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 |
|---|---|
ID: aiam2022OpenMr. Dennis Replansky, Four Penn Center Plaza, Philadelphia, PA 19103; Mr. Dennis Replansky Four Penn Center Plaza Philadelphia PA 19103; Dear Mr. Replansky: This responds to your recent request for a discussion of wha constitutes the manufacture of a new trailer when used components from an existing trailer are utilized. As you are aware, a newly-manufactured air-braked trailer must, in all but a few cases, be equipped with an air brake system that conforms to Standard No. 121, *Air Brake Systems*.; The use of new components in combination with used components t assemble a complete vehicle is a common practice in both truck and trailer operations. The National Highway Traffic Safety Administration (NHTSA) has recognized this commercial practice by establishing that the use of a new body on a used 'chassis' that has already been certified does not constitute the manufacture of a new vehicle. In contrast, placing a used body on a new chassis that has never been certified as a vehicle has been determined to create a newly-manufactured vehicle that must be certified. This distinction did not present difficulty to trailer manufacturers in the past, when they were only required to meet the lighting requirements of Standard No. 108, *Lamps, Reflective Devices, and Associated Equipment*.; Since implementation of Standard No. 121, however, manufacturers hav had to determine whether the particular assembly they undertake contains a used 'chassis' which would not be required to meet the air brake standard. As a general matter, the NHTSA has stated that, as a minimum, the running gear (the axles, wheels, suspension, and related components sometimes known as a bogie) and main frame of the existing vehicle must be used to qualify as a used 'chassis'. However, the many different types of trailer construction make it difficult to determine what constitutes the main frame of some configurations. The NHTSA has concluded that the load-bearing structural member(s) which run the length of the vehicle and support the trailer will be considered to be the 'main frame'.; In the case of monocoque van construction, the trailer side walls whic constitute the main load-bearing members through the length of the vehicle must be reused as the main frame in addition to the running gear, or else the rebuilding operation will constitute manufacture of a new vehicle.; In the case of container chassis, the box frame that consitutes (sic the main load- bearing member through the length of the vehicle must be reused as the main frame in addition to the running gear, or else the rebuilding operation will constitute manufacture of a new vehicle.; In the case of a platform trailer, the main frame members which run th length of the trailer must be reused in addition to the running gear, or else the rebuilding operation will constitute manufacture of a new vehicle.; In the case of a tank trailer in which the tank serves the purpose o and replaces frame rails, the tank must be reused as the main frame in addition to the running gear, or else the rebuilding operation will constitute manufacture of a new vehicle. If a separate frame serves as the load-bearing member through the length of the vehicle, the tank could be replaced without the operation constituting the manufacture of a new vehicle. An inner tank may be replaced without certification as a new vehicle if the inner tank does not serve as a main load-bearing member.; Modifications of existing trailers to increase or decrease volumetri capacity or vehicle length are generally permitted without recertification. For example, the barrel of a tank trailer may be lengthened in response to the new weight limits without recertification of the vehicle.; In closing, it should be noted that Bureau of Motor Carrier regulation may differ on modification or rebuilding of vehicles in interstate commerce.; Sincerely, Frank Berndt, Acting Chief Counsel |
|
