in such a vehicle must, on and after September 1, 1974, ensure that the hose conforms. #You may find some relief in S12 of the standard. To facilitate the depletion of inventories of hose manufactured before September 1, 1974, that conforms to all aspects of the standard except the labeling requirements, this provision permits the use of such hose in assemblies manufactured before September 1, 1976. #There are no Federal motor vehicle safety standards that apply to hydraulic brake system components other than Standard No. 106-74, *Brake Hoses*, and Standard No. 116, *Motor Vehicle Brake Fluids*. #Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicle Programs; |
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ID: aiam3974OpenThe Honorable John S. McCain, III, U.S. House of Representatives, Washington, DC 20515; The Honorable John S. McCain III U.S. House of Representatives Washington DC 20515; Dear Mr McCain: Thank you for bringing to our attention the problems experienced b your constituents due to conflicting State laws on motor vehicle window tinting.; The National Highway Traffic Administration (NHTSA) has issued Federal motor vehicle safety standard governing window tinting in new vehicles and replacement equipment, and Federal law also limits the extent to which certain commercial businesses may apply additional tinting. However, Federal law does not preclude individuals from tinting their vehicle windows. That matter is left to the States, and we understand the difficulties that may arise when the tinting laws of adjacent States are inconsistent.; Our agency has been discussing the issue of window tinting with th American Association of Motor Vehicle Administrators, in an effort to better explain the interaction of Federal and State laws in this area. That may also be an appropriate forum in which to consider ways to resolve conflicts between differing State tinting laws. While NHTSA and each state government has a valid interest in preserving its legal authority, we all share a common interest in promoting highway safety and in minimizing inconvenience to traveling motorists. In our view, a well-coordinated and cooperative approach among the various parties can help to address apparent problems in this area.; We will keep you advised of our progress in those discussions. appreciate knowing of your concern in this matter, and I hope you will feel free to contact me if this agency can be of further assistance.; Sincerely, Diane K. Steed |
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ID: aiam2666OpenMr. William B. Maddox, Secretary-Treasurer, Bedell Trailer Company, 1506-14 South Flores Street, San Antonio, TX 78295; Mr. William B. Maddox Secretary-Treasurer Bedell Trailer Company 1506-14 South Flores Street San Antonio TX 78295; Dear Mr. Maddox: This responds to your August 18, 1977, letter asking who is responsibl for compliance with the standards issued by the National Highway Traffic Safety Administration.; Compliance with Federal safety standards is the responsibility of th manufacturer of the motor vehicle or motor vehicle equipment. Manufacturer is defined in the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381; et seq*.) as 'any person engaged in the manufacturing or assembling o motor vehicles or motor vehicle equipment ....' Therefore, in the cases to which you refer, the assembler of the vehicle would be responsible for ensuring the compliance of the vehicle with all applicable Federal safety standards. The purchaser is not responsible for compliance with the requirements unless he assembles the vehicles, thereby becoming the manufacturer.; Dealers are prohibited by section 108(a)(1)(A) of the Act from sellin any completed motor vehicle that is not in compliance with the standards. A dealer is permitted, however, to rely upon the manufacturer's certification that the vehicle conforms to the standards' requirements. Therefore, prior to sale of a vehicle a dealer should make sure that the manufacturer has complied with the certification requirements of Part 567, *Certification*, and Part 568, *Vehicles Manufactured in Two or More Stages*, of our regulations which are contained in Title 49 of the Code of Federal Regulations.; A dealer is not prohibited from selling an 'incomplete vehicle' as tha term is defined in Part 568 of our regulations. Such an incomplete vehicle would require further manufacturing before its final certification for compliance with the standards. The incomplete vehicle manufacturer would need to fulfill it's (sic) responsibilities as outlined in Part 568. The person who completes the vehicle would then be responsible for the vehicle complying with standards. You should note that vehicles that lack merely readily attachable components are not 'incomplete vehicles.' They are completed vehicles. The sale of any such vehicle that was not certified for compliance with all applicable standards would be a violation of the Act.; Sincerely, Francis Armstrong, Director, Office of Standards Enforcement |
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ID: aiam5009OpenMr. C. Scott Thiss Chairman & CEO S&W Plastics, Inc. 10206 Crosstown Circle Eden Prairie, MN 55344; Mr. C. Scott Thiss Chairman & CEO S&W Plastics Inc. 10206 Crosstown Circle Eden Prairie MN 55344; "Dear Mr. Thiss: This responds to your letter of April 23, 1992 requesting a re-interpretation of the National Traffic and Motor Vehicle Safety Act as it applies to your after market product, 'High Light.' This request is occasioned by the modifications you have made pursuant to my letter of January 23, 1992, to Terry Semprini, and after a meeting with NHTSA personnel on April 16. Initially, we advised that it appeared that 'High Light' had the potential to render inoperative the required lighting equipment on a trailer by impairing its effectiveness. There were three reasons for this advisory. First, the placement of 'High Light' to the left of the vertical centerline did not fulfill basic locational requirements of Standard No. 108 applicable to required equipment on new motor vehicles that lamps be located one on each side of the vertical centerline and as far apart as practicable, and thus 'High Light's' signals could be perceived as conflicting or unclear when viewed simultaneously with the original equipment lamps. Second, the hazard warning portion of 'High Light' operated through the stop lamp portion of the device rather than through the turn signal system, which meant an observer could be faced with the necessity of interpreting the meaning of simultaneously flashing red and amber lamps on the rear of a trailer, as well as the meaning of the original stop lamps should the brakes also be applied. Finally, the stop lamp portion of the device comprised a combination of a 'V' and an inverted 'V', a lighting array unlike any currently in use, which could create a momentary delay by a following driver in taking appropriate action. To address these concerns, you have modified 'High Light' to eliminate the hazard warning portion, and have changed the stop lamp so that it now appears as horizontal lights across the center of the device. While it is not possible to change the intended location of 'High Light' due to the configuration of trailer doors, you believe that its placement in the direct line of vision of a following driver adds to its visibility. Although you have not fully described the revised configuration of 'High Light', we believe that it can now be described as follows. It is a diamond- shape lamp, the left side of which consists of four amber lamps which form a left turn signal, and the right side of which consists of four amber lamps which form a right turn signal. In addition, two red lamps in the center form a stop signal. We understand that the amber lamps flash when they are in use, and that the red lamps are steady burning. In this configuration, it would appear that the lamps can serve as auxiliary turn signal and stop lamps without impairing the effectiveness of the lighting equipment that Standard No. 108 requires on the rear of trailers. Assuming that our understanding is correct, 'High Light' would not appear to render inoperative, either in whole or in part, lighting equipment installed in accordance with Standard No. 108. Sincerely, Paul Jackson Rice 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.