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: aiam2334OpenMr. W. Wayne Daniel, Wayne Daniel Truck, Inc., P.O. Box 303, Mt. Vernon, MO 65712; Mr. W. Wayne Daniel Wayne Daniel Truck Inc. P.O. Box 303 Mt. Vernon MO 65712; Dear Mr. Daniel: This responds to your June 18, 1976, request for permission t substitute pre-121 brake components for certain components of the brake systems on trucks and trailers you own that were manufactured in conformity with Standard No. 121, *Air Brake Systems*.; From your description, I assume that you intend to remove portions o the brake system that were installed in satisfaction of the requirements of S5.3.1 of Standard No. 121. Section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. S 1397(a)(2)(A)) prohibits, with one exception, knowing disconnection of the antilock system by a manufacturer, distributor, dealer, or repair business.; A person that does not fall into these categories is not prohibite from disconnection of the systems. Thus, it would be permissible for you to make such modifications on your own trucks and trailers. Other State or Federal requirements, such as those of the Bureau of Motor Carrier Safety for operation in interstate commerce, may prohibit disconnection. In any case, the NHTSA urges that you not disconnect safety devices without consulting the vehicle manufacturer with regard to the safest configuration of the vehicle.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam5394OpenMr. Jerry Steffy Triumph Designs Ltd. Jacknell Road Dodwells Bridge Industrial Estate Hinckley, Leicestershire LE10 3BS England; Mr. Jerry Steffy Triumph Designs Ltd. Jacknell Road Dodwells Bridge Industrial Estate Hinckley Leicestershire LE10 3BS England; "Dear Mr. Steffy: This responds to your request to Mr. David Elias formerly of this office, for an interpretation concerning whether a motorcycle certification label may be placed in a location other than that specified in 49 CFR Part 567, Certification. As explained below, the answer is yes, the agency has permitted an alternative location in certain circumstances. 49 CFR 567.4(e) states that motorcycle certification labels 'shall be affixed to a permanent member of the vehicle as close as is practicable to the intersection of the steering post with the handle bars, in a location such that it is easily readable without moving any part of the vehicle except the steering system.' In your letter, you seem to refer to this intersection as the 'headstock area,' and ask whether the certification label can be placed elsewhere. In an interpretation letter of November 23, 1982, to Suzuki Motor Co., Ltd., (copy enclosed) NHTSA permitted the motorcycle certification label to be placed 'on the down tubes in front of the engine on either the right or left side.' The agency permitted the alternate location because some Suzuki motorcycles were equipped with fairings, obscuring labels placed in the specified location. Your inquiry seems to imply that Triumph's design would cause a certification label placed in the location specified in 567.4(e) to be obscured. If that is the case, please contact Mr. George Shifflett of NHTSA's Office of Vehicle Safety Compliance at (202) 366-5307. NHTSA would be happy to work with you on finding an alternative location for your certification label. I hope this information is helpful. If you have any further questions, please contact Ms. Dorothy Nakama of my staff at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosure"; |
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ID: aiam5125OpenMr. James L. Vasko 527 Old Canyon Road Fremont, CA 94536; Mr. James L. Vasko 527 Old Canyon Road Fremont CA 94536; Dear Mr. Vasko: This is in reply to your letter of January 13, 1993, t the agency in which you call our attention to your invention, the 'Front Brake Light System.' You have informed us that your invention utilizes 'the present turn signal lights . . . to notify the driver and or pedestrian in front of the vehicle that the vehicle is in a braking mode,' and that this is accomplished with only the present circuitry. You wish to 'open a dialogue' with us and will answer any questions we may have. We do have some questions about this invention. As you know, the individual front turn signal lamps also operate in tandem as hazard warning signal lamps, and flash simultaneously when the hazard warning switch is activated. We assume that your invention flashes both front signal lamps when the brake pedal is applied, and request confirmation of our assumption. We would also appreciate knowing how this is accomplished without 'necessity and expense of adding new, complicated apparatus' as you put it. If, on the other hand, the front signal lamps are activated in a steady-burning state, that would be of interest to us. Finally, we would appreciate your views as to how this device would enhance safety, as our concerns have been directed to warning those to the rear of the vehicle that it is about to stop, rather than those to the front. When we have this information, we shall be pleased to provide you with an interpretation as to the relationship of your invention to the statutes and regulations that this agency administers. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0666OpenMr. L. D. Brown, Manager Truck Tank Division, Renick & Mahoney Division, Garsite Products, Inc., 10 E. Grand Bouldvard (sic), Deer Park, L.I., NY 11729; Mr. L. D. Brown Manager Truck Tank Division Renick & Mahoney Division Garsite Products Inc. 10 E. Grand Bouldvard (sic) Deer Park L.I. NY 11729; Dear Mr. Brown: This is in reply to your letter of March 8, 1972, concerning th application of Federal standards and regulations to airport refuelers. In a conversation with Michael Peskoe of this office on March 30, 1972, you amplified certain questions you asked in your letter, which are dealt with below.; Initially, you asked whether the Federal motor vehicle safety standard apply to airport refuelers. In the conversation of March 30, you indicated that these refuelers are similar to most tank trucks, and that while operated on or about airports, may frequently be driven on public roads such as perimeter roads between oil tanks and the airport. We would consider these vehicles to be motor vehicles within the National Traffic and Motor Vehicle Safety Act because of their use on public roads, and would consider them to be trucks under the motor vehicle safety standards.; Your second question concerned the fact that, at present, curb weight of chassis furnished to you are not accurately reflected by the manufacturer's specifications, the latter generally being lower than the former. We indicated to you in our phone conversation that the Certification requirements which became effective January 1, 1972, will eliminate this problem by requiring manufacturers to provide gross vehicle and axle weight ratings.; Your third question concerns a chassis which you ordered before th Certification regulations became effective, on which you planned to install a specific tank. The chassis has now been delivered, and it has a GAWR for the rear axle which is 400 pounds less than the weight of the fully loaded tank. While the establishment of both GVWR and GAWR for the vehicle when completed is the responsibility of your company as the final-stage manufacturer, we would consider mounting the tank on this chassis without modifying the latter to accommodate the additional load to raise substantial questions as to the safety of the completed vehicle. If the chassis cannot be modified, we strongly recommend against installing the tank on it.; You ask how you can recognize chassis that have been manufactured afte January 1, 1972. Each such chassis, if an incomplete vehicle under the regulations, must be delivered to you with an 'incomplete vehicle document' specifying the date of manufacture. A chassis-cab manufactured before that date must bear a label stating its date of manufacture.; Finally, you ask whether in some situations the chassis manufacture can become the final-stage manufacturer. Sections 567.5 and 568.8 of the regulations provide for a situation where an incomplete vehicle manufacturer may assume all responsibility for the vehicle under the National Traffic and Motor Vehicle Safety Act. In such a case the incomplete vehicle manufacturer will have the responsibility for certification otherwise borne by the final-stage manufacturers.; We are pleased to be of assistance. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2081OpenHonorable Barber B. Conable, Jr., House of Representatives, Washington, DC 20515; Honorable Barber B. Conable Jr. House of Representatives Washington DC 20515; Dear Mr. Conable: This is in response to your letter of September 5, 1975, requestin information concerning an inquiry from one of your constituents, Mr. F. J. Guppenberger, relating to the permissibility of raising cars' rear bumpers.; Motor Vehicle Safety Standard No. 215, *Exterior Protection*, impose performance requirements on automobile bumper systems. One of these requirements specifies impacts at certain heights, and has the effect of requiring bumpers to be manufactured at fairly uniform heights.; The National Traffic and Motor Vehicle Safety Act (Pub. L. 89-563), a recently amended (Pub. L. 93-492), prohibits any manufacturer, distributor, dealer, or motor vehicle repair business from knowingly rendering inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable motor vehicle safety standard (S 108(a) (2) (A)). Therefore, if the bumper were raised by one of the above classes of persons causing it no longer to comply with the Standard No. 215 requirements, a violation of the Act would have occurred. That law does not, however, prohibit an individual from altering the bumper on his own car.; The National Highway Traffic Safety Administration, the agency tha administers the Traffic Safety Act, is not authorized by that Act to prohibit vehicles with raised bumpers from operating on the highways. Except for certain limited areas such as motor carriers in interstate commerce, the regulation of vehicles operating on the highways is within the authority of the States.; Sincerely, William T. Coleman, Jr. |