ID: aiam2472OpenMr. Michael E. Bufkin, 1136 Gail Lane, Sleepy Hollow, IL 60118; Mr. Michael E. Bufkin 1136 Gail Lane Sleepy Hollow IL 60118; Dear Mr. Bufkin: This responds to your November 12, 1976, question whether a tire bran name owner is required by S 574.7(b) of Part 574, *Tire Identification and Recordkeeping*, to establish and maintain specified purchaser information on its tires if the distributor or dealer fails to provide that information as specified by S 574.8 of the regulation. You also ask whether a tire registration form with dimensions other than those specified in Figure 3 of the regulation may be provided to tire distributors and dealers.; Section 158(b) of the National Traffic and Motor Vehicle Safety Act (1 U.S.C. S 1418(b)) mandates the tire manufacurer's (sic) (including brand name owner's) responsibility to establish and maintain the purchaser information, independent of the distributor's or dealer's cooperation:; >>>S 158(a)(1) * * * * * (b) Every manufacturer of motor vehicle or tires shall cause th establishment and maintenance of records of the name and address of the first purchaser of each motor vehicle and tire produced by such manufacturer * * *<<<; Thus, the brand name owner's responsibility is a statutory one independent of any interpretation of Part 574.; With regard to the size of the tire registration form, S 574.7(a permits the use of any size form unless a dealer requests forms that conform to the universal format set forth in Figure 3. The agency has interpreted the requirement for provision of the universal format to not apply in the case of a dealer that sells only one brand of tire.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
|
ID: aiam2188OpenMr. Stuart R. Perkins, Director, Vehicle Safety, Jeep Corporation, 14250 Plymouth Road, Detroit, MI 48232; Mr. Stuart R. Perkins Director Vehicle Safety Jeep Corporation 14250 Plymouth Road Detroit MI 48232; Dear Mr. Perkins: This responds to Jeep Corporation's October 16, 1975, petition t initiate rulemaking to amend the present definition of 'Unloaded vehicle weight' (49 CFR S571.3) which reads:; >>>'Unloaded vehicle weight' means the weight of a vehicle with maximu capacity of all fluids necessary for operation of the vehicle, but without cargo or occupants.<<<; Jeep requests that the definition be amended to 'indicate that th unloaded vehicle [weight] does not include work-performing accessories which may be available as original equipment accessories.' The Jeep petition argues that the impracticality of conducting some dynamic testing with 'work-performing accessories' in place may force the discontinuance of some factory-installed accessories although factory installation may be more safe than a subsequent aftermarket installation.; The Jeep Corporation petition is denied. As a general matter, the NHTS has established that a vehicle which is designed to accept an optional component must be capable of meeting all applicable standards with the component installed. The NHTSA has evaluated the potential problems of dynamic testing with heavy or protruding accessories in place and concludes that a decision on the practicality and wisdom of so doing should be made on a 'standard-by-standard' basis. As you noted, the NHTSA has provided for removal of work-performing accessories in conducting compliance tests under Standard No. 219, *Windshield Zone Intrusion*. If Jeep considers dynamic testing in other standards to be unjustifiably burdensome because of the necessity of testing with all accessories in place, it would be appropriate to petition for rulemaking to amend the standard in question.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
|
ID: aiam2921OpenMr. Dominic S. Piacenza, Franklin Pierce Law Center, 2 White Street, Concord, NH 03301; Mr. Dominic S. Piacenza Franklin Pierce Law Center 2 White Street Concord NH 03301; Dear Mr. Piacenza: This is in response to your letter of November 9, 1978, asking whethe a memorandum of understanding exists between the National Highway Traffic Safety Administration (NHTSA) and the Federal Trade Commission (FTC) concerning the apparent overlapping jurisdiction regarding tire marketing practices created by Section 203 of the National Traffic and Motor Vehicle Safety Act of 1966 (Safety Act)(15 U.S.C. 1423). You ask whether NHTSA's jurisdiction extends solely to safety- related issues.; NHTSA's authority is not confined solely to the area of motor vehicl and traffic safety. For example, under the Motor Vehicle Information and Cost Savings Act (15 U.S.C. 1901) the agency has been given authority over the areas of fuel economy and economic losses to consumers as they relate to automobiles. While the Safety Act is primarily concerned with safety issues, Section 203 of that law does provide NHTSA with limited authority over tire marketing practices. The Uniform Tire Quality Grading Standards (49 CFR 575.104), issued by NHTSA under the authority of Section 203, provide information to consumers in tire performance areas relating to both safety and economic issues.; While the FTC is aware of and supports NHTSA's efforts in the field o tire grading, no memorandum of understanding exists with regard to the scope of NHTSA's activities. Section 205 of the Safety Act (15 U.S.C. 1425) does state that, in the event of conflict between orders or regulations issued under the Safety Act concerning motor vehicle tires and FTC orders or interpretations, the orders or regulations issued under the Safety Act shall prevail.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
|
ID: aiam3633OpenMr. Matt Guzzetta, Vice President, Don Vesco Products, Inc., 7565 North Avenue, Lemon Grove, CA 92045; Mr. Matt Guzzetta Vice President Don Vesco Products Inc. 7565 North Avenue Lemon Grove CA 92045; Dear Mr. Guzzetta: This is in reply to your letter of September 15, 1982, asking about th legality of 'covering of a headlamp on a motorcycle with a clear cover.'; You reported that manufacturers of motorcycles and fairings ar producing such covers. The National Highway Traffic Safety Administration views this practice as prohibited and will take appropriate steps to make its views known. The legal authority for this is based upon a requirement of the SAE incorporated by reference in Motor Vehicle Safety Standard No. 108 or, alternatively, paragraph S4.1.3 of that standard.; SAE Standard J580 (both a and b versions), *Sealed Beam Headlam Assembly*, is incorporated by reference in Tables I and III of Standard No. 108 as one of the standards pertaining to headlamps for use on passenger cars, trucks, buses, and multipurpose passenger vehicles. A paragraph in each version states that, 'When in use, a headlamp shall not have any styling ornament or other feature, such as a glass cover or grill, in front of the lens.' SAE J580a applies to all sealed beam headlamps, while the scope of J580b is considerably narrower, including only those not covered by SAE J579c.; The principal referenced SAE material for motorcycle headlamps is J584 *Motorcycle Headlamps*. As options, both J584 and S4.1.1.34 of Standard No. 108 allow, in effect, a motorcycle to be equipped with one half of any sealed beam system permissible on four-wheeled motor vehicles.; Paragraph S4.1.3 of Standard No. 108 forbids the installation o additional equipment 'that impairs the effectiveness of lighting equipment required' by Standard No. 108. Because of moisture accumulation, discoloration, cracks, etc., a glass or plastic cover might tend over a period of time to diminish or distort the headlamp beam. This is of particular concern with reference to the unsealed headlamps implicitly permitted by SAE J584 because of the tendency of the reflector to deteriorate with age.; For the reasons stated above, the agency has concluded that no headlam may have a glass or plastic shield in front of it when in use, regardless of the type of vehicle on which it is used.; As for the turn signals, no part of the vehicle may impair thei visibility through horizontal angles 45 degrees to the right and left of the vehicle (for right and left turn signals respectively) measured at the longitudinal axis of the vehicle. An unobstructed illuminated area of outer lens surface of at least 2 square inches excluding reflex is necessary to meet this requirement. You will have to judge for yourself whether the turn signal requirements are met with your planned cover in place.; If you have any further questions, we shall be happy to answer them. Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam3263OpenMr. R.W. Strauss, Stewart-Warner Corporation, Washington Offices, 425 - 13th Street, N.W., Washington, D.C. 20004; Mr. R.W. Strauss Stewart-Warner Corporation Washington Offices 425 - 13th Street N.W. Washington D.C. 20004; Dear Mr. Strauss: This responds to your letter of January 24,, 1980, which requeste approval of an odometer design developed by Stewart-Warner in order to comply with section 4.2.3 of Federal Motor Vehicle Safety Standard No. 127, *Speedometers and Odometers*. Based on our understanding of the information that you have supplied, it appears that Stewart-Warner's design, which incorporates either a seventh wheel or a sixth wheel (for odometers which do not register tenths of a mile) printed with a series of the numeral 1 to indicate that the vehicle has traveled in excess of 99,999 miles or kilometers, would comply with section 4.2.3 of Safety Standard No. 127.; Section 4.2.3 of Safety Standard No. 127 requires that each odomete other than a motorcycle odometer:; >>>'clearly indicate to the vehicle driver by a sixth wheel or digi registering whole miles or kilometers or by a permanent means such as inking, when the number of whole miles or whole kilometers, as appropriate, has exceeded either at the manufacturer's option 89,999 or 99,999.'