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ID: aiam2916OpenMr. T.F. Brown, Mack Trucks, Inc., Engineering Division, P.O. Box 1761, Allentown, Pennsylvania 18105; Mr. T.F. Brown Mack Trucks Inc. Engineering Division P.O. Box 1761 Allentown Pennsylvania 18105; Dear Mr. Brown: I regret the delay in responding to your August 31, 1978, lette requesting an interpretation of S5.3 of Federal Motor Vehicle Safety Standard No. 120. In that letter, you stated that you had been contacted by an employee of this agency's enforcement office and advised that the certification labels for Mack trucks did not comply with the requirements of that section. The reason given for this conclusion was that the labels used the word 'on' between the tire and rim information instead of the comma shown in the example following S5.3.3.; S5.3 requires that the labeling information specified in S5.3.1 S5.3.3 must appear in the format shown in the truck example following S5.3.3. This requirements does not mean that certification labels must be identical to the example in every respect. Minor variations are permitted. By 'minor variations', I mean such things as a slight difference in punctuation mark that do not change or obscure the meaning of the label. Mack's substitution of 'on' for a comma is such a minor variation and, accordingly, is permissible under the standard.; The label enclosed with your letter shows spaces to provide informatio for the front, rear and tree intermediate axles. When this label is used on vehicles with fewer than five axles, you should stamp 'not applicable', or words of similar import, in the spaces provided for axles which do not exist on the particular vehicle which is being labelled.; Without this indication, the label could be confusing and so would fai to clearly provide the required information for that vehicle. And indication of nonapplicability would alert the reader to that fact.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1147OpenMr. Charles H. Sturgeon, Traffic Manager, Grove Manufacturing Company, Shady Grove, PA 17256; Mr. Charles H. Sturgeon Traffic Manager Grove Manufacturing Company Shady Grove PA 17256; Dear Mr. Sturgeon: This is in reply to your letter of April 23, 1973, requesting ou confirmation of certain issues discussed by you, and Michael Peskoe and David Fay of NHTSA, in a meeting in Mr. Peskoe's office on April 19, 1973.; It is correct that the NHTSA does not presently employ safet inspectors to inspect vehicles in service. Such inspections are made by inspectors of the Bureau of Motor Carrier Safety in the Federal Highway Administration, and it is true that their primary interest is the enforcement of the Bureau of Motor Carrier Safety regulations (49 CFR Parts 301-398). But if these investigators note violations of NHTSA regulations, the information will be forwarded to NHTSA and appropriate action will be taken.; It is correct that components of a vehicle in service may be added removed, or relocated at the discretion of a vehicle owner without violating NHTSA regulations. However, gross vehicle and axle weight ratings established by the vehicle manufacturer must be based on configurations of the vehicle which the manufacturer expects will be utilized in service. It is also correct that the weight imposed on each axle should not exceed the certified weight rating for each axle, but may be less than the certified weight rating.; Finally, it is correct that gross axle weight ratings may b established with a view towards the weight limitations of States in which the vehicle will be used.; Gross axle and vehicle weight ratings, under NHTSA regulations, ar manufacturers' figures, and may be set at any level as long as the figures are consistent with the limitations specified in the NHTSA certification regulations. However, the weight ratings must also, of course, be consistent with the vehicle's load-carrying capacity.