<<<; Stewart-Warner's design, as described in your letter, would registe whole miles or kilometers from 100,000 to 199,999. Once the vehicle in which the odometer was installed had traveled 200,000 miles or kilometers, or more, the additional wheel on the Stewart-Warner design would no longer register whole miles or kilometers but it would indicate that the vehicle milage had exceeded 99,999. Thus, the Stewart-Warner design, as we understand it, would apparently comply with section 4.2.3's requirement that each odometer indicate that such mileage has been exceeded.; Finally, I would emphasis that this letter only represents the agency' opinion based on the information supplied in your letter and the model that you provided. The National Highway Traffic Safety Administration does not pass approval on any vehicle design or design for vehicle equipment prior to the actual events that underlie certification. It is up to the manufacturer to determine whether its vehicles or items of vehicle equipment comply with all applicable safety standards and regulations and to certify its vehicles or items of vehicle equipment in accordance with that determination.; I hope that you will find this response helpful and have not bee greatly inconvenienced by our delay in sending it to you.; Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam3799OpenMr. Ben Barbie, Stapleton Public Schools, P.O. Box 125, Stapleton, NE 69163; Mr. Ben Barbie Stapleton Public Schools P.O. Box 125 Stapleton NE 69163; Dear Mr. Barbie: This is in further reply to your phone call of February 13, 1984, t the National Highway Traffic Safety Administration, regarding the remanufacture of school buses using older model bus bodies on new chassis. You asked whether the school bus safety standards apply to a school bus manufactured with a 1976 model year body mounted on a new chassis.; The applicability of Federal Motor Vehicle Safety Standards i determined by the date of manufacture of the motor vehicle. For vehicles that are completed in several stages, the manufacturer can treat as the date of manufacture the date of the incomplete vehicle, the date of final completion of the vehicle, or a date between those two dates. An 'incomplete vehicle' is defined in 49 CFR Part 568, *Vehicles Manufactured in Two or More Stages*, as:; >>>an assemblage consisting, as a minimum, of frame and chassi structure, power train, steering system, suspension system, and braking system, to the extent that those systems are to be part of the completed vehicle, that requires further manufacturing operations, other than the addition of readily attachable components, such as mirrors or tire and rim assemblies, or minor finishing operations such as painting, to become a completed vehicle.<<<; The effective date of the school bus safety standards was April 1 1977. Since the date of manufacture of the school bus chassis is after April 1, 1977, and the date of completion of the vehicle is after April 1, 1977, the completed school bus must meet the requirements of the school bus safety standards. It is extremely unlikely that the 1976 model year body will comply with the school bus standards since the body was manufactured before the effective date of the school bus standards. If your completed vehicle does not comply with the safety standards, your manufacturer, distributor, or dealer cannot certify it as conforming to such standards.; Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam0766OpenMr. Richard L. Curotto, Treasurer, Stutz Motor Car of America, Inc., Time & Life Building, Rockefeller Center, New York, New York 10020; Mr. Richard L. Curotto Treasurer Stutz Motor Car of America Inc. Time & Life Building Rockefeller Center New York New York 10020; Dear Mr. Curotto: This is in reply to your letter of June 21, 1972. As I understand it your company purchases Pontiac Grand Prix models for conversion into vehicles bearing the Stutz nameplate. Your converter, however, has a number of vehicles in stock, the majority of which will not be converted until after September 1, 1972. You ask, in effect, that we require compliance only with those Federal standards in effect on the date of manufacture of the original Pontiac Grand Prix, and that we do not require compliance with standards which may have come into effect after that time and before completion of the Stutz conversion.; The information contained in your letter indicates that the changes yo make to the Grand Prix are confined to cosmetic changes such as alteration of the exterior sheet metal, reupholstering the interior, and replacement of the back light with glazing conforming to Standard No. 205. If the converted Grand Prix conforms to those Federal motor vehicle safety standards for which temporary exemption was granted Stutz (Standards Nos. 104, 201, 205, 210 and 212), we will consider it permissible for General Motors to continue to be the 'manufacturer' of the vehicle for certification purposes. In that case, the date of manufacture is considered to be the date of completion by General Motors, and the original certification label should be retained on the car when converted.; The vehicle must nevertheless conform at the time of sale to all safet standards and other regulations (for example, 49 CFR Part 575, Consumer Information) that are applicable on its date of manufacture.; Sincerely, Douglas W. Toms, Administrator |