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1148OpenMr. Charles H. Sturgeon, Traffic Manager, Grove Manufacturing Company, Shady Grove, PA 17256; Mr. Charles H. Sturgeon Traffic Manager Grove Manufacturing Company Shady Grove PA 17256; Dear Mr. Sturgeon: This is in reply to your letter of April 23, 1973, requesting ou confirmation of certain issues discussed by you, and Michael Peskoe and David Fay of NHTSA, in a meeting in Mr. Peskoe's office on April 19, 1973.; It is correct that the NHTSA does not presently employ safet inspectors to inspect vehicles in service. Such inspections are made by inspectors of the Bureau of Motor Carrier Safety in the Federal Highway Administration, and it is true that their primary interest is the enforcement of the Bureau of Motor Carrier Safety regulations (49 CFR Parts 301-398). But if these investigators note violations of NHTSA regulations, the information will be forwarded to NHTSA and appropriate action will be taken.; It is correct that components of a vehicle in service may be added removed, or relocated at the discretion of a vehicle owner without violating NHTSA regulations. However, gross vehicle and axle weight ratings established by the vehicle manufacturer must be based on configurations of the vehicle which the manufacturer expects will be utilized in service. It is also correct that the weight imposed on each axle should not exceed the certified weight rating for each axle, but may be less than the certified weight rating.; Finally, it is correct that gross axle weight ratings may b established with a view towards the weight limitations of States in which the vehicle will be used.; Gross axle and vehicle weight ratings, under NHTSA regulations, ar manufacturers' figures, and may be set at any level as long as the figures are consistent with the limitations specified in the NHTSA certification regulations. However, the weight ratings must also, of course, be consistent with the vehicle's load-carrying capacity.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3230OpenMr. Raymond J. Salehar, Highway Safety Engineer, Motor Vehicle Administration, Maryland Department of Transportation, 6601 Ritchie Highway NE, Glen Burnie, MD 21062; Mr. Raymond J. Salehar Highway Safety Engineer Motor Vehicle Administration Maryland Department of Transportation 6601 Ritchie Highway NE Glen Burnie MD 21062; Dear Mr. Salehar: This responds to your February 8, 1980, letter asking whether it i permissible for a State to transport children to and from school on regular city transit buses. The answer to your question is yes, if the buses are on their scheduled transit routes and are transporting both school children and adults.; The National Highway Traffic Safety Administration has defined schoo bus in a way that allows buses sold for use as common carriers in urban transportation to transport school children without complying with school bus standards. This definition is located in Title 49 of the Code of Federal Regulations, Part 571.3. The agency permitted this exemption from the school bus safety standards in acknowledgment of the high costs involved in maintaining dual fleets of buses, one for school children and one for adults. Accordingly, the agency permitted cities with operating bus lines to transport children on those city buses. The agency also believes that joint bus fleets can help to conserve fuel.; The agency has made one restriction on the use of city buses t transport school children. The buses must be operating on their regular passenger routes and schedules and must not be operating on special school bus routes. Any vehicle that is operating exclusively as a school bus should be constructed in accordance with the school bus safety standards.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3231OpenMr. Raymond J. Salehar, Highway Safety Engineer, Motor Vehicle Administration, Maryland Department of Transportation, 6601 Ritchie Highway NE, Glen Burnie, MD 21062; Mr. Raymond J. Salehar Highway Safety Engineer Motor Vehicle Administration Maryland Department of Transportation 6601 Ritchie Highway NE Glen Burnie MD 21062; Dear Mr. Salehar: This responds to your February 8, 1980, letter asking whether it i permissible for a State to transport children to and from school on regular city transit buses. The answer to your question is yes, if the buses are on their scheduled transit routes and are transporting both school children and adults.; The National Highway Traffic Safety Administration has defined schoo bus in a way that allows buses sold for use as common carriers in urban transportation to transport school children without complying with school bus standards. This definition is located in Title 49 of the Code of Federal Regulations, Part 571.3. The agency permitted this exemption from the school bus safety standards in acknowledgment of the high costs involved in maintaining dual fleets of buses, one for school children and one for adults. Accordingly, the agency permitted cities with operating bus lines to transport children on those city buses. The agency also believes that joint bus fleets can help to conserve fuel.; The agency has made one restriction on the use of city buses t transport school children. The buses must be operating on their regular passenger routes and schedules and must not be operating on special school bus routes. Any vehicle that is operating exclusively as a school bus should be constructed in accordance with the school bus safety standards.; 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.