|
ID: aiam1874OpenHonorable John Rhodes, House of Representatives, Washington, DC (sic); Honorable John Rhodes House of Representatives Washington DC (sic); Dear Mr. Rhodes: This is in response to your letter of March 17, 1975, requestin information concerning correspondence from one of your constituents, Mr. William R. Langer, commenting on a proposed amendment to the Federal Bumper Standard.; On January 2, 1975, the National Highway Traffic Safety Administratio (NHTSA) issued a Federal Register Notice (copy enclosed) proposing to reduce the current 5 mph bumper impact requirements to 2.5 mph until the 1970 (sic) model year. The impact requirements would have been increased to 4 mph for 1979 and later model year cars.; The proposal was based primarily on the results of two agency sponsored studies which indicated that the cost and weight of many current production bumpers, in light of inflation and fuel shortages, made the bumpers no longer cost beneficial. Information presented at public hearings on the bumper notice and comments submitted to the docket in response to the proposal have brought to light additional data. The NHTSA has carefully examined all of this evidence and reviewed its studies in light of the new information. As a result, the agency has concluded that the 5 mph protection level should not be reduced. This decision is contained in a Federal Register notice that was published March 12, 1975, which is enclosed (Docket No. 74-11, Notice 7, Docket No. 73-19, Notice 6).; Mr. Langer has directed his comments to what he believes to be proposed requirement that vehicles manufactured in the future be equipped with plastic bumper systems. Such an understanding of the proposal is incorrect. The January 2, 1975 proposal was aimed at enabling a reduction in vehicle weight. In the preamble to that notice, the NHTSA cited soft face bumpers as one type of system that could produce a significant weight reduction. However, no proposal was made to require the use of soft face (plastic) systems. The March 12, 1975 notice reiterates the agency's position that bumpers which are lighter in weight than those currently in mass production could and probably would be developed. The requirements proposed in the March notice, however, ensure that a wide variety of materials could continue to be used in bumper systems.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
|
ID: aiam3849OpenBruce Henderson, Automobile Importer of America, 1735 Jefferson Davis Highway, Suite 1002, Arlington, VA 22202; Bruce Henderson Automobile Importer of America 1735 Jefferson Davis Highway Suite 1002 Arlington VA 22202; Dear Mr. Henderson: This is to follow-up on your phone conversation with Stephen Oesch o my staff concerning Safety Standard No. 201, *Occupant protection in interior impact*. Your specific question was whether a fuse box cover must comply with the requirements of section 3.3 of the standard. As explained below, a fuse box cover does not have to comply with section 3.3.; Section 3.3 of the standard provides that each 'interior compartmen door' in certain vehicle locations must remain closed when subjected to the specified performance tests. Section 571.3 defines an interior compartment door as 'any door in the interior of the vehicle installed by the manufacturer as a cover for storage space normally used for personal effects'.; The definition is meant to include such storage areas as the 'glovebox which has a large door which could fly open in a crash, and not a portion of the vehicle's electrical system such as a fuse box, which is not used as storage space.; Although not covered by the standard, we would urge a manufacture carefully to design the fuse box in such a way as to prevent injuries if it is located in an area which could be struck by an occupant in a crash.; If you have further questions, please let me know. Sincerely, Frank Berndt, 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.